Why do micro switches fail?

As a mechanical and electrical switch, the micro switch has a wide range of applications in the aerospace field. In long-term use, the failures that usually occur are generally divided into two categories: mechanical failures and electrical failures. The main modes of mechanical failure are the change of operating characteristic parameters exceeding the regulations and the fatigue fracture of elastic components; the main modes of electrical failure are the increase of contact resistance (or voltage drop) and the decrease of insulation performance of the switch.

Normal use of micro switch
When the stroke is used and the operating force on the actuator is without operating force (or torque), the actuator of the micro switch should be in the free position; after the micro switch is converted, the actuator is in (close to) the full stroke position ( No overpressure); the maximum operating force (or torque) applied must not exceed the full stroke force (or torque). For this reason, the best way for the operating mechanism to press the actuator is elastic pressing.

Intended use
In principle, all types of micro switches are suitable for low-voltage AC and DC circuits. Unless otherwise specified, switches can only be used in single-phase circuits, and cannot be used for phase-to-phase conversion.

General principles to be considered when selecting switches according to electrical loadsWhen the practical load is sufficient to generate an arc (greater than 8V, 0.5A), choose a switch with a higher electrical load rating; for the practical load, it is not enough to cause an arc, but the voltage is sufficient to melt the electrical contact material (about 0.5V~8V) , Choose a switch with a logic level rating; for a practical load with low voltage (below 0.5V), choose a switch with a low level rating.

Electronic logic circuit control
When the switch is used in a control circuit with a very fast response time, the contact bounce and switching time of the most sensitive and instantaneous basic micro switch may have an impact. For this reason, it is necessary to set up a 10ms buffer circuit in the fast-response logic circuit.