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- Building a 12 hour timer 2 answers
What would be the right thing to use if I want the base of a transistor to be high for 12 hours and low for 12 hours?
I ask because I would like to make a circuit that regulates temperature in a room. To do this I am using a ntc thermistor and a ptc thermistor that I have set to trigger a fan or a heater depending on the temperature of the room, but my question is not about the thermistors. I want the room to be hotter for 12 hours and cooler for 12 hours a day and I don't know what to use to switch between two temperature control circuits. I am building this for a garden. I want the plants to have a "daytime" and a "nighttime" (quotes because the plants are indoors and receive their light from lights that this circuit will help control).
I am pretty sure I can do this with a microcontroller like an arduino, but I am curious if there is another way to do this without a microcontroller. I was thinking of a 555 timer, but I don't think resistors and capacitors exist that are big enough. Thank you for any response you might provide.