Which of the following are the basic elements of a control system?

The basic elements of a control system include a controller, a controlled device, and a source of energy. The controller is responsible for regulating the operation of the controlled device, which is the component that needs to be controlled, such as a furnace, air conditioning unit, or refrigeration system. The source of energy provides the necessary power for the controlled device to operate.

In any control system, the controller processes information from various inputs (like sensor data) and makes decisions to maintain the desired state or performance of the controlled device. The controlled device, receiving instructions from the controller, performs the necessary actions to achieve the desired outcome, and the source of energy enables this process by supplying the energy needed for operation.

Therefore, the combination of these three elements—controller, controlled device, and source of energy—forms a complete basic control system, allowing effective regulation and functionality in HVAC and refrigeration applications.