Electronic Devices & Circuits

Phototransistor Working Principle

A phototransistor is similar to a regular BJT except that the base current is produced and controlled by light instead of

The below Figure illustrates the basic operation of a BJT as a switching device. In part (a), the transistor is in

A transistor amplifies current because the collector current is equal to the base current multiplied by the current gain, b. The base

Using a circuit like that shown in Figure (a), a set of collector characteristic curves can be generated that show how

As we all know, both Silicon and Germanium are semiconductor devices. But the present trend is to use Silicon instead

The below Fig. (i) shows CE transistor circuit while Fig.(ii) shows the output characteristcs along with the d.c. load line.

In the transistor circuit analysis, it is generally required to determine the collector current for various collector-emitter voltages. One of

The below Fig. shows the common emitter npn amplifier circuit. Note that a battery VBB is connected in the input circuit

Named after its inventor, a Shockley diode is a PNPN device having two terminals as shown in Fig. (i). This device

An optoisolator (also called optocoupler) is a device that uses light to couple a signal from its input (a photoemitter