Would like to log trans temp through XFI to keep an eye on it but not add another gauge in the car. I've searched here and CPG and have gotten mixed reports. I'm sure somebody must be doing it? Would like to use a sensor or transducer to keep it low budget. Saw this on CPG Nation. But looking for some confirmation it would work?
Trans temp through XFI
- Thread starter Justa6MB
- Start date
turbobitt
Well-Known Member
- Joined
- Feb 14, 2002
Ok thanks a lot, do not have EGT so this would be great. I'd love to know the theory behind how it works if somebody has time to explainMy little brain with basic electronics knowledge is having a hard time seeing how the circuit works?
It's a simple concept really but I'm not the best at explaining electronics but I'll give it a shot. The voltage drop in any single resister circuit will be the same as the input voltage. With 2 resisters in series the voltage drop across both will still be the supply voltage but between them it will be something less. If the resisters were the same value for example you would expect to see Half the input voltage between them. In the above diagram, you have basically two resisters in series and a voltage sensing leg between the two. So as the sending units resistance changes with temperature the voltage signal on the leg will change.
If you ever looked at making a home made volt booster for an alternator it works in a similar way but with 2 fixed resisters. Basically the resisters are sized so that the voltage between them is a few volts less than the alternator output so when it sees this on the voltage sending pin on the alternator it will crank it up.
AG.
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turbobitt
Well-Known Member
- Joined
- Feb 14, 2002
Couldn't answer that but If I would guess it won't require a lot of wattage and will probable work.
AG.
Ok great thanks. Next question is regarding the pins. The pins in the above drawing don't correspond with the pin out chart. I assume C24 for +5 volt reference, and I can pick an unused analog aux input, but what is the sensor ref ground? Would it be C11 - analog aux input return ground?
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That will work along with any other ground
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Hi fellas. Wondering if somebody could check my math on sensor gain and offset please? I set gain = 1, offset = 0, high = 5, low = 0, dec = 2. I took ice water at 35* = 4.04 and boiled water at 212* = 0.39. My math gives me sensor gain = "- 48.49" and sensor offset = "230.89".
