Made possible by design breakthroughs in the Twenties and Thirties, the electric kettle makes tea-making a piece of cake!
The electric kettle works thanks to two key design breakthroughs achieved in Britain in the Twenties and Thirties.
The first is the immersed heating resistor, the piece of technology responsible for actually raising the temperature of the water in the kettle. Resistors, which take the form of the heating element in the bottom of the kettle, work by resisting the flow of electric current passed through them. This creates resistance and consequently heat. This heat is then passed into the water, which is then subsequently heated up.
The second of these advances allowed for an automatic cut-off point, preventing the kettle from perpetually heating up the water. A bimetallic strip was introduced to the electric kettle by Russell Hobbs in 1955, which, when heated by steam expanded, triggering a shut-off switch.
Although some kettles have fancier and more complex heating and shut-off designs, it is through these two basic principles that the electric kettle evolved into the appliance we have in our kitchens and workplaces today.
Heating element – This works by resisting the flow of electrical current, which creates the heat the heats the water.
Detachable base – A feature on all modern kettles, the base contains contacts that allow the flow of electricity to the element.
Power adapter – Connecting the heating element to the power supply allowing the flow of current through the element.
Bimetallic strip – When the water heats up it causes the bimetallic strip to bend which triggers the switch that cuts off the power.