Hi Melanie,

As usual, you're right. Having a large capacitor at the regulator's output probably wouldn't have posed too much of a problem with the regualtor I'm using (an LM2941) because it has built-in short circuit protection. I'm also using a supply supervisor which keeps MCLR low until the regulator's output reaches an acceptable/stable voltage. However, I should not tempt fate.

My original idea was that the large cap at the output would continue to supply the PIC with an acceptable voltage for a time even if the input suddenly died. This would give the opportunity to "get my house in order" before the input died. However, the large cap at the input will result in more or less the same thing. It will discharge slow enough so that if I consider 7.0 volts unacceptable, the cap will have about 1.5 volts or so to discharge before I start having problems.

Also, it allows me to even keep that cap off of my board if I like and connect it nearer to the power supply. For my purposes (delaying input voltage drop) this should be OK.

Thanks again Melanie.