P
powerampfreak
- Jan 1, 1970
- 0
Greetings all!
I need to consult you guys for a concern regarding lab bench instrument's and laptop grounding scheme.
I'm using the laptop (which is a class-2 device, non earthed) together withthe Pickit3 programmer/debugger. The Pickit3 is connected to the target application which is powered by an external powersupply. Connected to the application board is one oscilliscope and two waveform generators.
So, how should I earth all this to prevent anything to burn.
Between the laptop "ground" (measured on an USB connector shield)and earth I have about 80VAC when the battery charges is connected to mains.
This should be due to some Y-caps in the charger SMPS. The charger has no connection to earth so those Y-caps are probably connected between primary and secondary ground (laptop ground).
I have had the oscilloscope floating, supplied from an isolation transformer since I've worked on SMPS's lately. But now I rather have it earth connected to minimize the leakage current from the oscilloscope SMPS and it's Y-caps to my application board.
So, my question is: Is it safe for the laptop and Pickit3 to connect to the application board if I earth all the instruments. What worries me is, will that 80VAC potential cause any damage to the Pickit3 or even worse, the laptop?
Thanks for your suggestions, and have a great weekend you all!
I need to consult you guys for a concern regarding lab bench instrument's and laptop grounding scheme.
I'm using the laptop (which is a class-2 device, non earthed) together withthe Pickit3 programmer/debugger. The Pickit3 is connected to the target application which is powered by an external powersupply. Connected to the application board is one oscilliscope and two waveform generators.
So, how should I earth all this to prevent anything to burn.
Between the laptop "ground" (measured on an USB connector shield)and earth I have about 80VAC when the battery charges is connected to mains.
This should be due to some Y-caps in the charger SMPS. The charger has no connection to earth so those Y-caps are probably connected between primary and secondary ground (laptop ground).
I have had the oscilloscope floating, supplied from an isolation transformer since I've worked on SMPS's lately. But now I rather have it earth connected to minimize the leakage current from the oscilloscope SMPS and it's Y-caps to my application board.
So, my question is: Is it safe for the laptop and Pickit3 to connect to the application board if I earth all the instruments. What worries me is, will that 80VAC potential cause any damage to the Pickit3 or even worse, the laptop?
Thanks for your suggestions, and have a great weekend you all!