حاسبة المؤقت 555.

Classic NE555 formulas; CMOS versions are close. Capacitor tolerance usually dominates the error. Everything is calculated in your browser; nothing you type is uploaded.

Astable: f = 1.44 ÷ ((R1 + 2R2) × C); high time 0.693 (R1 + R2) C; low time 0.693 R2 C. Monostable: t = 1.1 R C.

R1 = 1 kΩ, R2 = 10 kΩ and C = 10 nF oscillate at 6.871 kHz with a 52.4 % duty cycle.