Picture of STOP-LED
This is a STOP sign which lights up when you apply the BRAKE of your motor vehicle.

It is suitable for Cars, Scooters, and Motor Cycles.

I have made the Cirtuit Diagram for AC and DC type of vehicles.

You can buy one but making it is fun and cheap.
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Step 1: STEP-1

Picture of STEP-1
As you can see here that this little device can be fitted to any vehicle having a BRAKE LIGHT working on a Contact ON spring switch.

The concept is not new but it is cheap when you make your own light, out of a kids pencil box.

Older VEHICLES work on "magneto" or AC Generators for which a AC circuit is required.

The modern VEHICLES work on a 12 volts Battery, for which a DC circuit is required.

Here I have shown the circuit diagram of both types of currents AC and DC.

Step 2: STEP-2

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You need a KIDS PVC pencil box for construction of this Instructable.

Drill holes for the LED's on the cover of the pencil box.

Step 3: STEP-3

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66 -RED LED's.
22- Resistors 1/4 watt of 120 Ohms.
1-PVC pencil box.
2- pairs of Nut & Bolt to fix the unit to the vehicie.
Some electrical wires, solder, and insulating tape.

This circuit is for vehicles having battary for its power source.

Follow the circuit and soldier the LED's as shown in the diagram.

THREE LED are joined in SERIES with a Resistor and then they are joined PARELLRL to the main line.

The leads of the main line is joined to the wires of the BRAKE light in parellel.

When the Brakes are applied the both the brake light and the STOP sign lights up.

Step 4: STEP-4

Picture of STEP-4
This circuit diagram is for old vehicles which runs on AC generators.

The circuit is same but a bridge rectifier and a voltage stabilizer are added to the circuit.

4 Diodes IN7004 makes the Bridge rectifire.

One AN 7812 IC is the stabilizer. It works from 0 to 18 volts.
Mikey85675 years ago
Really nice idea, but you need to check your local laws as far as lighted sings on your cars, and trucks. A simple "Third brake light" is fine and is aproved by the DOT (Department Of Transportation) in the USA but some states don't allow signs (including the reader board type) on the car. They state it's a distraction to other drivers. If your state dosn't have such a law then this is a great addition to your car.

Dipankar (author)  Mikey85675 years ago
I am from INDIA.
Here anything goes.
If you see the the type of lights and stickers people put on their car's and bikes you will be astonished.
What id do is simple cut out STOP with a Bandsaw in some acrylic (any colour) add some white sheet under the stop to make waterproof Put two Crt tubes or a load of leds in the box and add a acrylic box to waterproof it .

Simpler and looks nicer
Tsjoptov6 years ago
what if you put a white sticker, with stop cut out, over your additional brake light ?
Motorcycles and motorscooters do not have an additional brake light.
Dipankar (author)  SandLizard5 years ago
 Yes There are two connections, one for BACK light and the other for BRAKE light.
mine does!
Dipankar (author)  Tsjoptov6 years ago
You can do it but the beauty of LED will not be there.
I just take 3-4 hours a day, usually, and read Instructables. I merely wanted to inform any further viewers that the PDF link is working.
Isn't 22 resistors just a waste of money?
Better then blowing all your leds, and then redoing the project and buying all the stuff again.
Dipankar (author)  thatmantheuser6 years ago
Hi thatmantheuser, No, in INDIA 200 resistors cost's you 1/2 a US Dollor.
bigaw6 years ago
Great fun. Just what I need for the back of my Caravan. But your adobe print out link does not work.
Dipankar (author)  bigaw6 years ago
What link?
bigaw Dipankar6 years ago
Hello, All instructables are supposed to be printable by using the Adobe software button on your last page. I have tried a variety of methods but get a fault message, something about the email was not decoded properly. Not your fault, something I am not doing right maybe. Best wishes.
Dipankar (author)  bigaw6 years ago
Hi bigaw, Sorry for your problem, If nothing works then enlarge the page and print screen the page and past it in PHOTOSHOP with 300 resulation. I hope it works. Good Luck.
Derin6 years ago
In Turkey buses have to be equipped with these lights. I think that this will be more efficient tan the incandescent ones they use
Dipankar (author)  Derin6 years ago
Hi Derinsleep, you are very correct.
Nice. Do you have any pictures of it on your car?
Dipankar (author)  GorillazMiko6 years ago
The red car and the scooter you see in the second photo are mine.
qs6 years ago
With 12volts DC supply, you can use, in series, 5 or even 6 red LEDs, (norminally rated 2.0v each @ 20mA). If you only use 3 LEDs, the Vf is only 6v, and, when the car battery is fully charged at 14v, the 120-ohm resisters will allow over 60mA of current, which is double what the LEDs are rated for. Similarly in the alternator circuit, use 5 LEDs and slightly underdrive them with a 7809 regulator and you don't even need the 120 resistors.
Dipankar (author)  qs6 years ago
qs Thanks. You are right, but as the brakes are applied for a short time I thought that overrunning the LED's will have no harm and the lights will be bright. If there is any problem i can change the resistors to 470 Ohms.
rimar20006 years ago
Excellent, Dipankar.