| 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