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[TCML] Fwd: Bleeder resistor for Maxwell cap



Subject:  Bleeder resistor for a Maxwell cap

Thanks guys for your helpful responses.  To answer Gary's question, my
Maxwell cap is .03uF (not .003uF which was a typo in my earlier email).

Here are the key points I take away from your suggestions:
 - To keep it simple, I'll attempt to duplicate the values of Gary's
bleeder resistor configuration:  78Meg, 1/4W.  Since this works for his
.04uF cap it should also work for my .03uF cap...right?
 - I'll use 2 or more separate sets of bleeders across the cap to act as a
safety back up.
 - I will also use use a bang stick each time for added safety measure.

I do have a question:  in lieu of putting together a string of 39 resistors
as Gary has, I'd like to see if I can safely get the same value in a single
High Voltage resistor.  I've tried checking the product specs on DigiKey's
& Mouser's websites, but honestly it got a little confusing for me with all
the additional specifications to choose from.  Could one of you suggest a
specific type of resistor that would do the job?  If possible a part number
would also really be helpful.
Thanks, Dennis MA

On Sat, Feb 10, 2018 at 3:01 PM, dennis otmaskin <dotmaskin@xxxxxxxxx>
wrote:

>
>
>
> Begin forwarded message:
>
> *From:* Gary Lau <glau1024@xxxxxxxxx>
> *Date:* February 7, 2018 at 10:30:18 PM EST
> *To:* Tesla Coil Mailing List <tesla@xxxxxxxxxx>
> *Subject:* *Re: [TCML] Bleeder resistor for Maxwell cap*
> *Reply-To:* Tesla Coil Mailing List <tesla@xxxxxxxxxx>
>
> Hi Dennis,
>
> The specs for a bleeder resistor are anything but critical.  Was your cap
> .003 uF or .03uF?  I use a .04uF cap.  I constructed a bleeder out
> of thirty nine 2.0Meg 1/4W resistors (78Meg total).  I calculated that with
> my .04uF cap, the time constant (R*C) is 3.2 sec.  Five times the time
> constant is generally regarded as how long it takes to completely discharge
> the cap.  My bleeder is pictured here, 5th photo from the top:
> http://www.laushaus.com/tesla/sync_gap.htm
> 1/4W resistors are normally not recommended for HV, but having so many in
> series keeps the voltage per resistor to acceptable limits.  The important
> thing is to make sure that it's soundly constructed and wired to the cap.
> 78 Meg is higher than most multimeters can read so you need to be creative
> in verifying that sub-sections of the series chain are intact, thereby
> implying that the entire chain is wired intact.
>
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> On Wed, Feb 7, 2018 at 1:40 PM, dennis otmaskin <dotmaskin@xxxxxxxxx>
> wrote:
>
> I would appreciate some guidance on the proper bleeder resistor for a 35kV
>
> .003uF Maxwell pulse capacitor (#367667) or where I can go to find this
>
> info.  Thank you!
>
>
> Dennis, Hopkinton MA
>
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