Quoting "Alan B. Pearce" : > >As for the comment made about breadboards being the worst way to > >go... keep in mind I'm just testing it now, I don't plan on boxing > >this up and using it with a breadboard :-) > > I suspect the problem is the breadboard. This is allowing all sorts of > horrible lead lengths at places they should not be, which is allowing the > switchmode chip to oscillate in all sorts of uncontrolled ways, and this is > what has destroyed your chips. > > The only way you are going to sort this is to go straight to a PCB which has > been laid out with current paths and suitable sized tracks straight off. > Then you will get something that will approach the stability you require. > Does veroboard have tracks suitable for this application? Seems to be my only option now, unless I reduce the capabilities of my supply. As to the type of inductor that I'm using, what is the 'correct' type? I wasn't aware that a special type of inductor was required for this application, so I would appreciate knowing what type of inductor I ned to obtain. Regarding Jochen mentioning that I need a bigger capacitor after the rectifier... do I really need something as big as 4700? The biggest cap I have seen used after a rectifier is a 2200 (at least looking at the example schematics on psu's). And yes, I did use heatsinks :-) While all these are great suggestions in improving my design, are any of these explanations as to why my regulator fried when I simply put in an appropriate resistor? It seems like all these suggestions could *improve* my design, but from what I understand, none of them seem to address why drawing 500mA would fry my regulator. I must be missing something. Nevertheless, thank you for all of your input thus far, Jai > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. > ---------------------------------------- This mail sent through www.mywaterloo.ca -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.