What is an SPDT Micro Switch 19mm

An SPDT (Single Pole Double Throw) micro switch 19mm is a compact, high-precision electrical switch designed for low-current, quick-action control. The "19mm" refers to its primary mounting or housing dimension (typically length or width), making it ideal for space-constrained applications where miniaturization is critical. As an SPDT-type switch, it features one common terminal (COM), one normally open terminal (NO), and one normally closed terminal (NC)—a configuration that enables versatile circuit switching, such as toggling between two separate circuits or activating/deactivating a load.

Key Specifications & Structure

Built with durability in mind, most 19mm SPDT micro switches have a rated voltage of 125V-250V AC and current of 0.1A-10A, depending on the model. The housing is usually made of flame-retardant thermoplastics (e.g., PA66) for heat and impact resistance, while internal contacts use silver alloy or copper for low resistance and anti-oxidation. A defining feature is its snap-action mechanism: a small actuator (lever, roller, or pin) triggers the switch with minimal force (typically 10-500g), ensuring fast, consistent contact separation (usually <10ms) to prevent arcing and extend lifespan (up to 100,000-1,000,000 operations).

Applications & Advantages

Its compact 19mm size and SPDT versatility make it a staple in consumer electronics, industrial equipment, and automotive systems. Common uses include: vending machines (detecting product dispensing), home appliances (washing machine door locks, microwave door interlocks), medical devices (small diagnostic tools), and automotive interiors (window lift controls, seat position sensors). Key advantages include: space efficiency (fits tight enclosures), reliable performance in harsh environments (resistant to dust and mild moisture), and easy integration with PCBs or panel mounts via solder terminals or quick-connect tabs. For engineers and designers, it balances precision, durability, and flexibility—an essential component for modern electronic control systems.