You need a specific frequency (e.g., $1\textHz$ for a blinking LED).
Add a diode + potentiometer in parallel with R:
+---[Ra]---+
| |
D1 |
+---[Rb]---+---C
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Inv1 out Inv1 in
Warning: At low supply voltage (3V), diode drop matters.
The frequency of oscillation ((f)) for a 74HC14 oscillator can be approximated using the formula: 74hc14 oscillator calculator
[f = \frac12 \cdot R_1 \cdot C_1 \cdot \ln(3)]
Or more simply for design purposes:
[f \approx \frac12.2 \cdot R_1 \cdot C_1] You need a specific frequency (e
Where:
The 74HC14 is one of the most popular integrated circuits for generating clock signals in digital electronics. It is a hex inverter with Schmitt Trigger inputs. This specific input characteristic makes it incredibly easy to build a stable relaxation oscillator with just one resistor and one capacitor.
A 74HC14 Oscillator Calculator is a tool used to determine the output frequency based on the resistor ($R$) and capacitor ($C$) values, or to find the required components to achieve a specific target frequency. Add a diode + potentiometer in parallel with
Use τ = R × C (time constant).
f ≈ 0.455 / τ because 1/(2.2) = 0.4545.
Example:
R = 47kΩ, C = 10nF → τ = 470µs → f ≈ 0.455 / 470e-6 ≈ 968 Hz