The 74HC14 switches at specific hysteresis thresholds, typically around (high) with a
Typical 74HC14 thresholds (approximate, depend on Vcc and part variation): 74hc14 oscillator calculator full
[ V_H = V_T+ - V_T- ]
f equals the fraction with numerator 1 and denominator cap T end-fraction equals the fraction with numerator 1.25 and denominator cap R cap C end-fraction For example, using a F capacitor 0.00000001 Hz (12.5 kHz) 74hc14 oscillator calculator full