Could these be wired to measure current instead of voltage?

http://www.ebay.com/itm/5PCS-Mini-B...7?hash=item41896d9197:g:DFIAAOSwdsFUMg1i#rwid

I rather like the look of these for my new power supply project.

Neil.

 

Current meters: http://www.ebay.co.uk/sch/i.html?_f...ter.TRS0&_nkw=mini+led+current+meter&_sacat=0
Combined current and voltage: http://www.ebay.co.uk/itm/Mini-Size...hash=item1eb34e291e:m:mmA0PRXuXeo8q7Z4kQ9KlLw

 

Thank you Albert

 

The basic method is to measure the voltage across a resistor to calculate the current, then send it to a digital display.

See that copper rod on the second meter? That's the high current resistor. Maybe it's 0.01 ohm. One amp through that resistance will cause a voltage difference of 0.01 volts. That ten millivolts is amplified and sent to the display which would then display 1.00 and the label is, "amps".

The Amprobe brand current meter uses a magnetic circuit that looks like a magnetic core that can be hinged open and then closed around a wire. There is a transformer winding on the magnetic core where you can't see it and the output of that winding is used to drive an amplifier which drives the display. That's about as much as I know about displaying amps without going through the conversion from amps to resistance to voltage to display. That is, I think amps can be measured without a resistor in series with the current, but only in AC because DC will not effectively couple into a magnetic core.

And then there are Hall Effect DC meters which I haven't gotten to yet.

 

So we are actually measuring a voltage with the meter....thanks, I have so much to learn

 

So we are actually measuring a voltage with the meter....thanks, I have so much to learn

Except for Hall Effect devices. as mentioned by #12, which responds to the magnetic field around a wire (AC or DC) to determine the current.

 

Here's another exception: http://practicalphysics.org/model-hot-wire-ammeter.html