DIY Taillight sequencers for $5-$6
 

I've recently started making and selling my own splice-in sequencers. The ones I personally make are on proper fabricated circuit boards and have an auto-calibration feature (no pun intended) for any speed of flasher. These however cost $12 and REQUIRE A PIC PROGRAMMER (around $80 if you don't have one) as well as some more detailed electronics knowledge.

FOR EVERYONE ELSE: Since I got a whole lot of interest at my local Mustang club selling these, it occurred to me that maybe people on here might like super-cheap sequencers too.

I have designed a splice-in sequencer circuit that would cost around $5-$7 to make and requires nothing but a bit of soldering to build (and maybe a little math to find the right resistor value to match the speed of your flasher).

Is there any interest in this? I have no problem doing up the schematics and maybe even a picture tutorial, but I won't bother if there's no interest.

That sound cool!!! go for it :tup

I think it would be appreciate from many of us..

I figure I probably will. It wouldn't take much to do. However this "easy" version is a concept at the moment. I'm waiting on a few parts from ebay (probably a couple of weeks) to make 100% sure it works, and then I can take pictures of assembly also.

I also forgot, add about $3 to the price I said before, you have to get a part off ebay to be able to add a Major wire to your two inner brake lights.

I'll post when I have 100% confirmed the design and have a tutorial done.

:cheers:

Interesting!

Is the time for the sequence determined by the R/C time constant?

To make math simple and to avoid one thing I'm concerned may or may not be a problem, I'll be using a pair of 555 timers. A quick google for "555 timer calculator" should bring up plenty of web apps that make it easy to find the resistor value you'd need (you probably only have to change 1 resistor from whatever I decide on for the stock one to get a custom speed).

The two 555s will feed into a CD4001 which will act as a pair of latches, and those will drive an IRF9540 Mosfet to switch the actual lights.

Pricing thus being approximately:
555 x4 = $1
CD4001 x 2 = $1
IRF9540 x 4 = ~$5
Pins to upgrade the minor/ground "inner" taillight to have major/minor/ground = ~$3

I'll post more, including ebay links for all the parts, once I'm done testing this to make sure I haven't overlooked anything!

VERY interesting. I'm looking forward to following this.

Just a quick update that rather upset me the other day: Mustangs made in November '05 or after have a type of taillight socket that can't easily be upgraded to have a third wire for Major. These people will have to get a taillight harness (only one would be necessary) from a local scrap yard and simply replace the third taillight instead of adding a wire to it. Since each side of a wiring harness has 2 fully wired sockets, you will only need 1 side to get both sockets.

Cheers

Used the 555 Timer lots when I was in college (many years ago). Major problem is that the stock flasher( which can be modified) ultimatly determines the time that the sequencer can operate in.

Yes, this is why I'll try to post values for a stock flasher and suggestions for modified ones. If you see here it's not hard to modify a flasher though. I personally have an 8.6uF cap for mine (just a 6.8, with the original one removed) and I love its speed. But this is why I opted to make the sequencers I sell self-calibrating to your flasher speed :)

It's possible to have a slow sequence taillight and normal flasher speed, but again it would involve a more advanced circuit (like the ones I personally make) as well as an always-live line run from the battery.

(Can't find the Edit button...)
That's 6.8uF, not 8.6. Just to clarify.

Unfortunately I have made a monumentally moronic mistake. The circuit will actually require a CD4011 instead of CD4001. I was under the impression that a 555 timer started low and pulsed high, however it is apparently the other way around so the circuit will need a NOTSR latch instead of an SR latch. This means instead of NOR gates, NAND gates must be used. Since the 7400 NAND chips I have are not pin compatible with the CD4011, the best I can do right now is some schematics and diagrams if anyone can build a circuit from a diagram rather than a picture. I'll post what I have in the next day or two for people to see :)

So, no diagram?

I'm truly sorry for the wait, I know I've sort of abandoned this thread for a while now. I'm afraid the parts arrived and due to a timing glitch during the 555 startup, the circuit doesn't work yet. I am hopeful that I will be able to fix it, but I started a new job in January and I've been very busy since. I got a PM just yesterday from another forum asking for this also. Since my work hours have finally settled and I now have 3 day weekends (Tuesday-Thursday), I'll do my best to work on this during this week. Just as soon as I have evidence that my circuit will actually work, I'll post stuff for people!

The 4520 counter chips just came in today so hopefully on my next weekend (Tuesday) I'll be able to put this all to rest and prove once and for all that it's all 100% working and doable. Then I'll do some pictures and board layouts.

For anyone who happens to be fluent in circuit design, I've attached the Eagle schematic and board layout (the board layout should only be used for a rough suggestion, as Eagle only does PCB layout, not protoboard).

Please note the file says .pdf, but it is actually a .zip file (this site seems to prohibit uploading zips?). Rename it to .zip and the project files are in it. To avoid any finger-pointing, there is nothing executable in the zip, so if you need Cadsoft Eagle just download the free version from Google.

Alright now, as some of you may have guessed, I simply have given up on these for now. THEY DO WORK! I prototyped some on a breadboard and they worked just fine. However actually building the circuit and trying to explain how to do so is far too tedious.

SO. Anyone with electronics knowledge sufficient to read a schematic and build a prototype from it, I have attached schematics. As above, they are in a zip file renamed to .pdf so that I can attach it to the post. Use EAGLE schematic editor to open the diagrams (free version works just fine).

ANYONE ELSE can *try* downloading the attached file. You must rename it to .zip and inside you will find a file called GERBER.zip. These are the gerber files for the circuit boards I designed based off of the included schematics. Look in the ReadMe.txt for a fabricaton site which will ask for the gerber files. I cannot guarantee their accuracy as I haven't ordered and tried them myself, but I am fairly confident they work. If you order some and they do not work properly, look at the ReadMe.txt to contact me and I'll try to diagnose the issue (whether you made a boo-boo, or whether I boo-boo'd in the schematics). The parts you need should be easy to find on eBay (except the resistors/capacitors - I suggest buying a set of each and messing with the values to get the speed you want).


If anyone has any questions feel free to post or PM me. I hope these work well and I hope they help someone in the future. If anyone decides to build them (especially if you use the circuit boards, which I HIGHLY suggest as PCBs are SOOOOO much better than protoboard, and in the ReadMe I give a link to a really cheap place to get them made - about $13 for 10) please post results!