Which technique specifically reduces high-frequency electrical noise to prevent false triggers in sensor inputs?

• A. Debouncing
• B. Isolation
• C. Filtering
• D. Amplification

Answer: (C)

Filtering targets the frequency content of the sensor signal, using a low-pass approach to attenuate rapid, high-frequency fluctuations. High-frequency electrical noise can cause the sensor input to spike and be interpreted as a false trigger; by smoothing these rapid changes, the signal that passes through is more stable and the chance of a false trigger drops. This can be done with hardware elements like RC networks or digital smoothing in software, both aimed at preserving the genuine, slower-varying signal while suppressing the fast noise.

Debouncing addresses rapid on/off transitions caused by mechanical switch bounce, not electrical noise on the line. Isolation provides a barrier to prevent noise from other circuits but doesn’t actively reduce high-frequency content in the sensor signal. Amplification raises both signal and noise; it doesn’t reduce noise and can even amplify erroneous spikes. So, when the goal is specifically to curb high-frequency noise causing false triggers, filtering is the correct approach.