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High Voltage Scope Probe Circuit what is wrong or can be improved?

DBingaman

Jun 27, 2021
103
Joined
Jun 27, 2021
Messages
103
Hi,
I wanted to get input from the community about the following circuit that will be used to measure high voltage by first conditioning it down to lower voltages that then get routed to a scope via simply BNC connector cables. I simulated this circuit, it has a little loss at 1Mhz that is acceptable. I prefer some stability over bandpass ability to avoid oscillations. The circuit is simulated using LTSpice.

Safety feature: There will be a banana jack input that connects the box ground to 120VAC earth ground via the following part:

https://www.digikey.com/en/products/detail/desco/09838/3043259

Safety feature: BNC outputs have clamping circuits if someone accidentally plugs in a voltage source to what normally goes to the scope.

The two 9V supplies will be two standard 9V batteries.

Picture of the Circuit:

Circuit.PNG

Schematic/LTSpice simulation model included along with Op Amp Datasheet.

Diode datasheet was to large to upload here is link:

https://fscdn.rohm.com/en/products/databook/datasheet/discrete/diode/switching/1ss380vmte-17-e.pdf

Plan on using Express PCB to make the circuit board.

Questions:

Is there anything here that I am doing that is inherently wrong?
Is there any issue with tying the circuit ground to earth ground for safety?
Should I have any additional components for added safety?

Thanks,
Dennis
 

Attachments

  • HighVoltageProbeCkt.asc
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  • AD8033_8034.pdf
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