Can I monitor a 1.4kV on an MCU via voltage div.? Will this break the MCU?

[samuelr]

Hi

I like to see if I can monitor the strike voltage on a lamp by a ballast, the strike voltage is about 1400V, using R1 to be 1M ohms and R1 to be 2.2k ohms on the divider I should see about 3.0V on the MCU's ADC pin, this looks workable but the most I have tried and seen working was 300V in theory this should work. Anyone have any experience on this?

 

[DeLorean]

Your MCU is probably loading your divider making your calculated values incorrect. You could use a high impedance FET op-amp to buffer the divider or account for the MCU load with your calculated voltage divider.