I have this bedside lamp thats lights when i touch any of its metalic part.whats the technology behind it?

Question

I touch it ounce,it comes on,touch it again it brightens and brightens further on the third touch.It will go off on the forth touch.

Answer 1

This application uses human body capacitance as the trigger for the switcing.

One application of a capacitance-activated circuit is to form a switch that is triggered by the touch of a human finger to a metal button. The circuit operates by measuring the capacitance change between the metal touch button and an earth ground.

The skin of the human finger is thin and the human blood under the skin makes a nice electrical conductor. The outside surface area of the human body is also large. The act of touching a human finger to a metal button will therefore form an electrical interface that will produce a sizable capacitance change, if there are any metal objects nearby that are connected to earth ground. This environmental capacitance will depend on many factors. The most important factors are the type of floor the human is standing on and the type of shoes he or she is wearing. The capacitance change will increase with bare concrete floors and thin sole shoes. Nearby metal shelves, tables, light fixtures, heating ducts and electrical wires will also effect the total capacitance between the human body and earth ground. Experiments have shown that seldom does the capacitance change measure less than about 30 picofarads. At the other end of the spectrum, if the human is also in contact with an earth grounded object, the finger/button interface can produce a capacitance change of several thousand picofarads. In most applications, a minimum capacitance change threshold can be set. When exceeded, the detected change is used to activate an electronic switch. With a carefully designed circuit a switch can be triggered with a capacitance change of only one picofarad.

Answer 2

Inside the base of the lamp is an electronic module, that has a capacitive touch sensor and lamp switch/dimmer. When you touch the metal on the lamp, you add your body capacitance to the capacitance of the lamp. The electronic module senses the extra capacitance and switches the lamp dim, brighter, brightest, off (on sucessive touches).

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Answer 3

it is so easy man. i think they used the same way as an electromagnet, but with a brightness contrast (whether you can bright it up or dim it down) when you touch the whole circuit which traps the brightness of the light bulb disconnects, when you touch it again, the inner circuit(its called sub circuit) disconnect and the light bulb brights up again. it also has another sub circuit which gives you the maximum brightness. finally, there is a whole circuit(called primary superior circuit) been produced when you disconnected all the sub circuits. for the final touch, the primary circuits disconnects so the sub circuits rejoins. when you touch, the circuits disconnects, because the current passes through you, so the circuit cannot be finished. the main basic is, when you touch, you disconnects the trap line of the brightness contrasts.

Answer 4

A lot of possibilities.

If your lamp is cheap then
1)The metallic parts are buttons.
2)Lamp is spoilt

If your lamp is expensive then
1)Unknown Advance Technology
2)Cap sensors (non metallic)