Calculadora de Timer 555 AstávelFormula

## 555 Timer Astable Mode

### Formulas

**f = 1.44 / ((R1 + 2R2) x C)**

**Duty Cycle = (R1 + R2) / (R1 + 2R2) x 100%**

Duty cycle is always above 50% in standard configuration. Use a diode across R2 for below 50%.

Exemplo Resolvido

R1 = 10k, R2 = 10k, C = 0.1 uF.

  1. f = 1.44 / ((10000 + 20000) x 0.0000001) = 1.44 / 0.003 = 480 Hz
  2. Duty cycle = (10 + 10) / (10 + 20) x 100 = 66.7%