In actual fact they work on current flow (this is chicken and egg argument).
The variable resistor in the sensor causes a change in the current flow in
the meter and deflects the pointer. However, together with the change in
the resistance and the corresponding change in current there should be a
change in potential at the 'S' terminal - either that or I totally
misunderstood Ohms' Law.
As I don't have the instruments on the bench - if that were the case I would
gather the data myself - I was asking if anyone had the change in potential
at the 'S' terminal or, could find them by bench test.
I accept I could have put the question better.
regards,
MP
----- Original Message -----
From: "Richard Holder" <rholder@avnet.co.uk>
Subject: Re: Europa-List: Engine Gauges.
>
> > If anyone has the Europa supplied (VDO) engine temperature and pressure
gauges
> > still waiting to be installed, I would be most grateful for a little
data.
> >
> > I am interested in the voltage required to give max and min readings on
the
> > oil/water temperature and oil pressure gauges.
> >
> > Is there any printed data anywhere.
> >
> > regards,
> >
> > Mike
>
> They don't work by voltage. The sensor connects to earth and the
resistance
> in that circuit defines the reading on the gauge.
>
> To test connect up 12 v+ and earth to the correct terminals on the gauge.
> Then get a variable resistor set and connect between the "S" terminal and
> the earth terminal.
>
> The you can calibrate he readings you need.
>
> One (the oil pressure) will work in the reverse sense !
>
> HTH
>
> Richard
> Richard F.W. Holder 01279 842804 (POTS)
> Bell House, Bell Lane, 01279 842942 (fax)
> Widford, Ware, Herts, 07860 367423 (mobile)
> SG12 8SH email : rholder@avnet.co.uk
> Europa Classic Tri-gear : G-OWWW, High Cross
> PA-28-181 : Piper Archer : G-JANA, EGSG (Stapleford)
>
>
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