Tuesday, November 03, 2009
I have introduce a knight rider light system before Lots of users ask more circuits so I did little bit changes and made this circuit.This circuit is based on Ic 4011 and IC40017.I haven't used NE555 IC here..In here you can see LEDs are chasing after one another.If you want to keep the LED on for a short time.give the current via 10uf capacitor.Then you can see LED is disappearing slowly.
R2 100K Pot
R3 1K 1/4W Resistor or 220Ohm if using blue LEDs
C1 0.1uF 16V Ceramic Disk Capacitor
R1 1 Meg 1/4W Resistor
U1 4011 CMOS NAND Gate
U2 4017 CMOS Counter
LED1-10 LEDs Of Any Colour
MISC Board, Sockets For ICs, Knob For R2
1# You may need to use a lower value resistor if you wish to use blue LEDs. Use 220 Ohm.
2# 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.
3#C1 may be replaced with a larger value for a slower "chase rate".
4#If you have problems with weird circuit behavior, try replacing R1 with a 33K resistor, and increasing C1 to 1uF.
5#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.