Electronics Engineering

Three Phase Rectifiers

Three Phase Rectifiers: Three-Phase Half-Wave Rectifier : Figure 9.11 illustrates a circuit for a 3-phase half-wave rectifier. The three diodes are connected to the three phases of a 3-phase transformer star-connected secondary. Neutral point N of the secondary forms the negative terminal for the load and is earthed, as illustrated in Fig. 9.11. Input and …

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Voltage Multipliers – Voltage Doublers, Triplers and Quadruplers

Voltage Multipliers – Voltage Doublers, Triplers and Quadruplers Voltage multipliers is a modified capacitor filter circuit that delivers a dc voltage twice or more times of the peak value (amplitude) of the input ac voltage. Such power supplies are used for high-voltage and low-current devices such as cathode-ray tubes (the picture tubes in TV receivers, …

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Baritt diode – Working and Applications

Baritt diode – Working and Applications: The barrier-inject transit time (BARITT) diode is basically a back-to-back pair of diodes biased into reach-through condition. It belongs to the transit-time microwave diode family. In this diode microwave oscillation occurs due to the thermionic injection and diffusion of minority carriers across the forward-biased barrier and a 3π/2 transit …

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What is a thermistor? – Definition, Symbol and V-I Characteristics

What is a thermistor? – Definition, Symbol and V-I Characteristics: The word thermistor is a combination of thermal and resistor. A thermistor is a resistor with definite thermal characteristics. Most thermistors have a negative temperature coefficient, but positive temperature coefficient devices are also available. The reason of negative temperature coefficient of resistance of a semiconductor …

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Varistors or Voltage Dependent Resistors (VDRS)

Varistors or Voltage Dependent Resistors (VDRS): Varistors, also called the voltage dependent resistors (VDRs), show a high degree of nonlinearity between their resistance value and the applied voltage. They are made of non-homogeneous materials giving a rectifying action at the contact of two particles. Various materials, such as silicon carbide, zinc oxide, are used to …

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Power Diode – Structure, Symbol, Characteristics and Types

Power Diode – Structure, Symbol, Characteristics and Types: Diodes find many applications in electronics and electrical engi­neering circuits. Power diodes play a significant role in power electronics for conversion of electric power. A diode acts as a switch to perform various functions, such as switching in rectifiers, freewheeling in switching regulators, charge rever­sal of capacitor …

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What is Schottky Diode? – Definition, Symbols and Construction

What is Schottky Diode? – Definition, Symbols and Construction: At lower frequencies, an ordinary diode can easily turn off when the bias changes from forward to reverse. But with the increase in frequency the diode reaches a point where it cannot turn off fast enough to prevent noticeable current during part of the reverse half …

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