COMPONENTS USED IN ELECTRONICS
PASSIVE TYPES
Components - Introduction
Basic components used in electronics can be split i...
Passive Components
The Capacitor
A capacitor is used to store electric charge and functions much like a battery.
A capacit...
Non Polarised Types
There are many types of non polarised capacitors which
are mostly used for small signal applications i...
Capacitor markings
Most capacitors use written markings indicating their value, working voltage and tolerance.
Some manufa...
RESISTORS
There are many types of resistor ranging from
miniature metal film used for small signal
applications
eg. biasin...
Value Multiplier Tolerance
Black
Brown
Red
Orange
Yellow
Green
Blue
Violet
Grey
White
0
1
2
3
4
5
6
7
8
9
Silver
Gold
Blac...
Light Dependant Resistor (LDR)
Light dependant resistors use a semicaonductor*
material whose resistance varies according ...
RECTIFIER DIODES
The diode is the simplest form of semiconductor device used in electronics and is formed using a
single P...
If the reverse bias of a rectifier diode is increased beyond its VRRM and breakdown occurs then
the diode will suffer perm...
BRIDGE RECTIFIER
The bridge rectifier is a special device made up of four diodes in one package and is used to
convert a.c...
LIGHT-EMITTING DIODES (LED)
Light-emitting diodes give off light when a current
passes through them in the forward directi...
INDUCTORS
Inductors store electrical energy in the form of a magnetic field and are made up of a winding
placed, usually, ...
RELATED CIRCUIT SYMBOLS
components-passive-130910015703-phpapp01.doc Page
A.1
Potentiometer Preset
Potentiometer
Variable
...
USEFUL PARAMETERS
Capacitors Working Voltage The maximum operating voltage
V DC. to be applied.
Resistors Power Rating The...
SEMICONDUCTORS
Semiconductor materials are the basis from which diodes, transistors thyristors, triacs and
integrated circ...
Course Work – Passive Components
Objective
To ensure an understanding of common terms and parameters used with passive com...
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Components passive

  1. 1. COMPONENTS USED IN ELECTRONICS PASSIVE TYPES Components - Introduction Basic components used in electronics can be split into three primary classes, 1. Passive 2. Active 3. Digital Passive components cannot generate an increase in power and consist of capacitors, resistors and inductors. Resistors are able to convert electrical power into heat. Inductors convert electrical energy into a magnetic force. Neither devices are able to increase the power in a circuit. Active components are devices that provide gain in an electronic circuit eg. a transistor has a low-power input from the base current but a high power output as collector current. Digital devices provide a logic function and operate in two states only, on or off, similar to a switch. There are many different types ranging from basic gates, counters, decoders etc to microprocessors and memory devices. components-passive-130910015703-phpapp01.doc Page C.1
  2. 2. Passive Components The Capacitor A capacitor is used to store electric charge and functions much like a battery. A capacitor is made up of two conductors (plates) seperated by an insulator called the dielectric. Their are two classes of capacitor, 1. Polarised 2. Non polarised Polarised Types Polarised types can only be connected one way in a circuit and are marked to show which lead is positive or negative. Fig 1 shows a wound alluminium electrolytic capacitor, the white bar and –ve sign one the right identifying the negative terminal. Polarised capacitors are generally electrolytic types. Electrolytic capacitors are available in a wide range of working voltages, care must be taken when selecting the circuit application as they can explode if the rating is exceeded. Wound alluminium capacitors (fig 1) are mostly used in power supply applications as filter (reservoir) capacitors due to the large values and working voltages that can be achieved. Operating voltages are generally specified as the DC Working voltage since the majority of applications are in dc circuits.and can range between 6.3 to 400V and capacity 2.2µf to 68,000µf. Another type of electrolytic capacitor is the Tantalum bead, these are miniature electrolytics used for local filtering on printed circuit board assemblies due to their small size and high capacitance ranging between 2.2 to 47µf. with a dc working voltage from 6.3 to 35V. They are very stable and have a much smaller leakage current than the aluminium capacitors. components-passive-130910015703-phpapp01.doc Page C.2 Fig 1
  3. 3. Non Polarised Types There are many types of non polarised capacitors which are mostly used for small signal applications in electronic circuits eg filtering, timing, coupling, de-coupling, at high frequences etc. Types include ceramic, mica, polycarbonate, polyester etc. There are also variable capacitors made up of two sets of metal plates seperated by air one of which is fixed while the other can be rotated. The most common use for this device is in radio tuning. components-passive-130910015703-phpapp01.doc Page C.3
  4. 4. Capacitor markings Most capacitors use written markings indicating their value, working voltage and tolerance. Some manufacturers of ceramic capacitors use a three digit code, the first two digits correspond to the value and the third digit is the multiplier giving the number of zeros to be added to give the value in picofarads. Value Multiplier (pf) Tolerance Voltage (DC) Black Brown Red Orange Yellow Green Blue Violet Grey White 0 1 2 3 4 5 6 7 8 9 Silver Gold Black Brown Red Orange Yellow Green Blue 0.01 0.1 1 10 100 1000 10000 100000 1000000 Red Gold Silver None ± 2% ± 5% ± 10% ± 20% Brown Red Yellow 100 V 200 V 400 V Brown Green Brown Red Brown 1 5 0 ±2% 100V DC 150pF ±2% 100V DC components-passive-130910015703-phpapp01.doc Page C.4 1st and 2nd significant figures
  5. 5. RESISTORS There are many types of resistor ranging from miniature metal film used for small signal applications eg. biasing in amplifiers, timing and level shifting etc, to large wire wound types used in power applications such as loads for test simulation or current sensing. Resistors are used extensively in electronics with a basic function of controlling levels of current and voltage. Variable resistors known as potentiometers are made up of a stationary resistance and a rotating contact. The resistance can be either carbon track or wire wound and may also be linear or non linear in their operation. Used in applications where there is a need for human interaction with continuous adjustment eg volume and temperature setting and timing etc. Ref Type Range PTOT Tol. Use CR12 Carbon Film 1Ω - 4.7MΩ 0.125W 5% General Purpose CR25 Carbon Film 0Ω - 10MΩ 0.25W 5% General Purpose VR25 Metal Glaze 3.9MΩ - 10MΩ 0.25W 5% High Voltage MR25 Metal Film 10Ω - 1MΩ 0.25W 1% Industrial Electronics MF40 Metal Film 10Ω - 9MΩ 0.4W 1% Industrial Electronics MSR25 Metal Film 1Ω - 10MΩ 0.6W 1% High power Industrial ES3W Wire Wound 0R1 – 270R 3W 5% Flameproof applications SQP5W Wire Wound R01 –100R 5W 5% Flameproof applications HSA25 Wire Wound 0R1 – 1K 25W 5% Alum. Clad High power HSA50 Wire Wound 0R05 – 1K 50W 5% Alum. Clad High power Resistor markings Fixed carbon, metal oxide/film resistors are usually marked with coloured bands indicating their value and tolerance. Two methods are in common use, (1) four coloured bands and (2) five coloured bands. Potentiometers and wire wound types have their values printed on them. components-passive-130910015703-phpapp01.doc Page R.1 Table 1. Example of Resistor Ranges
  6. 6. Value Multiplier Tolerance Black Brown Red Orange Yellow Green Blue Violet Grey White 0 1 2 3 4 5 6 7 8 9 Silver Gold Black Brown Red Orange Yellow Green Blue 0.01 0.1 1 10 100 1000 10000 100000 1000000 Red Gold Silver None ± 2% ± 5% ± 10% ± 20% components-passive-130910015703-phpapp01.doc Page R.2 1st and 2nd significant figures 1st , 2nd and 3rd significant figures Control shaft Sliding contact(wiper ) Slider Connection Connection Carbon track Construction of a Carbon Track Potentiometer
  7. 7. Light Dependant Resistor (LDR) Light dependant resistors use a semicaonductor* material whose resistance varies according to the amount of light falling on it. The resistance can range from 1MΩ in darkness to 500Ω in full light. LDR’s are used * a material which is neither a conductor or insulator. Voltage Dependant Resistor (VDR) The resistance of a voltage dependant resistor falls rapidly when the voltage across it exceeds a particular value. Under normal operating conditions the current flowing in a VDR is negligible, however when the resistance falls the current will increade considerably. VDR’s are used in protection circuits for clamping noise spikes to a safe value. components-passive-130910015703-phpapp01.doc Page R.3
  8. 8. RECTIFIER DIODES The diode is the simplest form of semiconductor device used in electronics and is formed using a single P-N junction. The diode will pass electric current in one direction only ie. its resistance is low in the conducting or ‘forward’ direction but very high in the opposing or ‘reverse’ direction. For a diode to conduct its anode must be connected positive with respect to its cathode. A diode which is reverse-biased will not pass a significant current, however if the reverse voltage rating is exceeded the diode will break down. This voltage is called the maximum reverse voltage (VRRM). Ref Type VRRM IF Case Use BAT42 schottky 30V 200mA glass General purpose signal BAT85 schottky 30V 200mA glass High speed signal BAT41 schottky 100V 150mA glass General purpose signal 1N4000 silicon 50 – 1000V 1A DO41 Rectifier 1N5400 silicon 100 – 1000V 3A DO27 Rectifier BYX99 silicon 300V 15A stud Power rectifier BYX97 silicon 1200V 47A stud High power rectifier Diode types range from small signal glass and general purpose ceramic to high current stud mounted. Applications include power supply rectifiers, protection and detector circuits for radio tuning. Markings and Package Styles Diodes are identified using an alphanumeric code and the cathode is identified by a bar. Package styles range from miniature glass bead to large metal stud. Stud mounted styles print the diode symbol orientated to identify the polarity. Zener Diodes components-passive-130910015703-phpapp01.doc Page D.1 + Holes - Electrons NP conventional current flow Cathode -Anode + +V If (mA) -Ir (μA) Forward bias -V 0.6V Silicon Diode Characteristics Table 1. Example of Diode Data + - R IL VLZ RL IZI Vi Fig 2. Biasing a Zener Diode Fig. 1 Stud Diode
  9. 9. If the reverse bias of a rectifier diode is increased beyond its VRRM and breakdown occurs then the diode will suffer permanent damage. The zener diode is design to be used in the reverse bias or breakdown region but must have a resistor placed in series to limit the diode current IZ. Zener diodes are manufactured with defined breakdown voltages which remain almost constant over a wide range of reverse current making them useful as a voltage reference in comparator circuits and stabilized power supplies to maintain a steady output. Ref Range PTOT Case Use BZX55 2V7 – 33V 400mW DO35 General purpose BZX85 4V7 – 39V 1.3W DO35 General purpose BZT03C 7V5 – 43V 3.25W SOD-64 Hermetically sealed 1N5300B 3V3 – 200V 5W DO41 High power Markings and Packaging Zener diodes are marked and packaged in the same way as ordinary diodes but include the zener voltage as part of the identification number, ie BZX85C4V7 for a BZX85 range 4.7 volt zener diode. Since they operate in the reverse bias mode the cathode polarity is made positive with respect to the anode. components-passive-130910015703-phpapp01.doc Page D.2 Zener Diode Anode - Cathode + conventional current flow -V forward bias +V 0.6V -Ir (mA) +If (mA) Breakdown current zener breakdown voltage Fig. 3 Characteristics and Symbol for Zener Diode Table 2. Example of Zener Diode Data
  10. 10. BRIDGE RECTIFIER The bridge rectifier is a special device made up of four diodes in one package and is used to convert a.c. waveforms to d.c. They are used in power supplies where a dc voltage is required from an ac supply usually the secondary winding of a mains transformer but can also be used direct on-line to the a.c. mains supply. Markings and Package Styles Generally they are four terminal devices with the two ac inputs marked ~ and the dc outputs marked + and -. the manufacturers type number is also printed on the device. Package styles range from pcb mounted dual-in-line to chasiss mounted with crimp or screw termination depending on current rating. Ref VRRM IF Case Use WO2-8 200V -800V 1.5A plastic Miniature pcb mounting 2KBP08 800V 2A plastic Miniature in-line KBU4J 600V 4A plastic Miniature in-line KBU8K 800V 8A plastic Miniature in-line KBPC608 800V 6A plastic Miniature pcb mounting KBPC2506 600V 25A Metal clad High power rectifier KBPC3506 600V 35A Metal clad High power rectifier components-passive-130910015703-phpapp01.doc Page D.3 Table 3. Example of Bridge Rectifier Data Fig 4. Examples of Bridge Rectifier
  11. 11. LIGHT-EMITTING DIODES (LED) Light-emitting diodes give off light when a current passes through them in the forward direction and must be connect the correct way round to work. An LED is a transducer which is used to change electrical energy into light energy, available colours are red, yellow, green, blue and white. The LED has a forward volt drop of approx 2 volts and a current of about 25mA therefore a resistor connected in series is required to limit the forward current. components-passive-130910015703-phpapp01.doc Page D.4 Anode + Cathode - conventional current flow + - Fig 4. Biasing the LED RLIM Vi Vf If F fi LIM I VV R − =Value of current limit resistor, Fig 5. Examples of LED and Seven segment LED display
  12. 12. INDUCTORS Inductors store electrical energy in the form of a magnetic field and are made up of a winding placed, usually, on an iron core. The specification for an inductor includes the value of inductance, the current rating and the tolerance. Typical applications include chokes, filters on supply rails and power supplies, tuned circuits for radio and television. Inductor markings Most inductors use either the colour code as applied to capacitors with the inductance expressed in microhenries or have their value and rating written on them components-passive-130910015703-phpapp01.doc Page I.1 Fig 1. Examples of Inductors
  13. 13. RELATED CIRCUIT SYMBOLS components-passive-130910015703-phpapp01.doc Page A.1 Potentiometer Preset Potentiometer Variable Resistor Fixed Resistor Fixed Inductor (ferrite-core) Electrolyic Capacitor Fixed Inductor (iron-core) Variable Inductor (air-core) Fixed Inductor (air-core) Diode LEDZener Diode LDR VDR V Fixed Capacitor Variable Capacitor Electrolytic Capacitor Preset Capacitor
  14. 14. USEFUL PARAMETERS Capacitors Working Voltage The maximum operating voltage V DC. to be applied. Resistors Power Rating The maximum power that can be mW dissipated in the device. Must also maintain device at 20˚C. Tolerance Minimum to maximum range the ± 1%, 2%, 5% device value can be, taken about the nominal value. Diodes Maximum Reverse Voltage Reverse Breakdown voltage (VRRM), 100 – 1000V Power Rating The maximum power that can be mW, W dissipated in the device. Must also maintain device at 20˚C. Forward Current The maximum operating current (IF), mA, A. allowed to flow through device. Forward Volt Drop The voltage lost across the (VF), 0.6V device during conduction. components-passive-130910015703-phpapp01.doc Page A.2
  15. 15. SEMICONDUCTORS Semiconductor materials are the basis from which diodes, transistors thyristors, triacs and integrated circuits are made. A semiconductor material is one that is neither a conductor or insulator. The operation of semiconductor devices depends on effects that occur at the boundary or ‘junction’ between p- and n- type materials. components-passive-130910015703-phpapp01.doc Page A.3 junction + Holes - Electrons n-typep-type p-n junction
  16. 16. Course Work – Passive Components Objective To ensure an understanding of common terms and parameters used with passive components. General 1. What is a passive component, give two examples. Capacitors 2. Capacitors are split into two categories ‘Polarised and Non-polarised’, what should we consider when using polarised types and why. 3. Polarised capacitors are known as ______________ capacitors. 4. Give an example of a common use for palarised capacitors. 5. Give two examples of typical values, markings and types of capacitor. Resistors 6. Name three styles of resistor. 7. Describe the make up of a potentiometer and its uses. 8. Give two examples of typical values, markings and types of resistor including its tolerance. Provide the maximum and minimum values for your examples. Inductors 9. How is an inductor formed? 10. What are the typical uses for an inductor? Components_Passive Section Test

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