A solar cell or photovoltaic cell is a semiconductor PN junction device with no direct supply across the junction. It transforms the light or photon energy incident on it into electrical power and delivers to the load. Figure 1: Solar Cell Symbol.
The light-emitting diode (LED) is a light-sensitive diode that emits light when it is forward-biased. Figure (1) shows the symbol of LED. Working Principle of Light Emitting Diode (LED) When a free electron from the higher energy level gets recombined with the holes, emits light or photon energy. Here, in case of LEDs, the supply
Two-transistor model is used to explain the principle of operation of Silicon Controlled Rectifier (SCR). Since, a SCR is a four layered PNPN device, it can be considered as a combination of two transistors, one transistor as PNP and the other transistor as NPN which are connected back to back. Figure 1: Structure of Two-transistor
What is the Two Transistor Analogy (Model) of SCR (Thyristor)? Read More »
A Silicon Controlled Rectifier (SCR) is a four-layer, three-junction semiconductor device used as a switch and rectifier in power control applications. It belongs to the family of thyristors and operates as a controllable switch. SCRs are widely used in industrial electronics, motor control, light dimming, and voltage regulation.
LASER diodes are one of the major optical sources, used in the optical communication for light generating purpose. LASER is an acronym for ‘Light Amplification by Stimulated Emission of Radiation’. It is a device that emits light (electromagnetic radiation) through a process of optical amplification based on the stimulated emission of photons. These are used as
A PN junction diode that acts as a voltage variable capacitor under reverse bias condition is known as varactor diode. The symbol and its equivalent circuit of varactor diode are as shown in figure (1). Figure 1: Varactor Diode.
UJT Relaxation Oscillator is a nonlinear oscillator which generates a non-sinusoidal signal such as sawtooth waveforms as output.
What is UJT Relaxation Oscillator? Working, Circuit Diagram, Waveforms & Derivation Read More »
An N-channel JFET is fabricated (or constructed) on N-type semiconductor bar that is as shown in figure (1). The left end of the N-type semiconductor bar is known as source and the right end is known as drain. Construction of N-channel JFET To design a N-channel JFET, the N-type bar is heavily doped with two
What is N-Channel JFET? Working, Diagram & Construction Read More »
A current transformer (CT) is nothing but a coil wound on a toroidal core. When a large current carried by a conductor is to be measured, it is advisable to avoid the direct connection of ammeter in this high current circuit. For this purpose a current transformer is used. Fig. 1 : Connection of Current
The three phase autotransformer is a combination of three single phase autotransformers. It has three windings, one per phase. Fig. 1 : 3 Phase Autotransformer.
What is 3 Phase Autotransformer? Working Principle, Connection Diagram & Applications Read More »