Touch Technology
TOUCH TECHNOLOGY
INRODUCTION
Touch technology has redefined the meaning of the term user-friendliness. This technology, once considered to be a distant dream, has touched all aspects of our life today. From mobile phones to personal computers to advanced applications in the field of scientific research, touch technology is everywhere. This is my attempt to bring you up to date with the very basics and also the new advancements in the field of touch technology, a technology that would forever change the way we look at and interact with the various gizmos at our disposal.
Touch switches
A touch switch is a type of switch that only has to be touched by an object to operate. It is used in many lamps and wall switches that have a metal exterior as well as on public computer terminals.
There are basically two types of touch switches. They are: • Capacitance touch switch A capacitance switch needs only one electrode to function. The electrode can be placed behind a non-conductive panel made of for example wood, glass or plastic.
• Resistance touch switch A resistance switch needs two electrodes to be physically in contact with something electrically conductive (for example a finger) to operate.
Capacitance touch switch
A capacitance touch switch works using body capacitance, a property of the human body that gives it great electrical characteristics. The lamp keeps charging and discharging its metal exterior to detect changes in capacitance. When a person touches it, it increases the capacitance and triggers the switch.
Capacitance
At the heart of any capacitive-sensing system is a set of conductors which interact with electric fields. The tissue of the human body is filled with conductive electrolytes covered by a layer of skin, which acts as a dielectric. It is the conductive property of fingers that makes capacitive touch sensing possible.
A simple parallel plate capacitor has two conductors separated by a
INRODUCTION
Touch technology has redefined the meaning of the term user-friendliness. This technology, once considered to be a distant dream, has touched all aspects of our life today. From mobile phones to personal computers to advanced applications in the field of scientific research, touch technology is everywhere. This is my attempt to bring you up to date with the very basics and also the new advancements in the field of touch technology, a technology that would forever change the way we look at and interact with the various gizmos at our disposal.
Touch switches
A touch switch is a type of switch that only has to be touched by an object to operate. It is used in many lamps and wall switches that have a metal exterior as well as on public computer terminals.
There are basically two types of touch switches. They are: • Capacitance touch switch A capacitance switch needs only one electrode to function. The electrode can be placed behind a non-conductive panel made of for example wood, glass or plastic.
• Resistance touch switch A resistance switch needs two electrodes to be physically in contact with something electrically conductive (for example a finger) to operate.
Capacitance touch switch
A capacitance touch switch works using body capacitance, a property of the human body that gives it great electrical characteristics. The lamp keeps charging and discharging its metal exterior to detect changes in capacitance. When a person touches it, it increases the capacitance and triggers the switch.
Capacitance
At the heart of any capacitive-sensing system is a set of conductors which interact with electric fields. The tissue of the human body is filled with conductive electrolytes covered by a layer of skin, which acts as a dielectric. It is the conductive property of fingers that makes capacitive touch sensing possible.
A simple parallel plate capacitor has two conductors separated by a