Building a high-voltage 1:1000 probe

his video is about building a 1:1000 high voltage probe, mainly for my scope but also usable for multimeters.
I considered publishing plans but then properly rated high voltage components are not easy to get and so I rather spent a bit more time on the design principles, so you can adopt the circuit to whatever component values you managed to get and of course what input impedance & capacitance your scope has.


WARNING:

If you build and use this probe, you do so at your own risk!
High voltage can seriously hurt you and damage your equipment!

parts:
Vishay 10MΩ 1W Metal Glaze Resistor ±5% VR68000001005JAC00 RS stock# 683-5326 10 for £4.70 ex VAT

Vishay Single Layer Ceramic Capacitor SLCC 15pF 3kV dc ±20% U2J (N750) Dielectric 564R Series Through Hole RS Stock# 831-3155 5 for £2.40 ex VAT

Vishay Single Layer Ceramic Capacitor SLCC 1.5nF 2kV dc ±10% S3N Dielectric F Series Through Hole RS Stock# 716-7254 10 for £2.50 ex VAT

RS PRO Black Flame Retardant Epoxy Potting Compound RS Stock# 199-1402 50gm £5.11 ex VAT

Videos mentioned:

[marco]

So nice to see someone getting the theory all right (and the final result as well) and explain it properly too.

[skifalu]

Great work, was just figuring out how others made their 1000X probes and stumbled across your excellent project.

[donepearce]

Oscilloscope attenuators are capacitive dividers. The resistors are just there to allow DC operation.

[AllTheFasteners]

Super job - and many thanks for listing the parts and suppliers - really helpful to me.

[fzigunov]

You, sir, just came at the right time! I was working with a laser driver circuit and didn't have the probing I needed to debug a flash lamp driver and didn't want to purchase an expensive 1000x probe. I think this will likely do the job for me!

[olivalle]

Thank you for sharing this project with us, very accurate design !

[sergatmel]

Great project ! Many thanks for the theory and demonstration of practical results. 👍

[ronniepirtlejr]

Nice project!
The high-frequency sound came through your video
@ 13:47 it was ear piercing!

[splitprissm]

About the capacitors: 3kv and even 10kv ceramic disc kits seem to be all over amazon, and y1/y2 capacitors can also be bought reasonably cheap or salvaged from SMPS junk. A smaller capacitance value can always be achieved by using several in series. 5kv insulation testers are also cheap these days, so no need to blindly trust salvaged or cheap stuff. What am I missing here?

[etiennebodart]

BRAVO ! Your video is comprehensive and very insteresting. Thank you very much !

[galileo_rs]

Alternative for high voltage compound: hardware store high temperature silicone (use the red one not the black). I used that stuff to repair the high voltage CRT supply (HV multiplier) in a old oscilloscope. Years latter it still holds. Takes quite a while (a few days) to cure fully.

[jijeshkorothpoyil]

Values for 100:1 resistor and Capacitor. And nos .
What about to measure triac chopper voltage wave forms and
Associated high frequency noise measurement?

[cryscrystiii]

I would have used for protection and some diodes (like BAS70LS with 100mA and 2pF in series with diode) in antiparallel on output

[mikeryan]

Great video. You could fill the outside of your mold space up with silicone sealant prior to pouring the epoxy, or at least stick down the plastic pieces with it.

[mahmoodmirza]

OScope in the experiment draws 300 mA to display 300 full screen!
What's the purpose of applying a 1 MOhm and 56 KOhm resistances each parallel to the I MOhm internal resistance of the OScope?
Oh, the Scope has flexibility to be configured!

[td]

Hi, Heinz... Another great project and video. I was glad to see that you (attempted to) pot the components in rosin. I suggest putting it in an additional box, or wrapping it with lots of electrical tape, until you can finish potting it. Shrapnel is not your friend. And, we want to keep you around...:-)

[danielmszczonow]

Jakie jest pasmo przenoszenia takiej sondy ???

[legpetruchka]

Merci beaucoup pour votre travail et vos explications claires et très précises. Je m'abonne car cette vidéo montre à quel point il est utile de vous suivre. Encore merci et Bravo.

[samueldavies]

Amazing video, could anything be done to help it work better at high frequency?

[TheDefpom]

I’m not sure about a plastic box being ok, especially a black one, black plastics use Carbon Black as a pigment, as we know carbon is conductive, if you check the datasheets for plastics material you can see that the dielectric resistance is lower for a black material compared to a white or natural coloured one, still I nice educational video though, well explained.