Pushbutton

Pushbutton is a type of electrical switch actuated by a button. When pressed, it alters the state of one or more electrical circuits, enabling functions such as starting a motor, issuing a command, or triggering a process. Pushbuttons are used in industrial control panels, consumer devices, and instrumentation.

Pushbuttons are classified by their actuation behavior: momentary and maintained (latching). Momentary pushbuttons return to the non-pressed position when released, making them suitable for transient signals. Maintained pushbuttons stay in their new state after being pressed, until another action changes it. They can be normally open (NO) or normally closed (NC), indicating the state of the circuit when the button is not pressed.

Construction and characteristics: A pushbutton comprises an actuator or plunger, a contact block with electrical contacts, springs, and a housing. The contacts may be metal alloys such as silver or gold plating to improve longevity. They are rated for a maximum current and voltage, and have specified mechanical life in cycles. Environmental ratings (IP codes) indicate resistance to dust and water.

Variants and applications: industrial emergency-stop pushbuttons are large, red, and locked in the pressed position; panel pushbuttons are smaller and may include illumination or tactile feedback. Pushbuttons can be momentary or latching, illuminated, shielded, or waterproof, depending on the application.