Altair 680 power supply...
ard at p850ug1.demon.co.uk
Tue Jan 19 14:43:00 CST 2010
> > It's all good--my idea of a "voltage regulator IC" used to be a 741
> > op amp feeding a darlington. :)
Of course the 723 is a referece supply and an op-amp (which you can use
to feed a darlington) ;-)
> Hey, there you go. ;) I'm a 2N3055 man, myself. You can arc weld
> with those things.
Ah yes. Good solid transistors. The PSU board of the plotter I am
currently repairing has 5 of them on it. One for the -15V logic supply
regulaotr, and 2 for each of the motor drivers (I would have expected an
NPN/PNP pair here, but I guess there wasn't a suitable PNP transsitor
available in 1959)
IIRC the 'modern' 2N3055 is actually a 2N3055H, you can't get the original
one any more. It doesn't matter for most applications, though. Either Bob
Pease or Jim Williams makes a comment in one of their books.
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