Re: where can i get a 20 amp relay?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Matthew Smith by way of Terry Fritz <teslalist-at-qwest-dot-net>" <matt-at-kbc-dot-net.au>


>If you don't mind a little overkill, you could try
>using an automotive start relay... those contacts
>are good for a couple of hundred amps DC (should do ok
>on AC as well).  And the coil is 12 volts like you
>need.  From what I've seen, they're relatively cheap
>as well.

I've also used ex-equipment 3-phase contactors with a 240V coil (relay 
coil, not Tesla coil ;-)  One phase contact for 
live/hot/phase/whatever-you-want-to-call-it, the second for neutral and the 
third hooked to the start control circuit (needs an external event, such as 
a push-button to energise).

OK, coil voltage is wrong, but if you're using 12V logic/control, you could 
drive a 240V (or 110V, whatever) intermediate control circuit with an 
opto-triac, giving you complete galvanic operation from the 'hot' end.

Like the auto solenoid, you can get quite a meaty switching device for not 
too great an outlay.

Cheers

M


-- 
Matthew Smith
IT Consultant - KBC, South Australia