I have a circuit that I want to be able to power from either solar or from a regulated power supply. The circuit runs an LED based light that draws 1A.
For solar I am using a solar panel with an M083 solar controller. The controller will charge the battery up to 13.8V.
I want to limit the light input to 12V so as not to damage the LED's, but I want it to keep working even if the battery voltage drops below 12V.
I did some experimenting with a 7812 and a 9v battery. Without the 7812 I get a reading of 8.1v across the battery under load and the light is still quite bright. When I insert the 7812 I am only seeing about 6.8V across the output under load and the light is very dim.
I don't think I can use a zener due to the current drawn.
So how do I limit the voltage to 12V without losing so much when the voltage goes below 12V?
For solar I am using a solar panel with an M083 solar controller. The controller will charge the battery up to 13.8V.
I want to limit the light input to 12V so as not to damage the LED's, but I want it to keep working even if the battery voltage drops below 12V.
I did some experimenting with a 7812 and a 9v battery. Without the 7812 I get a reading of 8.1v across the battery under load and the light is still quite bright. When I insert the 7812 I am only seeing about 6.8V across the output under load and the light is very dim.
I don't think I can use a zener due to the current drawn.
So how do I limit the voltage to 12V without losing so much when the voltage goes below 12V?
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