Re: current limiting choke

To: tesla-at-pupman-dot-com
Subject: Re: current limiting choke
From: Jim Fosse <jim.fosse-at-bdt-dot-com>
Date: Thu, 13 Jun 1996 05:03:25 GMT
On Sat, 8 Jun 1996 12:25:02 -0600, Tesla List
<tesla-at-poodle.pupman-dot-com>, you wrote:

>>From jim.fosse-at-bdt-dot-comSat Jun  8 10:56:00 1996
>Date: Fri, 07 Jun 1996 06:39:13 GMT
>From: Jim Fosse <jim.fosse-at-bdt-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Re: current limiting choke
Earlier I posted:

>Start out smaller. It will get warm over several minutes, just let it
>cool. Mine weighs about 2kg +-.
>

>My first (and only one so far) is 1000 turns of #16/1.3mm, well that
>is what I started out to do! I ran out of the 1.3mm at about 400
>turns, wound another 100 turns using #18/1.02mm and then finished off
>with #22/.64mm wire. I used a 12"/30cm by 3"/7.62cm PVC form (plastic
>water pipe, large;) I filled the form with all the I sections from
>some old transformers that I haven't built yet. About 3.8cm by 3.8cm
>by 18cm. The air core inductance is about 1mH, the iron core is about
>9mH. I also use 10 ohms of resistive ballast in parallel.
>
>The 0.64mm wire got very hot very fast. To hot to touch in 2 minutes
>at 10A. I removed it and replaced it with bifilar #19/0.9mm SCE wire.
>(the only size larger than #40(hair size) at the surplus store;)
>
After Kristian and Harri questioned my on this, I did some checking. I
found that my Pig/spark gap were acting as the ballast for my choke.
Without them in circuit, I get about 60A and start to smoke the choke
in 5 seconds! I couldn't believe that was smoke, so I touched it:
burnt finger.

Harri and Kristian, I apologize for posting without verifying my
numbers first.

	jim