NE555 Multi-Circuit Experiment Board

This project introduces
experimental boards for NE555 bistable, monostable, and astable circuits, allowing users to learn the basic principles of the NE555.
The project's function
involves observing the blinking of an LED and the generation of square and triangular waves by changing capacitors and adjusting resistance values.
Principle Analysis (Hardware Description)
: Bistable Circuit:
After pulling up pin 2 and pin 6, two switches are used to control the potentials of pins 2 and 6 respectively, achieving two stable states: on and off.
Monostable Circuit:
Pins 6 and 7 are shorted, a capacitor is connected to ground, and an adjustable resistor is connected to the power supply for current limiting. The rest is the same as the bistable circuit. After pin 2 is triggered, pin 7 no longer discharges to ground, allowing the power supply to slowly charge the capacitor, gradually raising the potential of pin 6. When the voltage reaches 2/3 of the power supply voltage, pin 6 is triggered, the LED turns off, pin 7 discharges to ground again, and pin 6 returns to a low potential. The LED's illumination time can be adjusted by changing the resistor and capacitor values.
Astable Circuit:
Pins 2 and 6 are shorted, a capacitor is connected to ground, and a resistor is connected to the power supply. After power is turned on, the capacitor's initial voltage is 0, pin 2 has a low potential, and the LED is on. As the capacitor voltage gradually rises to 2/3 of the power supply voltage, pin 6 is triggered, the LED turns off, and pin 7 discharges to ground. When the capacitor voltage drops to 1/3 of the power supply voltage, pin 2 is triggered, the LED lights up, and the cycle repeats.
By using a smaller capacitor value, a square wave is generated at pin 3, and a triangular wave is generated at pins 2/6, as shown in the diagram: [Image of
actual device demonstration]