ELECTRICAL - Meters and Gauges
7-17
Cross Coil
When current flows in the cross coil, a magnetic field is generated in
coil 1 and coil 2. Since the two magnetic fields pass directly through,
the actual magnetic field is a combination of the two magnetic fields.
Since the magnet is fixed to the pointer shaft, the magnet rotates to
try to align the magnetic axis of the magnet in the direction of the
combined magnetic field and thus rotates the speedometer pointer.
NOTE
The speedometer pointer is attached to the pointer shaft 20°
counterclockwise to the magnetic axis of the magnet.
RELATION BETWEEN POINTER ANGLE AND CURRENT VALUE
The angle of the pointer is determined by a variation of the current
value flowing in coil 1 and coil 2.
Example:
When the pointer is at 90°
• Maximum current flows in coil 1.
• No current flows in coil 2.
NOTE
When the pointer is at an angle of 0°, it indicates a speed of
o
km/h
(0 mph).
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