Posted by JohnD [162.158.78.211] on Saturday, March 04, 2017 at 18:18:51 :
In Reply to: Fuel Gauge voltage dropping resistor posted by Snowbird [162.158.142.97] on Saturday, March 04, 2017 at 12:22:13 :
You need to know two things to calcualte the resistor size:
1) voltage drop (6 volts) you want to convert 12 volt input to 6 volt, so you want a 6 volt drop.
2) amp draw of the circuit
Hook the sender and gauge up to 6 volts and make sure the sender is working propery. Use a DC ammeter to find out how much current is being drawn by the circuit. I guess it is milliamps, a small fraction of one amp, so use a digital amp meter.
Use this link to plug in your values to determine the correct resistor needed. Use the table at the bottom of the page on the website. Remember that a dropping resistor creates heat, so be careful how and where you mount the resistor