Introduction
Astable multivibrator mode has another name that is “the fast running or self-trigger mode”. But, It doesn’t have any stable state like mono state multivibrator. However, a stable multivibrator has two quasi-stable states that are state high and low. Also, there is no external triggering that happens in a stable multivibrator. The time duration of both resistors and capacitors determines the high and low states. In short, this astable multivibrator using 555 timer IC, oscillates at a certain frequency and rectangular wave pulses.
Certainly, Mostly stable multivibrators exist to generate time delays in the circuits. And, it has connecting resistors, capacitors with the 555 timer IC. Resistors and capacitors modulate the timing of output. Select appropriate resistors and capacitors to obtain the ON and OFF timings. The capacitor at pin 5 is used to avoid noise problems that can occur in the circuit.
Hardware Required
| S.no | Components | Value | Qty |
|---|---|---|---|
| 1. | Bread Board | 1 | |
| 2. | Timer IC | NE555 | 1 |
| 3. | Resistors | 2 | |
| 4. | Capacitors | 2 |
Circuit Diagram
Working Explanation
When the circuit Astable Multivibrator using 555 Timer is a power-up. The flip-flop in the IC gets reset. Meanwhile, discharge the transistor to its saturation state. The capacitor will discharge through that transistor in the IC. During, discharging the voltage across the capacitor becomes one-third of the Vcc. Therefore, triggers the comparator and sets the flip flop at pin 3 which goes high. As a result, it turns OFF the transistor and the capacitor starts charging. And, when it gets slightly greater than two-thirds of the Vcc, the output becomes high.
Application and Uses
- Firstly, o generate a pulse
- Also, for frequency modulation
- Moreover, In the pulse position modulator
- Similarly, for the square wave generation
