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First off I am a car guy, if I have a schematic or details I can solder what I need.

I have a client that fitted a digital temperature gauge to his car, he also wants to have the gauge on the instrument cluster to work. Now from experience, I know this can not be done by just splicing wires and I need to make an op-amp buffer from what I have read.

All I need are some examples of what wire goes where to the gauges and power and signal wire from the sensor. Also, what are the part numbers of components needed?

The sensor that is fitted is fairly common and from what I found is it decreases in resistance as the car warms up, unfortunately, there are no numbers on the sensor.

Hope this is enough information thank you.

TeilZeitGott
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LittleMonster
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  • Aside from it being a duplicate, we are not a design house. We will help you clarify design issues. Hope this is enough information, but you have not really given us any information aside from common sensor and decreasing resistance with temperature. – StainlessSteelRat Aug 03 '19 at 20:45

2 Answers2

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That is a NTC thermistor, the output is variation in resistance not voltage or current so you cant practically use a buffer circuit to do this. this would require some sort of circuit rather than just buffer. feeding two devices from one NTC is also not a good option since the input to these devices have voltage divider resistor and resistance may vary from device to device.The best way to do this without complications is to use two NTC of same type,value,manufacturer place them together and connect them individually to each device.

sudip kong
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a buffer basically looks like this.

schematic

simulate this circuit – Schematic created using CircuitLab

the problem is, assuming the sensor is a thermistor of some sort, the different gauges may have different voltages on the sensor for the same temperature.

so you probaly need to connect the stock sensor directly and use the buffer to connect the aftermarket sensor, and then re-calibrate the aftermarket sensor.

Jasen Слава Україні
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