110VAC On/Off to 5VDC signal

[btaz]

Any suggestions for an easy circuit that can tell me if 110VAC is on or off by providing a 5V(on) and 0V(off) signal? I don't need this to be a power source only a telemetry signal that will interface with an arduino digital input. So far the easiest thing I can think of is to just use an old wall wart to do the conversion, but if there is a simple circuit I could create then I'd prefer that. Thanks for the suggestions.

 

[KrisBlueNZ]

The simplest option is a relay with an AC coil like this one: http://www.digikey.com/product-detail/en/RT314615/PB961-ND/1095285

You can also make a circuit using an optocoupler. Google isolated mains voltage detector circuit.

 

[Arouse1973]

What about a simple 110- 5 Volt wall wart? Just for signalling purposes. They are quite cheap and should be relatively safe.
Adam

 

[Jouellet]

Check on the Microchip web site (www.microchip.com).

A while ago, I found an application note, to detect zero-crossing for generating X-10. By memory, they were simply using a 1 Meg resistor to drive an input... Check on their site to be sure.

I remember back then that I was surprised on how easy it was !!!

 

[Jouellet]

It was a 5 meg....

http://ww1.microchip.com/downloads/en/AppNotes/00236B.pdf