Leakage current

Thread Starter

udir

Joined Dec 31, 2013
2
Hi All,
Dont know if this is he right forum but ill try.Capture.JPG
I have a tens device (a device which emits low frequency pulses around 12. HZ) for muscle contraction.
I am testing it at a laboratory according to IEC 60601-2-10 for leakage current and failed the test.
Apparently theres a current flowing through the GND.
I have looked at the schematics (which i didnt design) and saw some resistors and capacitor on the output section of the transformer connected to gnd, and I really not sure why they are there...as I dont see any value in them.my next step would be to disconnect them gradually and see how it affects the signal and whether the leakage current has been reduced.any other thoughts? relevant pic attached :)
YUri
 

DickCappels

Joined Aug 21, 2008
7,449
It might be that the original designer intended for the output (that drives this network) to be isolated from ground. In that case, under normal operation there would be no ground leakage current. You might consider looking at the "upstream" circuitry.

It is a good idea to know where the outputs are with respect to ground, and apparently those resistors and capacitors you have shown are intended to do just that, so I would not modify that part of the circuit.
 

MisterBill2

Joined Jan 23, 2018
8,808
There is current flowing to the "ground" because there are components connecting that portion of the circuit to it.
Since the rest of the circuit is not shown there is no possible way to know about the isolation from the mains connection, which, since the test failed, the isolation is not adequate.
How can we possibly analyze a circuit that we can not see?????
 
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