which amp meters are you using

[Helz_McFugly]

Im trying to find a good DC amp meter that has the clamp around thing on top. what are you using?

[Philldpapill]

"Clamp on" meters are only for AC(as far as I know...). They work by measuring the change in magnetic flux produced by the changing AC current. When a wire has current flowing through it, it produces a magnetic field in a circular fashion around the wire. A CHANGING magnetic field then induces an electric field, in a loop of wire(or voltage). The meter works by measuring this electric field, which is a result of the changing magnetic field, which in turn is a result of the changing current.

If you have a DC current, there is no changing magnetic field, and thus no electric field produced.

Actually, come to think of it, I believe they now have DC clamp around meters that are based on the "Hall Effect" which is something different entirely. I'm not sure of the accuracy of those kinds due to the nature of how the hall effect works... In the design I'm making, I'm using a Hall Effect Sensor to measure current, but this is a dedicated "in line" device which the current flows through. These are accurate to about 1% on a 150A scale. This is the same sensor I'm using in your PWM.

EDIT: Yes, I'm an idiot sometimes. There are DC clamp on meters, and they DO use the Hall Effect to measure current. The "clamp" has magnetic flux through it when you clamp it on, and there is a Hall Effect Sensor breaking the clamp inside. The magnetic flux passes through the H.E. sensor, and the meter measures the voltage potential across the hall element due to the magnetic flux. Oops....

As for actual meters - No clue. I don't use them. Sorry.

[Roland Jacques]

I use analog and digital shunt type meters. Im on a tight budget so thats what i can afford.

Heres a cheep one that has a built in shunt 0-30. Better and more accurate than those typical ones you see at the auto shops. Sunpro...
http://www.altersystems.com/catalog/...dc-p-1144.html

[Helz_McFugly]

well Phill if your Hulk PWM already has a digital amp readout, Ill just wait. I can use this POS sunpro for now.

I thought everyone had the clamp around amp meters. I see them on every youtube video when they are showing off the amps.

[Philldpapill]

BTW, If any of you guys want a Meter that goes up to 150A, or 50A, I think I can do one for about $20 total. Since the parts required are such, it could also have a voltage readout with no extra cost.

Basically, it would be a voltage/Ammeter with simultaneous readouts, displaying Battery voltage, and Current draw at the same time. I think the accuracy of the current meter would be something like 1%, 2% maximum.

This is at cost, btw. I just like designing stuff.

[sweet7549]

I would like to have a digital readout to monitor current and temp for the cell.
Mounted inside drivers side.
Would yours work for this?
Thanks

[Philldpapill]

I think so... The would be three wires going to this meter.

Wire A: Thick enough to handle the current of your electrolyzer, comming from the negative terminal of the battery.
Wire B: Again, another thick wire coming from one the return end of your electrolyzer where the negative terminal of the battery would hook up to.
Wire C: Just a small wire to power the meter and measure the battery voltage.

Do you think that would be ok?

[sweet7549]

Yes and one to measure cell temp.
My email is sweet7549@aol.com.
Drop me a line
Thanks

[Helz_McFugly]

I just ordered this one.

http://grizzly.com/products/H0473

[biggy boy]

I just ordered this one.

http://grizzly.com/products/H0473

That will do it!!

I have a Fluke meter that is similar.