DIY LED Tail Lights

[S14DB]

Originally Posted by dsastr_clan

how could i do a progressive signal light, for example on the 300zx the turn signals are big and long. I would like to make it so when i signal the blink from the inner side of the tail towards the outside, how could i accomplish this?

I wouldn't do it. They are now illegal.

NHTSA Interpretations 2003-FMVSS 108 Related:
Sequentially illuminated stop and turn signal lamps are not permitted. All light sources must illuminate simultaneously. During the initial stage the stop and turn signal lamp would not comply, in this case, with the minimum luminous lens area requirement. Additionally NHTSA does not consider lamps with a changing illuminated area to be steady-burning.

[t_rempel]

^ What about the recent mustangs with oem sequentials? Was Ford able to get an exception?

[supersayianjim]

this I would also like to know??

[Digi7ech]

^perhaps the first initial turn lamp is sufficient enough "Space/Lumen" to cover this clause and the rest illuminating is excess?

[Digi7ech]

Man, NHTSA is a buzzkiller.

One of the notices in that letter is that you have to use Original headlights. Which means anyone doing H4 retrofits instead of sealed beams are illegal.

HID retrofits are illegal but that's been pretty obvious for a while.

[Digi7ech]

For people wishing to do sequential turns for track cars/Off road vehicles which do not require NHTSA certification...

There are two ways. Using a simple Decade counter logic chip(4017) and a timing chip(555).
THen there's the super cool way. Using a PIC or Arduino type chip to control arrays of led's or each one individually.

Here's my S4 FC turns I'm looking into. Uses 4017& 555 timer to control banks of led's at an adjustable frequency(to fit the on/off power pulse from stock harness). I use SCR's to keep each bank triggered so they stay on after each clock pulse.

[S14DB]

Originally Posted by Digi7ech

^perhaps the first initial turn lamp is sufficient enough "Space/Lumen" to cover this clause and the rest illuminating is excess?

Yeah, The center lights usually stay on and the outer lights just chase. The other method is to turn them on progressively so that you are keeping the minimum light on and just adding to it. The OEM's determine what is sufficient.

The reason this came up was the company's that sold the sequential kits for the 99-04 Mustang would do a chaser sequence(1,2,3) like the old cougars. None of the lights would remain on and the cheap kits wouldn't stay in phase and were confusing.

[Digi7ech]

Got some prototype boards in the mail to play with.

S4 FC tails in the works. Needs a little trimming but otherwise they fit.


Here's a half bread boarded video of the sequential turn signals. I didn't have all the components on hand so the timing circuit was on bread board at a static rate. The IC was sinking the current to the scr's so they wouldn't latch on. I've since put a board together and they stay lit once the scr is signaled.
https://www.youtube.com/watch?v=HON5H2MjwbQ

[moebiius]

^^^very nice!!!, u have any updates?

[Digi7ech]

Put the test set together and had them at Sevenstock last month.
Still working out an issue with the load resistor killing off the power cycle to the turns. Going to look at modifying the stock flasher circuit on the FC's to not hyperflash with LED's.

video of them working
http://instagram.com/p/vhvxpolJw5/

[moebiius]

OH SNAP! you've got a fan club too!!?? sign me up! All that said, you good sir, has done a pretty legit job...JDMness if you will with a touch of USDM style, I would buy!

[Digi7ech]

I just wanna do hoodrat stuff with my friends
https://instagram.com/p/7w7eBalJ0T/

https://www.youtube.com/watch?v=N56Jp79KnYQ