Dotnet

Hi All,

I'm just replacing my central heating programmer (with an incorrect one!!!) and need a quick and simple way of reproducing the one way action of a diode in dc but in ac (for the boiler only to fire up in a gravity hot water system).

I'm thinking of a triac - am I on the right lines - if so what about the trigger voltage can I use ac

thanks for any response

Matt

dknguyen

YOur question doesn't make sense. AC by definition flows in alternate directions every cycle so a "one-way effect for AC like a diode for DC doesn't make too much sense). Are you trying to rectify your AC so that it is the same polarity? If so, you are looking for a full-wave diode bridge rectifier.

eblc1388

From what the OP wrote, I think he wants:

If there are circuits or devices A,B,C and D and a target device T, he wants T to get AC when one or more of A,B,C or D get AC. However, un-powered devices remain un-powered.

Solution is to use four AC relays, connected across each device. All the relay contacts(normal open) are paralleled to power up device T.

But, messing with central heating is not something which one should just do without understanding the consequence.

__________________
L.Chung