[Milsurplus] BC-474

[David Stinson]

----- Original Message ----- 
From: "Al Klase" <al at ar88.net>


> Meir and the Group,
> 
> I built a 12-volt supply based on a DM-64A dynomotor...
>...  You can see the schematic here:  
> http://ar88.net/skywaves/SCR-288_Power.pdf

That is very cool, Al!
I would add this:  put a 1/2 or 3/4 Amp fuse 
in the 1.5 V filiment buss.  After the fuse, put three 
(3) silicon power diodes in series to ground.
The diodes won't conduct unless the filament  buss 
goes over 2.1 Volts.  That way, if the LM-317 fails
(and they occasionally do), the fuse pops instead
of the tube filiments.  Cheap insurance.
73 Dave S.