My battery charger recently quit working for one of my drills, so I decided to take it apart to see why and found the 120->~11VAC transformer wasn't outputing any voltage. I assumed the transformer got too hot one time and burnt out the temperature fuse sealed into the windings.
Anyway, the circuit used looked pretty simple, but I'm trying to figure out how exactly the paralleled resistor and resistor-LED work in the circuit (attached).
Its a simple bridge rectifier before that and the charger is rated for 10.15 V at 215mA and 11.3 V at 120mA, and my calculations seems to show a larger resistor is needed to limit the current to those values (but thats excluding the LED part that is confusing me - and the LED only comes on when a battery is instlled into the charger.
Does the battery charge somehow affect the LED?
Thanks,
Arthur
Anyway, the circuit used looked pretty simple, but I'm trying to figure out how exactly the paralleled resistor and resistor-LED work in the circuit (attached).
Its a simple bridge rectifier before that and the charger is rated for 10.15 V at 215mA and 11.3 V at 120mA, and my calculations seems to show a larger resistor is needed to limit the current to those values (but thats excluding the LED part that is confusing me - and the LED only comes on when a battery is instlled into the charger.
Does the battery charge somehow affect the LED?
Thanks,
Arthur