Here is a simple, cheap and vary interesting electronic pendulum. The project electronic pendulum can be used in various other gadgets i.e. it can be used in digital clock for pendulum view.
Circuit Description of Electronic Pendulum Using NE555:
The circuit of electronic pendulum comprises a timer IC NE555 (IC1), CD7400 (IC2), 4-bit up-down counter IC CD74193 (IC3) and a BCD to decimal decoder IC 7442 (IC4).
Timer IC NE555 (IC1) is configures in astable multivibrator mode and generate square wave. The frequency of square wave generating from timer IC1 is adjusted using preset VR1. The output of IC1 from pin 3 is given to two input of IC2 (pin 10 and pin 13) as shown in circuit diagram.
IC2 is a 2-input 4 NAND gate IC. Two gate of IC2 is configured in R-S flip flop mode whose output is given to input of another gate at pin 9 and pin 12. The output from these gates at pin 8 and 11 is given to input pin of IC3 at pin 4 and [in 5 respectively.
IC3 is a 4-bit up-down counter. The direction of counter (IC3) depends upon input given to pin 4 and 5. For up counter pulse is given to pin 5 and keep pin 4 at high state i.e. +5V is given to pin 4. For down counter pulse is given to pin 4 and keep pin 5 at high state. The output pulse from IC3 is given to IC4.
IC4 is a BCD to decimal decoder which changes the input pulse in order to drive LEDs. These all LEDs glow sequentially from left to right and vice-versa. Resistor R1 is used as current limiter in order to increase the brightness of LED, the value of resistor R1 should decrease to 150Ω or 100Ω.
PARTS LIST OF ELECTRONIC PENDULUM USING NE555
Resistor (all ¼-watt, ± 5% Carbon)
R1 = 220 Ω
R2 = 1 KΩ
VR1 = 1 MΩ
|C1 = 0.068 µFC2 = 0.01 µF|
|IC1 = NE555IC2 = CD7400
IC3 = CD74193
IC4 = CD7442
LED1 – LED10 = Any Color LEDs