SW-420 Vibration Sensor Module, Digital Comparator Output

The SW-420 detects physical vibration and shock using a normally-closed mechanical switch element that briefly opens when disturbed by vibration or sudden movement, with an onboard LM393 comparator converting that raw switch behavior into a clean digital signal a microcontroller can read directly rather than needing to debounce a noisy raw switch signal itself.

Output logic is straightforward: the signal stays LOW when the module is undisturbed and switches HIGH whenever vibration exceeds the configured threshold, with the output rated to drive at least 15mA, enough to directly trigger a small indicator LED or buzzer without needing an additional driving transistor stage for light loads. An onboard potentiometer lets the vibration sensitivity threshold be tuned, so the trigger point can be adjusted between picking up only strong shocks versus responding to subtle taps and vibrations, depending on what the specific application calls for.

Physical size is compact at 40 x 15 x 7mm, with mounting bolt holes for secure fastening inside an enclosure rather than leaving the board loose on wires - a detail that matters more than usual for a vibration sensor, since a loosely-mounted board could itself introduce false readings from its own movement. Operating voltage spans the common 3.3 to 5VDC range.

Builders working on a tamper-detection alarm, a package or door-knock notification system, a simple seismic or impact-trigger project, or any application needing to detect sudden physical disturbance will find the SW-420 a well-proven, inexpensive module with a straightforward digital interface and adjustable sensitivity to tune for the specific use case.