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Re: 4-125A, vacuum tube do's and donts



Original poster: "Wall Richard Wayne by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rwall-at-ix-dot-netcom-dot-com>

Matt,
 
Don't worry about filament amps.  That's built into the 5 vac requirement.
Best way is to use a small couple of amp variac feeding a filament 
transformer with 5vac sec .  When filament is fully lit and heated, tune 
variac for 5 vac across filament.  If you need to light more than one filament,
tune the variac up a bit until you get 5 vac.
 
Rick
>
>  
> Also,any way to hold the filament at 5volts?Maybe I could use a regulator for
>
> DC?I could rectify the output and feed it into a regulator circuit for 5volts
>
> dc.It would need a lot more though since it will pull 6.5amps.Also, it says 
> it draws 6.5 amps.Does that mean it DRAWS that or thats the MAX and goinmg 
> over kills it?Would it be wise to limit it to 6.5amps and no more?I hear its 
> thoriated tungsten.Is there a special deal I have to do to it?
>  
> MAtt
>