Re: Big Triode Tubes

To: tesla-at-pupman-dot-com
Subject: Re: Big Triode Tubes
From: Jim Fosse <jim.fosse-at-bdt-dot-com>
Date: Sat, 07 Sep 1996 03:40:03 GMT


>From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
>To: tesla-at-pupman-dot-com
>Subject: Re: Big Triode Tubes
>

>> Dan,
>>     How about a "blown" neon for the filament supply? 7.5V -at- 65A
>> is 12 turns of #4 on 1 half of my dead jefferson 15kV 60mA neon.
>> Winding the other side with the same number of turns will give you
>> 7.5V -at- 130A. You could also put half as many turns on each side and
>> then put them in series to put the center tap to ground.
>
>You could pop a heater winding on one leg and a suitable HT winding 
>on the other for an all-inclusive compact supply. The insulation 
>should certainly be there.
>    I wonder about the wisdom of using the shunted core for a 
>filament supply though. Seems to me that voltage regulation will be 
>rather poor.
>
Malcolm,
	The regulation will be poor, if one tries to run the xformer
near it's power limit. If one runs it below that it should be better,
particularly given tungsten's 10:1 resistance change over temp.

I just reread and rethough the previous paragraph. I'm not sure how
poor a shunt limited xformer's regulation really is. A test is in
order.

	Regards,

	jim