On Thu, 07 Jul 2005 18:44:55 +1000, you wrote: > At 07:36 PM 6/07/05 +0930, you wrote: >>On Wed, 06 Jul 2005 16:25:29 +1000, Mike Borgelt wrote: >>>A 20 watt light is hardly stunning, particularly against a glare >>>background >>>on a bright sunny day when the recipient is wearing dark glasses. >> >>I'm looking forward to seeing the Eckey ASH in its lightshow mode. >>Superbright LED lamps at 4W generate equal light output of 20W >>halogen dichroic. Their AC inverter is inbuilt in the lamp. > > Since when did LED's need AC inverters?
LEDs are best driven with constant current. The most efficient way (lowest battery drain) to do this is to use a switching regulator. there are several ICs specifically intended for this application, which use just a small inductor (the frequency is quite high) a couple of capacitors and a resistor or two to give constant current through the string of LEDs over a wide range of input voltage. John G. _______________________________________________ Aus-soaring mailing list [email protected] To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
