How do touch lamps work?
Touch-sensitive lights seem simple enough but their switches work on the principle of body capacitance.
Asked by: Richard Simpson, Hastings
Touch lamps work on the principle of capacitance – the amount of charge something can soak up. In circuits, components called capacitors store varying amounts of charge and are used to tune circuits like radio receivers or smooth out fluctuations in voltage. When we make contact with a touch lamp, we alter its capacitance. The lamp detects this and switches on or off accordingly.
Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.
Authors
Sponsored Deals
Subscription offer
Subscribe and try your first 3 issues for just £5. After your introductory period you will pay just £22.99 every 6 issues by Direct Debit. Receive every issue delivered direct to your door with FREE UK delivery.
