electronic dice

Power supply voltage: 4.5-5.0v Circuit principle: The circuit mainly consists of a pulse generator and a 5-digit counter circuit. The pulse generator consists of ne555 and peripheral components to form a multivibrator. When the "s1" button is pressed, the transistor is turned on, and the 3 pins of the ne555 output pulses, and the 5 output terminals of the CD4017 take turns to output high-level drive displays. Different points. After releasing the button, due to the voltage drop across the capacitor, the conduction degree of the transistor gradually decreases, the output pulse frequency of pin 3 slows down, and the speed of the counting phone slows down. Finally, when the capacitor is discharged, the transistor is turned off, the triangle of ne555 no longer outputs pulses, and the points stop changing. Changing c1 can change the waiting time, changing r3 can change the speed of LED movement.