Maybe I should apologize because I did not give enough information in the beginning:
The purpose of this circuit is to switch the UPS inverter of when my 220V camping fridge does not demand power (when thermostat is OFF). The reason is that while the inverter is not supplying power to any device it still draws power from the 12V battery. The inverter is switched on and off by two push buttons. If you push the ON button it closes the push button momentary and the inverter switches on. If you push the OFF button The OFF push button closes momentary and switches the inverter off.
My 12V circuit is therefore just mimicking the two ON OFF push buttons on the inverter. And I can still use the buttons on the inverter if I would like.
I hope this helps
The purpose of this circuit is to switch the UPS inverter of when my 220V camping fridge does not demand power (when thermostat is OFF). The reason is that while the inverter is not supplying power to any device it still draws power from the 12V battery. The inverter is switched on and off by two push buttons. If you push the ON button it closes the push button momentary and the inverter switches on. If you push the OFF button The OFF push button closes momentary and switches the inverter off.
My 12V circuit is therefore just mimicking the two ON OFF push buttons on the inverter. And I can still use the buttons on the inverter if I would like.
I hope this helps