Electronics switch

[ektan]

I want to know how to design an electronics switch by applying the TTL signal to switch the 240Vac 5Amp device to on and off. Thanks.

[Chris Smith]

SCR or Triac.

You will need to do some of your own research, but there is the starting point.

That or a relay and transistor driver.

[Michael J]

You can buy off the shelf devices called
(SSR) Solid State Relays, they have a Triac
inside which is switched via an optocoupler.
LED voltage, input = 4 to 40V DC using current
limiting resistor.(input usually 20mA MAX)

They come in 2 standard forms usually -
PCB mount which handle up to 3A 240V or others
about the size of a match box which can handle
up to 10 to 100A. (with Heat Sink)

They are also available Zero Crossing/Switching
(AC cycle) or not.

<small>[ February 19, 2006, 09:55 PM: Message edited by: Michael J ]</small>