Need advice for a circuit to turn off a small transmitter when dark

Thread Starter

jonnyvee

Joined Mar 6, 2021
5
I'm trying to find a circuit or Photocell that will run on 4-5 volts and turn off a small transmitter at night, I have a 6 volt solar cell with voltage dropped to 5 volts going into a charge controller that is powering a transmitter and charging a 3.7 volt battery for backup, I would like it to turn off the battery when the sun goes down as it doesn't need to work at night but can't find a photocell or similar device that does that, also need it to be small, anyone have a idea or where that could be found?
 

Bernard

Joined Aug 7, 2008
5,788
A diode could be connected between solar cell & battery, cathode to battery.
What needs to be disconnected, SP from battery, battery from Tx, , SP from Tx ?
 
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Thread Starter

jonnyvee

Joined Mar 6, 2021
5
The battery kicks in when the solar cell has no light, need the battery to go off when dark so like a off at dusk photocell
 

Yaakov

Joined Jan 27, 2019
3,519
I'm trying to find a circuit or Photocell that will run on 4-5 volts and turn off a small transmitter at night, I have a 6 volt solar cell with voltage dropped to 5 volts going into a charge controller that is powering a transmitter and charging a 3.7 volt battery for backup, I would like it to turn off the battery when the sun goes down as it doesn't need to work at night but can't find a photocell or similar device that does that, also need it to be small, anyone have a idea or where that could be found?
Does it need to operate on cloudy days when the light is poor?
 
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