Electronic – SMPS gives “electric shock”


I built the following circuit, a reference VIPer22A circuit.
VIPer22A Reference design

It works fine but I have a little problem. It gives an electric shock on the secondary side. It's not a "line" shock (sticking your fingers into an outlet), but rather, a "tingly" shock if you touch the device while you're grounded.

It's the same thing that happens when you have an PC power supply not connected to mains earth.

The obvious solution would be, of course, to connect the secondary GND to Earth. The problem I have with this is that this is an audio amplifier, so I'd rather leave GND floating.

Is there a way to eliminate this shock? Capacitively connecting GND to EARTH? Or should I just connect my circuit's ground to Earth?

Best Answer

There is 4.7nF between primary and secondary (hopefully a Y rated capacitor for safety). If the N is connected to 230VAC relative to ground, it will pass about 400uA which may be perceptible.

From information on the net, Argentina appears to use Australian style 3pin plugs with 230VAC 50Hz one side hot wrt ground.

Maybe your plug connections are reversed or the outlet is wired incorrectly.