i am making a rechargeable taser powered by a 3.7 volt battery the coil can take anything from 3.5 to 6,5 volts and outputs anything from 400 to to 600Mv
now i thought i was going to power the coil direct from teh battery but it says i use the Power out on the board so it stops the battery from draining too much
but if i do that the draw on the charger board is too much and it shuts off. but the coil works fine on my bench power supply using 3.6v and 1 amp i just need to limit the pull from the charger board to the coil as if left unlimited it will pull all 3 amps of my bench power supply under 3.5 volts
If I understand you right, you want it to power by the battery, and also have the battery connected to the charger so you can charge the battery; you will also want to use your load (taser) while it is charging?
If so, you can always have a by-pass.
- Have power-in connected to the TP4056
- The 4056 board output connects to the battery and also
to the load via a diode- Have power-in also connected to another voltage regulation circuit (at 4.3V to 6volt), say we choose 4.3V
- The voltage regulation circuit (which is connected to power-in) power-out connect
to the load via a diodeThe battery will never go beyond 4.3V. So, whenever power-in is on, power to the load comes directly from your voltage regulation circuit. At the same time, the 4056 board is charging the battery. When power-in is off, the voltage from your voltage regulation board is 0V, so power to the load comes from the battery.
Now you can control how much current the load and battery get.
- To control charge current, the Rs on TP4056' pin2 selects the current. I=1200/Rs, so Rs=1.2K for 1Amp, Rs=2.4K for 0.5Amp, so on.
- To control voltage-regulation circuit current, that depends on how you design the regulation circuit. There are zillion of examples out there. Or, you can just buy a cheap Chinese buck board that has both voltage and current control.
For the diodes, I would use
Schottky diode like 1N5817 (1Amp or less) or other Schottky diode if larger current is needed.