Ten Channel Sequential Lighting

The circuit “Ten channel Sequential Lighting” presented here gives a flashing light effect from left to right and then from right to left. IC1 (NE555) generates clock pulses for IC2. The output using rectifiers produce the effect of bulbs flashing from left to right.

As the carry output pin 12 of IC2 is connected to the clock input of IC3, the bulbs which are connected to IC5 also starts flashing from right to left.

As these outputs are not capable of handling large currents, they have to be amplified to the proper level so that 12V lamps glow with sufficient brightness.

The amplifier is built around two ULN2004 ICs. The IC consists of seven darlington stages, each of which has an open collector output.

The whole unit can be easily assembled on a Vero-board. The power supply for the gadget can be derived from any 12V battery.

circuit diagram of ten channel sequential lighting


Resistors (all ¼-watt, ± 5% Carbon)

R1 = 10 KΩ

VR1 = 100 KΩ


C1 = 10 µF/16V


IC1 = NE555

IC2, IC3 = CD4017

IC4, IC5 = ULN2004

D1 – D20 = 1N4001


LAMP1 – LAMP10 = 12V Lamps