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A time switch (also called a timer switch, or simply timer) is a device that operates an electric switch controlled by a timer. Intermatic introduced its first time switch in 1945, which was used for "electric signs, store window lighting, apartment hall lights, stokers, and oil and gas burners." A consumer version was added in 1952.
OpenTherm (OT) is a standard communications protocol used in central heating systems for the communication between central heating appliances and a thermostatic controllers. [1] As a standard, OpenTherm is independent of any single manufacturer. A controller from one manufacturer can in principle be used to control a boiler from another ...
English: Active indirect water heater. 1: Municipal water feed 2: Fluid from water storage tank to external (passive) heat source; passive heat source can be the ground (soil or groundwater), sun or air; eg via heat pump, or thermodynamic solar panel 3: Fluid from heat pump, or thermodynamic solar panel to water storage tank 4: Pump, actuator, controller and other parts 5: Water heater 6 ...
HVAC (Heating, Ventilation and Air Conditioning) equipment needs a control system to regulate the operation of a heating and/or air conditioning system. [1] Usually a sensing device is used to compare the actual state (e.g. temperature) with a target state. Then the control system draws a conclusion what action has to be taken (e.g. start the ...
A control loop is the fundamental building block of control systems in general and industrial control systems in particular. It consists of the process sensor, the controller function, and the final control element (FCE) which controls the process necessary to automatically adjust the value of a measured process variable (PV) to equal the value of a desired set-point (SP).
An aquastat is a device used in hydronic heating systems for controlling water temperature. [1] [2] To prevent the boiler from firing too frequently, aquastats have a high limit temperature and a low limit.
A good example of this is a central heating boiler controlled only by a timer, so that heat is applied for a constant time, regardless of the temperature of the building. The control action is the switching on/off of the boiler, but the controlled variable should be the building temperature, but is not because this is open-loop control of the ...
At that time central heating was coming into fashion in Britain, with steam or hot air systems generally being used. Details of furnace and expansion tube from Perkins' 1838 Patent Perkins' 1832 apparatus distributed water at 200 degrees Celsius (392 °F) through small diameter pipes at high pressure.