Body capacitance properties and effects
– Synthetic fabrics and friction can charge a human body to about 3 kV.
– Modest voltages of 100 volts can damage some electronic devices.
– Electronics factories take precautions to prevent static charge build-up.
– A branch of the electronics industry focuses on preventing electrostatic discharge.
– Footwear, low humidity, and a dry carpet can charge a person’s body capacitance to tens of kilovolts.
– Body capacitance can affect the resonant frequency of early radios.
– Body capacitance is utilized in the Theremin musical instrument.
– Capacitance of a human body is typically in the tens to low hundreds of picofarads.
– The occasional static shock has relatively low stored energy and does not harm a healthy person.
– The Human Body Model for capacitance is a 100pF capacitor in series with a 1.5kΩ resistor.
Body capacitance in touch sensors
– Body capacitance can operate pushbutton switches for elevators or faucets.
– Voltage tester probes rely on body capacitance.
– Capacitive touch sensors respond to the close approach of a human fingertip.
– Capacitive touch screens do not require applying force to their surfaces.
– People can act as good antennas, enhancing reception for small televisions.
Related concepts
– Triboelectric series
– Triboelectric effect
– Touch-sensitive lamp
References
– ESD Association (2010). Fundamentals of Electrostatic Discharge. Part Five—Device Sensitivity and Testing (PDF). Rome, NY. Retrieved 13 April 2023. Source: https://en.wikipedia.org/wiki/Body_capacitance
This article needs additional citations for verification. (July 2007) |
Body capacitance is the physical property of the human body that it acts 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 surroundings; it would be low when standing on top of a pole with nothing nearby, but high when leaning against an insulated, but grounded large metal surface, such as a household refrigerator, or a metal wall in a factory.
