When the 2-pin flip-flop detects an input higher than A 1, it will be reset. Of these eight feet, 2 feet and 6 feet are complementary feet, and 2 feet have leveling function below voltage, which has no effect on elegance. At this time, pin 3 is in a high voltage level state; Pin 6 is a threshold port, which has an effect on the high voltage level and has no effect on the low voltage level. The voltage of pin 3 is very close to the power supply voltage, and its maximum output current can reach 200mA.
Pin 4 is a reset port, which shall not be less than 0.4 volts. Pin 2 and pin 6 will make the output of pin 3 in a low level state in any state. Pin 5 is the control port of the whole timer, pin 7 is the discharge port of the timer, and pin 3 is in a synchronous state, especially their output levels are the same, but there is still a difference between them, that is, pin 7 has no output current, so pin 3 is defined as real high (low) and pin 7 is defined as virtual high (low).
555 timer is widely used:
1 and 555 timers are applied to Schmitt trigger, especially in the system interface of TTL and in the shaping circuit.
A 2,555 timer is applied to form a harmonic oscillator, which can be combined with the combined signal to form a circuit.
3, 555 timer is applied to monostable flip-flop, which can delay some timing switches to some extent.