A thermostat is a device that regulates the temperature of a system so that the system's temperature is maintained near a desired setpoint temperature. The thermostat does this by switching heating or cooling devices on or off, or regulating the flow of a heat transfer fluid as needed, to maintain the correct temperature.
Thermostats are used in a variety of applications in both industry and the home. In industry, thermostats are used in refrigeration, air conditioning, and heating systems, as well as in a variety of other systems. In the home, thermostats are used to control the heating and cooling of the home, as well as the temperature of the home's hot water.
There are a variety of different types of thermostats available on the market today, including mechanical, electronic, and programmable thermostats. Each type of thermostat has its own set of advantages and disadvantages that should be considered when choosing a thermostat for a particular application.
Mechanical thermostats are the simplest and most common type of thermostat. They typically consist of a bimetallic strip that expands and contracts with changes in temperature. This expansion and contraction causes the strip to bend, which in turn activates or deactivates a switch.
Electronic thermostats are more accurate than mechanical thermostats and can be more easily controlled. They typically use a thermistor, which is a type of resistor that changes resistance with changes in temperature, to measure the temperature. The resistance of the thermistor is then used to control a switch that turns the heating or cooling device on or off.
Programmable thermostats are the most sophisticated type of thermostat and can be programmed to turn the heating or cooling device on or off at specific times of the day. This allows the user to set the temperature for the times when they are home and awake and lower the temperature for the times when they are away or asleep.
When choosing a thermostat, it is important to consider the type of system that will be controlled, the accuracy required, the ease of use, and the cost.