This is a handy little board that I morphed from grj's DIY constant current passenger car lighting board (with his permission) a while back. It is based on the LM317T adjustable voltage regulator IC and is nice and compact and easy to build with only 6 components. This seems like it might be a good time and place to include it.
Yes, I know, I know, there is at least a zillion low cost regulators and buck converters available offshore for very low prices. But most only do DC to DC, and none have built in DCS interference protection. I wanted a nice compact board that was all in one, for engine or railcar use. It has proven to be very handy, and with offshore components the cost is less than a buck a board!
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