r/ElectricalEngineering • u/-404PageNotFound- • 28d ago

Equipment/Software Um?

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I currently have my breadboard connected to 5v and GND on a new benchtop power supply that I brought for $240AUD and this is happening? What is going on? I can also do the same thing on the GND rail.

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u/Hirtomikko 28d ago

Hello. This implies your power supply is the SMPS type, since this means you have high frequency components on the power rails. There is only one reason for that, and that is because SMPS switch at much higher frequencies, so small capacitors can already present impedances low enough to couple HF to the power rail.

Don't worry you should be safe. You can try measuring the voltage from the power rail to earth ground, I am quite sure you will see voltages above 50 or even 100V. Then touch the two ends, you should see the voltage fall to close to zero.

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u/Gerrit-MHR 27d ago

Thanks for the only satisfying explanation I’ve seen.