Thermostat facts for kids
A thermostat is a clever device that helps keep a place or a system at just the right temperature. Think of it as a temperature detective! It senses how hot or cold things are and then tells a heating or cooling system what to do.
A thermostat is a sensor that constantly checks the temperature. Its main job is to keep a heating or cooling system at a specific, desired temperature. This desired temperature is often called the "setpoint." It's like setting a goal for the temperature and making sure it stays there. The word "thermostat" comes from two old Greek words: thermos, meaning "hot," and statos, meaning "a standing" or "staying."
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How Do Thermostats Work?
Thermostats work by turning heating or cooling devices on or off. For example, in a central heating system or an air conditioner, the thermostat decides when to switch the furnace or AC unit on or off.
Sometimes, a thermostat works by controlling a special liquid or gas. This "heat transfer fluid" moves heat around. The thermostat turns its flow on or off as needed. This helps to keep the temperature exactly where it should be.
Simple Thermostats
The simplest type of thermostat uses a special strip of metal. This is called a bimetal strip. It's made of two different metals joined together. When the temperature changes, these two metals expand or shrink at different rates. This makes the strip bend.
When the bimetal strip bends enough, it can break an electrical circuit. This turns off the power to a heating device. When the temperature drops, the strip straightens. This closes the circuit again, turning the heat back on. Many kitchen toasters use this simple type of thermostat.
Thermostats as Control Systems
Thermostats are great examples of feedback devices. They are part of a control system. This means they watch what's happening (the temperature). Then, they use that information to make adjustments. This helps to keep the local environment stable. They protect it from big temperature changes outside.
In a field called cybernetics, a thermostat is a classic example. It shows how a machine can use feedback. This feedback helps to maintain the stability of a heating or cooling system. It's all about keeping things steady and comfortable!
Images for kids
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Honeywell's famous "The Round" model T87 thermostat. One is even in the Smithsonian museum!
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A modern Honeywell electronic thermostat in a store.
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A thermostat found in a car engine.
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A bimetallic thermostat often used in buildings.
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The inside parts of a millivolt thermostat.
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A digital thermostat for homes.
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The Lux Products WIN100 programmable thermostat, shown closed and open.
See also
In Spanish: Termostato para niños
