that is what he already did in post 11.
i just checked the specs and that unit requires input to be in 0..+/-200mV (or shunt resistors Ra and Rb need to be added)
so thee solution need to have additional 1000:1 divider (combined ratio 1000000:1).
but the 752M resistors can stay the same... just use 750 Ohm as a low side resistor of the voltage divider and connect panel meter in parallel with that 750 Ohm resistor.

View attachment 352500

So when the input is 1,000,000 volts the voltage across the 750 Ohm resistor is 1 volt. Is that right?

 

And I am left wondering about how somebody was able to have that sort of high voltage source around.

He has used a small ferrite transformer, a ZVS and voltage multiplier. The sparks are big but faint. He wanted to know the voltage reached

 

The voltage can be calculated from the length of the spark gap. The strength of the spark does not depend on the voltage, it depends on the power the transformer can supply (if continuous) or the energy stored (if not).

 

The voltage to strike an arc across a spark gap also depends on the electrodes shape. Once the arc is struck it can be much longer IN AIR.

 

So when the input is 1,000,000 volts the voltage across the 750 Ohm resistor is 1 volt. Is that right?

Correct... Or in his case 50000V input will result in 0.050V across 750 Ohm resistor. Since panel meter default range is 200mV, this will result in displayed value 50.

 

He has used a small ferrite transformer, a ZVS and voltage multiplier. The sparks are big but faint. He wanted to know the voltage reached

And he expects to get a meaningful reading of a transient event using a DC meter?

 

What sort of voltage multiplier??What kind/type number are the diodes?? What kind of capacitors?? I am curious now. That gets interesting.

 

Correct... Or in his case 50000V input will result in 0.050V across 750 Ohm resistor. Since panel meter default range is 200mV, this will result in displayed value 50.

Oh Ok I did not see the 200mv spec. The top end voltage is usually a major factor in these designs.
Sometimes the full scale current is given and that is used to set the top end voltage scaling.

 

And he expects to get a meaningful reading of a transient event using a DC meter?

Hi,

I've gotten meaningful transient readings with fast panel meters, but the transients were rather slow. I can't see fast transients being seen on the meter if not just for the inertial dynamics of the movement as small as they might be.

 

Well it doesn't work perfect but offer some readings. I recommended him using an ammeter in series to measure the current instead.

The multiplier is a crofton Walton. Caps are 1nf 20kv and the diodes are 20kv 100ns. Sinked in paraffin oil

 

Well it doesn't work perfect but offer some readings. I recommended him using an ammeter in series to measure the current instead.

The multiplier is a crofton Walton. Caps are 1nf 20kv and the diodes are 20kv 100ns. Sinked in paraffin oilView attachment 352576

Hi,

That's a cool picture of the voltage multiplier.