DEC H744 +5 supply

Mattis Lind mattislind at gmail.com
Fri Sep 21 15:08:20 CDT 2018


The H744 is a buck converter. You can read about buck converters here:
https://en.wikipedia.org/wiki/Buck_converter

You have a good description there.

Den fre 21 sep. 2018 kl 22:03 skrev Noel Chiappa via cctalk <
cctalk at classiccmp.org>:

> Oh, one thing I forgot to include:
>
>     > a lot of the incoming power in that 30V AC has to be thrown away, in
>     > producing +5V.
>
> So, if my understanding is correct, the 'switching' H744 really isn't much
> better than a classic linear supply. It still wastes a very large amount of
> the input power, and it still has a massively heavy transformer in it. Yes?
>
> So I wonder what exactly the advantage was in going to the switching
> approach?
> Yes, it keeps the output voltage steadier then a pure linear supply could -
> but I'll bet there are analog approaches that can do the same. (They'd need
> something that can produce a steady reference voltage, but the switching
> approach needs, and has, the same thing.) Maybe the main output transistors
> are happier being full-on or full-off, or something like that?
>
>     Noel
>


More information about the cctech mailing list