This document summarizes a patent for an apparatus that stores digital data on a moving magnetic medium. It allows for simultaneously reading stored data from a cell on the medium and overriding it by writing new data to the same cell. This is accomplished by using timing impulses to select cells for reading and writing, with the reading gate occurring slightly before the writing gate. This allows time to determine if the cell contents need to be changed based on the read data and other inputs, before overriding the data during the writing gate. The document describes the technical details and diagrams of how this simultaneous read/write process is implemented on the magnetic medium.
The document discusses phase shift keying (PSK) modulation techniques. It begins by explaining the basic concept of PSK where the phase of a carrier signal is shifted to represent digital data. It then discusses binary PSK (BPSK) where there are two possible phase shifts. It further explains the implementation of M-ary PSK where there are M possible phase shifts, allowing more bits to be transmitted. Finally, it discusses quadrature amplitude modulation (QAM) which combines phase and amplitude modulation to represent data.
enhancement of low power pulse triggered flip-flop design based on signal fee...Kumar Goud
Abstract: Low Power research major concern in today’s VLSI word. Practically, clocking system like flip-flop (FF) consumes large portion of total chip power. So in this paper we discuss about the design of the clock system using novel Flip-Flop design. In this paper, a novel low-power pulse-triggered flip-flop (FF) design is presented. Pulse- triggered FF (P-FF) has been considered as a popular alternative to the conventional master –slave based F. a low-power flip-flop (FF) design featuring an explicit type pulse-triggered structure and a modified true single phase clock latch based on a signal feed-through scheme is presented. The proposed design successfully solves the long discharging path problem in conventional explicit type pulse-triggered FF (P-FF) designs and achieves better speed and power performance in the applications of high speed. These circuits are simulated using Tanner Tools with TSMC018 technology.
Keywords: pulse-triggered flip-flop (FF), true single phase clock latch, clocking system
The document describes a proposed design for a low power implicit pulse triggered flip-flop (P-FF). P-FFs have advantages over conventional master-slave FFs in high-speed applications and can reduce clock power consumption. The proposed design uses only transistor switching logic with 8 transistors, reducing power and area compared to other P-FF designs. Simulations show the proposed design has lower power consumption of 2.339μW compared to other designs. The design achieves lower power and area through a reduced transistor count.
1. The document discusses load pull matching tuning for various bands (B1, B2, B3, B20, B28A, B28B) of a transmitter.
2. It provides port definitions and topology descriptions for multiple transmitter cases for each band.
3. It also calculates desense from receiver band noise of transmitter leakage for each band to determine the maximum transmitter power before desense occurs.
This document discusses offset quadrature phase-shift keying (OQPSK) modulation. It begins by explaining the drawback of traditional quadrature phase-shift keying (QPSK), which is that both the in-phase and quadrature components change simultaneously, resulting in abrupt 180-degree phase changes and large spectral side lobes. It then introduces OQPSK modulation as a modification of QPSK where the quadrature component is offset by one bit period, preventing simultaneous changes in both components and replacing the 180-degree phase jumps with multiple 90-degree phase shifts. This results in better performance for applications using high power amplifiers or satellites. Diagrams are provided to illustrate the difference between the phase transitions of QPSK and O
The document summarizes Hewlett-Packard's new Model 103AR Frequency Standard, which achieves a stability of 5 parts in 1010 per day. Key points:
- It is fully transistorized and uses a 1 MHz crystal oscillator housed in a double oven to maintain very precise temperature control, contributing to its high long-term stability.
- It provides outputs of 1 MHz and 100 kHz, with the 100 kHz output in a "fail-safe" configuration that stops if input is lost, important for applications like clock systems.
- Testing showed it exceeded its stability rating of 5 parts in 1010 per day over 50 days when compared to the US Frequency Standard.
- It has good short
Gaussian Minimum Shift Keying (GMSK) is a form of continuous-phase frequency shift keying that uses a Gaussian filter to generate a constant envelope signal. It provides better spectral efficiency than MSK through bandwidth reduction while maintaining low intersymbol interference. GMSK is used widely in wireless technologies like GSM and CDPD due to its power efficiency and good bit error rate performance compared to other modulation schemes. While more spectrally efficient than MSK, GMSK also has slightly higher error rates and requires more complex receivers.
This document summarizes an experiment to simulate a BPSK (Binary Phase Shift Keying) transmitter and receiver using MATLAB. The experiment involves generating a BPSK signal from digital input data by switching the carrier phase by 180 degrees. Noise is added to the modulated signal. At the receiver, the signal is demodulated using conventional DSBSC techniques and time integration to recover the original digital data. The simulation generates test input data, modulates and transmits the BPSK signal, adds noise, demodulates the signal at the receiver and recovers the original data successfully. BPSK is identified as the preferred digital modulation scheme due to its better noise performance compared to ASK and FSK.
The document discusses phase shift keying (PSK) modulation techniques. It begins by explaining the basic concept of PSK where the phase of a carrier signal is shifted to represent digital data. It then discusses binary PSK (BPSK) where there are two possible phase shifts. It further explains the implementation of M-ary PSK where there are M possible phase shifts, allowing more bits to be transmitted. Finally, it discusses quadrature amplitude modulation (QAM) which combines phase and amplitude modulation to represent data.
enhancement of low power pulse triggered flip-flop design based on signal fee...Kumar Goud
Abstract: Low Power research major concern in today’s VLSI word. Practically, clocking system like flip-flop (FF) consumes large portion of total chip power. So in this paper we discuss about the design of the clock system using novel Flip-Flop design. In this paper, a novel low-power pulse-triggered flip-flop (FF) design is presented. Pulse- triggered FF (P-FF) has been considered as a popular alternative to the conventional master –slave based F. a low-power flip-flop (FF) design featuring an explicit type pulse-triggered structure and a modified true single phase clock latch based on a signal feed-through scheme is presented. The proposed design successfully solves the long discharging path problem in conventional explicit type pulse-triggered FF (P-FF) designs and achieves better speed and power performance in the applications of high speed. These circuits are simulated using Tanner Tools with TSMC018 technology.
Keywords: pulse-triggered flip-flop (FF), true single phase clock latch, clocking system
The document describes a proposed design for a low power implicit pulse triggered flip-flop (P-FF). P-FFs have advantages over conventional master-slave FFs in high-speed applications and can reduce clock power consumption. The proposed design uses only transistor switching logic with 8 transistors, reducing power and area compared to other P-FF designs. Simulations show the proposed design has lower power consumption of 2.339μW compared to other designs. The design achieves lower power and area through a reduced transistor count.
1. The document discusses load pull matching tuning for various bands (B1, B2, B3, B20, B28A, B28B) of a transmitter.
2. It provides port definitions and topology descriptions for multiple transmitter cases for each band.
3. It also calculates desense from receiver band noise of transmitter leakage for each band to determine the maximum transmitter power before desense occurs.
This document discusses offset quadrature phase-shift keying (OQPSK) modulation. It begins by explaining the drawback of traditional quadrature phase-shift keying (QPSK), which is that both the in-phase and quadrature components change simultaneously, resulting in abrupt 180-degree phase changes and large spectral side lobes. It then introduces OQPSK modulation as a modification of QPSK where the quadrature component is offset by one bit period, preventing simultaneous changes in both components and replacing the 180-degree phase jumps with multiple 90-degree phase shifts. This results in better performance for applications using high power amplifiers or satellites. Diagrams are provided to illustrate the difference between the phase transitions of QPSK and O
The document summarizes Hewlett-Packard's new Model 103AR Frequency Standard, which achieves a stability of 5 parts in 1010 per day. Key points:
- It is fully transistorized and uses a 1 MHz crystal oscillator housed in a double oven to maintain very precise temperature control, contributing to its high long-term stability.
- It provides outputs of 1 MHz and 100 kHz, with the 100 kHz output in a "fail-safe" configuration that stops if input is lost, important for applications like clock systems.
- Testing showed it exceeded its stability rating of 5 parts in 1010 per day over 50 days when compared to the US Frequency Standard.
- It has good short
Gaussian Minimum Shift Keying (GMSK) is a form of continuous-phase frequency shift keying that uses a Gaussian filter to generate a constant envelope signal. It provides better spectral efficiency than MSK through bandwidth reduction while maintaining low intersymbol interference. GMSK is used widely in wireless technologies like GSM and CDPD due to its power efficiency and good bit error rate performance compared to other modulation schemes. While more spectrally efficient than MSK, GMSK also has slightly higher error rates and requires more complex receivers.
This document summarizes an experiment to simulate a BPSK (Binary Phase Shift Keying) transmitter and receiver using MATLAB. The experiment involves generating a BPSK signal from digital input data by switching the carrier phase by 180 degrees. Noise is added to the modulated signal. At the receiver, the signal is demodulated using conventional DSBSC techniques and time integration to recover the original digital data. The simulation generates test input data, modulates and transmits the BPSK signal, adds noise, demodulates the signal at the receiver and recovers the original data successfully. BPSK is identified as the preferred digital modulation scheme due to its better noise performance compared to ASK and FSK.
This document summarizes a new oscilloscope developed by Hewlett-Packard that has a frequency response extending up to 500 megacycles, providing a major breakthrough in the field of high frequency oscilloscopes. The instrument combines a very wide bandwidth of up to 500 MHz and high sensitivity with simplicity of use. It is described as a versatile, general purpose instrument by Hewlett-Packard. The oscilloscope achieves these capabilities through the use of a sampling technique that takes samples of the input signal on successive cycles and displays them on a slower time base, allowing it to clearly display even low repetition rate signals.
This document discusses inter-symbol interference (ISI) caused by frequency dependent loss in transmission channels. ISI results in data-dependent jitter and attenuation of high frequency signal components more than low frequencies. This causes signals to take longer to reach their transmitted voltage levels. The document then discusses how equalization techniques can counteract ISI by boosting high frequency components to restore signal shape. It provides examples of transmitter pre-emphasis, receiver equalization, and discrete-time linear equalization using multiple taps with varying coefficients to approximate the inverse channel response.
Design of all digital phase locked loop (d pll) with fast acquisition timeeSAT Journals
Abstract
A Digital PLL is designed with improved acquisition time and power efficiency. The implemented D-PLL can operate
from 6.54MHz to 105MHz with a power dissipation of is 7.763μW (at 210MHz) with 1.2V supply voltage. The D-PLL is
synthesized using cadence RTL compiler in 45nm CMOS process technology.
Keywords: Digital PLL, Digital Phase/Frequency detector, NCO, Divide by N counter.
This document discusses various digital modulation techniques. It begins by explaining binary amplitude-shift keying (ASK), where one amplitude encodes a 0 and another encodes a 1. It then discusses on-off keying (OOK) and multiple amplitude shift keying (MASK). Next, it covers frequency-shift keying (FSK), phase-shift keying (PSK), differential PSK, and quadrature PSK. It also discusses more advanced modulations like quadrature amplitude modulation (QAM), continuous phase modulation (CPM), and Gaussian minimum-shift keying. The document provides examples and discusses the pros, cons, and applications of different modulation schemes. It concludes by discussing a student project involving designing and analyzing a digital
This document discusses different digital modulation techniques:
1) Amplitude Shift Keying (ASK) represents digital data as variations in the amplitude of a carrier wave, keeping frequency and phase constant. It has simple modulation/demodulation but is highly sensitive to noise.
2) Frequency Shift Keying (FSK) represents binary digits by transmitting two different frequencies, with the peak amplitude and phase held constant.
3) Phase Shift Keying (PSK) varies the phase of a transmitted signal to convey information, with the simplest method being BPSK using two opposite phases. PSK has good noise immunity and no bandwidth limitation.
1.Oscilloscope. 2.Block diagram of Oscilloscope. 3.Types of Oscilloscope. 4.A...AL- AMIN
1.Oscilloscope.
2.Block diagram of Oscilloscope.
3.Types of Oscilloscope.
4.Applications of Oscilloscope.
5.Signal generator.
6. Types of signal generator.
7. Frequency synthesizer.
8.Analyzer.
9.Types of analyzer
This document summarizes a paper about optimizing cell reselection parameters in UMTS networks to improve standby time performance. The paper uses field measurements from commercial networks to simulate the impact of reselection parameters like DRX cycle length and Treselection time. Simulation results show that increasing the DRX cycle from 0.64 to 1.28 seconds improves standby time by 20-25% without significantly impacting camping cell quality. Shortening Treselection time from 2 to 1 seconds slightly improves cell quality but reduces standby time by less than 2%. The optimal parameters depend on factors like radio frequency environment and user mobility.
This document summarizes a lecture on non-coherent detection. It discusses coherent and non-coherent receivers, with non-coherent receivers not requiring estimation of carrier phase. It focuses on non-coherent frequency-shift keying (FSK), describing a quadrature receiver with two correlators per frequency to allow detection without phase information. The receiver squares and sums the correlator outputs before comparing to choose the detected frequency. Non-coherent FSK requires twice as many branches as coherent FSK but less bandwidth for the same symbol rate.
The document discusses delay modeling in digital VLSI circuits. It notes that circuit delay depends on many factors like charge, discharge, parasitics, transistor width-to-length ratio, fan-in, fan-out and topology. Existing delay models do not clearly indicate the contribution of each factor. This wastes circuit designers' time in simulation and tweaking. The document then presents a delay model based on logical effort that estimates delay based on the topology of the gate and relative sizes of its transistors. It shows how to compute logical effort values and parasitic delays for different gates. Applying this model helps optimize circuit design parameters like transistor sizes, number of stages in a path and topology for minimum delay.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
The document discusses the cathode ray oscilloscope (CRO) and how it can be used as a voltmeter and ammeter by connecting it across components or measuring voltage drops across resistors. It explains how to read measurements from a CRO, such as measuring time period by multiplying the distance between cycles by the time base setting. Finally, it notes that the CRO can be used to study AC waveforms, with mains electricity in Europe operating at 50 Hz and the relationship between peak and RMS voltages.
The document discusses various types of signal analyzers including cathode ray oscilloscopes, wave analyzers, harmonic distortion analyzers, and spectrum analyzers. It provides details on the working principles, components, and applications of general purpose cathode ray oscilloscopes, dual beam oscilloscopes, sampling oscilloscopes, analog and digital storage oscilloscopes, frequency selective and heterodyne wave analyzers, and fundamental-suppression and heterodyne harmonic distortion analyzers.
This document discusses the design and operation of an all-digital phase locked loop (ADPLL). It covers topics such as the digitally controlled oscillator (DCO) core design, noise modeling in the ADPLL, tuning the ADPLL for GSM, impairments like capacitor mismatch and compensation techniques.
The document discusses phase-shift keying (PSK) modulation techniques. It begins with an introduction to PSK and how it uses phases to encode digital data. It then discusses binary phase-shift keying (BPSK) which uses two phases separated by 180 degrees to encode one bit per symbol. BPSK is robust but has a low data rate. Quadrature phase-shift keying (QPSK) is then introduced, which uses four phases separated by 90 degrees to encode two bits per symbol, doubling the data rate of BPSK. Implementations of BPSK and QPSK modulators and demodulators are provided along with diagrams of their constellation plots.
This document describes the design of a digital phase locked loop (DPLL) circuit. It includes specifications for operating frequency ranges from 100MHz to 1GHz, block diagrams of the major components, schematics and test benches of the phase detector, charge pump, loop filter, voltage controlled oscillator (VCO), frequency dividers, and multiplexer. Simulation results show the DPLL locking at output frequencies of 1GHz, 900MHz and 800MHz for different control voltages and component values. The team contributions and challenges in designing and simulating the full DPLL are also noted.
Phase shift keying is a digital modulation technique where the phase of the carrier signal is changed to represent digital data. For binary PSK, a 0 bit is represented by shifting the carrier phase by 180 degrees and a 1 bit is represented by leaving the phase unchanged. Quadrature phase shift keying uses four phases to encode pairs of bits. Quadrature amplitude modulation contains digital information in both the amplitude and phase of the carrier signal.
Digital modulation techniqes (Phase-shift keying (PSK))Mohamed Sewailam
This document discusses different digital modulation techniques, focusing on phase-shift keying (PSK). It describes three types of PSK: QPSK, OQPSK, and π/4-QPSK. QPSK uses four phases shifts of 0, 90, 180, and 270 degrees to represent binary data. OQPSK and π/4-QPSK are variants that prevent abrupt 180 degree phase transitions to reduce spectral regrowth and allow use of non-linear amplifiers. OQPSK introduces a time offset between the in-phase and quadrature channels, while π/4-QPSK rotates alternating symbols by 45 degrees.
The document summarizes an improved nail packing machine that comprises a series of vibrating feeder chutes to efficiently pack nails into cases. An intermediate chute weighs the amount of nails received and interrupts the vibrator on the hopper chute if too many nails are received, allowing the intermediate chute to unload before restoring to normal operation. The machine also includes a vibratory table to further settle the nails into the cases without empty spaces.
This document describes a patent application filed in 1954 for improvements to cobalt-iron-chromium alloys. The alloys contain 45-70% cobalt, 15-22% chromium, 2-6% tungsten and molybdenum each, and 1-6% niobium and/or tantalum. Adding larger amounts of carbon, carbide-forming elements, and other strengtheners improves the heat-resisting properties of the alloys. The alloys are solution treated at 1150-1300°C and may be further improved with warm working at 500-900°C. Several example alloy compositions and their properties such as corrosion resistance are provided.
This document describes a 1957 British patent for an anti-skid control device for fluid pressure brakes used in aircraft. The device uses a rotary inertia element and valve system to sense wheel skidding and automatically reduce brake fluid pressure to prevent skidding, while maintaining braking force. It aims to maximize braking torque without skidding by varying the time to sense skid recovery based on wheel acceleration rates and controlling brake pressure buildup during recovery. The device was an improvement over prior anti-skid systems that would fully release the brakes until the wheel resumed non-slip speed.
This document describes a 1957 British patent for an anti-skid control device for fluid pressure brakes used in aircraft. The device uses a rotary inertia element and valve system to sense wheel skidding and automatically reduce brake fluid pressure to prevent skidding, while maintaining braking force. It aims to maximize braking torque without skidding by varying the time to sense skid recovery based on wheel acceleration rates and controlling brake pressure buildup during recovery. The device was an improvement over prior anti-skid systems which would fully release the brakes until the wheel resumed non-slip speed, resulting in greater stopping distances.
This document describes a patent application for improvements to regulating systems for dynamo-electric machines. Specifically, it describes a system that incorporates means to automatically prevent reduction of generator excitation below the stability limit. The system includes an automatic voltage regulator and overriding control means that prevent excitation from falling below a value determined by the magnitude of the generator load current.
This document summarizes a new oscilloscope developed by Hewlett-Packard that has a frequency response extending up to 500 megacycles, providing a major breakthrough in the field of high frequency oscilloscopes. The instrument combines a very wide bandwidth of up to 500 MHz and high sensitivity with simplicity of use. It is described as a versatile, general purpose instrument by Hewlett-Packard. The oscilloscope achieves these capabilities through the use of a sampling technique that takes samples of the input signal on successive cycles and displays them on a slower time base, allowing it to clearly display even low repetition rate signals.
This document discusses inter-symbol interference (ISI) caused by frequency dependent loss in transmission channels. ISI results in data-dependent jitter and attenuation of high frequency signal components more than low frequencies. This causes signals to take longer to reach their transmitted voltage levels. The document then discusses how equalization techniques can counteract ISI by boosting high frequency components to restore signal shape. It provides examples of transmitter pre-emphasis, receiver equalization, and discrete-time linear equalization using multiple taps with varying coefficients to approximate the inverse channel response.
Design of all digital phase locked loop (d pll) with fast acquisition timeeSAT Journals
Abstract
A Digital PLL is designed with improved acquisition time and power efficiency. The implemented D-PLL can operate
from 6.54MHz to 105MHz with a power dissipation of is 7.763μW (at 210MHz) with 1.2V supply voltage. The D-PLL is
synthesized using cadence RTL compiler in 45nm CMOS process technology.
Keywords: Digital PLL, Digital Phase/Frequency detector, NCO, Divide by N counter.
This document discusses various digital modulation techniques. It begins by explaining binary amplitude-shift keying (ASK), where one amplitude encodes a 0 and another encodes a 1. It then discusses on-off keying (OOK) and multiple amplitude shift keying (MASK). Next, it covers frequency-shift keying (FSK), phase-shift keying (PSK), differential PSK, and quadrature PSK. It also discusses more advanced modulations like quadrature amplitude modulation (QAM), continuous phase modulation (CPM), and Gaussian minimum-shift keying. The document provides examples and discusses the pros, cons, and applications of different modulation schemes. It concludes by discussing a student project involving designing and analyzing a digital
This document discusses different digital modulation techniques:
1) Amplitude Shift Keying (ASK) represents digital data as variations in the amplitude of a carrier wave, keeping frequency and phase constant. It has simple modulation/demodulation but is highly sensitive to noise.
2) Frequency Shift Keying (FSK) represents binary digits by transmitting two different frequencies, with the peak amplitude and phase held constant.
3) Phase Shift Keying (PSK) varies the phase of a transmitted signal to convey information, with the simplest method being BPSK using two opposite phases. PSK has good noise immunity and no bandwidth limitation.
1.Oscilloscope. 2.Block diagram of Oscilloscope. 3.Types of Oscilloscope. 4.A...AL- AMIN
1.Oscilloscope.
2.Block diagram of Oscilloscope.
3.Types of Oscilloscope.
4.Applications of Oscilloscope.
5.Signal generator.
6. Types of signal generator.
7. Frequency synthesizer.
8.Analyzer.
9.Types of analyzer
This document summarizes a paper about optimizing cell reselection parameters in UMTS networks to improve standby time performance. The paper uses field measurements from commercial networks to simulate the impact of reselection parameters like DRX cycle length and Treselection time. Simulation results show that increasing the DRX cycle from 0.64 to 1.28 seconds improves standby time by 20-25% without significantly impacting camping cell quality. Shortening Treselection time from 2 to 1 seconds slightly improves cell quality but reduces standby time by less than 2%. The optimal parameters depend on factors like radio frequency environment and user mobility.
This document summarizes a lecture on non-coherent detection. It discusses coherent and non-coherent receivers, with non-coherent receivers not requiring estimation of carrier phase. It focuses on non-coherent frequency-shift keying (FSK), describing a quadrature receiver with two correlators per frequency to allow detection without phase information. The receiver squares and sums the correlator outputs before comparing to choose the detected frequency. Non-coherent FSK requires twice as many branches as coherent FSK but less bandwidth for the same symbol rate.
The document discusses delay modeling in digital VLSI circuits. It notes that circuit delay depends on many factors like charge, discharge, parasitics, transistor width-to-length ratio, fan-in, fan-out and topology. Existing delay models do not clearly indicate the contribution of each factor. This wastes circuit designers' time in simulation and tweaking. The document then presents a delay model based on logical effort that estimates delay based on the topology of the gate and relative sizes of its transistors. It shows how to compute logical effort values and parasitic delays for different gates. Applying this model helps optimize circuit design parameters like transistor sizes, number of stages in a path and topology for minimum delay.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
The document discusses the cathode ray oscilloscope (CRO) and how it can be used as a voltmeter and ammeter by connecting it across components or measuring voltage drops across resistors. It explains how to read measurements from a CRO, such as measuring time period by multiplying the distance between cycles by the time base setting. Finally, it notes that the CRO can be used to study AC waveforms, with mains electricity in Europe operating at 50 Hz and the relationship between peak and RMS voltages.
The document discusses various types of signal analyzers including cathode ray oscilloscopes, wave analyzers, harmonic distortion analyzers, and spectrum analyzers. It provides details on the working principles, components, and applications of general purpose cathode ray oscilloscopes, dual beam oscilloscopes, sampling oscilloscopes, analog and digital storage oscilloscopes, frequency selective and heterodyne wave analyzers, and fundamental-suppression and heterodyne harmonic distortion analyzers.
This document discusses the design and operation of an all-digital phase locked loop (ADPLL). It covers topics such as the digitally controlled oscillator (DCO) core design, noise modeling in the ADPLL, tuning the ADPLL for GSM, impairments like capacitor mismatch and compensation techniques.
The document discusses phase-shift keying (PSK) modulation techniques. It begins with an introduction to PSK and how it uses phases to encode digital data. It then discusses binary phase-shift keying (BPSK) which uses two phases separated by 180 degrees to encode one bit per symbol. BPSK is robust but has a low data rate. Quadrature phase-shift keying (QPSK) is then introduced, which uses four phases separated by 90 degrees to encode two bits per symbol, doubling the data rate of BPSK. Implementations of BPSK and QPSK modulators and demodulators are provided along with diagrams of their constellation plots.
This document describes the design of a digital phase locked loop (DPLL) circuit. It includes specifications for operating frequency ranges from 100MHz to 1GHz, block diagrams of the major components, schematics and test benches of the phase detector, charge pump, loop filter, voltage controlled oscillator (VCO), frequency dividers, and multiplexer. Simulation results show the DPLL locking at output frequencies of 1GHz, 900MHz and 800MHz for different control voltages and component values. The team contributions and challenges in designing and simulating the full DPLL are also noted.
Phase shift keying is a digital modulation technique where the phase of the carrier signal is changed to represent digital data. For binary PSK, a 0 bit is represented by shifting the carrier phase by 180 degrees and a 1 bit is represented by leaving the phase unchanged. Quadrature phase shift keying uses four phases to encode pairs of bits. Quadrature amplitude modulation contains digital information in both the amplitude and phase of the carrier signal.
Digital modulation techniqes (Phase-shift keying (PSK))Mohamed Sewailam
This document discusses different digital modulation techniques, focusing on phase-shift keying (PSK). It describes three types of PSK: QPSK, OQPSK, and π/4-QPSK. QPSK uses four phases shifts of 0, 90, 180, and 270 degrees to represent binary data. OQPSK and π/4-QPSK are variants that prevent abrupt 180 degree phase transitions to reduce spectral regrowth and allow use of non-linear amplifiers. OQPSK introduces a time offset between the in-phase and quadrature channels, while π/4-QPSK rotates alternating symbols by 45 degrees.
The document summarizes an improved nail packing machine that comprises a series of vibrating feeder chutes to efficiently pack nails into cases. An intermediate chute weighs the amount of nails received and interrupts the vibrator on the hopper chute if too many nails are received, allowing the intermediate chute to unload before restoring to normal operation. The machine also includes a vibratory table to further settle the nails into the cases without empty spaces.
This document describes a patent application filed in 1954 for improvements to cobalt-iron-chromium alloys. The alloys contain 45-70% cobalt, 15-22% chromium, 2-6% tungsten and molybdenum each, and 1-6% niobium and/or tantalum. Adding larger amounts of carbon, carbide-forming elements, and other strengtheners improves the heat-resisting properties of the alloys. The alloys are solution treated at 1150-1300°C and may be further improved with warm working at 500-900°C. Several example alloy compositions and their properties such as corrosion resistance are provided.
This document describes a 1957 British patent for an anti-skid control device for fluid pressure brakes used in aircraft. The device uses a rotary inertia element and valve system to sense wheel skidding and automatically reduce brake fluid pressure to prevent skidding, while maintaining braking force. It aims to maximize braking torque without skidding by varying the time to sense skid recovery based on wheel acceleration rates and controlling brake pressure buildup during recovery. The device was an improvement over prior anti-skid systems that would fully release the brakes until the wheel resumed non-slip speed.
This document describes a 1957 British patent for an anti-skid control device for fluid pressure brakes used in aircraft. The device uses a rotary inertia element and valve system to sense wheel skidding and automatically reduce brake fluid pressure to prevent skidding, while maintaining braking force. It aims to maximize braking torque without skidding by varying the time to sense skid recovery based on wheel acceleration rates and controlling brake pressure buildup during recovery. The device was an improvement over prior anti-skid systems which would fully release the brakes until the wheel resumed non-slip speed, resulting in greater stopping distances.
This document describes a patent application for improvements to regulating systems for dynamo-electric machines. Specifically, it describes a system that incorporates means to automatically prevent reduction of generator excitation below the stability limit. The system includes an automatic voltage regulator and overriding control means that prevent excitation from falling below a value determined by the magnitude of the generator load current.
1) The document describes improvements relating to electrical storage apparatus, specifically storage systems for numerical data in binary form using an array of double base transistors.
2) A double base transistor has two base electrodes with a trigger electrode and collector electrode in between. Applying a bias voltage between the base electrodes and a trigger voltage to the trigger electrode can trigger the transistor to store data.
3) The transistors can be arranged in a matrix with rows and columns connected to busbars. Applying trigger pulses simultaneously to a row and column can selectively trigger a transistor at that intersection to store a 1, while other transistors remain off and store a 0. Stored data can then be read out without erasing it.
This document describes patent GB780002 (A) for an electronic switching circuit arrangement. It includes a detailed description of the circuit components, including a central conductor, rectifiers, resistors and switching units. The circuit allows for rectifiers to act as either controlling or controlled components depending on how they are connected between relay circuits. Figures 1 and 2 illustrate example circuit configurations. The switching circuit can be used in applications like code converters to convert between binary input signals and converted output codes.
This patent document describes a combustion process for internal combustion engines that features:
1) A subdivided combustion chamber, such as a pre-combustion chamber or turbulence chamber.
2) Combustion air is caused to rotate in the chamber and fuel is injected into the rotating air.
3) The temperature of the chamber wall is automatically controlled based on engine operating conditions to optimize combustion.
1) The document describes an electronic switching unit comprising two tubes (Bla and Bib) that can alternately conduct or not conduct based on the control grid voltage of the first tube (Bla).
2) The switching unit uses voltage dividers to regenerate the amplitude of the applied switching potential and output nominal and inverted values of the potential at its terminals.
3) By applying multiple switching units in series and connecting their reference potentials, only one voltage source is needed to power the circuit.
This document describes a water softening device that uses ion exchange to soften water from mains before it reaches domestic or industrial premises. It contains a cartridge holding the ion exchange medium that is detachably mounted to a frame. The frame can be fixed to a wall. Water enters the bottom of the cartridge, passes through the ion exchange medium, and exits the top, now softened. The cartridge design makes the water softener inexpensive enough to use with water heaters.
1) The document describes a packaging machine that inserts soft products like rubber goods into envelopes. It does this by first inserting the product into a flattened tube, then inserting the end of the tube containing the product into an open envelope.
2) A gripping device then presses on the part of the product protruding from the tube to hold it in place as the tube is withdrawn.
3) The machine uses a rotating spider arm mechanism to position flattened tubes containing products above open envelopes on a rotating turntable, transferring the products into the envelopes as the tubes are inserted and withdrawn.
This document describes improvements to textile ring spinning machines. It discusses prior art machines and limitations around friction and speed. The invention aims to allow for higher speeds by reducing friction through various means, including driving the spinning ring with an electric motor and using magnetic bearings on the spindle. Diagrams are provided to illustrate the invention, showing the arrangement of motors, magnetic components, and other elements.
This document describes a patent for a soap holder and applicator. The soap holder is made of a flexible material shaped like a soap cake with a slit that can be opened by squeezing to insert pieces of used soap. Part of the wall has a criss-cross lattice formation to expose the soap and allow direct contact between the soap and skin during use. When squeezed, the two halves of the holder separate to form an opening for inserting soap pieces.
This document provides details on patent GB780046 (A) which relates to a process for preparing lubricating compounds of the formal type. Specifically, it involves first forming a mixture of Oxo alcohols via an Oxo synthesis reaction using a mixture of polymeric olefinic hydrocarbons containing mostly C12 to C18 olefins. This is then contacted with excess formaldehyde in the presence of an acid catalyst to form a residue with lubricating oil characteristics after removing more volatile components.
This document describes a preparation and process for permanently changing the shape of hair, such as imparting a permanent wave, using a reducing solution containing a mercaptan (such as thioglycollic acid), a sulphite, and formamide or a substituted formamide (such as urea). Applying the solution to hair wrapped in curlers and heating it to 40-60°C (tepid waving) allows the concentration of mercaptan to be substantially reduced compared to conventional preparations while still effectively changing the hair shape. The preparation pH is preferably 9-10 and concentrations of ingredients like mercaptan, sulphite and formamide or substitute are provided.
The document describes an improved copper-aluminum alloy containing 5.5-8% aluminum, 1-2% cobalt, and 2-6% nickel (replaceable by manganese). The alloy exhibits high resistance to creep at temperatures up to 500°C and good mechanical properties at ordinary temperatures due to precipitation hardening. Preferred proportions are 7% aluminum, 1.5% cobalt, and 4% nickel. Samples of the alloy with this composition demonstrated tensile strengths up to 65 tons/in2, elongations up to 10%, and creep rupture lives over 1000 hours at loads up to 4 tons/in2 when given appropriate heat treatments.
This document describes an improved animal holding device consisting of a pair of movable side arms that can embrace an animal's neck. The side arms are pivotally mounted and given simultaneous movement by contact with a pivoted operating lever. In the closed position, the side arms imprison the animal's neck, while in the open position they leave a wide space for the animal to put its head. The device allows animals to be safely held for inspection, medical treatment, or other purposes in a simple and humane manner.
This document describes a patent filing from 1957 for an improved clamping device. The device comprises two bifurcated members that can be secured together in different relative positions using a connecting screw. One member has a strip or rail that prevents relative rotation when the two members are secured together. The arrangement allows a shelf or panel to be firmly supported in any of several selected positions relative to a support.
This document provides a summary of GB780031 (A), which describes a process for manufacturing acid amide derivatives of azo-compounds. Specifically, it involves condensing an amine containing at least two reactive amino groups with a carboxylic acid halide from an azo compound, where the azo compound contains a carboxylic acid ester group next to the azo linkage. The starting materials used do not contain groups that impart water solubility. A variety of diamine and azo compounds are described that can be used in this process.
This document describes an apparatus for storing intelligence signals as electric pulses on a magnetic medium. It provides:
1) A storage medium with multiple storage elements that can each store a signal.
2) Means for recording signals in the storage elements and reading the recorded signals.
3) Adjustable means for examining only a selected portion of a read signal, by varying the position within the signal width that is examined.
This document describes an apparatus for storing intelligence signals as electric pulses on a magnetic medium. It provides:
1) A storage means with multiple storage elements, each capable of storing a signal. It records signals in the elements and includes fixed and adjustable means for reading and examining a selected portion of a read signal.
2) A storage device with a movable magnetic medium, recording and reading heads, and a clock pulse source. It includes means for recording signals based on clock pulses and generating multiple control pulses within a signal width to selectively examine a portion of a read signal.
3) A storage device can also use a sonic delay line medium, with similar recording, reading, and control capabilities to selectively examine a
This document provides 116 technical questions covering a wide range of topics including integrated circuits, amplifiers, transistors, digital logic, microprocessors, C programming, electronics, and instrumentation. The questions test knowledge of concepts like heat dissipation, gain calculations, transistor characteristics, digital logic gates, microprocessor instruction cycles, data types, and more.
AREA OPTIMIZED FPGA IMPLEMENTATION FOR GENERATION OF RADAR PULSE COM-PRESSION...VLSICS Design
Pulse compression technique is most widely used in radar and communication areas. Its implementation requires an opti-mized and dedicated hardware. The real time implementation places several constraints such as area occupied, power con-sumption, etc. The good design needs optimization of these constraints. This paper concentrates on the design of optimized model which can reduce these. In the proposed architecture a single chip is used for generating the pulse compression se-quence like BPSk, QPSk, 6-PSK and other Polyphase codes. The VLSI architecture is implemented on the Field Programm-able Gate Array (FPGA) as it provides the flexibility of reconfigurability and reprogrammability .It was found that the proposed architecture has generated the pulse compression sequences efficiently while improving some of the parameters like area, power consumption and delay when compared to previous methods.
Three Phase Digitally Controlled Power Factor Improvement SystemIOSR Journals
This document summarizes a three phase digitally controlled power factor improvement system. The system uses a digital control circuit to determine a count representing the phase shift between the line voltage and current as well as the load current. This count addresses a pre-programmed ROM with switching combinations of capacitors to improve the power factor. Power factor improvements up to 0.95 were achieved for loads up to 20A. The same control circuit can be used for higher loads by altering the ROM programming and switching component ratings.
This document discusses the design and implementation of digital pulse compression in pulsed radars using linear frequency modulation (LFM) waveforms on an FPGA. It describes how LFM waveforms achieve pulse compression to overcome peak power limitations while maintaining range resolution. The key aspects covered are:
1) The LFM waveform is generated digitally using counters, PROMs, and DACs to produce the frequency modulated signal.
2) Matched filtering is used at the receiver to compress the received signal through correlation with the known transmitted LFM waveform. This is implemented using an FFT.
3) Simulation results on the FPGA show generation of the LFM waveform and resolution of multiple targets after pulse compression
Design of a High Precision, Wide Ranged Analog Clock Generator with Field Pro...VLSICS Design
This paper presents a circuit of a high-precision, wide ranged, analog clock generator with on-chip programmability feature using Floating-gate transistors. The programmable oscillator can attain a
continuous range of time-periods lying in the programming precision range of Floating Gates. The circuit consists of two sub circuits: Current Generator circuit and Wave Generator circuit. The current of current generator circuit is programmable and mirrored to the wave generator to generate the desired square wave. The topology is well suited to applications like clocking high performance ADCs and DACs as well as used as the internal clock in structured analog CMOS designs. A simulation model of the circuit was built in T-Spice, 0.35µm CMOS process. The circuit results in finely tuned clock with programmability precision of about 13bit [1]. Simulation results show high amount of temperature insensitivity (0.507ns/°C) for a large range of thermal conditions. The proposed circuit can compensate any change in temperature. The circuit design can be operated at low supply voltage i.e., 1v.
DESIGN OF A HIGH PRECISION, WIDE RANGED ANALOG CLOCK GENERATOR WITH FIELD PRO...VLSICS Design
This paper presents a circuit of a high-precision, wide ranged, analog clock generator with on-chip programmability feature using Floating-gate transistors. The programmable oscillator can attain a continuous range of time-periods lying in the programming precision range of Floating Gates. The circuit consists of two sub circuits: Current Generator circuit and Wave Generator circuit. The current of current generator circuit is programmable and mirrored to the wave generator to generate the desired square wave. The topology is well suited to applications like clocking high performance ADCs and DACs as well as used as the internal clock in structured analog CMOS designs. A simulation model of the circuit was built in T-Spice, 0.35µm CMOS process. The circuit results in finely tuned clock with programmability precision of about 13bit [1]. Simulation results show high amount of temperature insensitivity (0.507ns/°C) for a large range of thermal conditions. The proposed circuit can compensate any change in temperature. The circuit design can be operated at low supply voltage i.e., 1v.
This document describes a frequency divider circuit that divides an input clock frequency into lower output frequencies. It consists of two stages: 1) A first stage that divides the clock frequency by a number n using a delay line register, outputting a pulse every n cycles. 2) A second stage that counts the pulses from the first stage using a binary half adder and delay line, outputting a pulse every 2^N counts, where N is the delay of the second stage delay line. This provides an overall frequency division of 1/(n*2^N). The circuit includes amplifiers and compensatory delay lines to synchronize components and account for delays introduced.
An electronic measurement system using an interdigitated capacitive sensor has been developed to more accurately measure spinal fusion progress by detecting cartilage formation, allowing earlier rehabilitation. The sensor will be mounted on a spinal plate and connected to circuitry to measure its changing capacitance during plate bending. The circuitry design includes stages for capacitance measurement, analog to digital conversion, and wireless data transmission. The objective is to complete the first capacitance measurement stage. Testing of different circuits found the Low-Z Amplifier accurately measures capacitances in the picofarad range needed. Preliminary work has been done on later stages using an Arduino, with challenges including wireless transmission through body and circuit miniaturization.
This document describes an electron discharge device with improvements for reading and writing information. It discusses prior art barrier-grid storage tubes and issues with collecting secondary electrons from the target. The invention addresses this by reading signals directly from the target and applying writing signals to the back plate through a coaxial transmission line, effectively isolating the input and output circuits. This eliminates problems like shading and increases signal magnitude.
A 20 gbs injection locked clock and data recovery circuitVLSICS Design
This paper presents a 20 Gb/s injection-locked clock and data recovery (CDR) circuit for burst mode
applications. Utilizing a half rate injection-locked oscillator (ILO) in the proposed CDR circuit leads to
higher speed operation and lower power consumption. In addition, to accommodate process, voltage, and
temperature (PVT) variations and to increase the lock range, a frequency locked loop is proposed to use in
this circuit. The circuit is designed in 0.18 μm CMOS and the simulations for 27-1 pseudo random bit
sequence (PRBS) show that the circuit consumes 55.3 mW at 20 Gb/s, while the recovered clock rms jitter
is 1.1 ps
This document provides instructions for experiments using a cathode ray oscilloscope (CRO). The first experiment introduces the basic functions and controls of a CRO. Students will learn to display waveforms and measure the dc voltage, peak-to-peak voltage, and frequency of signals. The second experiment describes how to use a CRO to measure dc and ac voltages. The third experiment explains how to measure the frequency of an unknown signal by adjusting the time base to display one cycle over two divisions and calculating from the period. The overall document provides step-by-step guidance for using a CRO to visualize and analyze electrical signals.
Frequency dependency analysis for differential capacitive sensorjournalBEEI
A differential capacitive sensing technique is discussed in this paper.
The differential capacitive sensing circuit is making use of a single power supply. The design focus for this paper is on the excitation frequency dependency analysis to the circuit. Theory of the differential capacitive sensor under test is discussed and derivation is elaborated. Simulation results are shown and discussed. Next, results improvement has also been shown in this paper for comparison. Test was carried out using frequency from 40 kHz up to 400 kHz. Results have shown output voltage of Vout=0.07927 Cx+1.25205 and good linearity of R-squared value 0.99957 at 200 kHz. Potential application for this capacitive sensor is to be used for energy harvesting for its potential power supply.
This document summarizes a study on wireless power transfer using induction technique. It describes how electrical power is converted to magnetic energy in a transmitter coil, generating a time-varying magnetic field. When a receiver coil is placed within this field, the magnetic energy is reverted back to electrical energy to power a load without the use of wires. The document outlines the circuit designs for the transmitter and receiver, and analyzes the relationship between current, magnetic flux, and power transfer through mathematical equations and simulation results. Experimental data shows different voltages induced in receiver coils with varying numbers of turns. The summary concludes that induction-based wireless power transfer over short distances is possible by controlling current harmonics to reduce power losses.
The document discusses several types of specialized oscilloscopes:
1. Delayed time base oscilloscopes allow studying all parts of a pulse waveform by delaying the signal to the vertical plates. This ensures no part of the waveform is lost.
2. Analog storage oscilloscopes can retain an image for longer periods through mesh or phosphor storage techniques, allowing viewing of very low frequency waveforms.
3. Sampling oscilloscopes use a staircase-ramp generator to take samples that are displayed as the beam moves across the screen. Synchronization ensures sampling is timed with the input signal frequency.
4. Digital storage oscilloscopes digitize the input signal using an analog-to-
This document presents a new method for locating ungrounded faults in underground distribution systems using wavelet analysis and artificial neural networks (ANNs). Voltage and current signals are simulated for different fault types, locations, and conditions using EMTP software. Wavelet analysis is used to extract features from the signals related to fault classification and location. ANNs are then applied to classify fault types based on the extracted features and to determine the fault location for each fault type based on additional extracted features. The results indicate the technique can accurately locate faults under a variety of system conditions.
This document describes a patent from 1957 regarding improvements to electron discharge devices using photoconductive targets. It discusses how scanning a rectangular raster on the target results in uneven sensitivity and dark resistance across the target. The patent proposes a method of bombarding the entire photoconductive target area with a high beam current while applying a voltage gradient and uniform illumination. This treatment is intended to impart a substantially uniform sensitivity and dark resistance across the entire target.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
This document describes a travelling wave tube comprising a ceramic envelope bonded to ceramic discs at each end, with a helix inside. It includes coaxial input/output feeders external to the envelope. Dielectric-loaded stripline impedance transformers couple each end of the helix to the respective feeder. The couplings are formed by a ground plane on the disc joined to the feeder outer conductor, and a radial conducting strip bonded to the disc inner face connected to the helix and feeder inner conductor.
This document describes a patent for a novel looped pile fabric and method of making it. The fabric is woven flat on a simple loom with heat-shrinkable yarns running in one direction and other yarns crossing perpendicularly. Soft lofty yarns are floated over the crossing yarns to form piles. When heat-treated, the shrinkable yarns contract and draw the pile yarns together to form dense upright loops on the surface. The opposite side can then be coated to anchor the piles. This allows inexpensive production of looped pile fabrics on simple looms.
This document is a patent application for improvements to domestic firegrates. It describes a firegrate with a chamber below the oven and a baffle located at the front of the chamber. The baffle extends upward from the firegrate to form a passage below the oven, drawing some combustion gases downward and upward through the chamber and passage to heat the oven. The baffle may include flanges to direct gases and support a firebrick facing the chamber. This design improves oven heating over previous domestic firegrates.
This patent document describes improvements to sealing glands for rotating machines using sintered metals. It discusses how sintered forms of metal like iron or nickel rub away more readily with less heat generation than cast or wrought metals when used in sealing glands between a rotating shaft and surrounding casing. The invention involves using sintered metal for one or both parts of a labyrinth gas gland that are liable to rub against each other.
This document describes improvements to reflex klystrons. It discloses a reflex klystron design that avoids the formation of a virtual cathode in the reflector space by ensuring the ratio of the reflector surface area to the cathode surface area is more than twice the ratio of the length of the retarding path in front of the reflector to the length of the acceleration path in front of the cathode. The klystron is suitable for modulation purposes due to its relatively large bandwidth.
This document describes improvements to heat exchanger tubes made of thin-walled aluminum or light alloy. It discusses two improved modes of manufacturing the tubes. The first involves forming a strip into a tube shape with the longitudinal edges turned inward and joined. The second involves forming a tube from two complementary strips with abutting longitudinal edges joined. Both methods involve coating the strips with brazing filler and brazing the joined edges.
The document describes an improved can packing mechanism for textile drawing frames. The mechanism uses vertical cylinders attached to the base of the machine, each containing a slidable rod connected to a chain. The rod carries a head that packs sliver into cans. The chains are connected to wheels on a shaft that is oscillated back and forth, causing the rods and heads to move up and down in a tramping motion to pack the sliver. This mechanism eliminates extending levers and allows for close spacing of the cans. Diagrams show two embodiments using springs or weights to assist the up and down motion of the rods and heads.
This document describes a process for stabilizing textile materials against shrinkage during laundering by treating cellulosic materials with non-volatile acetals of monoaldehydes and dialdehydes containing up to eight carbon atoms, and heating the treated material in the presence of an acidic catalyst and curing at over 121°C. Specific examples are provided of treating fabrics like viscose with acetals then evaluating them for shrinkage after multiple washes. The treatment is said to impart shrink resistance with minimal discoloration and retention of strength and handle.
This document describes improvements to ion traps in cathode-ray tubes. Specifically, it describes a cathode-ray tube design where the axis of the tubular anode adjacent to the cathode is not coaxial with but intersects the common axis of preceding electrodes. This allows the ion trap to operate satisfactorily while avoiding disadvantages of prior designs that required the anode to have a coaxial part. The new design allows for a shorter overall electrode system length compared to prior bent anode designs.
This document describes a patent for improvements in the production of molds and cores. Specifically, it involves a process where a mixture of sand and gas-hardenable binder is blown into a mold or core box. A gaseous hardening agent is then applied to the mixture as it enters the mold box. This allows the molds and cores to be formed and hardened rapidly. The document provides detailed descriptions of the process and apparatus used, including the use of a venturi tube-shaped orifice in the blowing plate to control where the hardening agent is introduced.
This document describes an apparatus for measuring high rotational speeds ranging from 2500 to 30000 RPM. The apparatus uses a cathode ray oscilloscope connected to an electromagnetic impulse generator attached to the rotating member. This causes the spot on the oscilloscope to move in a circular pattern proportional to the rotational speed. Timing circuits switch the spot on to create a short spiral trace indicating the broad speed range, then off. After a delay, the spot is switched on briefly to create a dot, indicating the precise speed within the range.
This document is a patent application from 1957 relating to locker and cupboard door fastenings. It describes a three-point locking mechanism that locks the door at the top, bottom, and side for increased security. The mechanism includes a lever that projects from the side of the door and upper and lower bolt members connected to the lever that project from the top and bottom when the lever is engaged. One of the bolt members has an abutment that can be locked in place by a lock to secure all three points.
This document describes a lubricant composition for aviation gas turbine engines. The composition includes a blend of dinonyl sebacate and di-2-ethyl hexyl sebacate as the major components. It also includes a complex ester in the amount of 10-30% by volume to increase viscosity and improve high temperature performance. Additionally, it contains an oxygen-containing polymer such as polyacrylate in the amount of 20% by weight to further improve properties.
This document describes a flux composition for soldering metals like aluminum that comprises a zinc chloride complex salt of a pyrazoline hydrohalide and a nitrogen salt component. The flux composition has advantages for production line soldering as it can be used in an inexpensive, non-flammable aqueous solution without hydrolysis or oxide formation issues seen in other fluxes. The document provides details on preparing the complex salt and flux, and examples demonstrating its effectiveness in soldering aluminum.
This document describes improvements to teaching apparatus for elementary arithmetic instruction. The apparatus uses a rigid board with numerical scales and movable counters to teach counting and basic arithmetic operations. Key improvements include omitting or outlining numerical symbols on the scales so students fill them in as they move counters. Counters are also marked with arrows or other symbols to associate direction of movement with addition and subtraction. Having irregular edges on the board conveys the infinite nature of numbers to students.
This document summarizes a patent for an apparatus that stores digital data on a moving magnetic medium. It allows for simultaneously reading stored data from a cell on the magnetic medium and overriding it by writing new data to that same cell. This is accomplished by using timing impulses to select cells for reading and writing, with the reading gate impulse occurring just before the writing gate impulse. This provides time to determine what new data should be written based on the read data and other inputs. The document describes the technical details and diagrams of how this works.
This document describes improvements to methods and apparatuses for filling large collapsible shipping containers. Specifically, it describes pressurizing the container before filling to expand it fully, then filling it while maintaining pressure. This ensures utilization of the container's full capacity. The document provides detailed descriptions and drawings of various apparatuses that can pressurize and fill the container through separate or same openings, including features like telescoping filling tubes and screw conveyors to direct filling material.
The document summarizes an improved nail packing machine that comprises a series of vibrating feeder chutes to efficiently pack nails into cases. An intermediate chute weighs the amount of nails received and interrupts the vibrator on the hopper chute if too many nails are received, allowing the intermediate chute to unload before restoring to normal operation. The machine also includes a vibratory table to further settle the nails into the cases without empty spaces.
This document describes patent GB780026 (A) filed in 1957 regarding improvements to rotary pumps, compressors, and engines. It includes a rotor with blades that form conveyor chambers and an abutment slide that separates the suction and pressure sides. The blades curve forward in the direction of rotation to fully fill the chambers and prevent ejection of the medium. The abutment slide has a cylindrical packing part that follows the sharp blade tips for improved efficiency. The abutment slide is controlled via a crank to match the rotor profile for various applications including high speed operation.
This document describes GB780027 (A), which relates to a new group of compounds called 3-piperidyl ethers and thioethers. These compounds have desirable therapeutic properties, particularly oxytocic activity and selectivity of action upon the in situ uterus without undesirable side effects. The document provides the general chemical formula for these compounds and examples of their synthesis, including by reacting piperidinols with aralkyl halides. Therapeutic uses including preventing or treating postpartum hemorrhage are also described.
1. * GB780030 (A)
Description: GB780030 (A) ? 1957-07-31
Apparatus for storing digital data on a moving magnetic medium
Description of GB780030 (A)
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The EPO does not accept any responsibility for the accuracy of data
and information originating from other authorities than the EPO; in
particular, the EPO does not guarantee that they are complete,
up-to-date or fit for specific purposes.
PATENT SPECiIFCATION
Date of Application and filing Complete
Specification: Dec. 15, 1953.
709030 No. 34940/53.
Application made in Netherlands on Dec. 29, 1952.
Complete Specification Published: July 31, 1957.
Index at aceptance:- geiss 106(), 0 1I A I nternaftnnaD
CRassaficaun:-GO8", The inventor of this invention in the sense of
being the actual deviser thereof within the meaning of Section 16 of
the Patents Act, 1949, is Leendert Kosten, a subject of the Queen of
the Netherlands, of 16, Duchattelstraat, The Hague, the Netherlands.
COMPLETE SPECIFICATION
Apparatus for Storing Digital Data on a Moving Magnetic Medium We,
STAATSBEDRIJF DER POSTERIJEN, TELEGRAFIE EN TELEFONIE, a Public
Department of the Netherlands, of Kortenaerkade 12, The Hague, the
Netherlands, do hereby declare the invention, for which we pray that a
2. patent may be granted to us, and the method by which it is to be
performed, to be particularly described in and by the following
statement: For recording large quantities of coded information, use is
often made of a movable magnetic wire, tape, disk or drum as the
information storage medium. The information is often recorded in a
binary form in fixed spots on this medium (the information cells) by
means of differences in magnetization.
For the purpose of electromagnetic writing on and reading from the
medium, the position of a given information cell is determined 20by
the selection of a specified recorder or reproducer, or by time
selection.
When information has once been recorded on the medium, it is preserved
for an arbitrarily long time. Other types of recording systems
(mercury tube memory, electrostatic memory) do not possess this
quality.
In said other types of recording system the information stored in each
cell must be read within a rather short time to be re80written. Thus
each element of information is constantly refreshed.
It is possible at any refreshing moment in these systems to read the
old information contained in a cell and to record at the same time new
information in its place. This possibility is inherent of the
regenerative character of the recording system.
In an ordinary non-regenerative magnetic recording system it is
possible to change at suitable moments the information contained in
specified cells. Because of the large writing signal, however, it is
not possible, in that case, to read the old information at the same
time. The invention provides means for reading the information
contained in a cell [Price 3/6] and overriding it by writing other
information in its place simultaneously (or practically
simultaneously) at the same selection moment.
The invention will be described in connection with the example
(illustrated in Fig.
1 of the accompanying drawings) of a magnetic drum, on which only one
magnetic head will be used for writing upon, and for reading from the
drum, and consequently, involv- s5 ing only one track on the drum. The
drum has a second track on which a series of equidistant impulses has
been stored. The signal extracted from this track, when passed through
the amplifier KV and the impulse 60 regenerator IR results in a series
of impulses (the timing impulses), which mark on the information track
a number of spots equal to the number of impulses of the timing
impulse track. The neighbourhoods of these 65 spots are the
information cells. Gating impulses pi, and pi, for the selection of
cells with a view to writing into and reading from these cells,
respectively, are derived from the timing impulses ki. 70 It is
3. supposed, though this is not essential, that the magnetic medium is
originally neutral and that the binary digits " 1 " and "0" are
written into a given cell by the transmission of short current
impulses of different directions through the magnetic head.
Fig. 2 shows at a and d the curves of these impulses plotted against
time, in this figure the time scale must be taken in relation to the
equidistant timing impulses mentioned 80 above. If in the cell under
review a " 1 " has been recorded and if this " 1 " is overridden in a
next revolution at the correct instant by a " 0," the medium will
assume practically the same condition as if a " 0" had been 85 written
directly. Thus the after-effect of former recordings is negligible.
If in a revolution in which no writing occurs, the voltages appearing
at the terminals of the magnetic head are plotted 90 -- - A 'S.-S
780,030 against time, the curve obtained will have a character as
shown in Fig. 2 at c or f according as the last digit recorded has
been a " 1" or a "0." By sufficient amplification and by the use of
the gate operating in the hatched interval a definite determination of
the last recorded digit can be obtained. The reading pulse operates on
the reading gate during the interval represented by the right-hand
hatched period and the writing pulse during the interval represented
by the left-hand hatched period.
Curves b and e show the magnetisation of the drum after its passage
under a head excited with either a 1 (curve a) or a 0 (curve d). This
magnetisation corresponds with that (curves a or d) of the head and
takes into account the diffusion effect due to the finite size of the
head and the finite air-gap between the head and drum. During a
succeeding drum revolution, the voltages induced in the head, as
represented by curves c and f, are obtained by differentiation from
curves b and e, with a similar diffusion.
If the air-gap or slot of the magnetic head were infinitely narrow and
the clearance between the head and the medium were infinitely small,
the recording of one element would cause the magnetization of an area
called herein area A equal to air-gap width in the direction of travel
times the distance covered tangentially by the drum in an interval
equal to the recording gate impulse.
As the said air-gap-width and distance are 35not infinitely small,
there will be a certain diffusion of the magnetic field. As a result
of this the actually magnetized area per cell will be larger than the
said defined area A.
Further, during the reading operation a magnetic dipole lying on the
medium will already have an appreciable influence on the magnetic head
before this dipole has arrived right under the air-gap. The diffusion
effects occurring during writing and reading add up, so that in the
case of reading, a notable signal can be obtained at a moment (in
4. relation to the timing impulse) lying before the interval in which the
writing impulse for recording occurs (see Fig. 2).
Consequently, it is possible to place the reading gate impulses a
short time before the recording gate impulses. In carrying out the
present invention, this effect is made use of for scanning during a
revolution the information from a cell during a reading gate impulse
and changing. if necessary, the content of this cell during the
immediately following writing gate impulse. The time between the
reading and writing gate impulses is available for determining, if
necessary from the information read together with information supplied
from another source, any new information to be stored in the cell.
Fig. 3 gives the diagram of such an instal651ation. The timing
impulses picked up by the magnetic head KI, are amplified by KV and
regenerated by IR. These impulses are directly applied, as impulses
pi2, to the reading gate P2, through which the signals coming from the
information head K, as amplifled by AV can pass.
The signal passed by P.) at a certain moment arrives at a device RO,
which may be a computing device and in which it is determined from the
information carried by this 75 signal and from other information
present in RO or supplied from the outside, whether, and in the
affirmative case. which new information must be recorded in the
relevant cell.
The term " computing " in computing device is used in this case in the
broad sense of forming new coded information by the application of
logical operations on given information. This information may be
passed from RO to Ki as a writing signal, a 85 suitable part of this
signal being passed by gate P. The gate impulse pi. applied to P, is
obtained from the timing impulse ki, suitably delayed by the impulse
delay circuit IV.
The circuit described exhibits another difficulty, in that during the
recording of new information a large current impulse is sent through
Ki; this current impulse causes also a large voltage impulse at the
input of AV.
This voltage impulse may be as much as 80 95 db above the level of the
reading signal normally to be handled by AV.
If, as is normal, AV is an a.c. amplifier, it becomes so overloaded
during the writing operation that it is for some time irresponsive to
reading. The time during which this irresponsiveness exits is long
relatively to the periods of the lowest frequency components of the
reading signal.
As the amplifier AV must be able to 105 handle the information
recorded in the next cell, a serious limitation as regards the number
of cells per unit length in a tangential direction is imposed on the
system.
5. In order to avoid this difficulty AV may 110 be arranged as a d.c.
amplifier, the anode and screen grid voltages being obtained from
batteries or from electronically stabilized voltage sources (so having
no inertia). In that case over-control does not entail
irresponsiveness. This solution. however, is not very attractive.
According to this invention a data processing arrangement comprising a
processing device for deriving bv means of logical operations new
coded information from given information, a device for recording coded
information on a movable ferromagnetic medium by means of a magnetic
head and for reading as determined by a reading gate 125 recorded
information from this medium by means of the same head. recording into
and reading from the information cells on this medium being effected
by time selection, the information read being fed to the said device
13 780,030 and the information to be recorded originating from this
device, in which arrangement during one passage of the medium each
time selection impulse for reading from a cell arrives at the reading
gate a little earlier than that for recording information in the same
cell and in which arrangement, moreover, the said device determines
from the information extracted under control of a given reading
selecting impulse and from any information available in another way,
whether, and, in the affirmative case, which information shall be
substituted for the extracted information in the said cell during the
recording selecting impulse immediately following the said given
reading selecting impulse, is characterized in that the signals read
by the magnetic head are modulated on a carrier current having a
frequency which is large with respect to the frequency of reading
successive information cells and in that the modulated signals are
subsequently amplified and detector and then led to the gate
controlling the reading operation.
In practising the present invention instead of the direct current
amplifier AV, use is made of a combination of a carrier oscillator 0,
a modulator M, a high frequency amplifier V and a detector D. An
embodiment of the invention is illustrated in Fig. 4 of the
accompanying drawings.
In Fig. 4, 0 is a carrier oscillator, the frequency of which is large
with respect to the highest frequency essentially present in the
reading signal from Ki. M is a ring modulator to which the carrier
current is applied and in which it is modulated with the signal from
Ki. The modulated carrier is then amplified in V. D is a detector in
which the signal is detected. The detected signal is applied to P2
(see Fig. 3). In order to obtain different states of P2 for 1 or 0 as
read, M must be adjusted to be " out of balance."
For this purpose use can be made of the variable resistor Rd shown, or
of a polarizing voltage inserted in the cross connection.
6. The gate P, of Fig. 3 is represented in Fig.
4 by the double triode. As a result of the connection, by means of
rectifiers, between the grids of this tube and the conductors coming
from RO and point pi, which are all normally at a potential of e.g.,
-20 V, neither triode normally carries any current.
The series connection of the cathode resistors R7, and R1.0 produces
an attenuation of only a few dB during the reading operation.
If a " 1" has to be recorded, potential of e.g., + 10 V is applied by
left-hand conductor RO. As soon as the gate impulse appears, the grid
potential of the left-hand triode rises to +10 V and anode current
begins to flow. The cathode current flows partially through resistor
R,1, partially through the series connection KX and R7u,.
The resistors are so dimensioned that the latter current flowing
through Ki and R7, is large enough for writing a " 1 " on the drum.
The recording of a " 0 " is done in an analogous way by means of the
right-hand triode.
In this case the current flow through Ki is 70 in the Opposite
direction.
During the writing operation a large voltage is applied to Ki and also
reaches V, which is rendered irresponsive in consequence. This is due
to changes in energy 75 content of various reactive coupling and
decoupling elements also under the influence of detection phenomena
attendant upon the large voltage aforesaid. Actually V needs only to
amplify frequencies in the neighbourhood of the carrier frequency.
Consequently, the relaxation times of coupling and decoupling circuits
need only to be a little larger than the carrier period. Decay times
of circuits may be chosen somewhat larger. The 85 abnormal state of V
passes to the normal one practically in a time of the order of a few
times the said intervals, that is in a few carrier periods. As this
period is small with respect to the high frequency practically 90
occurring in the reading signal, and consequently, still more with
respect to the interval between two timing impulses, the amplifier V
can have reached, after a recording impulse, its normal state again
before the 95 arrival of the next reading gate impulse.
The detector D can work at such a high energy level that overcontrol
during writing can be avoided by simple means, such as limiting
rectifiers. 100
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