I was bread boarding a simply lm317 circuit to drop 24vdc to 18vdc but I have some problems ..I am trying to charge a JumpBox or Jump Pack( It's what you use to jump your car when the batteries dead )... The original charger was a wall wart that was 120vac to 18vdc 500ma and it took a crap ..But I found a 120vac to 24vdc wall wart and I hook up my lm317 circuit in order to the 24vdc to 18vdc .. The problem came when I was measuring the output voltage ..When I breadboard it ,I used my power supply set to 24vdc -400ma and the output set to 18vdc with a small load ..I hook up the output to charging port of the jump box and the voltage suddenly jumped down and the power supply output voltage dropped too but I tried to increase the voltage but nothing changed but I could increased the current but not would change ..I am using ebay bought lm317 and I am not sure if they where the problem ..
Specs
R1-240ohm
R2-3.3Kohm
Power supply
Mastech D3003
Max 30vdc\3amps
Thanks
Jay Sr
Specs
R1-240ohm
R2-3.3Kohm
Power supply
Mastech D3003
Max 30vdc\3amps
Thanks
Jay Sr