From: Watson 'Atto Parsec' Name
Subject: Batt Charger 7905 discussion
X-Newsreader: MicroPlanet Gravity v2.60
Date: Sun, 15 Dec 2002 15:56:06 -0800
NNTP-Posting-Date: Sun, 15 Dec 2002 16:53:28 PST
Organization: InReach Internet
I made up this constant current charger after some design on the web.
But I used a 7905 instead of a 7805, because I've got a lot of 'em
laying around from scrapped SMPSes. And I've seldom needed a negative
5V supply. It works pretty good. I can switch between 50 or 150 mA.
But one question. Should the output lead to the battery have a 1N4002
in series to keep the battery's 6v from going back thru the regulator?
After a short while, the batts should charge up the cap in the wall wart
and no further current should flow. But when it charges up, it'll be
thru the regulator chip. In reverse.
See the pictorial in alt.binaries.schematics.electronic.
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you put NOSPAM in the
Subject: line. alondra101 hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html