Knight Rider Running Light Schematic

4017 Knight Rider circuit, the 555 is wired as an oscillator. It can be adjusted to give the desired speed for the display. The output of the 555 is directly connected to the input of a CD 4017.

Part List :

R1 22kΩ

R2 220Ω

VR1 50kΩ Preset

C1 1µF 16V

C2 0.01µF (103)

C3 10µF 16V

D1 – D10 1N4148

D11 – D16 LED

IC1 NE 555

IC2 CD 4017

The input of the counter is called the CLOCK line (555). The 10 outputs become active, one at a time, on the rising edge of the waveform from the 555. Each output can deliver about 20mA but a LED should not be connected to the output without a current-limiting resistor (220Ω in the circuit above).

The first 6 outputs of the chip are connected directly to the 6 LEDs and these “move” across the display. The next 4 outputs move the effect in the opposite direction and the cycle repeats. The animation above shows how the effect appears on the display. Using 6 LEDs, the display can be placed in the front of a model car to give a very realistic effect.