Multi-Pattern Running Light

Running lights effect is not a new idea for electronics  hobbyist. But this multi-pattern running light becomes unique as four patterns can be selected. In the first pattern, out of eight lights, alternate light go ‘on’ and ‘off’. In the second pattern, two adjacent lights go ‘on’ and the following two go ‘off’. This pattern is shifted from left to right. In the third pattern, four adjacent lights go ‘on’ and these are sifted to right. In the fourth pattern all the eights light go ‘on’ and ‘off’ one by one from left to right. All the lights are of ordinary 230V bulbs controlled by triacs.

Circuit Description of Multi-Pattern Running Light

The heart of the circuit multi-pattern running light is a serial-in-parallel-out shift register IC 74164 (IC3). When clock pulses are applied at pin 8, for every clock pulse, output at pin 3 is sifted to pin 4 and output at pin 4 is sifted to pin 5 and so on, as per the logic state given at input pins 1 and 2.

An oscillator of multi-pattern running light is wired around IC1 NE555 and the square pulse are applied to IC2 (7493) and IC3 (74164). The frequency of oscillator can be varied with VR1.

circuit diagram of multi pattern running light

IC2 is divided by 16 counter and its output pins are 12, 9, 8, 11. By connecting these outputs through rotary switch to inputs of IC3, four different pattern can be selected as mentioned above.

Switching circuits of multi-pattern running light constitutes transistors and triacs. As output of IC3 cannot drive triacs directly, 8 transistors (BC148) are used for driving 8 triacs. Triacs of 4 Amps, 400 PIV (Peak Inverse Voltage) can handle 30 nos. of light.


Resistor (all ¼-watt, ± 5% Carbon)

R1 = 22 KΩ

R2 – R9 = 10 KΩ

R10 – R17 = 100 Ω

R18 – R25 = 100 KΩ

VR1 = 100 KΩ


C1 = 1000 µF/16V (electrolytic capacitor)

C2 = 10 µF/16V (electrolytic capacitor)

C3, C4 = 0.01 µF (ceramic capacitor)


IC1 = NE555

IC2 = 7493

IC3 = 74164

IC4 = 7805

T1 – T8 = BC148

D1, D2 = 1N4001

TRIAC1 – TRIAC8 = 4 AMP, 400 PIV


X1 = 230V AC Primary To 9V-0V-9V, 500mA Secondary Transformer

SW1 = Single pole 4-way rotary switch