With R = 1 MΩ and C = 470 µF, the calculator predicts ~0.0038 Hz (one pulse every 4.4 minutes). Perfect for plant watering alerts or ultra-slow LED faders.
Hysteresis creates two distinct threshold voltages:
The difference between these thresholds is the hysteresis voltage:
[ V_H = V_T+ - V_T- ]
For a standard 74HC14 at 5V supply:
This hysteresis creates a "memory" effect, making the circuit immune to noise and perfect for constructing simple RC oscillators.
Feed the enable pin (tie two inverters in series, use third as AND gate) — the calculator still applies for the active time. 74hc14 oscillator calculator full
Resistors have 1%, 5%, or even 10% tolerance. Capacitors often have 5–20% tolerance. A full calculator should output a tolerance range (e.g., ( 810 \pm 15% ) Hz).
Not a replacement, but a cheap oscillator for non-critical apps. Calculator helps you hit standard baud rates (e.g., 115.2 kHz for UART).
Because the 74HC14 has a hysteresis window that is roughly centered around $V_DD/2$ (but rarely perfectly centered), the output duty cycle is not exactly 50%. It is typically between 40% and 60%. With R = 1 MΩ and C = 470 µF, the calculator predicts ~0
Replace R with:
Example: R_fixed = 1 kΩ, R_pot = 100 kΩ, C = 100 nF
→ Frequency range:
Min (R_total ≈ 101 kΩ): ( 1.2/(101k × 100nF) \approx 119 Hz )
Max (R_total ≈ 1 kΩ): ( 1.2/(1k × 100nF) \approx 12 kHz )
— over 100:1 range.