Section 3 - Applications
3-17
Applications
Balance, Level, Vibration, Acceleration
A magnet suspended from a pendulum, free to move in the X - Y plane, may be used to detect level posi-
tion, acceleration and vibration. Figure 12 shows a magnet with the center as a North pole and an outer
ring of South pole. In a level, stable condition, the North pole turns OFF the switch. Motion will cause
the magnet to move in such a way that the South pole is over the Hall IC, turning the switch ON.
Obviously, the mechanical configuration is not trivial, and will vary greatly depending on the application.
Switches like this are used in some washing machines.
Figure 17, Level and Motion Switch
A-18
S
N
S
S
S
The magnet is free to move relative to the Hall IC.
Any force disturbing the magnet may result in a South pole
facing the Hall IC, resulting in an ON condition