Fusion Message Board

In this space, visitors are invited to post any comments, questions, or skeptical observations about Philo T. Farnsworth's contributions to the field of Nuclear Fusion research.

Subject: Re: Home Made Spot Welder
Date: Jun 21, 11:10 am

On Jun 21, 11:10 am, wrote:

>>2. A really superior SCR would be needed to handle the discharge firing along with some snubbers and other anti kickback protection circuitry. Looking at ratings for the SCR seems simple. In practice, the 1000 volt plus pulse at 100 or more peak amps into a totally inductive load is a duanting task for the survival of the small silicon pellet switch. Regardless, I would think 80 joules should be the absolute limit of the stored energy.
>>40 joules might be better with a superior output transformer.
>>Naturally, let us know how it works out.
>>Richard Hull
>Thanks for the comments Richard. I was just wondering, do you know how the commercial welders
>handle the pulse switching.
>Maybe some sort of gas tube thyratron would be more appropriate.

Why not just a use a spark gap type trigger
if you can't find a tube. The main disavantage
would be the slow time for air gap to restore
it self, but with a slow charge time for the caps
that may no be a problem.