06/10/2021
The Room thermostat or Room stat is mechanical or electronical device
A THERMOSTAT is a regulating device component which senses the temperature of a physical system and performs actions so that the system's temperature is maintained near a desired set point.
Thermostats are used in any device or system that heats or cools to a set point temperature, examples include building heating, central heating, air conditioners, as well as kitchen equipment including ovens and refrigerators.
Thermostats use different types of sensors to measure the temperature:
- The mechanical thermostat, a bimetallic strip in the form of a coil directly operates electrical contacts that control the heating or cooling source.
- The electronic thermostats, instead, use a thermistor or other semiconductor sensor that requires amplification and processing to control the heating or cooling equipment.
- Electronic wireless thermostat.
A thermostat exerts control by switching heating or cooling devices on or off, or by regulating the flow of a heat transfer fluid as needed, to maintain the correct temperature. A thermostat can often be the main control unit for a heating or cooling system, in applications ranging from ambient air control. Thermostats are used in any device or system that heats or cools to a set point temperature.
A thermostat is an example of a "bang-bang controller" as the heating or cooling equipment output is not proportional to the difference between actual temperature and the temperature set point. Instead, the heating or cooling equipment runs at full capacity until the set temperature is reached, then shuts off. Increasing the difference between the thermostat setting and the desired temperature therefore does not change the time to achieve the desired temperature.
The rate at which the target system temperature can change is determined both by the capacity of the heating or cooling equipment to respectively add or remove heat to or from a target system and the capacity of the target system to store heat.
