[sdiy] MG-1 first mods, VC res

[Roy J. Tellason]

On Sunday 31 October 2004 12:36 pm, Scott Gravenhorst wrote:
> "jamhoney" <jmahoney at gate.net> wrote:
> >> ... 35V is the MAXIMUM
> >> for all 78xx and 79xx regulators, except the 7824 and 7924.
> >
> >Can you cascade 2 regulators? Like, transformer --> 7824 --> 7815? I
> >believe it's okay, but...
>
> Well, you *can*, but the 7815 will get pretty warm.  These regulators
> are happiest with the input voltage just above the dropout voltage plus
> the regulator output voltage.  How much above dropout+output depends on
> several things, including ripple at the input.  I try to maintain input
> about 3 volts above the regulator's output voltage.  The more input
> voltage you apply, the more the regulator's shunt transistor has to
> "waste" current - creating heat.

Those are not shunt regulators...