Re: Ammeter internal current draw

On Thu, 02 Mar 2006 11:29:39 -0600, John Fields
<jfields@xxxxxxxxxxxxxxxxxxxxx> wrote:
This is really a digital millivoltmeter reading the drop across the
shunt and, typically, the input impedance to these voltmeters is
about 10 megohms, so the current in the leads (and, thus, the drop
across them) will be negligible compared to what's going through the
shunt.

Thank you. I still don't think I have enough information to avoid
trial & error.

The voltage drop along the meter leads will indeed be very small in
absolute amount, but not as a fraction of the voltage drop across the
shunt -- which will also be very small.

I think I need to know either the typical current through the meter
leads or the typical voltage drop across this kind of shunt.

I don't have instruments accurate enough to measure such small
variables. My only recourse is to try different lead lengths and to
see what happens to the readings.

Ken C


.

Relevant Pages

  • Re: Ammeter internal current draw
    ... shunt and, typically, the input impedance to these voltmeters is ... about 10 megohms, so the current in the leads (and, thus, the drop ... and if your meter impedance is 10 megohms, ... AWG copper wire. ...
    (sci.electronics.basics)
  • Re: Ha! A One Button Multimeter
    ... yes can be done with a shunt, but a shunt drops voltage. ... The shunt is just inside the meter. ... Becomes some sort of a reflex to always put those leads back after ...
    (sci.electronics.design)
  • Re: Ammeter internal current draw
    ... Does anyone know how much current typically flows in the leads from ... the shunt to this kind of digital meter? ... I am trying to determine how far I can put the meter from the shunt ...
    (sci.electronics.basics)
  • Re: NFB 101 shunt voltage NFB.
    ... shunt NFB when tried say between an output tube and input tube. ... There are two arms of the NFB resistance divider, R1, and R2. ... The model of the input tube needs to be considered, a voltage generator ...
    (rec.audio.tubes)
  • Re: NFB101 part 3
    ... That is shunt (voltage) derived, ... A cathode follwer is NOT shunt NFB. ... In a CF the feedback is taken from directly across the load and is ...
    (rec.audio.tubes)
Quantcast