Re: Homemade Voltage Divider

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Yurtle Turtle <yurtle_t@xxxxxxxxx>

What kind of PSU do you have? I have this one:

http://hot-streamer.com/adam/garage/psu_34kV_1.jpg
http://hot-streamer.com/adam/garage/psu_34kV_2.jpg

and built this controller from an old VTVM:

http://hot-streamer.com/adam/garage/psu_34kV_3.jpg

My PSU outputs a voltage, 0 - 5 volts I believe,
relative to output. For calibration, I used a Maxwell
30nf 35kV cap and cranked it up until I hit my target,
which was 10 kV. I simply used the VTVM gauge and a
pot to fine tune it to match my DMM and HV probe.
Although I have used it as a handheld, my HV probe
cane with a removance tip, allowing me to hardwire it
to the circuit I'm measuring. I disconnect my PSU from
the shrinking circuit before firing it.

Adam

--- Tesla list <tesla@xxxxxxxxxx> wrote:

> Original poster: "David Rieben"
> <drieben@xxxxxxxxxxxxxxx>
>
> Hi all,
>
> I am pondering a way to reliably measure 10 KVDC
> across the terminals of (2) 100 µFd energy dis-
> charge caps that I plan to build a quarter shrinker/
> can crusher project with. I will have up to a total
> of 450 µFd at 10 kV when I get 2 other 120
> µFd, 10 kV caps added to my collection. Anyway,
> I was originally going to just use my Beckman HV
> probe in combo with one of my DVMs to monitor
> the voltage at the cap terminals to insure that I
> do not overvolt the caps, since my HVDC supply
> can go up to about 20 kVDC. However, I believe
> the HV probe isn't desinged to be used like this
> as its ergonomics lends it for hand held operation
> so I was thinking of getting some 10K or 100K
> carbon resistors and building a 100 resistor di-
> vider to get a 100:1 reduction to safely
> read 10 kV on my DVM as 100 volts. What
> are the best resistance values to go for 10 K
> or 100 K? A 1 Meg total with 10K(X100) would
> still allow 10 mA of current flow at 10 kV and that
> would translate to 100 watts (WOW)! I suppose
> that I just answered my own question- don't think
> (100) 1/4 resistors would take much of that! Better
> go
> for 100 K per resistor, that would only allow up to
> 1 mA
> of current flow at 10 kV and 10 watts. I believe 10
> watts spread over (100) 1/4 watt resistors would
> work ;^)
> Any comments or suggestions?
>
> David Rieben
>
>
>