>> I think they use IGBTs to control the flash current (interrupt it >> before the photoflash cap is discharged too much). IGBTs are >> generally a more appropriate choice than MOSFETs in this kind >> of application. I think inductors/chokes come into it somewhere too. Not as the primary switch (if I can invent such a term) but to limit current -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist