Isolate/split power supply

This is the place for any magazine-related discussions that don't fit in any of the column discussion boards below.
Post Reply
solar3000
Posts: 71
Joined: Fri May 10, 2013 1:55 pm
Contact:

Isolate/split power supply

Post by solar3000 »

What do you even call it?

I have a battery. I want to test it's voltage and current passing through.

The easiest way is to break the circuit and insert a separate multi-tester to find voltage and current, etc....

And now, for constant monitoring. There are two wire [panel] digital volt meters scattered throughout amazon and ebay. Same for amp meters. I can insert an analog panel amp meter in the circuit for constant monitoring. There are also digital ones that can monitor the current in the same circuit. They range from 6 to 100 volts, etc... To monitor 0 to 100 volts, you need a separate power supply. I want to simulate that on the same circuit.

I could use a transformer.

Is there another way?
sghioto
Posts: 326
Joined: Wed Dec 26, 2007 5:16 pm
Location: Colorado
Contact:

Re: Isolate/split power supply

Post by sghioto »

I'm looking at some of those units on Amazon that might work.
What is your battery voltage?
What's the maximum current to monitor?
You can always use separate analog meters.

SG
User avatar
haklesup
Posts: 3136
Joined: Thu Aug 01, 2002 1:01 am
Location: San Jose CA
Contact:

Re: Isolate/split power supply

Post by haklesup »

you don't need to break the circuit to monitor voltage, just attach the sense point and ground. Some of those little meters are powered from a separate supply and some are powered from the supply you are measuring. (3 and 2 wire respectively). Use 3 wire if the voltage might go below 2V or the meter might wink off if you use the 2 wire type.

For current you can break the loop and insert the 3 wire current meter, this will give you best accuracy for low current. The transformer types exist but tend not to be very good at measuring small current or seeing small transients on a larger signal.

Look for a combined V and I display panel meter and that will save you parts count and from having to mount two displays.

But for battery monitoring, there are more specialized modules. Search on "battery charge monitor" "battery capacity meter" or similar keywords and be sure to match the battery type, V and I range to the solution you select. Hall effect transformer and sense resistor versions of these are also available with similar pros and cons. The difference is these meters also show accumulated charge, Wh and more. Not all meters show charge and discharge directions so read descriptions carefully
Post Reply

Who is online

Users browsing this forum: Ahrefs [Bot] and 11 guests