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auto-sensing voltage switch

I need to find or design a circuit that detects the input line voltage (it will be either 110vac or 24vac), and then toggle a switch (or relay) to the output path to the proper circuit.

The logic of the circuit would be something like:

If line-in voltage is 110v then switch position A If line-in voltage is 24v then switch position B

Unit should handle 2amp max current draw.

Is anything like this commercially available? If not, any ideas?

I know this is probably something quite simple for you guys...

Thanks!

Reply to
440roadrunner
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It's a 120 VAC relay. When 24 VAC is applied to its coil, nothing happens, and the relay stays de-energized. When

120 VAC is applied to its coil, the relay is energized, and the contacts transfer. +------Normally Open | | +------ Common | | o o o------ Normally Closed ----- | | | Vin ------|Relay| | | | ------|Coil | |> |
Reply to
ehsjr

I saw a guy do this to switch from 120V to 240V mains, but he added a diode and a cap for some reason, and every time I plugged one in to 240 to test, I kinda cringed expecting an explosion. It did seem to work OK, however. :-)

Cheers! Rich

Reply to
Rich Grise

SGS-Thomson once made an IC specifically to do this ( except it was 120/240V ). One important thing to note is that the status needs to be latched once detected or you may get a loud band under brown-out recovery conditions !

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Graham

Reply to
Pooh Bear

~~~~~~~~~~~ like Deep Purple -

Smoke Upon the Water

(sorry)

Bye. Jasen

Reply to
Jasen Betts

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