If anyone has suggestions for inexpensive assemblies that are complete (with the exception of a standard battery) I would be most appreciative. I would also consider a very simple small bulb and socket assembly with standard electric cord.

If possible, please respond before February 15, 2010. But even after that date i would still welcome responses.

Thanks!

I, too, wonder about the frequency selection. the timing resistor remains the same, but reducing the capacitor to a smaller, hence cheaper, value would satisfy both flicker-reduction and lower per-unit cost.

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yea places like autozone probably carry old generation led type lighting. they aren't really a cutting edge type of place, and generally neither are their consumers. you can tell by the cheesy led flashlights they sell..5mm cluster garbage and all that. it'll take a long time for good stuff to trickle down to autozone/kragen type places

I should also add that I drive a Volvo, so the lights are on all the time...

Pulse-width modulation brightness control, however, is an easy and inexpensive way (in this world of supercheap ICs) to efficiently control the perceived brightness of LEDs. So if there's some regulation that says that trailer-truck side marker lights have to be between brightness X and brightness Y, I can see them using a PWM controller to dial the brightness of LED markers down to match the regulation.

(If there's no such regulation, I don't see why you wouldn't make simple little resistor-fed modules that plug into a standard 12V socket instead and run the LEDs at whatever brightness you happen to get. A bit less efficient, but the difference is zero from a truck's point of view.)

I've noticed that cars with LED brake lights often seem to run them at full, no-flicker brightness when they're actually braking, and in flickery PWM half-brightness mode when the lights are just on as driving lights.

I did not, of course, test this by waving my head around like an idiot while driving home the other day, endangering myself and others. I've no idea where you heard such nonsense.

1: Some very poor designs. Say, a circuit that ran the first kind of LEDs they put in it at full rated power and worked OK, but was then changed to use newer LEDs with lower voltage drop without changing anything else, resulting in horrible overdriving. Bonus points will be awarded if the circuit works such that the first LED to die increases the current flowing through the unfortunate survivors.

2: Nonexistent quality control. Particularly applicable to the bottom-feeding eBay dealers we all know and love. So lights with dry solder joints, lamps that aren't quite glued together, et cetera, head out into the market along with the ones that're properly made.

Not sure how you could test this though... any bright ideas Dan?