24 Jul
2012
24 Jul
'12
2:16 p.m.
The ripple is on the output. I figure the filter cap is causing the problem.
As for the "sent from my iPad" bit, that's just a signature the iPad adds as
a default. I've been too lazy so far to change it. I've updated it with my name
and callsign.
--------
Paul Anderson -- VE3HOP
On 2012-07-24, at 2:59 PM, ard at p850ug1.demon.co.uk (Tony Duell) wrote:
You're right, it is an emitter follower with a full-wave rectifier.
The ripple is quite bad, I figure it at 3.5%. I'll have to hunt down an
appropriate capacitor.
Is that ripple on the input or output? If on the output, you need to do
some reapirs. If o nthe input, it migth be OK. Provided the input votlage
to the regualtor circuit doesn't drop too low, the output will be stable.
What is 'too low? Well, the zenner still ahs to pass enough current to
regulates, the emitter follower needs enough votlage o nthe3 collector
for the emiter to be able to remain at 5V. But I would hav eguessed that
if the input always stays about, say, 7V, you won't have problems.
Sent from my iPad
Why does anyone need ot know this?
-tony
(Sent from a classic IBM 5170)