Input conditioning in the digital clock project: A 60 Hz mains signal is conditioned through a Schmitt trigger to produce clean logic pulses at 60 pulses per second (pps). Does this circuit create “sine wave pulses,” or square logic pulses?

Introduction / Context:
Schmitt triggers are used to clean up slow or noisy input waveforms by adding hysteresis. When a sinusoidal mains-derived signal (for example, 60 Hz) is fed into a Schmitt trigger, the output becomes a crisp digital square wave at the same fundamental rate, suitable for clocking counters.

Given Data / Assumptions:

• Input: 60 Hz sine or rectified waveform after isolation and scaling.
• Conditioner: a Schmitt-trigger buffer or inverter with defined upper and lower thresholds.
• Output: logic-level transitions whenever the input crosses thresholds.

Concept / Approach:
A Schmitt trigger does not output sine waves; it outputs near-rail square pulses determined by the device thresholds and supply rails. The purpose is to remove indecision around the switching point and prevent chatter due to noise. Therefore, describing the output as “sine wave pulses” is incorrect.

Step-by-Step Solution:

Verification / Alternative check:
Oscilloscope traces of Schmitt outputs show crisp edges at rail levels, not sinusoidal shapes, with edge timing established by threshold crossings.

Why Other Options Are Wrong:

Common Pitfalls:
Confusing the input waveform with the conditioned output; assuming analog filtering is present when the intent is digital edge cleaning.

Final Answer:
Incorrect