[Diy_efi] Sending unit confusion

[Perry Harrington]

Measure the highest resistance of the sending unit, then substitute a pot of
the same general value.  Just use 2 poles of the pot and leave the 3rd pole
unconnected.

--Perry

On Thu, Feb 20, 2003 at 03:12:35PM -0500, Toyota Supra wrote:
> that makes sense, so it measures the current loss, it is sending 12vDC out, 
> but after grounding or whatever, only receives 0 to 3.5vDC ?
> 
> so, how can i simulate what is in the car? can i measure resistance between 
> the brown w/ black wire, and ground, and then use that resitor between my 
> inverters ground and that particular wire? as well as running 12vDC into the 
> yellow wire?
> 
> thanks for the help perry
> 
> -j
> 
> 
> 
> 
> 
> 
> 
> 
> 
> >Subject: Re: [Diy_efi] Sending unit confusion
> 
> >
> >The sending unit may be connected like a temp sensor.  The sender has
> >a bias resistor between ground and the input.  12v is supplied to the
> >input of the sender and the output pulls the voltage up or down through
> >the bias resistor.  If the sending unit isn't grounded, then with 2
> >wires it has to be biased externally.
> >
> >--Perry
> >
> 
> 
> 
> 
> > > >
> > > > > in my never ending quest to conquer this circuit, i have encountered
> > > > > something very strange. when i removed the fuel level sending unit 
> >to
> > > >try
> > > > > and test my circuit, i found that i am not able to simulate its
> > > >electrical
> > > > > function.
> > > > > the sending unit has 2 wires, a yellow and a brown w/ black tracer. 
> >when
> > > >the
> > > > > sending unit is not plugged into the body harness, the yellow wire 
> >has
> > > > > +12vDC (or whatever battery voltage may be) on the body harness side 
> >of
> > > >the
> > > > > connector, and the brown w/ black tracer has approximately 15k of
> > > >resistance
> > > > > to ground, or 35mV of positive voltage.
> > > > >
> > > > > when the connectors are plugged in, the yellow wire will have 
> >anywhere
> > > >from
> > > > > 0 to 3.5vDC, dependent on the position of the "float". the variable
> > > >resistor
> > > > > will have resistance ranging from 0k to 55k.
> > > > >
> > > > > now, my problem is, i can't simulate the variable voltage outside of 
> >the
> > > > > vehicle, to test my circuit. if i put 12vDC into the yellow wire, 
> >the
> > > >brown
> > > > > w/ black tracer will also have 12vDC, so what could that wire 
> >possibly
> > > >be
> > > > > doing, or connected to, that would make the circuit and unit work
> > > >properly?
> > > > >
> > > >
> 
> 
> _________________________________________________________________
> Add photos to your e-mail with MSN 8. Get 2 months FREE*.  
> http://join.msn.com/?page=features/featuredemail
> 
> 
> _______________________________________________
> Diy_efi mailing list
> Diy_efi at diy-efi.org
> http://www.diy-efi.org/mailman/listinfo/diy_efi

-- 
Perry Harrington			Data Acquisition & Instrumentation, Inc	
perry at dainst dot com					 http://www.dainst.com/

Those who would give up essential liberty to purchase a little temporary safety
deserve neither liberty or safety. Nor, are they likely to end up with either.
                             -- Benjamin Franklin

_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://www.diy-efi.org/mailman/listinfo/diy_efi