2. Basic function: fact almost any quantity after suitable conversion into
voltage can be analyzed as a function of time. Functionally CRO is
capable of displaying two quantities Y versus X in Cartesian coordinate
system, however in most cases the Y axis is amplitude and the X axis is
time. It is widely used for trouble shooting radio and TV receivers as well
as laboratory work involving research and design. It can also be
employed for studying the wave shape of a signal with respect to
amplitude distortion and deviation from the normal. In true sense the
cathode ray oscilloscope has been one of the most important tools in
the design and development of modern electronic circuits.
3. Construction of CRO
The oscilloscope is basically an electron beam voltmeter. The main part
of oscilloscope is the Cathode Ray Tube (CRT) which makes the applied
signal visible by the deflection of a thin beam of electrons striking a
phosphor screen. The electron beam can be moved to follow waveforms
varying at a rate of times/second using proportionate electric fields.
Thus, the electron beam faithfully follows rapid variations in signal
voltage and traces a visible path on the CRT screen.
The major blocks in a general purpose CRO shown in figure given below
are as follows:
CRT, vertical amplifier, delay line, time base gnerator, horizontal
amplifier, trigger circuit, and power supply.
4.
5.
6. Specifications for this item
Brand Name Seeed studio
Part Number 01714965113
UPC 787461659526 , 609408180781
Body Style Handheld
EAN 0609408180781 , 0787461659526
Included Components Digital Storage Oscilloscope
Is Recalled? N
Number of Items 1
UNSPSC Code 41113638
Specifications for this item
7. CRT: A CRT is the cathode ray tube which emits thin beam of focused electrons that strike the
phosphor screen illuminating the point to provide a visual display of signal.
Vertical Amplifier: It is a wide band amplifier used to amplify signals in the vertical section. The
gain of the amplifier is set by V/Div knob.
Delay Line: It delays signal in vertical section so that the part of the signal just before trigger
event can be displayed.
Time Base: It generates the sawtooth voltage (sweep) required to deflect the beam along X axis
and to refresh the display every cycle giving stable image on the screen. The sweep rate is set by
Time/Div knob.
Horizontal Amplifier: It is used to amplify the sawtooth voltage before it is applied to horizontal
deflection plates.
Trigger Circuit: It is used to convert the incoming signal into trigger pulses so that the input signal
can be synchronized with the sweep generated in the time base. The Level knob adjusts the
instant of triggering on the input waveform.
Power Supply: There are two power supplies, a -ve High Voltage (HV) supply and a +ve Low
Voltage (LV) supply. Two voltages are generated in the CRO. The +ve voltage supply is from + 300
to 400 V. The –ve high voltage supply is from -1000 to -1500 V. This voltage is passed through a
bleeder resistor at a few mA. The intermediate voltages are obtained from the bleeder resistor
for intensity, focus and positioning controls.
