SPD3303X-E hissing when outputs are on

[ElectronicsHobbyist]

Hi Guys

I recently recieved my SPD3303X-E and hacked it right away to mV and mA resolution. After powering it up i noticed a hissing sound as soon as i turned one or more of the channels on. Because i hate noise i opened up the case and started looking for the culprit. I was looking for some kind of power inductor which could cause the hissing. There was nothing like this on the board so i looked for other components and saw the beeper. I was really surprised that the hissing stopped as soon as i placed my finger on the beeper . The fix was to take some tape and stick it on there. Now it works like a charm.

Has anyone else experienced similar behavior with his power supply?

[jrgandara]

Interesting! My PS was generating a kind of hiss latelly. But now it is not been working long enough to check that. If I manage to fix the PS I will check the buzzer.

Thank you for this tip.

JR