On Jan 3, 2009, at 3:41 PM, Jinx wrote:

> 0.5 - 18V example on page 9 of the 78L05 regulator datasheet.

Now I see where the negative voltage Olin was speaking of comes into  
play.   A mite more complicated than the proper solution, which would  
be to use a lm317 or the like.

> http://www.robotstore.com/download/51182.pdf
>
> You can make -5V with an oscillator (555, PIC pin, bistable etc)

A couple years ago, I used a 555 as the oscillator for a 170v Nixie  
supply.  Despite it being over 30 years old, it's still a versatile  
chip.

Joe

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist