Re: LED at 60 HZ? (was RE: Radio Shack Strobes)

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Willem Bosma" <wbosma-at-stud.tue.nl> 

When using a LED as a strobe light, use a high feed voltage e.g. 24 V
rectified, and swallow up most of it with high voltage zeners. Instead of a
resistor use a constant current scource. This can be a FET with the gate
connected to the underside of a drain resistor. The value of this resistor
(several 100's of Ohm's) sets the current thru the LED. Succes!
Willem
 >
 >  > Original poster: "Daniel Kline" <daniel_kline-at-med.unc.edu>
 >  > An engineering friend says a high-brightness LED on a
 >  > low-voltage transformer, like 6 Volts, connected through
 >  > a suitable resistance, should flash at 60Hz in sync with
 >  > the 60Hz mains. (50Hz for you all over there :)
 >  > It seems too easy to me...he thinks that the LED may have
 >  > a "persistence" issue. In other words, just because it
 >  > turns off quickly doesn't mean it stops emitting quickly.
 >  > Comments?
 >  > Thanks,
 >  > Dan K
 >
 >
 >