Smiths Fuel Gauge To Tank Sender

[robert]

Re: Smiths Fuel Gauge To Tank Sender

How about a small electronic unit that connects between the sender and the gauge converting the sender signal to suit the gauge (and providing a low fuel warning light).
I know it's a bit sad, but I've got interested in this problem and have started to develop such a device. The only problem is calibrating it to each application - could some kind person measure the resistance of the Ford Escort tank/sender at Empty and Full (and Half full is possible)?
Jon Cox - have you got the European standard round the wrong way in your post?

[amalgamated users from prior forum]

Re: Smiths Fuel Gauge To Tank Sender

Message originally posted by: Don
I too have been thinking along the same lines, I think that I can do it with just one transistor, I am still working on it. However we achieve a solution there should be no need to calibrate it for every application, with the right design we could provide two trimmers or pots one to adjust the maximum reading the other to adjust the empty one. What happens in between is less important, the most vital thing is to know when you need to fill up. The ford Fuel sender seems to give (on mine) about 90 ohms empty and 20 ish full although I have seen the range quoted as 90 to 0, the Smiths guage seems to need about 10 full to 180 empty. Any ideas welcome.

[robert]

Re: Smiths Fuel Gauge To Tank Sender

One transistor? Thats pretty impressive, Don - I've cheated and used a PIC microcontroller! A sledgehammer to crack a nut, yes but a small and cheap sledghammer (but not as cheap as one transistor, I admit).
I have two pots on my design but they interact slightly making it impractical to set up on the vehicle (it is no problem if you use substitute resistors for the sender but maybe not everyone would be confident in doing this).
Would a fixed nominal Ford to nominal Smiths be of any use?

[robert]

Re: Smiths Fuel Gauge To Tank Sender

Not sure if anyone is still reading this but here is my solution to the problem using a quad op amp. I built this using adjustable presets although the diagram shows fixed resistors that suit my particular guage. Beware if you do try this using presets as they are quite difficult to set up.
The one in the picture is now spare if anyone wants it.

[kronos1664]

Re: Smiths Fuel Gauge To Tank Sender

has anyone connected a smiths or other non ford sender to a ford fuel gauge sucessfully?

[stevejgreen]

Re: Smiths Fuel Gauge To Tank Sender

has anyone connected a smiths or other non ford sender to a ford fuel gauge sucessfully?

The answer is yes, there are various solutions. Mine was to carry a gallon can of petrol onboard.

Various options exist but I am confused.
Most Roadsters were fitted with an Escort Van fuel tank, with an Escort sender, and then matching up to Marina or Smiths gauges was the problem!

[scott h]

Re: Smiths Fuel Gauge To Tank Sender

has anyone connected a smiths or other non ford sender to a ford fuel gauge sucessfully?

https://www.spiyda.com/fuel-gauge-wizard-mk3.html

[listerjp2]

Re: Smiths Fuel Gauge To Tank Sender

Got this on and works well with the Marina instrument.

Have also got there little device for the tachometer, again works well.

Adrian

https://www.spiyda.com/fuel-gauge-wizard-mk3.html

[nightsurfer]

Re: Smiths Fuel Gauge To Tank Sender

I am lucky enough to have an accurate fuel guage in my Marina based Roadster.
There is a seperate sender unit to the fuel feed unit.
I do however, suffer from the fuel guage bouncing around wildly when it is anything but full.
Can anyone recomend a suitable damper / resistor?

[HairyDave]

Re: Smiths Fuel Gauge To Tank Sender

Maybe the gauge is very sensitive and the fuel sloshing around makes the float bob around. no solution I'm afraid. I solved the Escort to Marina problem by cutting the Escort sender out and fitting a Marina sender in the Escort tank. Time consuming and fiddly but a full scale fuel gauge. It is somewhere in the forum.

[ggrum]

Re: Smiths Fuel Gauge To Tank Sender

I believe the damping function is normally incorporated unto the gauge itself. Bearing in mind that the normal sender is just a variable resistor, any resistance added will change the calibration but won't necessarily provide any damping. I'm not an electronics engineer but a capacitor in the circuit might do it. If I'm talking absolute nonsense I'm sure someone will point it out.

[stevejgreen]

Re: Smiths Fuel Gauge To Tank Sender

I believe the damping function is normally incorporated unto the gauge itself. Bearing in mind that the normal sender is just a variable resistor, any resistance added will change the calibration but won't necessarily provide any damping. I'm not an electronics engineer but a capacitor in the circuit might do it. If I'm talking absolute nonsense I'm sure someone will point it out.

Most automotive gauges are sluggish deliberately, certainly those with bimetallic strips. They are damped and not intended to give an instantaneous measurement like an electricians

A capacitor essentially blocks blocks DC but let’s AC through. So a capacitor alone in a DC circuit like a fuel gauge will have no effect.

[listerjp2]

Re: Smiths Fuel Gauge To Tank Sender

The spiyda system allows for damping and again works well.

Adrian


[.QUOTE=ggrum;54760]I believe the damping function is normally incorporated unto the gauge itself. Bearing in mind that the normal sender is just a variable resistor, any resistance added will change the calibration but won't necessarily provide any damping. I'm not an electronics engineer but a capacitor in the circuit might do it. If I'm talking absolute nonsense I'm sure someone will point it out.[/QUOTE]

[nightsurfer]

Re: Smiths Fuel Gauge To Tank Sender

The spiyda system allows for damping and again works well.

Adrian


[.QUOTE=ggrum;54760]I believe the damping function is normally incorporated unto the gauge itself. Bearing in mind that the normal sender is just a variable resistor, any resistance added will change the calibration but won't necessarily provide any damping. I'm not an electronics engineer but a capacitor in the circuit might do it. If I'm talking absolute nonsense I'm sure someone will point it out.

[/QUOTE]

Yes, I saw that. Perhaps I will have to go that way, or just live with it.

[listerjp2]

Re: Smiths Fuel Gauge To Tank Sender

I wanted to keep the Marina dials so was the easiest way forward.

Adrian