What is a Single Pole Double Throw (SPDT) Switch?

SPDT Switch Diagram

Basic Definition

A Single Pole Double Throw (SPDT) switch is an electrical switch that has one input terminal (pole) and two output terminals (throws). It allows you to connect one input to either of two different outputs, but never both simultaneously.

Key Characteristics

Single Pole

One input connection point

Double Throw

Two possible output connections

Mutually Exclusive

Only one output active at a time

How It Works

The SPDT switch has three terminals: one common terminal (C) and two switching terminals typically labeled as Normally Open (NO) and Normally Closed (NC). When the switch is in one position, the common terminal connects to the NC terminal. When actuated, it breaks that connection and makes a new connection to the NO terminal.

Common Applications

  • Three-way light switches
  • Motor direction control
  • Signal routing in electronics
  • Safety interlocks
  • Audio/video switching

Advantages

  • Versatile switching capability
  • Reliable operation
  • Cost-effective solution
  • Simple wiring requirements
  • Available in various sizes

WEUP's SPDT Switch Solutions

As a professional switch manufacturer with over 35 years of experience, WEUP produces high-quality SPDT switches that meet international standards including UL, VDE/TUV, ENEC, and CE certifications.

Product Range: Rocker switches, toggle switches, and push button switches in SPDT configuration
Applications: Household appliances, medical equipment, automotive parts, and new energy systems
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