I'd modify the circuit like this...



|----serial LEDs(3?)----Resistor----+12V
|----serial LEDs(3?)----Resistor----+12V
|
| repeat as necessary...
|
|----serial LEDs(3?)----Resistor----+12V
--------- |----serial LEDs(3?)----Resistor----+12V
| | |
| LM555 |------|
| | |-----gnd
--------- IRF2804

By putting the LEDs in series instead of parallel you'll cut the
current drain by 2/3 (in the case of 3 leds series). Also with each
leg having its own resistor the LEDs don't have to be matched by
forward voltage.

Regards

(Jeff Peterson) wrote in message . com...
Eric Jones wrote an nice description of leds as nav and strobe lights he

http://www.periheliondesign.com/down...ing%20LEDs.pdf

the rear and side strobes are fairly easy do with about 5 ea 5 watt luxeons

i used 6 in my tail strobe.

the required strobe intensity in the forward direction is a bit
tougher to accomplish with LEDs. still possible.

i think for my tail strobe i will uses 50% duty cycle.
not as "flashy" as a quick pulse, but actually easier see at a distance.

the human eye averages for 200 ms so for quick pulses its the
total light energy in the pulse that matters. stobes cant make long pulses
but LEDs can, so long pulses are the right choice with leds.


circuit will be like this

IRF2804
---------
| | |----parallel LEDs----Resistor----+12V
| LM555 |--------|
| | |-----gnd
---------

the 2804 is WAY overkill. it can switch 100s of amps. but its only 3 bucks,
so why not use the best.

i ordered a handful and when i get back form snf i will give the circuit a try.

-Jeff