Amazon has 100:1 high voltage scope probes for around $25. They have a
99M internal resistor, so they work with a 10 Meg DVM, too. The division ratio becomes 10.9:1.-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
And the Vmax is...?
2KV for the $24 Hantek 100 MHz probe.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
freq ?
Jamie
That aint bad The last time I got 100:1 probe it cost me $75 from probemaster.com and I think that one is around 1500V at 200Mz or more and gold plate.HV Looking at their site, It seems they don't have it any more ? I have a couple of the Hantek 10mA- 6/60 amp 20kHz current clamps that work as advertised.
About 1/20 the Tek price!
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Yeah, but what's the derating?
I suspect it won't last long on a Tesla coil, for instance (well, the primary... well, part of the primary).
Tim
-- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: http://seventransistorlabs.com
Good thing I don't have a Tesla coil. Is a Tesla coil actually good for anything? I'm building a 1200 volt pulse generator, with a 1400 volt power supply, so this probe works with a scope or a DVM.
With a 1.11 M resistor across the DVM, it becomes a 100x probe again.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
Wow. A whopping 2kV.
Read the thread, IDIOT!
At less than 1/20th the performance as well.
snip
You could easily build your own divider and put it in a fluorinert bath or pot it in RTV and dial in better precision and stability and reliability than hantek.
Think so? What would be better about a Tek probe?
Even Tek scopes aren't anything special these days. Some are downright terrible.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
Gold plate to ensure consistently minimal resistance when in series with 99M. It's a funny world.
NT
Is this just a 99 Mohm resistor and the probe relies of the 1 Mohm scope input resistance to get that 100:1 division ratio.
Does the probe have a tunable shunt capacitance ?
There must be a small capacitor across the 99 Mohm resistor to balance out the cable and scope input capacitance and usually a small tunable shunt capacitor. The total shunt capacitance should e 100 times the probe series capacitance. This will give a 100:1 capacitance reactance voltage divider that matches the 100:1 resistance ratio, giving a flat frequency response.
Tune the shunt capacitance until a 1:100 total capacitance ratio is achieved.
This coming from the idiot who thinks the ISS has not produced any science.
Probmaster makes beautiful stuff. I use their DVM probes exlusively.
Cheers
Phil Hobbs
It is NOT "just a 99MOhm resistor.
It has to have the voltage withstand capacity as well.
One can achieve better precision with a series string of HV resistors as well, and the HV does not shift the resistance value when the pressure is applied as much either.
That is what is inside the long HV probes.
2KV ain't that much. I have an old Avo 30KV probe that's about 45 years old now and I can trust it 100%. I wouldn't trust anything HT/EHT made in China!
Hmm, I had this semi-crazy idea the other day. I've used piezo sparkers (from butane lighters) as ESD testers... spark things and see if they survive. I was thinking if one could hang an RC on it and maybe a HV monitor it could be more useful.
+----+---RRR---+----+ | | | | | | HV DUT Piezo C mon. | | | | | | | | +----+---------+----+But how to do the monitor?... (well and all the other HV stuff.)
George H.
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