scoop
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| posted on 18/5/10 at 01:17 PM |
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Voltage stabiliser's?
I have the Premier wiring loom fitted and the the locost fuel sender in the tank. It always registers full, which has caught me out once, but i now
see from the guide that i needed to fit a voltage statbiliser.
My question to you is do i fit one tank end or dash end and does one fit all or do they come with different amounts of resistance and if so which one
would i need?
Cheers, Steve
[Edited on 18/5/10 by scoop]
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02GF74
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| posted on 18/5/10 at 01:51 PM |
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yes and no.
the circuit is as follows:
12 v - voltage stabiliser - gauge - sender - 0 V
depending on the gauge - make/model, it may not need a stabiliser but run directly off 12 V.
It is older smiths (70s) that use a voltage stabiliser - a metal box about the size of 2 sugar cubes - pinned to the back of the gauge.
So question you have to ask yourself is:
1. does my gauge need a voltage stabiliser?
2. have I wired it up correctly?
3. is my sender compatible with the guage?
4. have I wired that correctly
6. is my guage working?
8. is my sender working?
there are a number of simple tests you can carry out to answer some of the above.
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scoop
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| posted on 18/5/10 at 02:12 PM |
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Thanks for all that.
The intruments are from the donor f reg sierra with rev counter. So old but not as old as the Smiths. The rev counter thinking about it is a bit
eratic as well. Does this need something?
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02GF74
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| posted on 18/5/10 at 02:25 PM |
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rev counter, no - this works of pulses from the coil - or i more modern, from the ecu.
so assuming the sender is from same car as instruments, then we are left now with 2, 4, 6, and 8
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sucksqueezebangblow
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| posted on 18/5/10 at 03:38 PM |
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It depends on the voltage swing that you require for the guage. If you have a variable voltage supply (Maplin sell a 10V one in kit form for a tenner)
you can connect it to the guage and wind the voltage up until the dial reads full. Note the voltage (with a volt meter) and then wind it down until
you get empty and measure again.
I used an 8 volt regulator (again from Maplin) and a 68 Ohm resistor. The sender is a 90 Ohm sender.
I wired 8V to the resistor, the resistor to the sender and the guage, and earthed the sender and the guage.
Thus with the sender at max resistance (usually full but can be empty) it will deliver a voltage of (8 V/158 O)*90 O=4.56 V to the guage.
To work back from the voltage you have measured for a full reading (VF) to give you a value for the resistor (RR) use;
RR=((RF/VF)*VR)-RF
Where;
RF is the resistance of the sender for "full".
VR is the voltage from the regulator.
VF is the voltage for "full"
You can and should try different voltages for VR as regulators come in a variety of voltages.
Your aim should be to get a resistance for RR that is available "off the shelf", but also bear in mind you can combine resistors to get
different resistances. Also note that you do not want a resistance that is much less than 2/3 of the sender resistance or the current drain will get
too high
It is a good idea to use a regulated voltage as battery/alternator voltage can swing quite significantly below 12V and up to 13.5V or more leading to
less accurate readings.
[Edited on 18/5/10 by sucksqueezebangblow]
Better to Burnout than to Fade Away JET METAL ~ AndySparrow © 
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