Hi
Toatally new to this forum so bear with me.. I've tried searching but I could only find a bunch of threads discussing inverting the voltage output. My dilemma is slightly different.
I have an old classic car with analog instruments that I want to keep intact. But I want to use a new type of sensor since it also has a second switching contact output in the same unit. So here it is;
-Oil pressure gauge in car sends out a 5vdc feed and the input reads ohms. 0psi=75ohm and 80psi=10ohm. I haven't measured but with ohms law this should be then 66mA at 0psi/75ohm and 500mA at 80Psi/10ohm.
-New Oil sensor is capable of 0Psi to 150Psi but the output is switched. 0Psi=10ohm and 80Psi=90ohm (150Psi=180ohm)
After reading up some I thought an op-amp could be the way to go but I'm having a hard time figuring out how the circuit should be designed and what resistors to use?
-Should it be a single feed circuit where I use the 5Vdc to power the op-amp or should I add a 12Vdc feed into the circuit? Whatever works for me.
-The new Oil pressure sensor is only a single wire output that drives the circuit to ground, so it's not like a three-wire pot or similar.
Any help is appreciated. Oh and I added a picture of the classic in question for attention.. and below is a link to my car build project if anyone is interrested.
https://www.forbbodiesonly.com/mopa...arger-ray-barton-528-hemi-pro-touring.135133/
Toatally new to this forum so bear with me.. I've tried searching but I could only find a bunch of threads discussing inverting the voltage output. My dilemma is slightly different.
I have an old classic car with analog instruments that I want to keep intact. But I want to use a new type of sensor since it also has a second switching contact output in the same unit. So here it is;
-Oil pressure gauge in car sends out a 5vdc feed and the input reads ohms. 0psi=75ohm and 80psi=10ohm. I haven't measured but with ohms law this should be then 66mA at 0psi/75ohm and 500mA at 80Psi/10ohm.
-New Oil sensor is capable of 0Psi to 150Psi but the output is switched. 0Psi=10ohm and 80Psi=90ohm (150Psi=180ohm)
After reading up some I thought an op-amp could be the way to go but I'm having a hard time figuring out how the circuit should be designed and what resistors to use?
-Should it be a single feed circuit where I use the 5Vdc to power the op-amp or should I add a 12Vdc feed into the circuit? Whatever works for me.
-The new Oil pressure sensor is only a single wire output that drives the circuit to ground, so it's not like a three-wire pot or similar.
Any help is appreciated. Oh and I added a picture of the classic in question for attention.. and below is a link to my car build project if anyone is interrested.
https://www.forbbodiesonly.com/mopa...arger-ray-barton-528-hemi-pro-touring.135133/
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