A microswitch is a mechanical switch with a snap-action mechanism. Its contacts change state quickly around a defined operating point. This does not mean that every model is bounce-free or suitable for every load.
Check these five points before choosing
- Contact form: SPST-NO closes when operated, SPST-NC opens when operated, and SPDT changes from NC to NO through COM. Check the circuit diagram and terminal markings for the exact model; terminal positions are not universal.
- Actuator and mechanics: choose a plunger, lever or roller for the movement, operating force, travel, overtravel, mounting and available space. Avoid unintended side loading.
- Electrical load: compare voltage, AC or DC, resistive or inductive load, inrush current and minimum applicable load. A headline current rating does not apply to every load or switching condition.
- Environment and life: check sealing, dust, moisture, temperature, vibration, and the difference between mechanical and electrical life.
- Signal and safety: mechanical contacts can bounce; use suitable hardware or software debounce when the signal requires it. A standard basic switch is not automatically a safety switch. Safety functions require a demonstrably suitable, monitored circuit and component.
Frequently asked question
Can a microswitch with a high current rating switch a microcontroller input?
Not automatically. A value such as 22 A at 250 V AC applies under specified test and load conditions. A general-load switch can have contact-reliability problems at a very small signal load. Check the datasheet for the minimum applicable load, contact material, AC/DC suitability and the actual load type. Use hardware or software debounce when the input signal requires it.
Next step: browse microswitches or search by type, contact form or manufacturer part number. Then compare the product drawing and datasheet for the exact part.
