Transistors and Relays

Discussion in 'General Electronics Chat' started by Nocturnicon, Dec 18, 2008.

  1. Nocturnicon

    Thread Starter New Member

    Dec 18, 2008
    Howdy everybody!

    About two weeks ago I decided to finally start in the world of electronics. Got all the gear I wanted and soldered one or two simple projects and loving it. :D I'm busy reading up on the different components and there are two concepts that I am struggling with. What is the real difference between a relay and a Transistor?

    I have found many examples of their applications and they are used in completely different ways but from what I can gather they are pretty much doing the same thing. Can somebody please explain to a noob what the difference really is? I'm sure that I'm over complicating it for myself.

    Thanks a lot in advance!
  2. eblc1388

    AAC Fanatic!

    Nov 28, 2008
    Simply put it is the electrical isolation and safety that a relay can offer. When one use a transistor, the load is somehow still connected to the circuit and there is no electrical isolation.

    This is obviously not good say when a load on AC120 or 240V is being switched.

    A relay is also a mechanical device and thus will take on more abuses than semiconductor regarding transient and surge.

    However, a relay cannot compete with the speed, life time and power consumption of semiconducting devices.
  3. Nocturnicon

    Thread Starter New Member

    Dec 18, 2008
    Awesome, thanks for the quick response and clear answer.