41 LED Flasher Circuit using 555 IC

I made this as a quick project I made to use a lot of the LEDs I recently got. It basically connects via a 555 8 pin IC and allows for adjusting the time between the flashings by changing the resistor or capacitor values. It provides for a cool looking effect in a dark room. Use your favorite color LEDs and enjoy!

Step 1 Gather the parts

Okay, so let's beign.
Here is what you will need:

1 - Timer 555 8 pin IC
1 - 2N3905 PNP general switching transistor
1 - 2N3053 NPN general purpose amplifier (I dont know if this is a switching or amplifer but I used MPSA2222A instead and it worked fine, I also tried 2N3904 and it worked, but a littler worse than the one I used)

20 - red LEDs (although you can use any color choice you want)
20 - blue LEDs (although you can use any color choice you want)
1 - LED (this is used to verify if your circuit works, can be any color)

1 - 1uF Electrolytic capacitor
1 - .1uF disc capacitor

1 - 150k resistor
1 - 4.7k resistor
1 - 160 ohm resistor
1 - 220 ohm resistor (although I used a 160 ohm)
20 - 100 ohm resistors (I didnt have 20 so I used 10 of 100 ohm and 10 of 120 ohm)

1 - 6V source
wire

Comments

[scottinnh]

Supes,

Could this be modified to not do flashing at all, or to flash at such a quick rate that it is not visible flicker? (I'm assuming that removing the flash altogether would be hard on the batteries, if they even can supply enough current.)

I'd like to just run this many batteries off AAs without requiring a million resistors, or losing 1/3 the energy as dissipation through the resistors.

[dragon7689]

If your flash rate is too fast they will come on but be very dim. You can make this work very easily without flashing involved. For a beginner i would suggest finding a different diagram to follow rather than trying to figure out what components to remove. (IC, Caps, extra resistors, even possibly the transistors (depending on Ea - Applied Voltage).

[miguelvelarde10]

where is the negative side of the battery??? i cant see it

[dragon7689]

The negative side of the battery is everywhere you see the
_
- ofcourse there are three little lines but everyone of those should be connected to ground or in this case the negative (-) side of battery

[MROHM]

Excellent Instructable!!!!!!!!! 41 LED Flasher is Awesome,,,,,,Yee-Ha!!

[MROHM]

Hi! Just a Suggestion Here,,,,I built this little baby and noticed one thing,,after leaving this circuit on i noticed the transistors were getting warm especially the 2N3053 (Max Ic of 600 M.A.) To Alleviate the Problem I subbed 2N3053 for Tip31(Power transistor,,,Ic of 3 amps) and 2N2905 for TIP41 (Power Transistor Ic of 3 amps) 2 advantages here,,,,, 1) Transistors will remain cooler here. 2) you will be able to add a pile of extra Led's to this circuit and the Tip's should be able to Handle the extra loads.. This is still a really Good Instructable,, but If we can improve the circuit why Not??!!?? We might be able to double or even triple the Led output and the TIP's should be able to take it!!! Supes this is a SUPER INSTRUCTABLE!!!

[umair naqash]

nice

[hummvee3]

I bought everything needed to build this but i have a problem understanding how to read a schematic and the photo does not show where all wires go. if any one has built this please email me some photos to [e-mail] it would be much appriciated. i would really like to make this and this is my fisrt time making a circuit of any type and i like the idea. please help with photos that shows where to place wires on the bread board. thanks again

[benny_resendez]

did anyone ever send you anything to help on your problem? If so can you send it to me I am trying this for a project and just cant seem to figure it out.. [e-mail]

[72bobbert]

the ground is negative. the leade on the transistor that has the arrow is the emitter, the center one is the base, and the other one is the collector. all l.e.d.'s are polarized. if you look at the two leads one will be longer than the other. the shortest lead is negative. thats basically all what a novice wouldnt know. go to bluedashlight.webs.com to see my modified schematic for 12-14 volts.

[rcisneros]

I know what you mean. A lot of diagrams are made for people who already know electronics.

The simpler ones show (+) & (-) wires so us novices can follow them. This diagram has many different ground symbols when I believe it's where the (-) lead goes.

[MROHM]

You are right on this one my Friend!!! My only advice to you is to build or breadboard Simpler Circuits and once you feel comfortable you can move on to more complex ones. I have been in electronics a long long time and enjoy simple circuits over complex circuits,,,,because;;; 1) They work~~~~100% of the time and 2) they are easier and faster to construct, 3) you can build your knowledge faster so you can tackle the tougher circuits at a later date!!! Good Luck and Happy Building!!! I must go now,,,, I smell my Weller!!!!

[miiwii3]

it does show where all wires go you just need to use jumper wires to connect things. the schematic does not show wher wires go but what they connect to just draw it out trust me i built this and like from 6 to 2 just use a jumper wire either over the ic or around it. it is easier if you use a breadboard for this.

[mased007]

So cheap LEDs. I live in Slovakia and I bought 1LED=0,50€

[kctess5]

if you don't have a pnp transistor you can always just add more leds on the same circuit with the npn transistor with some minor changes

[fjm9898]

i built this using a 2907 without a diode and that bank of LEDs seemed fine. i had a problem with my other bank of LEDs. i believe it may be because i used a 12v source but i am not sure. my mpmps2222 got very hot as well as that banks 100 resistors. also i only used 21 leds. two banks of 10. also i used a 100k POT instead of the 150k resistor so i could change the speed. but here is what i noticed with the upper bank running off the 2222. it duty cycle was a full on most the time where as the 2907s bank had a few fast flash. probably a 10/90 duty cycle. also the 2222s bank when the leds were suppose to be off they were dimmly lit. i am guessing this is because of the 12v supply and the that bank is tired directly into the supply where the other bank the supply goes through the 2907 first. but i am not sure. can some one please verify my problem.

[MROHM]

(removed by author or community request)

[scottinnh]

The project inspiration URL is now http://www.bowdenshobbycircuits.info/ (not http://ourworld.compuserve.com/homepages/Bill_Bowden).

I'd actually never seen that site before, so I got 2x value from reading this instructable. Thanks!

[barbaros4ever]

PLEASE I HAVE BOUGHT 5 TIMES THE PARTS AND THEY DONT WORK.... PLEASE TELL ME ALL THE PARTS AGAIN BECAUSE I CANT FIND SOME OF THEM IN MULTISIM.....

[markee2]

i have a   

similar flasher circuit but the rate of flashes is variable 

the difference is it has a potentiometer taken from
http://electronician.blogspot.com/2010/11/led-flasher-circuit-using-555-ic.html

[bfaridnia]

Got it to work but now I notice the stand that is connected to2n3053 is way dimmer than the other stand. I played with the resistor between the transistor and the 3 pinout but nothing worked. Can someone explain this to me? I think it had to do with forward voltage at the high output being less that at the low. But not sure how to correct. Thanks

[bfaridnia]

*strand

[Complex12]

Hey, your supplies list a 2N3905, but the picture of the schematic you have uploaded shows a 2N2905 in use.

Please clarify.

Thanks!

[bfaridnia]

Connected everything and the led lights but doesn't flickr. I replaced the 150k r with a 1 meg pot and still nothing. There is a noticeable haze of a flickr. Not sure what's going wrong. Could I try a 10mfd capacitor instead of the.1? Any one else have same problem.

[bfaridnia]

Connected everything and the led lights but doesn't flickr. I replaced the 150k r with a 1 meg pot and still nothing. There is a noticeable haze of a flickr. Not sure what's going wrong. Could I try a 10mfd capacitor instead of the.1? Any one else have same problem.

[geeklord]

so do PNP's stop conducting when there is a current at the base?

[miiwii3]

positve negative postive negative is the base and since the timer output is + - + - it turns on and off with the positve and negative votage. its like you quickly switch the red a black wire on the battery it would go + then when u switch it becomes - make sense? basically the 555 switches th polarity for you at a specific rate.

[Rajeshkm]

hai geeklord... the the transistor is said to be in on state ,only when it gets a forward bias across its base and emitter....the polarity configuration depends up on the type of transistor .. NPN or PNP...

[supes]

the radio shack 555 should work...

[geeklord]

K, just wanted to make sure that radio shack wasn't doing what they do best!

[arkangel888]

can i replace the 2n3053 with bc184 or c829?

[miiwii3]

maybe you can also replace it with a NTE128. the other one you can replace with NTE159.

[M45]

 I have a problem understanding how to read a schematic and the photo does not show where all wires go. if any one has built this please email me some photos to [e-mail] it would be much appriciated. i would really like to make this and this is my fisrt time making a circuit of any type and i like the idea. please help with photos that shows where to place wires on the bread board. thanks again

REPLY

[flag]

[pgg123]

Is it possible to wire the 555 to make the LEDs pulse instead of flashing?

[geeklord]

In the third picture i am pretty sure that that is a 160 ohm resistor on the top.

[Silversting]

No it is a 150K ohm resistor you can just barely see the yellow third line. If it was 160 ohm than the color code would be Brown,Blue, Brown.

[geeklord]

*Third picture on step one, that is*

[nbl2]

add a 1n4004 silicon diode in series with the other one which is connected to the base of the 2N2907 transistor in order to reduce the voltage. That is what i did and it worked

[13thThief]

 yeah....diode can be used as a resistor...which dissipates 1.5v.... 

[raikut]

And I guess how long the 4 battery will last when continuously lit.