The most basic semiconductor materials are silicon and germanium. Atoms in metallic elements hold their peripheral electrons loosely, such materials make good conductors. Peripheral electrons in non-metallic elements are tightly bound, such materials are insulators. Germanium and silicon fall somewhere between the two categories but are mostly insulators when pure. Doping with impurities increases their conductivity.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Pure germanium and silicon are doped with impurities to produce the basic semiconductor materials. Certain doping impurities add free electrons, forming N-Type material while others accept electrons, thus creating 'holes' found in P-Type material.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Pure germanium and silicon are doped with impurities to produce the basic semiconductor materials. Certain doping impurities add free electrons, forming N-Type material while others accept electrons, thus creating 'holes' found in P-Type material.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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P-Type material was robbed of free electrons, positive 'holes' are the electric charge carriers. N-Type material comprises extra electrons which serve as the electric charge carriers.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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N-Type material comprises extra electrons which serve as the electric charge carriers. P-Type material was robbed of free electrons, positive 'holes' are the electric charge carriers.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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The most basic semiconductor materials are silicon and germanium. Atoms in metallic elements hold their peripheral electrons loosely, such materials make good conductors. Peripheral electrons in non-metallic elements are tightly bound, such materials are insulators. Germanium and silicon fall somewhere between the two categories but are mostly insulators when pure. Doping with impurities increases their conductivity.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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The most basic semiconductor materials are silicon and germanium. Atoms in metallic elements hold their peripheral electrons loosely, such materials make good conductors. Peripheral electrons in non-metallic elements are tightly bound, such materials are insulators. Germanium and silicon fall somewhere between the two categories but are mostly insulators when pure. Doping with impurities increases their conductivity.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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The most basic semiconductor materials are silicon and germanium. Atoms in metallic elements hold their peripheral electrons loosely, such materials make good conductors. Peripheral electrons in non-metallic elements are tightly bound, such materials are insulators. Germanium and silicon fall somewhere between the two categories but are mostly insulators when pure. Doping with impurities increases their conductivity.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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The most basic semiconductor materials are silicon and germanium. Atoms in metallic elements hold their peripheral electrons loosely, such materials make good conductors. Peripheral electrons in non-metallic elements are tightly bound, such materials are insulators. Germanium and silicon fall somewhere between the two categories but are mostly insulators when pure. Doping with impurities increases their conductivity.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Pure germanium and silicon are doped with impurities to produce the basic semiconductor materials. Certain doping impurities add free electrons, forming N-Type material while others accept electrons, thus creating 'holes' found in P-Type material.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Zener diodes maintain a constant voltage across a range of currents. The Varactor (or Varicap) is a diode used under reverse bias as a "voltage-variable capacitor". Hot-carrier (or Schottky-barrier) diodes have lower forward voltage and good high-frequency response: their speed make them useful in Very High Frequency mixers or detectors; in power circuits, they are excellent rectifiers in switching power supplies. PIN diodes (with a layer of undoped or lightly doped 'intrinsic' silicon between the P and N regions) are used as switches or attenuators.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Zener diodes maintain a constant voltage across a range of currents. The Varactor (or Varicap) is a diode used under reverse bias as a "voltage-variable capacitor". Hot-carrier (or Schottky-barrier) diodes have lower forward voltage and good high-frequency response: their speed make them useful in Very High Frequency mixers or detectors; in power circuits, they are excellent rectifiers in switching power supplies. PIN diodes (with a layer of undoped or lightly doped 'intrinsic' silicon between the P and N regions) are used as switches or attenuators.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Zener diodes maintain a constant voltage across a range of currents. The Varactor (or Varicap) is a diode used under reverse bias as a "voltage-variable capacitor". Hot-carrier (or Schottky-barrier) diodes have lower forward voltage and good high-frequency response: their speed make them useful in Very High Frequency mixers or detectors; in power circuits, they are excellent rectifiers in switching power supplies. PIN diodes (with a layer of undoped or lightly doped 'intrinsic' silicon between the P and N regions) are used as switches or attenuators.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Diodes conduct in one direction only: under forward bias, maximum forward current is limited by acceptable junction temperature. The voltage drop across the junction (volts) multiplied by the forward current (amperes) gives rise to heat dissipation (watts). Surviving a reverse bias is determined by the Peak Inverse Voltage (PIV) rating.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Diodes conduct in one direction only: under forward bias, maximum forward current is limited by acceptable junction temperature. The voltage drop across the junction (volts) multiplied by the forward current (amperes) gives rise to heat dissipation (watts). Surviving a reverse bias is determined by the Peak Inverse Voltage (PIV) rating.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Point-contact diodes, where a small metal whisker touches the semiconductor material, exhibit low capacitance and serve as RF detectors or UHF mixers. Junction diodes are formed with adjacent blocks of P and N material; these are usable from DC to microwave.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Point-contact diodes, where a small metal whisker touches the semiconductor material, exhibit low capacitance and serve as RF detectors or UHF mixers. Junction diodes are formed with adjacent blocks of P and N material; these are usable from DC to microwave.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Zener diodes maintain a constant voltage across a range of currents. The Varactor (or Varicap) is a diode used under reverse bias as a "voltage-variable capacitor". Hot-carrier (or Schottky-barrier) diodes have lower forward voltage and good high-frequency response: their speed make them useful in Very High Frequency mixers or detectors; in power circuits, they are excellent rectifiers in switching power supplies. PIN diodes (with a layer of undoped or lightly doped 'intrinsic' silicon between the P and N regions) are used as switches or attenuators.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Zener diodes maintain a constant voltage across a range of currents. The Varactor (or Varicap) is a diode used under reverse bias as a "voltage-variable capacitor". Hot-carrier (or Schottky-barrier) diodes have lower forward voltage and good high-frequency response: their speed make them useful in Very High Frequency mixers or detectors; in power circuits, they are excellent rectifiers in switching power supplies. PIN diodes (with a layer of undoped or lightly doped 'intrinsic' silicon between the P and N regions) are used as switches or attenuators.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Heat flows from hot to cold. If ambient temperature is higher, less heat can be drained from the junction, the junction will reach maximum safe operating temperature quicker.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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In a 'common base' configuration where the Emitter is the input and the Collector is the output, the Alpha factor (or common base forward current transfer ratio) is a ratio of a change in Collector current to the corresponding change in Emitter current. In a 'common emitter' configuration where the Base is the input and the Collector is the output, the Beta factor (or common emitter forward current gain) is a ratio of a change in Collector current to a given change in Base current. The Beta factor applies equally to a Common Collector configuration where the Base is also the input.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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In a 'common base' configuration where the Emitter is the input and the Collector is the output, the Alpha factor (or common base forward current transfer ratio) is a ratio of a change in Collector current to the corresponding change in Emitter current. In a 'common emitter' configuration where the Base is the input and the Collector is the output, the Beta factor (or common emitter forward current gain) is a ratio of a change in Collector current to a given change in Base current. The Beta factor applies equally to a Common Collector configuration where the Base is also the input.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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The terms Emitter, Collector and Base refer to bipolar transistors, of which there are two types: NPN and PNP. The Base-Emitter junction must be forward-biased for Base current to exist. A positive voltage on the Base supposes P material for conduction to take place, the 'sandwich' is thus NPN. Inversely, a negative Base voltage relates to a PNP.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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The Alpha being a number smaller than 1, many authors refer to it as the "common base forward current transfer ratio" rather than a gain. In a 'common base' configuration where the Emitter is the input and the Collector is the output, the Alpha factor (or common base forward current transfer ratio) is a ratio of a change in Collector current to the corresponding change in Emitter current. In a 'common emitter' configuration where the Base is the input and the Collector is the output, the Beta factor (or common emitter forward current gain) is a ratio of a change in Collector current to a given change in Base current. The Beta factor applies equally to a Common Collector configuration where the Base is also the input.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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In a 'common base' configuration where the Emitter is the input and the Collector is the output, the Alpha factor (or common base forward current transfer ratio) is a ratio of a change in Collector current to the corresponding change in Emitter current. In a 'common emitter' configuration where the Base is the input and the Collector is the output, the Beta factor (or common emitter forward current gain) is a ratio of a change in Collector current to a given change in Base current. The Beta factor applies equally to a Common Collector configuration where the Base is also the input.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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In a 'common base' configuration where the Emitter is the input and the Collector is the output, the Alpha factor (or common base forward current transfer ratio) is a ratio of a change in Collector current to the corresponding change in Emitter current. In a 'common emitter' configuration where the Base is the input and the Collector is the output, the Beta factor (or common emitter forward current gain) is a ratio of a change in Collector current to a given change in Base current. The Beta factor applies equally to a Common Collector configuration where the Base is also the input.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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In a 'common base' configuration where the Emitter is the input and the Collector is the output, the Alpha factor (or common base forward current transfer ratio) is a ratio of a change in Collector current to the corresponding change in Emitter current. In a 'common emitter' configuration where the Base is the input and the Collector is the output, the Beta factor (or common emitter forward current gain) is a ratio of a change in Collector current to a given change in Base current. The Beta factor applies equally to a Common Collector configuration where the Base is also the input.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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The terms Emitter, Collector and Base refer to bipolar transistors, of which there are two types: NPN and PNP. The Base-Emitter junction must be forward-biased for Base current to exist. A positive voltage on the Base supposes P material for conduction to take place, the 'sandwich' is thus NPN. Inversely, a negative Base voltage relates to a PNP.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Alpha ('common base') is always a number lesser than 1 ( the Emitter current is necessarily larger than the Collector current because the Base current also flows through the Emitter ). Beta ('common emitter') is normally a number greater than 10 ( the Collector current is always several times the Base current ). The Alpha is equal to Beta divided by 1 plus Beta. The Beta is equal to Alpha divided by 1 minus Alpha.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Alpha ('common base') is always a number lesser than 1 ( the Emitter current is necessarily larger than the Collector current because the Base current also flows through the Emitter ). Beta ('common emitter') is normally a number greater than 10 ( the Collector current is always several times the Base current ). The Alpha is equal to Beta divided by 1 plus Beta. The Beta is equal to Alpha divided by 1 minus Alpha.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Alpha ('common base') is always a number lesser than 1 ( the Emitter current is necessarily larger than the Collector current because the Base current also flows through the Emitter ). Beta ('common emitter') is normally a number greater than 10 ( the Collector current is always several times the Base current ). The Alpha is equal to Beta divided by 1 plus Beta. The Beta is equal to Alpha divided by 1 minus Alpha.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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An Enhancement-mode Insulated Gate Field Effect Transistor (IGFET) is constructed without a channel. There is no Drain current with zero Gate voltage. A voltage applied to the gate leads to the creation of a channel. A forward bias on the gate heightens the concentration of charge carriers which, in turn, 'enhances' conduction. A Depletion-mode Insulated Gate Field Effect Transistor has a channel. Drain current is possible even without a Gate voltage. A reverse bias on the Gate depletes charge carriers in the channel, thus reducing Drain current. A forward bias on the Gate can make the channel even more conductive.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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An Enhancement-mode Insulated Gate Field Effect Transistor (IGFET) is constructed without a channel. There is no Drain current with zero Gate voltage. A voltage applied to the gate leads to the creation of a channel. A forward bias on the gate heightens the concentration of charge carriers which, in turn, 'enhances' conduction. A Depletion-mode Insulated Gate Field Effect Transistor has a channel. Drain current is possible even without a Gate voltage. A reverse bias on the Gate depletes charge carriers in the channel, thus reducing Drain current. A forward bias on the Gate can make the channel even more conductive.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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The Gate in an Insulated Gate Field Effect Transistor (IGFET or metal-oxide-semiconductor FET, MOSFET) is insulated from the channel by a thin oxide layer. Static electricity or excessive voltage can easily destroy the dielectric layer.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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The Gate in an Insulated Gate Field Effect Transistor (IGFET or metal-oxide-semiconductor FET, MOSFET) is insulated from the channel by a thin oxide layer. Static electricity or excessive voltage can easily destroy the dielectric layer.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Bipolar transistors are operated with a forward-biased (conductive) Base-Emitter junction. Bipolar transistors are current amplifiers. Impedance, as a ratio of voltage to current, is necessarily low when voltage is low and current is high. The Field Effect Transistor, with a reverse biased Gate to channel junction, and the Insulated Gate Field Effect Transistor (IGFET or metal-oxide-semiconductor FET, MOSFET) with a Gate separated from the channel by a dielectric, are high impedance devices.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Remember your Basic Qualification? The FET comprises a Source, a Gate and a Drain. They come in two types: N-Channel and P-Channel.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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Remember your Basic Qualification? The FET comprises a Source, a Gate and a Drain. They come in two types: N-Channel and P-Channel.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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The SCR, part of the Thyristor family, is made of four layers of alternating P and N type material, namely PNPN. It comprises three electrodes: Anode, Gate and Cathode. As can be expected, the two outermost electrodes, the Anode and the Cathode are respectively type P and type N material. Without gate current, the SCR looks like a regular non-conducting junction diode. Once triggered via the Gate, the SCR resembles a forward-biased (conducting) junction diode. Conduction continues unless current falls below a critical level. One typical application is an overvoltage protection circuit in a power supply.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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The SCR, part of the Thyristor family, is made of four layers of alternating P and N type material, namely PNPN. It comprises three electrodes: Anode, Gate and Cathode. As can be expected, the two outermost electrodes, the Anode and the Cathode are respectively type P and type N material. Without gate current, the SCR looks like a regular non-conducting junction diode. Once triggered via the Gate, the SCR resembles a forward-biased (conducting) junction diode. Conduction continues unless current falls below a critical level. One typical application is an overvoltage protection circuit in a power supply.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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The SCR, part of the Thyristor family, is made of four layers of alternating P and N type material, namely PNPN. It comprises three electrodes: Anode, Gate and Cathode. As can be expected, the two outermost electrodes, the Anode and the Cathode are respectively type P and type N material. Without gate current, the SCR looks like a regular non-conducting junction diode. Once triggered via the Gate, the SCR resembles a forward-biased (conducting) junction diode. Conduction continues unless current falls below a critical level. One typical application is an overvoltage protection circuit in a power supply.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
Tags: none
The SCR, part of the Thyristor family, is made of four layers of alternating P and N type material, namely PNPN. It comprises three electrodes: Anode, Gate and Cathode. As can be expected, the two outermost electrodes, the Anode and the Cathode are respectively type P and type N material. Without gate current, the SCR looks like a regular non-conducting junction diode. Once triggered via the Gate, the SCR resembles a forward-biased (conducting) junction diode. Conduction continues unless current falls below a critical level. One typical application is an overvoltage protection circuit in a power supply.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
Tags: none
The SCR, part of the Thyristor family, is made of four layers of alternating P and N type material, namely PNPN. It comprises three electrodes: Anode, Gate and Cathode. As can be expected, the two outermost electrodes, the Anode and the Cathode are respectively type P and type N material. Without gate current, the SCR looks like a regular non-conducting junction diode. Once triggered via the Gate, the SCR resembles a forward-biased (conducting) junction diode. Conduction continues unless current falls below a critical level. One typical application is an overvoltage protection circuit in a power supply.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
Tags: none
The SCR, part of the Thyristor family, is made of four layers of alternating P and N type material, namely PNPN. It comprises three electrodes: Anode, Gate and Cathode. As can be expected, the two outermost electrodes, the Anode and the Cathode are respectively type P and type N material. Without gate current, the SCR looks like a regular non-conducting junction diode. Once triggered via the Gate, the SCR resembles a forward-biased (conducting) junction diode. Conduction continues unless current falls below a critical level. One typical application is an overvoltage protection circuit in a power supply.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
Tags: none
The SCR, part of the Thyristor family, is made of four layers of alternating P and N type material, namely PNPN. It comprises three electrodes: Anode, Gate and Cathode. As can be expected, the two outermost electrodes, the Anode and the Cathode are respectively type P and type N material. Without gate current, the SCR looks like a regular non-conducting junction diode. Once triggered via the Gate, the SCR resembles a forward-biased (conducting) junction diode. Conduction continues unless current falls below a critical level. One typical application is an overvoltage protection circuit in a power supply.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
Tags: none
The SCR, part of the Thyristor family, is made of four layers of alternating P and N type material, namely PNPN. It comprises three electrodes: Anode, Gate and Cathode. As can be expected, the two outermost electrodes, the Anode and the Cathode are respectively type P and type N material. Without gate current, the SCR looks like a regular non-conducting junction diode. Once triggered via the Gate, the SCR resembles a forward-biased (conducting) junction diode. Conduction continues unless current falls below a critical level. One typical application is an overvoltage protection circuit in a power supply.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
Tags: none
The SCR, part of the Thyristor family, is made of four layers of alternating P and N type material, namely PNPN. It comprises three electrodes: Anode, Gate and Cathode. As can be expected, the two outermost electrodes, the Anode and the Cathode are respectively type P and type N material. Without gate current, the SCR looks like a regular non-conducting junction diode. Once triggered via the Gate, the SCR resembles a forward-biased (conducting) junction diode. Conduction continues unless current falls below a critical level. One typical application is an overvoltage protection circuit in a power supply.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
Tags: none
The SCR, part of the Thyristor family, is made of four layers of alternating P and N type material, namely PNPN. It comprises three electrodes: Anode, Gate and Cathode. As can be expected, the two outermost electrodes, the Anode and the Cathode are respectively type P and type N material. Without gate current, the SCR looks like a regular non-conducting junction diode. Once triggered via the Gate, the SCR resembles a forward-biased (conducting) junction diode. Conduction continues unless current falls below a critical level. One typical application is an overvoltage protection circuit in a power supply.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
Tags: none
The SCR, part of the Thyristor family, is made of four layers of alternating P and N type material, namely PNPN. It comprises three electrodes: Anode, Gate and Cathode. As can be expected, the two outermost electrodes, the Anode and the Cathode are respectively type P and type N material. Without gate current, the SCR looks like a regular non-conducting junction diode. Once triggered via the Gate, the SCR resembles a forward-biased (conducting) junction diode. Conduction continues unless current falls below a critical level. One typical application is an overvoltage protection circuit in a power supply.
Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.
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