Cannot agree more with you on the power supply design. It only
serves the purpose of demonstrating the nice use of PIC 10F
as a SMPS controller but it can not beat a simple SMPS
controller. Since the maxim supply for this board is only
5V, a simple 9V supply with a 7805 will be the cheaper
and more robust design. 

If I use a 10F as a power supply controller I will put 
some over voltage protection in the output as well just
in case the 10F runs wild. The design already consider
the soft-start (with Q1, R1 nd D3, C5), why not put
a 6V2 zener after the 5V5 output? Maybe I will even put
a fuse (at least a resistor) in front for over current 
protection.

Xiaofan

-----Original Message-----
From: Jan-Erik Soderholm [mailto:jan-erik.soderholm@telia.com]
Sent: Thursday, May 19, 2005 9:02 AM
To: piclist@mit.edu
Subject: RE: [PIC] PIC prototype board comments?

Just thinking here...

*Must* a PSU for a rather small board have *that*
many components and beeing so complex. What happend
to the simple DC-in/7805-and-a-couple-of-caps type of PSU ?
Isn't that good enough for this kind of board ?

Otherwise, on the rest of the pages, I can't see any particular
problem right now.

...

Jan-Erik.
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