# What is an electronic timer? Its Principles and Working Principle

Hello friends, in today’s article I am going to tell you what is an electronic timer? Its principle and working, principle and working of timer, on what basis are electronic timer classified? If you also want to know, then keep reading this article completely. so let’s start

## Principle and Working principle of Timer

To understand the principle and working of timer, here we take an electronic timer. In electronic timers, the timing of the timer is determined by the RC time constant. An electronic timer circuit is shown in the figure.

A simple electronic timer circuit using SCR is shown in the figure. The three terminals of SCR are anode, cathode and gate. It conducts when the signal is applied between its gate and cathode ends. After the start of conduction, it conducts even if the signal is removed from the gate end. For its conduction at the anode positive and. A negative supply is required at the cathode.

In the figure, the transformer and diodes D, and D. provide 12V supply to the electronic circuit.When the switch is closed, 12V DC is available to the timer circuit. Here the resistance R and capacitor C, RC form the charging circuit. The gate of SCR is connected to capacitor as shown in the picture. As soon as the capacitor potential is sufficient for triggering the SCR, the SCR starts conducting. Here the resistance R keeps the gate current in a limit. As soon as the SCR starts conducting, the relay coil closes its contact ends. Here the time constant is changed by changing the value of the variable resistance R.

The time range of an electronic timer is determined by the values ​​of R, and C.

## Electronic Timer

In this type of timer, the timing is determined by electronic circuits and devices.

An electronic timer is used for the very best or ultimate measurement of time. Therefore, electronic timer is used more than other timers.

Electronic timers are of the following types

1. R-C controlled timer
2. Transistor timer
3. SCR timer
4. IC controlled timer

The working and principle of electronic timer has already been described. Only its types are being given here.
Electronic timers are classified on the basis of the components used, the system and the potential source.

(i) Components Based Electronic Timer- On the basis of the components used in the timer, the timers are of the following types

1. transistor timer
2. triode timer
3. SCR Timer.
4. UJT Timer
5. IC timer

(ii) On the basis of the system the electronic timer- timers are of the following types depending on the circuit used in the timer and the nature of the components or the structure of the system-

1. Analog Timer
2. Digital Timer

(iii) Based on the Potential Source Electronic Timer- On the basis of which type of potential source the timer is working, the timers are of the following types-

1. D.C.Timer
2. A.C.Timer

Now you must know what is an electronic timer? Its principles and working – What is electronic timer, principle and working of timer, on what basis electronic timers are classified.