The vintage automotive fuel gauge circuit uses a 0-30 ohm sending unit. The gauge is then just a glorified ohm meter that tells the driver 0 Ohms is Empty, 30 Ohms if full, or anything in between depending on where the float is in the tank. [this is my understanding].
The 0-30 ohms of course wouldn't be possible without some voltage. The voltages are 100 millivolts for empty and 2.1 volts for full. The objective is to make a LOW FUEL WARNING CIRCUIT. I want to be able to sense the voltage that is present without effecting the operation of the existing circuit. When the voltage reaches [ an adjustable range ] of between 0 and 1 volt, I want an LED to come on.
Has this been discussed before? I am looking for all the clues I can get as to what this circuit would look like. Thanks!
The 0-30 ohms of course wouldn't be possible without some voltage. The voltages are 100 millivolts for empty and 2.1 volts for full. The objective is to make a LOW FUEL WARNING CIRCUIT. I want to be able to sense the voltage that is present without effecting the operation of the existing circuit. When the voltage reaches [ an adjustable range ] of between 0 and 1 volt, I want an LED to come on.
Has this been discussed before? I am looking for all the clues I can get as to what this circuit would look like. Thanks!