Johnson Counter Style Turn Signal

[ChristianCMcKay]

So my cars tail lights comes divided into four rows, that (as of right now) just all light up at once. I've gotten the idea to make them flash in more of a Johnson counter sort of fashion.

Here's my idea in schematic form, and I just realized that I forgot to draw all the diodes as LED's. So forgive me for that.

**broken link removed**

I would use a 4017 IC

Q0 would be connected to pin 3 (Output 0)
Q1 would be connected to pin 7 (Output 3)
Q2 would be connected to pin 5 (Output 6)
Q3 would be connected to pin 11 (Output 9)

The resistors are in there for me to add a volt meter so I can have an indicator that one of my turn signal LED's is out. (Not shown in schematic)

The biggest part of this project will be fabrication, in all probability. This is just something I thought I would share with the forum.

 

[audioguru]

Does the car use 16 LEDs on each side in the turn signals now?
They all light up probably so they are bright enough. The outputs of the 4017 will light only 4 LEDs at a time so they will not be bright enough and will be illegal. It is illegal in many places to tamper with vehicle lighting.

 

[ChristianCMcKay]

Yeah, that's something I've noticed now. It's hard to find LED's strong enough to put out enough light. I suppose I'll have to go surface mount and have 16 on each strip.
Also, as far as I know, Mississippi doesn't have any laws against tamper with the light. Either that or they don't enforce. I seem mustangs with a setup similar to this a lot around here except it's more like this

B2 B1 B0
0 0 0
0 0 1
0 1 1
1 1 1
Then back to
0 0 0

 

[audioguru]

Some cars come from the factory with the waving blinker for bright enough turn signals.
A 4017 does not produce the wave, its outputs turn on one at a time.

 

[ChristianCMcKay]

Oh, right it is. Looks like I'll have to make a ring counter to make the waving blinker.

 

[OlPhart]

I use an LM3914 with the input fed by a resistor (56k) and a cap (1u) to ground. Takes about a second to full sweep. 10 stages, current controlled and 12 volt tolerant: a 1 chip answer. <<<)))

 

[ChristianCMcKay]

Well after some searching, I've decided that my idea would work if I could find LED's bright enough.

 

[audioguru]

Many bright LEDs are simply dim ones in a focussed case that makes a narrow beam. Useless for a vehicle.
You need bright LEDs with a wide beam.