I connected my multimeter from +5 on the battery to the circuit and it =
reads about 75 mAmps.  I'm quite new to this, but that seems like a lot.

Since all the LED's are connected to a common ground in my circuit =
(already soldered), can I add a resistor between the cathode of the =
LED's to the battery ground?

-----Original Message-----
From: pic microcontroller discussion list =
[mailto:PICLIST@MITVMA.MIT.EDU] On Behalf Of Fred Hillhouse
Sent: Friday, June 04, 2004 21:11
To: PICLIST@MITVMA.MIT.EDU
Subject: Re: [PIC:] First Project Finished! But... it used up all my bat =
tree

Although many LED clocks have 9V batteries in them, usually the LEDs are =
off
if the AC power fails for some reason. The 9V battery only powers the =
'time
keeping' circuit, not the 'time displaying' circuit.

You may want to consider a 9V wall wart instead.



-----Original Message-----
From: pic microcontroller discussion list
[mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Lindy Mayfield
Sent: Friday, June 04, 2004 2:48 PM
To: PICLIST@MITVMA.MIT.EDU
Subject: [PIC:] First Project Finished! But... it used up all my bat
tree


Hi Guys.

I finished my first project!  Finally.  I got the idea from Mike =
Predeko's
book for the LED clock.  But I couldn't find the right parts to put =
together
the multiplexing for all the LED's, so I decided to work with what I =
have
available and made a binary clock:  20 small 3mm LED's that show the =
hours,
minutes, and seconds in bcd binary.

The design so far is simply a 9v battery, a 5v voltage regulator, a PIC
16f877, a 32.768 kHz crystal + 2 22pf caps, resistors and LED's, and one
resistor tied to MCLR.

The programming was fun.  Building and soldering the rat's nest out of =
wires
on the back of the board wasn't.  (-:  (Took 3 weeks.)

I left it running for a test last night and it sucked all the juice out =
of
my 9 volt battery in just a few hours.

Would someone give me hints as to how to figure out what the problem is =
why
it is using so much power?

Thanks in advance.
Lindy



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