Push button switches

A push button switch looks like a button which is a pilot device used in control circuits. It provides control of equipment by pressing an actuator. Two parts of push button switch are mechanical actuator and contact block. Mechanical part is also known as button assembly. Contact block is the electrical portion of the push button switch. The mechanical actuator is comprised of momentary-contact spring. This spring can be returned type or maintained contact type. Returned type category remains actuated as long as the button is physically held pressed by the human operator. Maintained contact type can be held actuated by some latching mechanism even after the operator withdraws the pressure on the push button. Based on the type of actuator assembly used, push button switches are classified into four categories. They are recessed button type, key lock type, mushroom head type and illuminated type. A push button station is a system where more than one push button switches are mounted on a steel enclosure. In a three push button station, one push button is used for running the motor in forward direction, the second one is used for running motor in the opposite or reverse direction and the third one is used for stopping the motor.