Chris Eddy wrote:

> Associates;
>
> I have a PIC that must live off of a 220uF cap for 7 seconds.  I can get
> the PIC to consume low power,

O.K.  What is the current the PIC consumes?

> but I am having trouble getting the
> regulator designed.  The 78L05 sucks 2-3mA Q current, way too much.
> Looking for 50-100uA.

Do you mean you can stand a regulator burden of 100 ua?

> The low dropout regs are neat, but they have a
> very limitted Vin max.  I need 30V.  I built a pass regulator with a
> res, zener, and NPN trans, which meets my goals, but since the current
> through the zener is low, then as the V on the C drops off, then the V
> on the zener drops off, and the V on the PIC droops as well.  This
> causes the RC osc to skew, and my highly important timer gives me
> predictable garbage!
>
> Any great ideas?

Yes, but I need more info.

>
>
> Chris Eddy
> Pioneer Microsystems, Inc.

--
Thomas C. Sefranek  WA1RHP
ARRL Instructor, Technical Specialist, VE Contact.
http://www.harvardrepeater.org
http://hamradio.cmcorp.com/inventory/Inventory.html