I want to build a mosfet switch into the tailcap of a small regulated flashlight. I am good at soldering, I have all the tools and all of the solder and irons. However, I am not good with the technical side of electronic circuits. The flashlight is small, takes 1 3.7 V battery. The + of the battery touches a spring in the head. The - touches the spring on the on/off switch. In the head of the flashlight there is a circuit regulated that will draw 10 amps from the battery. The on/off switch connects the spring to the body of the flashlight. The problem is this much current will destroy pretty much any small flashlight switch.
I want to build a Mosfet switch in the tailcap that works the same as the switch thats there now, pretty much it will open and close the circuit between the flashight body and the spring that goes to the main battery -. Theres no room to wire anything to the + on the main battery. I want to include a flat lithium battery in the tailcap to provide the power to the mosfet to open and close the gate. The inside of the tailcap is about 18-20 mm. I'm doing my best to explain this please let me know if you need some clarification.
I want to build a Mosfet switch in the tailcap that works the same as the switch thats there now, pretty much it will open and close the circuit between the flashight body and the spring that goes to the main battery -. Theres no room to wire anything to the + on the main battery. I want to include a flat lithium battery in the tailcap to provide the power to the mosfet to open and close the gate. The inside of the tailcap is about 18-20 mm. I'm doing my best to explain this please let me know if you need some clarification.