I'm looking for a simple on/off timed switch, this switch must be fixed to daily 20 hours on and 4 hours off.
Ideally starting at midnight 00:01 (on) to 20.00 (off) daily repeat. 5 to 12V DC to run it and 220V AC 4A switching.
Tried to buy something like this but it's all Chinees bad designed, functioning and unreliable stuff out there.
Would a timer circuit do the trick can you time for 1200 Minutes or 72000 Seconds?
Anybody has a circuit layout with components that could do the job or any other hints and tips to make this happen.
It depends on how accurate the timing has to be and whether it needs to find out the time for itself.
You can do it with timer circuits but over such long periods it becomes tricky to be accurate as small component tolerances and temperature drift start to become significant. I use timed devices like this but buy Sonoff basic switches and reprogram them for my needs. Its a simple task and they have the power supply internal to them and fed from the un-switched side of the power. My program links to WiFi and sets the clock automatically so it is very precise and the times can be changed remotely.
Thanks for your replies, a mechanical relay (switching 220V 4A) is okay it's just the timing part and it needs to be as small as possible to fit my project and the project uses a 5V to 12V DC power supply. Accuracy: it can be a little bit off but not much. As long as it does the daily 20 hours on and 4 hours off.
I'm able to make/etch my own circuit board if I have a layout and components... (did this about 20 years ago)
Again I've looked online to buy something like this but didn't find something yet...
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do an ebay search "ESP relay module".
Almost every module (I´ve seen) will be suitable.
You need to search for (Arduino) code and maybe modify it for your needs. No rocket science.
Double check the relay ratings, and also check module has protection
diodes for inductive loads on it if thats what you are controlling. Thats
not always obvious in listing.
alliexpress.com and banggood.com all have tons of these for sale.