Digital Amp/Volt Meter

freddmc

Just bought a digital volt/amp meter and the directions are a little--ummm-sketchy.
http://cgi.ebay.com/HHO-EV-Car-Boat-...item27b4ec8643

Anyway it says to adjust current first and then voltage. What do you adjust it to? Can you use a handheld volt meter?

Thanks

Fred

BGW

__________________
This advertising will not be shown in this way to registered members.
Register your free account today and become a member on Buggies Gone Wild Golf Cart Forum

dougmcp

You will need a digital ammeter to adjust the new ammeter and a hand held digital voltmeter will work for voltage adjustments.
Be advised these are not waterproof gauges.

freddmc

Thanks. Its for my motorhome so will be inside.

freddmc

Doug, I was hooking the gauge up today and am a little confused(OK, a lot confused) on the wiring for the shunt. The schematic they show ( http://cgi.ebay.com/HHO-EV-Car-Boat-...item27b4eca3bd) shows wire #1(Voltage signal)attaching AFTER the load. Am I correct in assuming that this wire basically connects to the positive side of the battery.
Am I also correct in assuming that the wires going to the shunt(#2 and #3)measure amps flowing OUT of the battery regardless of what items are creating the load(i.e. furnace, lights etc.)Is it important that wire #2 goes to the positive end of the shunt and #3 goes to the negative side of the shunt?

Thanks for you help.

Fred Mc.

dougmcp

shows wire #1(Voltage signal)attaching AFTER the load. Am I correct in assuming that this wire basically connects to the positive side of the battery.
That is correct.

Am I also correct in assuming that the wires going to the shunt(#2 and #3)measure amps flowing OUT of the battery regardless of what items are creating the load(i.e. furnace, lights etc.)Is it important that wire #2 goes to the positive end of the shunt and #3 goes to the negative side of the shunt?
That too is correct.
Do you have a shunt for this meter?
Here is a visual of how a shunt is wired:

freddmc

Yes, I have a shunt.

Thanks for the help.

Fred

freddmc

Doug
When I hook this all up it is supposed to give me a voltage reading. But this reading appears to be quite erratic flashing between different numbers. For example it will read 12.36, then 12.08, then 12.44, then 12.33 when the actual reading should be 12.31(via handheld votlmeter) Eventually it will settle down to one number. Is this normal or a bad gauge?

Thanks

Fred

dougmcp

Not knowing the meter exactly, it has an IC circuit with some diodes and resistors and the voltage reading can/will take time to settle, even as long as 30 seconds.
The readings may be out a little from your handheld but I'd say if it's within 2% I'd call it good.
They draw almost 0 power so they are safe to leave on constantly.

freddmc

Doud,
I have a question about amp meters and shunts.

In my motorhome(converter bus) I have my "house" electrics(12V) that draws power from the main electrical system(including the starter-also 12 v.). The starter can draw a huge amperage on starting. The house electrical system draws power from the same circuit that feeds power to the starter, in other words it branches off. In using a shunt can I place it between the start circuit and the house circuit so it only measures power that is drawn for the house circuit. Will it also then measure amps used when the starter is used. The reason I ask is that if the shunt has to handle amps to the starter it has to be huge whereas it it only measure power going to the "house" system it only needs to be 15-20 amps.

Thanks

Fred

dougmcp

You are correct, if you place the shunt in the house line it will only measure the house current as long as it is not part of the circuit for the starter.