Relés

Relés are electromechanical switches that use an electromagnet to operate one or more sets of contacts. When an electric current passes through the coil of the electromagnet, it generates a magnetic field that attracts an armature. This armature, in turn, moves the contacts, either closing an open circuit or opening a closed circuit. Relés are used to control a high-power circuit with a low-power signal, or to control multiple circuits simultaneously.

The basic components of a relé include a coil, an armature, and contacts. The coil is typically made of copper wire wrapped around a soft iron core. The armature is a movable piece of metal that is attracted by the magnetic field of the coil. The contacts are small pieces of metal that make or break the electrical connection. Relés come in various types, such as SPST (single-pole, single-throw), SPDT (single-pole, double-throw), DPDT (double-pole, double-throw), and others, each with different arrangements of contacts.

Applications of relés are widespread in electrical and electronic systems. They are commonly found in automotive systems for controlling lights, horns, and starter motors. In industrial automation, relés are used for controlling machinery, sequencing operations, and providing safety interlocks. Consumer electronics also utilize relés, for example, in washing machines, refrigerators, and power supplies. The ability to isolate control circuits from power circuits makes relés valuable for safety and signal isolation. While solid-state relays (SSRs) offer advantages in certain applications, traditional electromechanical relés remain prevalent due to their simplicity, robustness, and cost-effectiveness.