THE PRINCIPLE BEHIND HEATING ELEMENTS

Heating elements are made out of a resistor such as nichrome wire. A resistor is a material which lets electric current flow, but resists the flow. The current will still be allowed to flow but the rate at which it will flow will be low because of the resistance in the wire. A large electric current contains a lot of energy. When that current is sent through a resistor, almost all of that energy is turned into heat. Thus in that process of trying to pass through the wire, because and electric current must flow, heat is generated. The heat generated is simply as a result of electrical energy converted to heat energy in the wire. That heat is what is used in electric ovens, furnaces, heat lamps and other heated devices.

We Can Do A Little Study Using an Electric Kettle

Electric Kettle Basics

At the
bottom of the kettle is a sealed electric heating element. Above the heating element is a canister that holds water. The canister can be removable, or it can be built into the kettle. The controls are on the side of the kettle. Typically, there is an on/off switch and a thermostat which controls how hot the kettle gets.

The Heating Element

Electric kettles are powered by a heating element which works in the same way an electric range does. The heating element is a resistor—a material that resists the flow of electricity. When electricity flows into the resistor, it is turned into heat. That heat is what heats up the water inside the kettle.

The Thermostat

The heating element is controlled by the thermostat. The thermostat has a variable resistor inside. The higher you set the temperature, the lower the resistance is. A small current runs through the thermostat, usually controlling an electronic switch called a transistor. The transistor, in turn, controls the heating element. When the resistance goes up in the thermostat, less current flows through, which causes less current to flow through the heating element. This keeps the heating element and the water cooler. When the resistance is reduced, the current through the thermostat increases, which causes the transistor to increase the current through the heating element. This raises the temperature of the water.

Other heating element works with almost the same principle. This is just one of the ways to explain the working principle of a heating element.