Recommended way to measure 20A current with race capture?

ppressle · Post by **ppressle** » Mon Dec 16, 2019 4:43 pm

Hi,
I'd like to measure and log current to a device (fuel pump) in the race car. I find existing devices that convert 0-20MA to a 0-5V voltage, and I can set up a current divider in line with the pump to generate a the 20MA current.

This seems overly complicated though. Is there an easier way to do this?

Thanks,
Pete

ferg · Post by **ferg** » Sat Dec 21, 2019 12:22 am

I have used a sensor like this one, to produce a 0-5V signal that can be calibrated:

https://www.digikey.com/product-detail/ ... ND/2500500

Connect this to an analog input and log or display the current consumption.

Billy C · Post by **Billy C** » Mon Jan 06, 2020 10:10 am

Most modern cars use some form of load detection. I'm most familiar with the honda setup. 88-01 civics have a little unit in the fuse box under the hood. The factory setup outputs a 0-5v to the ECU to control the alternator to adjust for the load. I currently have a standalone in one of my cars that logs that signal just in case I need to go back and diagnose a problem. Right now it's not calibrated to an actual amperage value but that wouldn't be too hard to do.