<HTML><FONT FACE=arial,helvetica><FONT SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">In a message dated 2/27/2003 3:42:43 PM Eastern Standard Time, harrybissell@prodigy.net writes:<BR>
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<BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">Hi Bob:<BR>
<BR>
You need a series resistor and a zener (of course)<BR>
<BR>
Zener (or shunt) regulators are a good choice if<BR>
you only need a small current. They become very<BR>
wasteful of power at larger currents. They are<BR>
VERY stable and do not ever oscillate or overshoot<BR>
like linear regulators can...<BR>
<BR>
The 7805 (series) linear regulator is another good choice<BR>
for higher currents.<BR>
<BR>
If you contact me with the current you think you need<BR>
(you HAVE to estimate this if you want a successful<BR>
design) I can help you with the (simple) math to choose<BR>
the correct components.<BR>
<BR>
Rule of thumb (for me) I like Zener regulators below maybe<BR>
20mA tops... I prefer 10mA<BR>
<BR>
H^) harry</BLOCKQUOTE><BR>
<BR>
That's exactly what I needed to know. Great! Thanks!<BR>
<BR>
Robert </FONT></HTML>