I've seen that done before and have wondered why they didn't just use 4
AAs instead. Specially when in that case they were using a linear
regulator after the 9V source.

I would recommend using ORing diodes instead of a resistor though.

Shahid

-----Original Message-----
From: Jesse Lackey [mailto:jesse@CELESTIALAUDIO.COM]=20
Posted At: Monday, February 16, 2004 10:42 AM
Subject: [EE:] Using two 9V in parallel for greater capacity... ok?


Hello all,

I have a project that involves blinking LEDs that the client would like
to have run for 2 months per battery or battery set.

2 9V wired in parallel would do it and is preferable to 4 AA.

Is this a reasonable thing to do?  Is it dangerous at all if both are
fresh of the same kind?  How about if not?  Would a 5ohm resistor in
series with each before being wired in parallel alleviate any dangers
from users who don't follow directions?  (its a consumer product).  The
current is pretty low so the loss due to a small resistor is not a
problem.

Any advice?
Thanks ...
Jesse



--
"There are 10 kinds of people in the world; those who understand binary
and those who don't."

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads