A touch-sensitive lamp is a combination of a lamp and a touch switch. They act on the principle of

body capacitance Body capacitance is the physical property of the human body that has it act as a capacitor. Like any other electrically-conductive object, a human body can store electric charge if insulated. The actual amount of capacitance varies with the surro ...

, activated by human touch rather than a flip, push-button, or other mechanical

switch In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type ...

. They are popular as desk and nightstand lamps. Touch-sensitive lamp switches may be dimmable, allowing the brightness of the lamp to be adjusted by multiple touches. Most stop at level 3, which is for the brightest use. These lamps contain an oscillator that changes frequency when the metallic plate is touched.

History

Alladin Industries filed key "Aladdin Lamps" patents in 1954 and 1956, and commercial models were available by 1955. However, due to low electrical efficiency and high price of the

vacuum tube A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied. The type kn ...

-based product, the concept was not popularized until later versions of the touch mechanism used integrated circuits and

transistor upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink). A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch ...

s to improve efficiency and reduce cost in the mid 1980s.

References

External links

HowStuffWorks question: How do touch-sensitive lamps work?Video: "The touch lamp; a neat idea, and older than you'd think!" by Technology ConnectionsTouch Sensitive LED Light Read more
Light fixtures Types of lamp Articles containing video clips {{Electronics-stub