Re: Hello again / New MOT coil (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Sat, 21 Jul 2007 13:49:11 +0100
From: Tom Trevethan <t.trevethan@xxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Hello again / New MOT coil (fwd)

Hi Jason,

What kind of diode strings did you use in your level shifter?
I decided to really go over-kill with 20 1N5408 diodes in each level-shifter
string and 40 diodes in the de-q-ing diode string (the 1N5408 are rated 
at 3 A,
unlike the 1N4007 at 1 A). The cost of these is tiny.

I have not had any trouble at all (with 14 kv DC coming out of the supply),
having run the coil for some time now.
I also have two air-cored filter chokes connecting the power supply to 
the tank
circuit, which may have helped. I assume you were using a charging choke?

Tom.

Quoting Tesla list <tesla@xxxxxxxxxx>:

>
> ---------- Forwarded message ----------
> Date: Fri, 20 Jul 2007 10:52:11 -0400
> From: Jason Johnson <jasonmsusolar@xxxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Subject: Re: Hello again / New MOT coil (fwd)
>
> Greg,
>
> In your diode friendly design, are you using the Mark III circuit shown on
> your website? Also, what kind of spark gap setup are you using with this
> power supply?
>
> Thanks,
> Jason
>
> On 7/19/07, Tesla list <tesla@xxxxxxxxxx> wrote:
>>
>>
>> ---------- Forwarded message ----------
>> Date: Thu, 19 Jul 2007 16:31:05 -0700 (PDT)
>> From: G Hunter <dogbrain_39560@xxxxxxxxx>
>> To: Tesla list <tesla@xxxxxxxxxx>
>> Subject: Re: Hello again / New MOT coil (fwd)
>>
>> Thanks for all the info.  I'm both pleased and
>> impressed you made it work using the low-voltage,
>> high-current AC approach.  I avoided this route so I
>> wouldn't have to deal with the problems you seem to
>> have solved.
>>
>> My level shifter had diode issues too at first, but I
>> was able to solve the problems quickly, and now my
>> diode strings have an indefinite life span.  I built a
>> second such coil and power supply for a friend, and
>> his exhibited the same reliability.  In other words, I
>> was able to make it work more than once.  I was so
>> confident about diode life, I sent him on his way with
>> no spares.  I don't think he'll need them.
>>
>> Nothing against level shifters, but I'm always looking
>> for a cheaper, easier way to use MOTs.  A 100%
>> silicon-free TC intrigues me, especially with so many
>> coilers going the opposite direction.  A 4200vac
>> MOT-powered, spark gap coil seems like a throwback.
>> That appeals to me.  If I ever get my workshop built,
>> I'll have to give it a try.
>>
>> Cheers,
>>
>> Greg
>>
>>
>
>
>