Source for replacement caps in H744 regulators

Jonathan Chapman lists at
Thu Jan 6 06:59:31 CST 2022

> One of the H744 regulators whines

FWIW, none of mine are silent under load. If they're not being loaded (e.g. on a test bench, with no dummy load, or if you have all the boards out) they can whine excessively due to no minimum load.

> it seems higher than the expected values printed on the meter

Beware cheap test equipment. $client has a few of these Chinese handheld LC/RLC meters, they're wildly inaccurate on some parameters, including ESR on large electrolytics. We've got a proper Gen-Rad RLC Digibridge in the shop to compare against. We couldn't figure out why some of their tuned filter stages were failing QC at a much higher rate than expected. They were off-frequency because the cheap meters were giving consistently incorrect measurements when trying to match capacitors.

That said, it's not like replacing them with new will *hurt* -- it just might not fix the whine.


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