How to make a timer switch?

I want to make a timer circuit for my aquarium light so it  stays on for  12 hours and off for 12 hours. Can anyone provide a circuit diagram?

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iceng3 years ago

Use a wall wart for the 12VDC

iceng iceng3 years ago

Thanks for the best answer.

In adjusting the unit, when set for 24 hrs the yellow LED

should blink every 5min 37sec.

aborah3 years ago

I have been using something similar for some time. It is a DIY. The final mess is in the enclosed photo. It does the following:

  1. Switches on my aquarium lights at evening and switches it off at bed time.
  2. Switches the aquarium pump on and off at stipulated intervals through out the day.

I used the following:

  1. Arduino microcontroller.
  2. RTC module.
  3. Relay modules.
  4. LCD module (optional)
  5. Power supply modules, wires etc.

I have used a "cannon to kill a mosquito" (lazy me). If you are interested, I can prepare an instructable for you.


Buy one. It's cheaper and has warranty. But if really want to make one just use an old microwave oven's one:

microwave timers can't be set so they stay on for 12 h and then switch off and switch on again after 12 h

One of the timers from one of those projects can however be set to turn on or off at a certain time, so it would work the same way, so as the store bought ones.

rickharris3 years ago

Best buy a plug in timer. they are cheap and accurate.