Hello friends, welcome to ELECTRICAL ENCYCLOPEDIA. In this article we will study about AIR FRICTION DAMPING.
AIR FRICTION DAMPING
As we all know the purpose of providing damping in the Electrical Instruments i.e, to prevent the unnecessary oscillation of the pointer about the final position . There are several methods of damping and Air Friction Damping is one of them.
In this method of damping, a light aluminium piston (as shown in fig)is attached to the moving part of the system. This piston is placed inside a cross section called Air Chamber, which is closed at one end hence providing a very small clearance.It can be either circular or rectangular.
Amount of Damping of the oscillation of pointer depends upon the compression and suction action of the light aluminium piston on the air enclosed in the chamber.
Such methods of damping are not favoured nowadays.