Batteries in Series and Parallel Animation
What happens when we connect the batteries in series and parallel? When we connect the Batteries in Series, we will get sum of voltages of both the Batteries. Here we…
How transformer works?
A transformer is based on the fact that when an AC current flows through a wire, it generates a magnetic field commonly known as a "magnetic flux" all around…
Optocouplers Working Principle
What is optocoupler? Â An optocoupler is an optical link and it connects two circuits via this link. The optical link is contained within a chip. A Light Emitting Diode inside…
Phototransistor Circuit Example
Phototransistors are used in a variety of applications. A light-operated relay circuit is shown in below Figure (a). The phototransistor Q1 drives the BJT Q2. When there is sufficient incident light…
Phototransistor Working Principle
A phototransistor is similar to a regular BJT except that the base current is produced and controlled by light instead of a voltage source. The phototransistor effectively converts light energy to…
How a Transistor Switch Works
The transistor in Figure is used as a switch to turn the LED on and off. For example, a square wave input voltage with a period of 2 s is applied…
Transistor as a Switch Working Principle
The below Figure illustrates the basic operation of a BJT as a switching device. In part (a), the transistor is in the cutoff region because the base-emitter junction is not forward-biased.…
Basic Transistor Amplifier Circuit Principle
A transistor amplifies current because the collector current is equal to the base current multiplied by the current gain, b. The base current in a transistor is very small compared to the collector…
Transistor Collector Characteristic Curves
Using a circuit like that shown in Figure (a), a set of collector characteristic curves can be generated that show how the collector current, IC, varies with the collector-to-emitter voltage, VCE,…
Why Silicon is preferred over Germanium ?
 As we all know, both Silicon and Germanium are semiconductor devices. But the present trend is to use Silicon instead of Germanium. What may be the reasons? Although both silicon…
