Switches

About switches

Switches are electromechanical components that control the flow of current in a circuit. They are broadly categorized by their actuation method and contact configuration. Common types include toggle switches, actuated by a lever; rocker switches, which pivot on an axis; push-button switches, momentary or latching; rotary switches, with multiple positions; and selector switches, offering distinct detented positions. Limit switches are a specialized type, often used for position sensing in machinery, available in plunger, roller, or lever actuator styles. Key selection parameters include contact rating (voltage and current, AC/DC), number of poles and throws (e.g., SPST, DPDT), actuation force, operating temperature range, and electrical life cycles. Environmental considerations, such as IP rating for dust and water ingress, are critical for industrial applications. Materials for contacts typically include silver alloys for conductivity and arc resistance, while housings are often molded from engineering plastics like nylon or polycarbonate, or metals such as brass or stainless steel for robust applications. Terminations vary from solder lugs and quick-connect terminals to screw terminals or PCB pins.