Author Topic: HV measuring  (Read 2807 times)

0 Members and 1 Guest are viewing this topic.

Offline Login to see usernames

  • Moderator
  • 50+
  • *
  • Posts: 68
HV measuring
« on: January 11, 2009, 04:36:32 am »
So  I wish to measure HV.

And to measure HV you need a good probe , scope is not the big issue , I just want a scope That has precision / durability , with voltage indication on screen preferably ...

check out the 80K-40 HV PROBE @ fluke.com

I wont buy 3 of these hell no .. only , there wont be much potential difference inside the secondary itself .

It seems like Eclipsed has blown his scope onwce so I dont want this happening to me , in this thread we had a discussion about how Dogs measured his voltage , plz see this very6 interresting conversation , and plz see Dogs post.

http://waterfuelcell.org/phpBB2/viewtopic.php?t=1176&postdays=0&postorder=asc&&start=0

I will try and corrolate any pattern between resonance with HV probe and Dogs technique , I will try to confirm this method for future experimenters ... It would be great if we could pickup resonance from just the BEMF...

« Last Edit: January 11, 2009, 09:03:53 am by Dankie »

Offline Login to see usernames

  • Moderator
  • 50+
  • *
  • Posts: 68
Plz share your HV story
« Reply #1 on: January 11, 2009, 05:11:30 am »
Plz share all your HV measuring stories ...

Offline Login to see usernames

  • Member
  • **
  • Posts: 235
Re: HV measuring
« Reply #2 on: January 11, 2009, 05:37:24 am »
I have the Fluke 40Kv probe.
Although I do not want to use it on the secondary it could be used.
You will find that a DMM measures in RMS.
There may be slight variables of what the DMM can pick up even with the high-voltage probe.
The o'scope will see peak to peak and signal information.
I have worked on high-voltage testing equipment to 40KV.
I remember seeing resistor banks on this equipment for the measurement of high-voltage on analogue meters.
If you calibrate your o'scope to a decent resistor bank possibly 20 to 50 megohms I am thinking we can then use our o'scopes for accurate measurements.
Calculate the voltage drop on the resistor bank on a circuit that provides 1KV.
Some testing needs to be done for accuracy.
IE: 1000V peak to peak or RMS into Resistor bank X-Megohms hypothesize = 10V. So 40KV into same resistor bank will =  400V the scope should measure to this limit.
Or caculate the limit  of your scope.
I have not tried this but I have seen this working.
Care and testing and always remember your safety.
Resistor bank should be fed with High-Voltage wire (silicon covered) pay attention to decent resistor spacing so you have no arc's.
Assemble in well insulated plastic box.
Good luck!

Offline Login to see usernames

  • Moderator
  • 50+
  • *
  • Posts: 68
Re: HV measuring
« Reply #3 on: January 11, 2009, 05:46:21 am »
Nice Komtek , so how much voltage did you measure with your probe .

I will probably buy one and try to create a probe and measure it compared to the Fluke probe , it seems pretty straightforward but there it appears that a good hume-made probe is tricky to do .

I cant destroy the oscope at least , Ill just get a funny waveform.


http://www.repairfaq.org/sam/hvprobe.htm

Offline Login to see usernames

  • Member
  • **
  • Posts: 235
Re: HV measuring
« Reply #4 on: January 11, 2009, 06:15:54 am »
I went all the way up with my Fluke probe.
And then some. I like to push the limit.
Not to much but the equipment can handle a little push.
The resistor bank is the proper way.
Its not homemade.
The equipment I work on is high dollar, not just tossed to gether junk from a backyard.
This is labratory equipment that works for Nation Wide Industry.
Oh well I made the post take it or leave it. Its fundamental.
From experience. Commen sense.