Would this work?

[Justin98TransAm]

Tryinig to make a custom LED array for my taillights that will function as Taillights, Brakes, and Sequence Turn signal

This may not be the best way to accomplish something, but I'm trying to create a circuit with my limited knowledge of components. I started off with this circuit as a base point https://www.aaroncake.net/circuits/chaser.htm and modified it to this circuit.

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My LED arrays aren't 100% decided on at this moment, but most likely each one will contain about 25 LEDs (3.2v~3.6v 20mA)

as for the "red question mark" is there a way to make a transistor or maybe a "NOT" gate that will turn off when it is supplied with voltage?

That's all the info I can think of at the moment. Please help, I could use the learninig experience, and suggestions.

Thanks,

 

[audioguru]

Hi Justin,
The 4017 has a small output current, 10mA if you're lucky. Since each of its outputs is driving strings of LEDs that must share the current, each LED will get only a couple of mA or less without having transistors to boost the current for each output.

When power is applied to a 4017 that isn't reset, it might start counting on outputs you aren't using, causing a delay. You can make a "power-up reset" with a couple of diodes and a resistor and capacitor. Then it will start its sequence on the 1st LEDs every time.

A PNP transistor can be used to switch the Brake line. Power to the blinker circuit will turn it off.
Is it legal to sequence all the lights for one side without also having a separate brake light there?

When the tail lights are turned on at night, the sequencing turn signals won't work. You will need another PNP transistor to switch off the tail lights when the blinker is on, like the Brake line above.
When the tail lights are on, the brake lights will be brighter since they are fed more current. Maybe the brake lights should also switch off the transistor for the tail lights.

You need more diodes to make complete "OR" gates. The way it is now, you are feeding power to the outputs of the 4017 when it is on or off.

LEDs shouldn't be paralleled. Each string should have its own current-limiting resistor. Because each LED will have a different voltage than the others and if paralleled, the lower voltage LED will hog the current.

 

[Justin98TransAm]

sweet, this is the kind of feedback i'm looking for. as per your question about legality, that is the way the factory brake/blinker is setup, if you are braking and turning at the same time only the blinker shows on the side you are turning, the opposite side and 3rd brake light stay on at all times however. This diagram would be for only one side, there would be an identical circuit on the other blinker.

Does this diagram look like it can be made to work for my purpose?
Do you see an eaiser way?
What would you suggest for the given LED specifications and assuming there are 25 per array?

 

[audioguru]

Hi Justin,
It's too late now over here for me to figure current and parts. Tomorrow.
He, he. Shouldn't the 3rd brake light indicate only when you are in a 4-wheel drift? It seems that it would be a blur if you were just spinning around!

 

[Justin98TransAm]

Hi Justin,
It's too late now over here for me to figure current and parts. Tomorrow.
He, he. Shouldn't the 3rd brake light indicate only when you are in a 4-wheel drift? It seems that it would be a blur if you were just spinning around!

haha, no you must be in a different country, 3rd brake lights in the U.S. are just for more visability they work just like a normal brake light.

i've changed he diagram a little how's this look? also which type of PNP transistor? I assume B would connect to the "blinker" E would connect to the Output, and C would connect to the Brake? but that would be on when the blinker is on right?

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[audioguru]

Hi Justin,
I'm on the same continent as you. I think my 3rd brake light flickers a bit when I'm in a 4-wheel drift! I use my handbrake to turn on a dime.

Hey, are you one of the the guys who blinds me every day with high-beam daytime running lights? It seems that only big trucks and SUV's, and swivel-lights like yours that need adjustment use high-beams in the daytime. Even when dimmed, they shine all around and blind everybody. My new car uses dimmed low-beams in the daytime and can be seen just fine (I hope).

Aren't cars complicated for the average stupid Joe?
1) Too many pedals to get mixed-up. Go or stop. What's the difference? Many people drive into stores or just drive with both pedals down.
2) Too many clicks on the light switch so many people drive at night with dimmed high-beam daytime running lights and "parking" lights. They can't see the road, but they see their lights reflecting off the back of the neck of the guy (me) in front of them!
3) A turn signal switch that goes up and down instead of left and right. How confusing! When I see a rare turn signal, I wait to see which way they turn.
4) Steering that's backwards when driving in reverse. How dumb! Many people back-up on the highway when they miss their exit.

I won't go on anymore about people who never check the oil or who put the wrong "antifreeze" into the wrong container. Many people drive smoking cars with glycol "salad dressing" on the windshield!

 

[Justin98TransAm]

Hi Justin,
I'm on the same continent as you. I think my 3rd brake light flickers a bit when I'm in a 4-wheel drift! I use my handbrake to turn on a dime.

Hey, are you one of the the guys who blinds me every day with high-beam daytime running lights? It seems that only big trucks and SUV's, and swivel-lights like yours that need adjustment use high-beams in the daytime. Even when dimmed, they shine all around and blind everybody. My new car uses dimmed low-beams in the daytime and can be seen just fine (I hope).

Aren't cars complicated for the average stupid Joe?
1) Too many pedals to get mixed-up. Go or stop. What's the difference? Many people drive into stores or just drive with both pedals down.
2) Too many clicks on the light switch so many people drive at night with dimmed high-beam daytime running lights and "parking" lights. They can't see the road, but they see their lights reflecting off the back of the neck of the guy (me) in front of them!
3) A turn signal switch that goes up and down instead of left and right. How confusing! When I see a rare turn signal, I wait to see which way they turn.
4) Steering that's backwards when driving in reverse. How dumb! Many people back-up on the highway when they miss their exit.

I won't go on anymore about people who never check the oil or who put the wrong "antifreeze" into the wrong container. Many people drive smoking cars with glycol "salad dressing" on the windshield!

No my headlights are actually 100 year old technology, they are just regulare sealed beam incandecent lights none of that fancy blue tint HID stuff My driving lights are very dim, infact my blinkers are actually brighter than my fog lights haha, my daytime running lamps are actually my blinkers just not blinking. Unfortunatly I'm more at home with my hands in an engine compartment than I am at creating circuitry as you can probably tell i've got a limited knowledge of components, but I've played around with my share of home made circuits, and tinkering. I took one semister of EE in college.

These are the things I typically do with my spare time, which would explain where this project has it's roots.

This is my Car (you can see the orange daytime running lamp)

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here's a few pics and a link from when I rebuilt the engine
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Here's a pic of the supercharger that i put on about 2 years ago

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and last but not least a video of me running at the local 1/4 mile track

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Anyway, you sound like you may enjoy this website https://www.lightsout.org/ haha..

actually I just noticed where you're from, in fact my car was made in your country in 1998 Maybe you should've just gone to the factory and told them to put LED lights in it and then we wouldn't be having this conversation haha..

really though, I love learning about stuff like this, it's extremely fasinating to me. So again thanks for all your input and help.. As for the Transistor in the circuit, wouldn't that allow current to flow when current is applied to the base? so in effect that is the opposite of what I want?

 

[audioguru]

Aw, I wanted to see you do a wheelie! Your car is pretty quick.
My son has a quick Eagle Talon all-wheel-drive turbo.
I used to drive a turbo every day. Lots of fun. The light turns green, where did everyone go? Why are they way back there?

Thanks for your pics and the article about ridiculous high-beam high-intensity-discharge daytime running lights. A lot of average Joe's are too stupid to turn on their lights when they are needed so now millions of cars burn an awful lot of fuel to power them all day long even when it is sunny. Then the carmakers are allowed to disconnect the lights for fuel consumption testing. Ha!

 

[bmcculla]

I don't know how legal this would be but it would be neat to use a microcontroller to drive your LED array like a display. The micro would multiplex through the LED rows You could vary the on time of the mutliplexing to vary the brightness. You could display various graphics on your tailights or even have a dynamic dispalay - show your engine RPM when you're on the track.

Because all the driving intelegence lives in the controller you would also be able to keep the driving hardware fairly simple.

 

[Justin98TransAm]

yeah I don't know if I want to take is so far as to use a microcontroller or anything.

So how about the transistor i should use to control the current from the brake light? what kind should I get and how would I hook it up?

Also on the arrays of 25 LEDs, would it be better to just run the entire array in a parallel type circuit? or like a 5 groups of 5 LEDs in series paralleled together?

oh and i guess most importantly will this thing work with the couple of modifications mentioned in the thread?

 

[David Bridgen]

Hi Justin

This should do what you want. It takes audioguru's observations into account, i.e. you can adjust the intensity of each function, turn, brake and tail independently, braking inhibits the "tail" current, turn inhibits both "brake"" and tail" functions.

When only the "tail" supply is on Tr1 turns on through R1 and supplies current to the l.e.ds.

When the "brake" supply is on Tr1 is prevented from turning on (through D1). Tr2 turns on through R2 and supplies the l.e.d. current.

When the "turn" supply is present both the tail and brake currents are inhibited through D2 and D3.

The tranistors should have an Ic max significantly higher than the maximum l.e.d. array current (in the interests of longevity.)

The base resistors .... 1k should be ok.

 

[audioguru]

Hi Justin,
Here's the way I would do it. You can add a PNP transistor to the tail-lights if you want them to shut-off during blinking.

 

[Justin98TransAm]

sweet thanks again for all your help guys, I'm waiting on my LED's to come in from mail order. I'll need to go pickup the 4017's and 4011's somewhere also. Hey audio, what is the resistor for in the path between the diode coming from the blinker signal and the transistor?

 

[audioguru]

Hi Justin,
That resistor turns-on the transistor. Use 470 ohms 1 Watt.
The taillight resistor must be determined by how bright you want it. I would use about 36 ohms but it could be anything from 15 ohms 2W for bright to 68 ohms 1/2W for dim.

 

[pike]

good god :shock: That car sounds well...MEATY :twisted: :shock:

edit: damn, i'm more interested in your car than your LED problem.

 

[audioguru]

How about having that nice car with its fancy new LEDs and a pretty, barely-dressed girl inside? :lol: :lol:

 

[Justin98TransAm]

hmm.. i may be able to swing the pretty girl, but not the LED's yet I hope my LED's come in today, Do you guys think Radio Shack would have the 4017, and 4011?



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[Justin98TransAm]

what type of diods should I be looking for? anything in particular like model number or rating?

 

[audioguru]

Goodlooking car, goodlooking girl! :lol:

What? Oh, sorry. I got distracted. 1N4001 or 1N4002 diodes are good in this circuit.

 

[gerty]

Car ?? What car !!