|The value of capacitance
is determined by:
(a) the area of the plates
(b) the distance between the plates
(c) the type of dielectric between the plates
|The picture above shows how the area of the plates can be adjusted by varying the overlap.|
|In the above diagram the
flexible diaphragm act as one of the capacitor plates.
As pressure is applied to the input it bends towards the fixed plate thus increasing the capacitance.
|In the above capacitor the
position of the dielectric is varied to vary the capacitance.
The picture below shows an application of this.
|The last diagram shows an
application for capacitive transducers.
The frequency of the oscillator is determined by the LC combination.
The output of the oscillator is converted to a DC voltage.
The value of the voltage can be displayed on a digital meter as inches.
Copyright Graham Knott 2004