Knight Rider Lights Project
|Circuit diagram for standard LED output.|
|You can use 12V bulbs for the output, simply substitute the IC for the LEDs,
the bulbs are then connected to the IC's outputs.
This set up is ideal for running off a car battery.
|Alternative output driver for 12V bulbs.|
HOW IT WORKS
The 555 timer IC is connected for Astable Operation, the clock pulses are fed to the 4017 IC via the
10K resistor. The 4017 is a 10 stage counter, each of the outputs is connected to the appropriate LED,
as some LEDs need to be on for more than one count, we use diodes to avoid a short circuit situation between outputs.|
The capacitor and resistor on pin 15 of the 4017 are used to reset the counter to zero at initial power up.
The ULN2001N used on the bulb version is a seven channel Darlington Driver IC, a small signal on one of the inputs is enough to drive the bulb on the output.
|(Maplin part numbers are show in brackets)|
| ||6* 1K
| ||1* 3.3K
|LED Version||1* 8.2K
| ||6* LED
| ||1* 10K
|Bulb Version||1* 100K
| ||6* 12V/2.2W
|Plus 6* suitable Bulb Holders.|