# controlling one 110v device from three inputs

I have a commercial controller that turns on/off three separate 110v AC outlets based on atmospheric conditions for a small horticultural tent. I want to have this controller enable/disable one 110v AC device no matter which or how many of the 3 outlets from the controller is hot. As long as any of the three outlets is hot the switched outlet should be hot as well and visa versa.

I'm pretty good at putting basic circuits and all together including basic through hole soldering so I could make a basic circuit board up and box it up for actual use.

• Welcome to EE.SE. Do you have a diagram for us? Words alone are difficult to form a picture. Also, I think you have a typo. "As long as 1,3, or 3" should be "As long as 1,2, or 3"?
– user105652
Feb 14 '18 at 1:11
• commercial controller ... how many outputs can it have? ... is it programmable? Feb 14 '18 at 1:45
• how does it "that turns on/off three separate 110v AC outlets"? Feb 14 '18 at 2:16
• You can always wire three 110V AC coil pr solid state relays with the switches in parallel.... Not going to be small though. Feb 14 '18 at 2:33

I'd go with 3 DC-output power-supplies one connected to each of the 3 circuits you want to watch. connect their outputs wired in parallel and use that to operate a relay to swtch your new circuit.

• Jasen...THANKS! This looks like the simplest option...I'm a completely clueless newbie when choosing components. Would you be willing to recommend something from sparkfun or digikey for the DC power supplies and a proper relay to power the output circuit. Feb 15 '18 at 2:40
• choosing the right relay for an unspecified task is impossible. Feb 16 '18 at 23:49
• exactly...see comments above....thanks for you input! Feb 18 '18 at 1:39
• you still haven't said what the relay needs to be capable of. not knowing the detiail I'd feel compelled to pick a $300 part to be on the safe side, while for most tasks a$3 part is probably sufficient. Feb 18 '18 at 9:47
• yes I haven't...got a life with other things too..still looking for my multimeter..thanks for your help. FYI it's an turbine blade exhaust fan. Feb 19 '18 at 15:23

Easiest way is to use 3 opto isolators with open collector as "Wired OR" logic and hold cap for a few cycles of half-rectified input current to drive one DC relay ... or then drive an opto triac or drive AC relay depending on rating.

DIP-8 IC Sockets in veroboard if you can choose proper insulated wiring.
Is any DC available?

Does that seem doable?

Do you want off-the shelf- DIY or cheap or small? How about Triac Wired OR?

• Tony this actually could provide the solution I seek. The outputs from the existing controller are all 110v internally switched. Is this circuit 110v on the input side? If it is, then it's certainly the simplest solution I could muster. Would you be willing to guide my selection of parts? Armed with that and this circuit schematic I think I could mash this up. Thanks.. Feb 15 '18 at 13:09
• Input is on top left with switched Line. Output bottom left. Parts depends on load, but get Current ratings much higher than rated load for cooler operation or buy 3 dimmers suited for your undefined load. Connections are anywhere to internal switched load. So nothing can be said until you define load. Feb 15 '18 at 14:42
• recently moved..trying to find the multimeter to get a reading...once I have that then we can talk...thanks so much! Feb 18 '18 at 1:38