Example: Debouncing a Push Button Using RC Circuit
Suppose you are designing a digital circuit with a mechanical push button. Mechanical switches tend to bounce, causing multiple transitions. To eliminate this, you decide to use an RC low-pass filter for debouncing.
Goal:
Design an RC filter to produce a debounce delay of 10 ms.
Engineering Insight:
To allow the voltage to settle close to its final value, engineers typically use:
\[ t_{debounce} = 5 \cdot R \cdot C \]
Step 1: Choose Resistor
Assume \( R = 10\;k\Omega \).
Step 2: Calculate Capacitor
Rearrange the formula to solve for \( C \):
\[ C = \frac{t_{debounce}}{5 \cdot R} = \frac{10 \times 10^{-3}}{5 \cdot 10 \times 10^3} = 0.2 \times 10^{-6}\;F = 0.2\;\mu F \]
Step 3: Use the Calculator
Enter the following values into the calculator:
- Target debounce time: 10 ms
- Resistor: 10 kΩ
The calculator should suggest a capacitor value of approximately 0.2 µF.
Disclaimer: These calculators are provided for informational purposes only. Always verify your designs against relevant engineering standards and consult a qualified professional. We do not take responsibility for any errors or damages resulting from the use of these calculations.