Single Phase Half Wave Controlled Rectifier (or Converter): In a Single Phase Half Wave Controlled Rectifier only one SCR is used in the circuit. It is included in between the ac source the load. The transformer is used on the supply side in order to change the voltage level to suit the requirements. The performance of the …
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Power Converter – Definition and Classification: Solid-state power converter are employed for obtaining the appropriate form of electrical energy such as direct current or adjustable-frequency alternating current (required to operate most electronic circuits and motor drives) from fixed-frequency alternating current. Classification of Static Power Converter: AC/DC converters, AC/AC converters, DC/DC converters and DC/AC converters. AC/DC …
UJT as Over Voltage Detector Circuit Diagram: UJT as Over Voltage Detector Circuit Diagram – A simple dc overvoltage detector circuit is given in Fig. 26.96. It operates on the fact that the device remains switched off as long as the input voltage remain less than the peak point voltage VP of the UJT and …
UJT Relaxation Oscillator – Circuit Diagram and its Workings: UJT Relaxation Oscillator – The relaxation oscillator shown in Fig. 26.94 (a) consists of UJT and a capacitor C which is charged through resistor RE when interbase voltage VBB is switched on. During the charging period, the voltage across the capacitor increases exponentially until it attains …
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UJT Triggering of SCR Working Principle: UJT Triggering of SCR Working Principle – One common application of the unijunction transistor is the triggering of the other devices such as the SCR, triac etc. The basic elements of such a triggering circuit are shown in Fig. 26.91. The resistor RE is chosen so that the load …
Power BJT – Construction, Operation and its Characteristics: Power transistors are large-area devices. Because of differences in geometry and doping concentrations, their properties tend to vary from those of the small-signal devices. The structure of a vertical NPN power transistor is shown in Fig. 26.74. In the vertical configuration for power BJT, the collector terminal …
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Light Activated SCR (LASCR) – Symbol, Construction and Operation: Light activated SCR is just an ordinary SCR except that it can also be light triggered. Most LASCRs also have a gate terminal for being triggered by an electrical pulse just as a conventional SCR. Construction: The basic construction of an Light Activated SCR (LASCR) is …
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Silicon Controlled Switch (SCS) – Symbol, Operation, Advantages and Application: Silicon controlled switch (SCS), like the SCR, is a unilateral, four layer, three junction P-N-P-N silicon device with four electrodes namely cathode C, cathode gate G1, anode gate G2 and the anode A, as shown in Fig. 26.59. Infact, the Silicon Controlled Switch is a …
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Gate Controlled Switch (GCS) Circuit Operation and Advantages: As mentioned earlier, low-current drop out is the normal way in which the SCR is turned off. Gate controlled switch is designed for easy opening with a reverse-biased trigger. A GCS is closed by a positive trigger and opened by a negative trigger (or by low-current drop out). …
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What is Shockley Diode? – Symbol, Operation and Applications The four layer diode, also called the Shockley diode after its inventor Willian Shockley, is essentially a low-current SCR without a gate. It is classified as a diode because it has only two external terminals viz. anode and cathode. Because of its four doped regions, it …
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