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Topic: Switching 120VAC with 5V (Read 1 time) previous topic - next topic


I need to switch a submersible 120V fountain pump with a thermostat for a water-cooling application. My thermostat has a relay output, that I can hook up with 5V or 12V DC, 500mA or so. What's the best way to switch 120V? Another relay would be fine but I don't know where to find a 120V one. I have 12V 30A automotive relays; would that work with 120VAC ok?


Did you try searching at Digikey?
I found models like this
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.


The "best" way to switch 120VAC depends on the current. Do you have any idea how much current your fountain pump draws? You could go with a "power" relay (as CrossRoads suggested) or for lower currents an optically isolated triac.

A 12VDC automotive relay is unlikely to be able to withstand 120V and may be destroyed.

The Ruggeduino: compatible with Arduino UNO, 24V operation, all I/O's fused and protected


One of these?
... it is poor civic hygiene to install technologies that could someday
facilitate a police state. -- Bruce Schneier

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