I'm working on a stroboscope; the LED's frequency will be until I find the fastest one that causes stop-motion in the object under test. I'll include an LCD to display the frequency, and then the frequency of motion of the object under test will be known. As far as I know, an electronic flash has a duration under 100uS. I realize that I'm undershooting it by an order of magnitude, but I thought that would still be enough for the eye's retension, and would give an even better stop-motion effect for higher speed objects. As I mentioned, I'm not really sure what on-time I will end up using. If 10uS is too short, I'll be able to increase it in software (hopefully without blowing the LED). I built a very similar project several years ago using a xenon tube. I never really used it much because it was big and bulky, couldn't run off batteries, and didn't have a digital frequency readout (I had to guess based on the position of a pot). The main problem was I never found a suitable enclosure and I was uncomforntable holding an exposed circuit board with 340 volts at decent current and much higher voltage from the trigger transformer. This LED-based project should solve all those problems and if I find a small LCD, fit into a pocket-sized enclosure. Jason From: "Lawrence Lile" Sent: Thursday, July 29, 2004 5:21 AM > You probably won't be able to SEE 10uS pulses, I hope you are trying to > accomplish something else with these LEDs. What is the purpose? -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu