I have found a schematic for constructing a solar panel charger for charging a Sealed Lead Acid battery, but I have a problem.
The schematic is this:
The problem is that on input (the voltage that comes from the solar panel) I measure 8,1 Volt instead of 12 Volt (ok I didn't have too much sun today), but the output I get is 1,8 Volt. If I have understood the circuit correct, shouldn't I have the (input voltage)/2 at the output (so 4 Volts), or I am wrong?
Also, I didn't connect the VR as in the schematic. I connected the "middle" pin to the upper circuit, and one of the "side" pins to the ground. Am I wrong?