Flashing L.E.D. Using 555 Timer





Introduction: Flashing L.E.D. Using 555 Timer

I was trying to put in a video but it didn't work for me, so here is a link to YouTube http://www.youtube.com/watch?v=9rS9nFG8xdI
This is a detailed instruction showing how to build a flashing L.E.D. using 555 Timer.
There is no knowledge of electronics required in order to complete this project.
All the parts needed are listed, priced and links to them are also included. 

There are two sets of pictures, the top shows the progression of the project and the bottom shows each step individually.

This is my first instructable and it is also an assignment so please leave comments.
Thank you.

Step 1: Parts List

Here you will find a list of all required parts, their pictures, prices and where to get them.
There is also an excel file attached.

1. Breadboard
2. 9v Battery
3. Battery clip
4. Jump Wires
5. 555 Timer
6. Capacitor 1μF
7. Resistor   1k Ohm            x 2 (brown, black, red)
8. Resistor    470k Ohm            (yellow, purple, yellow)
9. L.E.D.

Time needed to finish this project: 5 - 10 min.

All the above parts can be bought at http://radionics.rs-online.com/web/ next day delivery (Ireland).

Step 2: 555 Timer Pin - Out and Breadboard Layout

First picture shows a pin-out for the 555 Timer. This will be needed in order to connect the chip.
The second picture shows how the paths in the breadboard are connected.

Step 3: Putting All Together

This project contains small parts which can be ingested or inhaled, so keep away from young children.

Make sure to push all the parts in to the breadboard that they make contact with it.

1. Place the 555 Timer chip in the middle of the breadboard, make sure to put it in the right way round other wise when you will connect the battery the chip will burn.

2. Using short length of jump wire connect Pin 1 (negative) to the bottom row of the breadboard   (ground).

3. Connect Pin 8(positive) to the top row of the breadboard (VCC).

4. Take another length of jump wire and connect Pin 4 with Pin 8.

5. Identify the legs on the capacitor C1, the short one is the negative and the long one is positive. Connect the positive leg to Pin 2 and the negative leg to the ground (GND).

6. Now connect Pin 2 with Pin 6 using piece of jump wire.

7. The resistors can be connected either way round. Using the 470k Ohm (R1) resistor connect Pin 6 with Pin 7.

8. Take the 1k Ohm (R2) resistor and connect Pin 7 to VCC.

9. Connect one end of the second 1k Ohm (R3) resistor with Pin 3 (output) and any empty row on the breadboard (this resistor will be connected with L.E.D. in the next step).

10. Identify the legs on the L.E.D., short one is the negative(-) and the long one is positive(+). Connect the positive leg with the resistor and the negative leg to the GND.

11. The final step is to connect the battery clip, the red lead to the VCC and the black lead to the GND. Connect the 9v battery and enjoy the effect.

16 People Made This Project!


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I don't have a 1µF capacitor. Will a 4.7 work?

I'm new to electronics, and I tried making this project, but the LED just stays on solid...I've ripped it apart and restarted 10 times now..what am I doing wrong?

I had the "stayed on solid" problem and it turns out that what was supposed to be my 470K resistor was actually much much much less resistance... I read the resistor code wrong. AND so... it looked like it was solid LED light but actually it was just flashing very very very fast. fixed the resistor and it worked. No idea if that is related to your problem.

I built this and it works great! I added in some potentiometers and i
can control the speed of strobe. I then added a circuit on the other
side of my bread board with a little rumbler motor with variable speed
as well. Then i can control the speed of the strobe and get the motor to
have cool optical illusions when the frequencies match or are slightly

Now i want to change the LED out for a led strip
with 60 leds — which calls for 12v at 1.5amps. I tried hooking up a
power supply with 12v at 1 amp and the led strip and i fried my 555.
woops. How can I handle more juice?


If you want to add an LED strip, add it on Pin 3, that is before the resistor to the output Single LED. The resistor lowers the voltage.

Take positive for LED strip from Pin 3 before R3 (1k ohm
resistor). Connect the Negative end of LED strip to ground.

555 can
operate between 4.5 v and 16 v (SE555 maximum is 18 V). So your 12 v should
not have fried 555. I used 16 v input and it worked fine.

Check this for specs from Texas Instruments on 555.


You will fry the 555 yet again if you do it this way. The 555 can not output 1 amp. You need a transistor for this to work. You need to connect the output of the 555 to the transistor and the transistors collector and emitter to plus and minus.

Hey, i made, but it doesn't work, i used tinkercad circuits, did i get it wrong?: