No LED output when probe is connected

[GokulSharma]

I was investigating why TVS diode was getting damaged by looking in to the waveforms (voltage and current) across Z100. However when I connect a differential probe to the mains between L and N and an HV analog probe across Z100, there is no LED output. The moment I take out either the differential probe or the analog probe, I am getting output. Can anyone explain why this is happening? Circuit diagram is attached here.

 

[tepalia02]

I think, when you connect the probes, current is flowing through the probes and the LED is not getting sufficient current.

 

[GokulSharma]

I think, when you connect the probes, current is flowing through the probes and the LED is not getting sufficient current.

I think, when you connect the probes, current is flowing through the probes and the LED is not getting sufficient current.

Hi tepalia, Thank you for your reply. Could you please explain it a bit more? Because if I remove the differential probe from L and N and keep the analog probe across Z100 , I am getting LED output. If I do the reverse I am still getting LED output. Only when both are present there is no output. Could you please tell me what is the current path?

 

[danadakk]

Your diff probe probably pretty hi Z ?

I see no led in the schematic ?


Regards, Dana.