An Electronics KALEIDOSCOPE

Attention-catching elements prove valuable in warnings, raising awareness of danger, and in exhibitions, providing visual delight. Numerous electronic circuits utilise blinkers, winkers, and LED flashers for these purposes.

- RAJEEV N. DESHPANDE

This mosaic display of LEDs, reminiscent of a kaleidoscope, exudes charm and fascination. As this is a straightforward detection system, you have the freedom to construct and present it any way you like for amusement. The author’s prototype is shown in Fig. 1.

Circuit and working

Fig. 2 shows circuit diagram of an electronics kaleidoscope. The circuit comprises a 555 timer (IC1), a 14-bit binary counter/divider 4020 (IC2), and nine different-colored 5mm LEDs (red, orange, pink, green, yellow, blue, white, etc) with LED holders (LED1 through LED9) and various other components. A 9V power adaptor may be used for the power supply.

The 555 timer is configured as an astable multivibrator. It connects output pin 3 directly to timing capacitor C1 via resistor R1. When the output at pin 3 is high, capacitor C1 charges through resistor R1. When the voltage across the capacitor reaches 2/3Vcc, pin 6 triggers the output at pin 3 to shift to a low state.