I'd like to have a light switch that turns on for at most 1 hour. My idea is to put a USB charger (110AC -> 5DC) + arduino + relay inside the wall. When the switch is turned on, it will turn the arduino, which should be programmed to close the relay, sleep 1 hour, open the relay.

Then I'd need to turn off/on to restart the arduino or just optionally turn off in order to save power.

But I feel this solution is a bit overkill (and not too nice). Maybe a physical button that turns off (using a spring?) after a timer? I couldn't find it; or some other suggestion?

Oh, and it would be nice if the solution doesn't have a high probability of setting my house on fire.

  • \$\begingroup\$ Why do you think that the solution with the Arduino is "overkill"? \$\endgroup\$ Apr 27 '16 at 6:09
  • \$\begingroup\$ Whatever way you set it up, consider whether a neutral is required. If there isn't one in your switch location then you won't be able. (There are several questions that asked about this.) You could put the controller in the ceiling and use an IR remote to control it / restart it. \$\endgroup\$
    – Transistor
    Apr 27 '16 at 6:11

Is this the type of switch you're looking for?

1800 Watt 7 Button Countdown Timer Switch Maximum 60 Minutes Delay https://www.maxximastyle.com/wall-timers-and-switches/7-button-timer-switch-turns-lights-off-automatically?gclid=CMunxuL1rcwCFcNehgod2FAHrw

Also, the more analog type:
FF Series Commercial Auto-Off Timer, SPDT (60 Minutes) http://www.supplyhouse.com/Intermatic-FF360M-FF-Series-Commercial-Auto-Off-Timer-SPDT-60-Minutes?gclid=CMDY3eb2rcwCFYsmhgodDXkK5Q

To use these you just replace it for the original wall switch.

  • \$\begingroup\$ Yeah, that kinda works. Only issue is that I lied trying to simplify the problem. Actually I wanna do this with a ceiling fan (I usually don't need it 2 hours after I'm already sleeping), and the wall have 3 switches (light/mode/speed).. so I my idea would be to add the arduino to the (clockwise, counter-clockwise, OFF). \$\endgroup\$
    – Lem0n
    Apr 27 '16 at 4:06

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