An electromagnetic switch with two sets of contacts that may concurrently control two different circuits is known as a DPDT (Double Pole Double Throw) relay. A common terminal (COM), a normally open terminal (NO), and a normally closed terminal (NC) are the three terminals that each set of contacts possesses.
The coil is energized by applying a voltage across its terminals, creating a magnetic field that pulls the movable switch contacts towards it. When the coil is not energized, the contacts return to their default positions due to the force of a spring.
What is a DPDT relay?
DPDT Relay Diagram
The DPDT relay has two sets of switch contacts that can be mechanically actuated simultaneously. Each set has a common terminal (COM), a normally open terminal (NO), and a normally closed terminal (NC). The common terminals are connected to the moving armature, and the NO and NC terminals are connected to the stationary contacts.
When the coil is energized, the movable armature moves, and the switch contacts change their positions. The normally open contacts, which were initially disconnected, are close to establishing a connection. Conversely, the normally closed contacts, which were initially connected, open to break the connection. This double-throw action allows the DPDT relay to switch between two separate circuits simultaneously.
DPDT relays find various applications in areas such as industrial control systems, automation, telecommunications, and electronic circuits. They are commonly used in situations where multiple circuits need to be controlled simultaneously or where polarity reversal or switching between two different loads is required.