At 13:01 25/06/99 +0200, you wrote:
>> Van: Stewart Pye <stew@UQ.NET.AU>
>> Aan: PICLIST@MITVMA.MIT.EDU
>> Onderwerp: Battery Power Supply?
>> Datum: vrijdag 25 juni 1999 10:30
>>
>> Hi All...
>
>Hello Stewart,
>
>> I'm doing a project with a PIC16F84 that I want to run from batteries.
>The
>> person I'm doing it for would prefer to use a 9V battery. My question is:
>>
>> Should I use a 78L05 regulator, or resistor voltage divider, or
>> resistor/zener diode?
>> Which one would consume the least current. I'm guessing a 78L05 would be
>> the way to go. Any Ideas?
>
>Not a good idea.  Your 78L05 would consume about 4 to 5000 ! times the
>current the PIC would take.  A PIC run's well on 3 volts.  Why not take 2
>penlights, put them together in a case with contacts on top like a 9 volt
>block (available in any electronics store) and use them like you would a 9
>volt block ...
>
>Greetz,
>  Rudy Wieser
>
>

Also not such a great idea. Unless the contacts and the package are totally
different
from a 9V battery, you can be sure that sooner or later someone will try to
fit 
a 9 Volt battery into it.

Linear Technology make what they call Micropower switching regulators (LT1073)
They cost IR£5 in single quantities according to my Farnell catalog. I've
never used them so I don't know what the quiescent current consumption is.  

Joe