Well, I've not had a close look at a Street Appearance Focus, but if I had the chance, I might be able to take a few notes. Can't guarantee anything, though
since I have all sorts of other mini projects on the back burner.
As for the side-discussion about Series vs. Parallel: How you wish to run your LEDs is your cup of tea. In this case, I use a parallel and series hybrid, because it's the simplest to layout and put together by hand.
Here's the problem: LEDs are supposed to be power saving devices. Therefore, it makes little to no sense to me to design a circuit with LEDs such that the resistors are dissipating more power than the LEDs, themselves. It is, indeed, a more robust, fault tolerant circuit, yes, but it's still a wasteful one.
If you want to rig up 24 LEDs in parallel, and assuming you design the circuit such that each LED has its own resistor to dissipate (14.5-3.3)V [so if only 1 LED dies, you have 23 still working] realize that you have 24 resistors wasting a ton of power. If were talking about your standard configuration of 3.3V, 20mA LEDs, then that's 480mA of current drawn... that's up there with the incandescent bulb you're replacing! In short, each LED dissipates 66mW whereas each resistor dissipates 224mW. Multiply each by 24 and see what I mean
Do note, you can rig up 24 LEDs in parallel but only use one big-ass resistor at the end of it. Realize, though, that for each failure thereafter, the remaining LEDs will have less brightness compared to the case where each has its own independent resistor. In other words, the resistance would be ideal for 24 LEDs, but is slightly too high for 23, and even higher for 22, etc, etc. But for a handful of failures, this is OK, as the elevated resistance serves as an extra safeguard.
On the other hand, if you rig this same set of 24 LEDs in series... well, you'll have to rig it up in a hybrid series/parallel mix. So you can do 6 parallel sets of 4 LEDs in series. Now, the drawback is that you lose the functionality of a "row" of LEDs should one of the LEDs in series die or be shorted, etc. BUT, you have much less current consumption - in this case, 20mA x 6, which is 120mA. And, when you calculate it out, the LEDs, this time, are consuming the bulk of the power, and the resistor(s) are doing very little because you're dissipating [14.5-(3.3 x 4)]V instead of the 11.2V from the parallel example. In this case, each set of 4 LEDs dissipates 264 mW while each resistor per row dissipates 27.2mW.
In this case, the same can be done like in the parallel example. Do a 6 parallel by 4 series LED array and have it all leveled off with one single resistor at the end of the circuit. Sure, similar to before, if you lose a row in this configuration, the remaining rows have less power... but you get that extra margin of current safety.
I won't get into special things like Voltage Regulators because I really don't have much experience with 'em. I did buy some 3.3V ones, which really could solve the resistor issue, but the problem is, these things will still get pretty hot if you start running half an amp through 'em. Getting hot is not much different than what the resistors do, so
Anyway, for the masses inquiring about the license lamps - I placed an order of 10 pairs. There's usually a day of delay in fulfilling my order, but I can only hope that the goods arrive at my door by this Friday. If not, we're looking at another 1.5 week lead time
The real hassle with a new shipment of OEM lamps is the work involved with taking them all apart and then coating the copper in the liquid tin solution. Then, of course, they have to be reassembled and finally I can make the circuit boards with LEDs and seal and solder. That's a quarter of a Saturday, right there
But I wanted to let everyone know that things are moving... and about half of the new ones are spoken for.
Re: My LED license lamp solution
frantic...awesome.
