At 07:00 AM 6/24/97 -0500, you wrote:
>>
>>My challenge is this.  I would like to hear about all of the low power
>>'successes' out there, and how you did it.  Good books and tales are hard
>>to come by, so I hope to pick up a few tricks here.  The prize amounts to a
>>heartfelt Thanks!
>
>...
>Other tricks: If you are using batteries, try to use a voltage the circuit
>can use directly without a regulator. Regulators use power. If you must use
>a regulator, pick one with very low quiescent current. Switching regulators
>can be more efficient than linear ones if  you have high current needs from
>time to time but usually have higher quiescent current draws.  Many of the
>new switcher circuits have shutdown control pins that can be operated by the
>micro.
>
>
>- Gary
>
One other note on low power. If you _have_ to use a regulator be carefull
which one you choose. I did a design for lighting control which stole power
from the line to the safety ground, and which terefore had to be limited to
a few hundred microamps maximum. Our first try using a low quiesent current
regulator showed that when the regulator starts up, the current draw is
initially quite high ( a few milliamps) until the inout voltage was a volt
or so higher then the output. This caused our system to hang up. Nowhere in
the data sheets was this mentioned.

Mark Walter
M Walter