Re: MOT mod.

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: BunnyKiller <bunikllr-at-bellsouth-dot-net> 


Hi Chris...

considering that most MOTS have about 105 winds for primary and 3 winds for 
the filament ( which produces 2.8 -3.2 V)  I would suggest wrapping 6 winds 
on the transformer ( should give 5.25V) . With the secondary gone it should 
be easy...  use either a #10 or # 8 solid copper THHN wire to do this ( 
going thicker is an option too if you have the room) . Amperage output 
should be capable of an easy 12 + A. ( theoretically it should be 160 
A  but core saturation keeps that from happening) either way dont directly 
short the filament wires once its on the transformer...   gets hot fast...

Scot D



Tesla list wrote:

>Original poster: "Christopher 'CajunCoiler' Mayeux" <cajuncoiler-at-cox-dot-net>
>
>In an attempt to throw together a tube style TC, I have
>determined (mainly by the state of my finances) that I
>will need to modify an old MOT to supply the 5 volts
>that the tubes use.  After about an hour of work, and a
>massive quantity of frustration, I was able to fully
>remove the secondary winding, and the original filament
>winding, leaving the MOT's primary and shunts unscathed.  Now I need to know
>how many turns of wire to insert into
>the MOT core to get the voltage and sufficient amperage to
>run the tubes.
>
>The tubes are a pair of 4-125A (Sylvania) radial beam
>power tetrodes, wired in triode mode.  The specs say the
>filaments require 5 volts -at- 6.5 amps.
>
>I'm sure with the huge collective of experience there is
>in this list, someone must have a pretty good idea of
>what I need to do to get the job done.
>
>Help!
>---
>C.L. Mayeux
>Owner, MSB Data Systems
>http://www.msbdatasystems-dot-com
>
>