LED Chaser

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I don't know why, but people like blinking lights. You see LED chasers everywhere, in TV shows (Knight Rider), movies, and store windows. This schematic is my version of a simple 10 LED chaser. There is no 555 timer used because at my local electronics store they are over $4 Cdn. Instead, an oscillator made up of two sections of a 4011 NAND gate is employed. This chip is very inexpensive and extremely common.

Schematic

Parts

Part	Total Qty.	Description	Substitutions
R1	1	1 Meg 1/4W Resistor
R2	1	100K Pot
R3	1	1K 1/4W Resistor	220Ohm if using blue LEDs
C1	1	0.1uF 16V Ceramic Disk Capacitor
U1	1	4011 CMOS NAND Gate
U2	1	4017 CMOS Counter
LED1-10	10	LEDs Of Any Colour
MISC	1	Board, Sockets For ICs, Knob For R2

Notes

Use R2 to adjust the "chase rate".

You may need to use a lower value resistor if you wish to use blue LEDs. Try 220 Ohm.

You can also use incandescent lamps instead of LEDs. Use transistors to drive them by connecting the base of the transistors to each of the outputs of the 4017 through a 1K resistor. Connect one end of the lamp to the positive supply. Then connect the other end to the collector of the transistor. The emitter then goes to ground. Depending on the lamps, you may need power transistors that are heat sinked.

C1 may be replaced with a larger value for a slower "chase rate".

If you have problems with weird circuit behavior, try replacing R1 with a 33K resistor, and increasing C1 to 1uF.

If you plan to use this circuit in your car, be warned that in some areas it is illegal to have red, blue or yellow flashing lights unless you are an emergency vehicle.

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Comments

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max Henderson LED Chaser Tuesday, April 06, 2010 9:11:34 AM

hey, i have a pretty poor understanding of how all this works and suck at the physics/technical aspects, however all that important stuff aside I really want to create this, however slightly modified. instead of having one led in each place, i want to attach a relay, and to this relay hook up say 10 leds, the idea being that i create something that looks like a dart board with the light 'rippling' out like the surface of water. was hoping for any advice as to how to do this all, i know it's ambitious for someone that is way out of their depth, i still really want to do it, any help that anyone could offer would be greatly appreciated i have just bought all the stuff listed here online, should be with me in the next couple of days

anonymous LED Chaser Friday, March 26, 2010 1:15:52 AM

can you mail me the latest (improved version) of the circuit? because i want to make it for my workshop project.

anonymous LED Chaser Thursday, January 14, 2010 7:40:03 PM

I removed the section that uses the nand gates and attached a long wire to pin 14 of the 4017 and held it in the air and it worked!

Lee LED Chaser Friday, September 11, 2009 5:57:20 AM

hahahahahaha, you got detention for it not working?!? Your teacher is a stupid SOB.

brandon LED Chaser Thursday, September 03, 2009 12:22:10 AM

this circuit failed me and i got a after school detention because it didn't work.

Todd Longwell LED Chaser Wednesday, September 02, 2009 9:58:11 PM

I dont know the first thing about any of this, but i need help; wheather itsLED, flourenscant, or aregular bulb set up, i need someones help. i needa setup that when i hit a switch, 5 to 7 bulbs turn on and the chase or blink or something. dont kow the first thing about it, im a 12 volt man, but usd all my options. email me if you can help, please, thankyou.

Roy LED Chaser Tuesday, September 01, 2009 4:33:39 PM

If you wish to use a 555 to replace the 4011, consider a CMOS version of the 555 as a; National semi LMC555, Maxim 7555 or TI TLC555. They use less power and do not require a capacitor couple across the supply.

aravind LED Chaser Saturday, August 29, 2009 6:41:34 AM

i really like the circuit but it would have been a little more impressive if it worked from 6volts .if you can please send me the circuit

amruta from india LED Chaser Friday, July 17, 2009 4:35:54 AM

i am really very thankful to the designer of this circuit. It really worked. I will suggest that use 555 timer ic instead of 4011 then your circuit will work properly.

benzilal LED Chaser Saturday, March 07, 2009 5:12:43 AM

To construct a led chaser with more then 10 channels and with various effects with simple circuit diagram.

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max Henderson	LED Chaser	Tuesday, April 06, 2010 9:11:34 AM
hey, i have a pretty poor understanding of how all this works and suck at the physics/technical aspects, however all that important stuff aside I really want to create this, however slightly modified. instead of having one led in each place, i want to attach a relay, and to this relay hook up say 10 leds, the idea being that i create something that looks like a dart board with the light 'rippling' out like the surface of water. was hoping for any advice as to how to do this all, i know it's ambitious for someone that is way out of their depth, i still really want to do it, any help that anyone could offer would be greatly appreciated i have just bought all the stuff listed here online, should be with me in the next couple of days
anonymous	LED Chaser	Friday, March 26, 2010 1:15:52 AM
can you mail me the latest (improved version) of the circuit? because i want to make it for my workshop project.
anonymous	LED Chaser	Thursday, January 14, 2010 7:40:03 PM
I removed the section that uses the nand gates and attached a long wire to pin 14 of the 4017 and held it in the air and it worked!
Lee	LED Chaser	Friday, September 11, 2009 5:57:20 AM
hahahahahaha, you got detention for it not working?!? Your teacher is a stupid SOB.
brandon	LED Chaser	Thursday, September 03, 2009 12:22:10 AM
this circuit failed me and i got a after school detention because it didn't work.
Todd Longwell	LED Chaser	Wednesday, September 02, 2009 9:58:11 PM
I dont know the first thing about any of this, but i need help; wheather itsLED, flourenscant, or aregular bulb set up, i need someones help. i needa setup that when i hit a switch, 5 to 7 bulbs turn on and the chase or blink or something. dont kow the first thing about it, im a 12 volt man, but usd all my options. email me if you can help, please, thankyou.
Roy	LED Chaser	Tuesday, September 01, 2009 4:33:39 PM
If you wish to use a 555 to replace the 4011, consider a CMOS version of the 555 as a; National semi LMC555, Maxim 7555 or TI TLC555. They use less power and do not require a capacitor couple across the supply.
aravind	LED Chaser	Saturday, August 29, 2009 6:41:34 AM
i really like the circuit but it would have been a little more impressive if it worked from 6volts .if you can please send me the circuit
amruta from india	LED Chaser	Friday, July 17, 2009 4:35:54 AM
i am really very thankful to the designer of this circuit. It really worked. I will suggest that use 555 timer ic instead of 4011 then your circuit will work properly.
benzilal	LED Chaser	Saturday, March 07, 2009 5:12:43 AM
To construct a led chaser with more then 10 channels and with various effects with simple circuit diagram.