Current limiters?

[sho14u]

Ok, so another question. I see that most of us have issues with too much of a current draw. I am running an independant circuit in my Explorer that has a 40amp relay and a 30amp fuse. I don't want to pull more than 20 amps on the system, but when we have a run away or not knowing what our electrolyte limits are, we run into trial and error mode and sometimes, like me, have a melt down. Is there something that can be integrated into the circuit that can limit the current to a desired peak?

[mytoyotasucks]

PWM - Pulse-width modulation

[M Bell]

The best way to determine how your cell draws amperage is to start with only distilled water. Check and see what the amperage draw is. Start adding your chemicals at only 1 gram increments. You will be surprised what change 1 gram can make to the electrolyte. After addind you need to let it run for a while to let the additive get mixed in. I actually mix each gram with the water and add it with an eye dropper.

[sho14u]

A PWM doesnt limit current does it? It just turns the current on and off at a preset frequency, right?

[Jaxom]

Correct, but there's more to it. By cycling the genny on and off you reduce the average current proportional to the on-time (duty cycle.) You can use a feedback circuit to monitor the current flow, and control the duty cycle to maintain current at a preset level. This thread (http://www.hhoforums.com/showthread.php?t=917) will tell you all about it.

[mytoyotasucks]

A PWM doesnt limit current does it? It just turns the current on and off at a preset frequency, right?


a pwm will limit the current.

A PWM was originally built to reduce the heat built up in dc motors.

and a pwm can adjust the motor speed, just like adjusting how many amp u want to use.

but if u dont have a amp meter on , that ur just shooting in a dark - with a pwm and without.

how do u know how much chemical to put in if u dont know how many amps its drawing.