Transistors..

Hi Guys,

This time I have got a fairly famous analogy to share..the one used to explain the working of a transistor.

Transistors are quite famous. It can be thought as an electronic switch/amplifier. So what makes us dependant on transistors and why not those mechanical switches? Mechanical switches are at least easy to understand! The reason to this (and probably the only reason) is that these mechanical switches are bulky. Given the fact that we are moving towards miniaturisation, we badly needed a switch preferably manufactured using Silicon technologies. Transistors just did that! In fact, you might not realise as to how many transistors you deal with in your daily lives today. Also, you carry several thousands of transistors daily! (Mobile phones, Laptops,Mp3 players…) .  Would you not want to know what it is then? Nothing technical..just an analogy to help you correlate..! Keep reading..

Analogy:

Now, consider a large vessel housing a cork and another pipe inlet. If water is supplied to the mouth of the vessel (let us term this point as “COLLECTOR”), it might flow all the way down to the other end (“EMMITTER”). However, in the arrangement shown in the picture above, the cork blocks water to flow from the Collector to the Emitter. Well, then how does this water flow down? The pipe inlet (“BASE”) comes to the rescue here! If a sufficient amount of water is sent through the Base, into the vessel, the cork is slightly pushed upwards allowing the Emitter to receive (Collector water + Base water)! So in a nutshell, NO sufficient base water => NO Emitter water provided there is Collector water. Does this not itself seem like a switch? A switch controlled by the BASE? Maybe also an amplifier? EMITTER receives more than what was sent by the COLLECTOR..

There we go! You now know what happens in a transistor.. The Base, Emitter and Collector are the transistor pins. The collector is fed with the input current and the Emitter is the output. The Base current controls the switching operation!