A key structure includes a movable element, an elastic element, a light-emitting element and a pressure sensing element. The pressure sensing element is arranged between the elastic element and the light-emitting element. The elastic element is disposed on the movable element. The light-emitting element emits a light beam. The light beam is transmitted through the pressure sensing element and projected to the movable element to illuminate the key structure. While the key structure is depressed, the elastic element is pushed by the movable element. The pressure sensing element is pushed by the elastic element according to different magnitudes of the depressing force. Consequently, the key structure generates different pressure sensing signals.

A pivot supporting structure for a circuit breaker and a circuit breaker. The pivot supporting structure comprises: a supporting body having a supporting hole for receiving and pivotally supporting a pivot pin connected to an actuating mechanism of the circuit breaker, wherein at least one strain gauge are mounted to the supporting body for sensing the force acting on the pivot supporting structure by the actuating mechanism. This pivot supporting structure can accurately sense the characteristic force applied, such that the contact force and mechanical characteristics of the circuit breaker can be on-line monitored.

An apparatus for an imbalance test includes a strain measurement module that measures a strain voltage across terminals of a strain gauge. The strain voltage is representative of an amount of force on the strain gauge. The apparatus includes a test measurement module that measures a test voltage across the terminals of the strain gauge while a test resistor is connected in parallel with a resistor of the strain gauge. The test resistor is connected while the test measurement module measures the test voltage and is disconnected while the strain module measures strain voltage. The apparatus includes an average module that calculates an average strain voltage from two strain voltage measurements. The strain voltages are measured preceding and after the test voltage measurement. The apparatus includes a difference module that determines a difference voltage. The difference voltage is a difference between the average strain voltage and the test voltage.

A switch structure and an electronic device using the same are provided. The electronic device has a casing, and the switch structure is disposed at an inner side of the key portion of the casing. The switch structure includes an elastic member, a force transmission member and a strain sensor. The elastic member is connected to the casing. The force transmission member is located inside the casing. The strain sensor is disposed on the elastic member, and the strain sensor and the force transmission member are disposed are two opposite sides of the elastic member respectively. The elastic member is configured to be deformed by the force transmission member when an external force is applied to an outside of the key portion.

A cable pull switch includes a polychotomous sensor configured to provide a reading of at least one of a plurality of values, the reading corresponding to a tension on a pull cable or a linear displacement of an end of a pull cable. A processor coupled to the polychotomous cable pull sensor configured to determine a rate of change of the value of the reading from the sensor and determine an occurrence of a cable pull event, the determination based on the determined rate of change of the value, and determine whether the rate of change of the value of an electrical resistance through the polychotomous cable pull sensor is below a threshold rate of change value, and adjust an upper pull threshold value to a new upper pull threshold value that is based on a present reading of the value of the electrical resistance through the strain gauge.

A switch according to the present invention includes a base including a recessed portion on one surface of the base; a click spring having a dome shape, the click spring being provided at the recessed portion such that the bottom of the recessed portion is contacted at a dome-shaped opening side of the click spring; a cover provided to cover the recessed portion and to house the click spring at the recessed portion; and a strain detecting element attached to another surface of the base. The strain detecting element is configured to detect strain of the base, the strain occurring in accordance with a depression amount of the click spring that is depressed.

A switch according to the present invention includes a base including a recessed portion on one surface of the base; a click spring having a dome shape, the click spring being provided at the recessed portion such that the bottom of the recessed portion is contacted at a dome-shaped opening side of the click spring; a cover provided to cover the recessed portion and to house the click spring at the recessed portion; and a strain detecting element attached to another surface of the base. The strain detecting element is configured to detect strain of the base, the strain occurring in accordance with a depression amount of the click spring that is depressed.

A pushbutton includes a base extending in a longitudinal direction, a sensor module mounted to the base, a keycap disposed above the sensor module, two scissor switch modules, a main pushbutton module and two side pushbutton modules. The sensor module has a first sensing member and two second sensing members. The main pushbutton module is operable to switch between a released state, where the main pushbutton module is not in direct contact with the first sensing member such that each of the scissor switch modules would not be in direct contact with a respective one of the second sensing members, and a depressed state, where the main pushbutton module comes in direct contact with the first sensing member.

A switch device includes an operation switch including a switch knob formed integrally with a recess configured to allow a finger to be inserted. The operation switch includes a detector configured to detect a change in a physical amount caused by operation of the switch knob.

A cable pull switch includes a polychotomous sensor configured to provide a reading of at least one of a plurality of values, the reading corresponding to a tension on a pull cable or a linear displacement of an end of a pull cable. A processor coupled to the polychotomous cable pull sensor configured to determine a rate of change of the value of the reading from the sensor and determine an occurrence of a cable pull event, the determination based on the determined rate of change of the value, and determine whether the rate of change of the value of an electrical resistance through the polychotomous cable pull sensor is below a threshold rate of change value, and adjust an upper pull threshold value to a new upper pull threshold value that is based on a present reading of the value of the electrical resistance through the strain gauge.