Can't lower current on PWM

I Just got Shane's PWM hooked up. The instructions say to turn the limit and duty pot's CCW all the way then to add Electrolyte till the target current is reached. Then adjust the limit pot CW till the current starts dropping and the same with the duty pot.

I added enough electrolyte to hit 30amps. I wanted to lower the current to about 20amps. I started to turn the limit pot CW, I had made a few turns to try and lower the current. While I was turning the pot CW, The current just stayed constant. Then I hit a point where the current started to rise. The power supply started to buzz when this happened. The more I turned it CW, the higher the current rised. Same with the duty pot.

The power supply is a Audio Authority 50amp continuous power supply. It's not a switching power supply. It weighs about 35lbs.

Anybody have any suggestions?

Thanks!

Hrmm... I found this on Zero's site.

"Pots are 20 turn. Crank the "I" pot fully CW for MAX current. Turn the "%" CW until you just hit 100%, straight DC at the output, or just a hair less. Connect to the cell. Adjust your electrolyte for the target current while cold. Rotate the "I" pot CCW until it Just starts to fold back while still cold. Done!"

That's opposite from the instructions that I got from Shane. I don't have those instructions in front of me at the moment to see if i'm mis-reading it. It's highly possible I mis-interpreted the instructions, but I'll double check it when I get home.

If it's indeed opposite, It's possible I have dumped too much electrolytle into the reservoir and I can't lower the current anymore, but only raise it.

How are people with Shanes PWM adjusting their current?

Ok, that's good that i'm not totally on crack. After I saw Zero's site, I questioned myself If I read your directions correctly. I was hoping I just mis-read it, since it would be a simple fix.

I'm using a 75mv shunt that's connected to a LED panel meter rated up to 50amps. I got the kit off of ebay.

I have the negative output terminal on the PWM hooked up to the Shunt. The other end of the Shunt goes to the cell's negative terminal.

The weird thing is, as i'm adjusting it CW, once I hit ~36amps, the power supply starts to make a high frequency buzz. It may not even be related, but could be just from the higher load its outputting.

Hey Shane, Thanks for the tip. It's indeed the panel meter that's screwy. I measured the shunt and it was dropping as I turned it CW, while the meter was rising. heh.

I wonder why the meter is acting up.

Thanks Shane!