In this tutorial, we are going to learn about electronic switching.
Electronic Switching –
In many electronics device required to make or break an electrical circuit. It is sometimes desirable and necessary that his making and breaking should be very quick and without sparking. Generally Mechanical switches cannot be used for the switching there is for two main reasons which is a mechanical switch because it has high inertia which limits its speed of operation and Secondly, there is always sparkling at the contact during the breaking operation which results in the burning of the contacts.
Which Types of Device use for Electronic Switch?
In electronic switches there is main parts are used which is tubes and transistors can serve as switching devices. The can turn ON and OFF power in an electrical circuit at a very high speed without any sparking. Such switching is known as electronic switches. Electronic Switches are being used extensively to produce non-sinusoidal wave’s e.g. square, rectangle, triangular or saw-tooth waves. These non-sinusoidal waves are extensively used in solid-state switching circuit. We shall here confine ourselves to transistors as switch.
It is an electronic device which can turn ON and OFF current in an electric circuit e.g. transistor and tubes. Now days the Electronic Switches become very popular due to their high speed of operation and absence of sparking. The transistor can be used as a switch by driving it back and forth between saturation and cut-off.
What is Features of Electronic Switch?
- In electronic switch does not have moving part and hence there is little wear and tear.
- It has smaller size and weight.
- In electronic switch has the trouble free service because of solid state.
- It is cheaper other switches and required little maintenance.
- It has a very fast speed of operation say up to 109 operations per second. On the other hand the mechanical switch has small speed of operation like less than 5 operative in a second.
How Transistor Work as Switch?
There is below are the main points for Transistor Work as Switch.
As we know that transistor is ideal conditions when VCE = VCC (or IC = 0) in this case it is OFF state and when the VCE = 0 (IC = saturation) then it will be ON state.
- When the base input voltage is enough negative, the transistor is cut off and no current flows in the collector load as per showing circuit. As a result, there is no voltage drop across RC and the output voltage is ideally VCC and IC = 0 and VCC = VCE and this is open state it means OFF.
- When the input base voltage is positive enough which the transistor saturate, then IC (Sat) will flow through RC and this condition the entire VCC will drop across collector load RC and output voltage ideally is zero like – IC = IC (Sat) = VCC / RC and VCE = 0. In this conditions it is similar to that of a closed switch (ON state)