Relays & switches

Electrical switches are devices utilized to manually control electric current flow. Manually operated switches include an actuator used to cause making/breaking action of switch contacts to energize or de-energize one or more electrical circuits associated with the contacts. In addition to switching electrical signals responsive to physical actuation of the switch, electrical switches may include actuation indication including tactile feedback or audible feedback. Switches are available that are equipped with lamps used for helping people find the switches in the dark. There are several different types of light switches. Common switch types include rocker, toggle, push button, rotary, keylock, slide, snap action and reed switches. Switches are highly varied based on their intended utility. In electromechanical systems, switches provide the function of making and breaking electrical contacts and consequently electrical circuits. Switches responsive to fluid levels have utilized a variety of approaches for opening and closing an electrical circuit. Switches have found particular use in industrial control systems, where it is often desirable to monitor conditions so that appropriate actions may be taken in response to the monitored conditions. A relay is used to perform automatic electrical switching. An electromechanical relay is opened or closed by energizing an electromagnet to either attract or repel a metal contact on a movable strip of metal. A solid state relay has all its components made from solid state devices and involves no mechanical movement. They are compatible with digital circuitry and have a wide variety of uses with such circuits.