[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [TCML] charging reactors



Hi Jim H., Jim M.,

I think Jim Mora's idea of using the HV side of a PT or a
pig and ignoring the LV side would be a good solution to
this situation. However, IIRC, the original poster of this
thread was looking for something that could withstand
10 to 20 kV AND 1 to 2 amps. So, that would probably
leave out a PT or a SMALL pig. Maybe the HV side of
a 15 or 25 KVA, 14,400 volt pig would fit the bill?

David Rieben



----- Original Message ----- From: "Jim Harvey (UDN)" <harvey.james@xxxxxxxxxxxxxxx>
To: "'Tesla Coil Mailing List'" <tesla@xxxxxxxxxx>
Sent: Tuesday, March 03, 2009 8:25 AM
Subject: RE: [TCML] charging reactors


Has anyone here ever wound their own charging inductor?

The laminations, core bobbins, etc., etc., should be readily available.
Using an E core would facilitate tearing it apart and starting over if you
didn't get the HV insulation just right.

My thinking is that winding such a core is less labor that hunting the earth
to find one that meets the spec.

Just a thought...

73 & Stay Vertical,

Jim Harvey (W7YV) - The Great Curmudgeon



-----Original Message-----
From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf
Of Jim Mora
Sent: Monday, March 02, 2009 11:45 PM
To: 'Tesla Coil Mailing List'
Subject: RE: [TCML] charging reactors

What about a beefy HV transformer secondary say a small pig or PT?
Jim Mora

-----Original Message-----
From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf
Of bartb
Sent: Monday, March 02, 2009 6:58 PM
To: Tesla Coil Mailing List
Subject: Re: [TCML] charging reactors

Good points Ed.

You know, I've been a crappy guitar player since I was 5. With that
experience, I couldn't help but look at Hammond Manufacturing when Jim
mentioned the "charging inductor" (many good tube amps use Hammond RF
Transformers). Hammond does build a 5H 500mA choke which would suffice for
this application if it were not for the high voltage. Voltage is a big
problem here with the charging inductor. In order to create the voltage
winding standoff, the insulation thickness becomes a burden on winding a 5H inductor. Even the 5H 500mA choke Hammond produces (193P) is about the size of a hefty MOT, and it's rated at only 800V. It's not an easy assignment as
stated earlier. Digikey offers the 193P at $170. I can't imagine what a 10
to 20kV version would run if there were such a beast.

Regards,
Bart



Ed Phillips wrote:
I hate to be negative but you're talking about really serious chokes
here and nothing you can do with "several hundred turns on a U core".
You want a lot of inductance with a lot of DC flowing through the coil
and that's something you're not going to get by casual
experimentation.  I would guess you'd need a high-quality transformer
iron core with cross section of at least 4 square inches, a fairly
large air gap, and lots of wire with special attention to insulation.
You can probably find power inductor design information on the web if
you hunt around.  If you can find something meeting your
qualifications for $50 that would be a super bargain!  I'm looking at
a 1958 Stancor catalog and see that a 6 henry, 500 ma choke has a base
size of 5-5/8" x 5-1/2" and is 8-1/8" high.  Shipping weight is 24
pounds and list price 50 years ago was $54.00.  A 10 henry, 1 amp
choke from UTC is 4-3/4" x 6-7/8" x 10-1/2" and weighs 40 pounds.  Net
price was $40 half a century ago!  Neither of these transformers is
designed for high pulse voltage across the windings and that would of
necessity require more insulation with more iron and more copper.

Good luck,
Ed
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla


_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla