Isolator

An isolator is a device or system that provides separation between two circuits, components, or domains to prevent unwanted transfer of energy, signals, or vibrations. Isolators are used to improve safety, protect equipment, and reduce interference. They come in many forms, from simple mechanical devices to complex assemblies, and are employed in electrical power systems, electronics, and structural engineering.

Electrical isolator

In electrical power and control, an isolator (or disconnect switch) is a mechanical device that can physically separate parts of a circuit from the supply for safety during maintenance. It provides a visible open gap but is not intended to interrupt fault currents; protection is provided by fuses or circuit breakers. Typical configurations include single-, double-, or multi-pole devices with latching mechanisms and interlocks to prevent misoperation. They are used in substations, switchgear, and industrial plants.

Optical isolator

In electronics, an optical isolator (opto-isolator) transfers signals between circuits with galvanic isolation using light. It typically consists of an LED and a photodetector in an enclosed package. Isolation prevents ground loops and protects low-voltage circuitry from high voltages or transients. Isolation ratings vary and may include voltage ratings from a few hundred to several thousand volts, depending on design.

Mechanical and seismic isolators

In mechanical and structural engineering, isolators reduce transmission of vibrations, noise, or seismic energy. Vibration isolators include rubber mounts, springs, and more complex pendulum or tuned-mass systems. Seismic base isolators, used in buildings and bridges, decouple structures from ground motion to improve safety during earthquakes; they employ bearings or pneumatic systems with dampers to absorb energy.