Cannot take the reading of the amps

[Philldpapill]

It really depends... There's a common misunderstanding out there about "amps". There are two types of "amps" - RMS and Average. When you talk about gas produced per amp, you are talking about the number of electrons that have passed through your cell, so you would be interested in average current. On the other hand, you need to consider RMS(Root Mean Square) amps when you are using a PWM to ensure that you aren't dumping HUGE spikes of current(large spikes of current means excess power loss). Ideally, your RMS current reading and average current reading would be the same, like in the case of DC when you just use a direct connection to your cell from your battery. Your RMS reading will ALWAYS be greater than or equal to an average current reading.

If you go with an analog current meter, then you will definitely be getting an average current reading. If you go with a digital meter, you could be getting either one...

[chris0147]

Well, I don't want to spend more than $40. I am thinking of buying this product:

http://cgi.ebay.co.uk/Uni-T-UT203-Cu...item3cb033ab5c


Does it looks good for hho production if it does match in my needs?

[Bill Foote]

Check Ebay for DC ammeter. It will have a digital read-back panel and a shunt. Mine has a 75A=75mV shunt, it's stamped on the shunt.
You need a separate power supply for the ammeter than the power supply you are reading. You can't use your car battery to power the ammeter because you are measuring the car battery current. It seeks ground through the ammeter and smokes it good!
I use a 9VDC battery to power my ammeter. It has an aqua blue background and black numbers.The connection is battery, breaker, solenoid, shunt, PWM, dry cell positive, then negative of dry cell to negative of battery or good frame ground.
My ammeter and shunt was $25.00 with free shipping direct from Japan in one week.
The solenoid is to turn on the system safely, I built a box with temp read-back,current read-back, time to fill reservoir led, on/off switch and a Eurotherm PLC with a normally closed relay that will open if the temp goes to 165F. Remember to use a 9 volt battery for your ammeter/shunt circuit.
Have Fun, Bill

[thedore]

Most meters have a 0 to 200 mv volt range. This can be used with a shunt like this one
http://www.google.com/products/catal...CDkQ8wIwBTgA#p

to provide a 0 to 50 amp meter. 50 mv = 50 amps