555 Timer LED Flasher - Operating Modes of 555 Timer
Operating Modes of 555 Timer
The 555 Timer IC has basically three operating modes.
- Monostable Mode
- Astable Mode
- Bistable Mode
Monostable Mode
- In this mode, the IC generates only single pulse when the timer obtains a signal from the triggers input button.
- Period of the pulse depends upon the Resistor and Capacitor values.
![Monostable Mode](https://wikitechy.com/final-year-project/electronics/555-timer-led-flasher/img/555-timer-led-flasher-images/monostable.png)
Monostable Mode
Astable Mode
- In this mode, the IC generates nonstop pulses with exact frequency depends on the values of the two Resistors and Capacitors.
![Astable Mode](https://wikitechy.com/final-year-project/electronics/555-timer-led-flasher/img/555-timer-led-flasher-images/astable.jpg)
Astable Mode
Bistable Mode
In this mode, the IC generates two stable states :
- High
- Low
The output signal of these two states are forbidden by a trigger and reset input pins, not by the charging and discharging of the capacitors.
![Bistable Mode](https://wikitechy.com/final-year-project/electronics/555-timer-led-flasher/img/555-timer-led-flasher-images/bistable.png)
Bistable Mode