Control devices, in their simplest form, turn the circuit on and off and are designed for power management. Depending on the application and its scope, control switches can be of several types. They are designed to work in many different environments from extremely high pressure to extremely low pressure. Some control switches are designed to operate automatically whereas some require manual handling. Here are some of the various types of switches which are used for control applications-
- Single-break or double-break switches- Switches can be categorized on the basis of breaks. A single-break switch has one opening at the terminal in the circuit. Double-break switches, on the other hand, break the circuit in two places. The upper part of the schematic symbol indicates that the contacts are in the open position. The circuit gets closed when the switch is acted upon (manually or automatically). The lower symbol represents closed contacts. The contacts open the circuit when the switch is acted upon. PCB mounted switches are an example of double break switches.
- Rotary Switches - Rotary switches are control devices known for their wide use at industrial settings. In a full or partial circle, a rotary switch is a mid-contact switch part of the schematic with the contacts arranged. The mechanism used to select the contact moves in a circular motion and must be turned Instead of pressing a button or toggling. Rotary switches can be both automatic or manual. Automobile distributors, ignition switches on motor vehicles are a few examples of rotary switches.
- Multi-contact switches - As the name itself suggests, multi-contact switches have multiple contacts and they are used to either control more than one circuit or select one of several possible circuits.
Apart from temperature, environmental conditions which influence the decision of choosing a switch include humidity, liquid splashing or immersion, ice, corrosion, shock, and vibration.
