ELECTRONIC CONTROL SYSTEM
- Vehicle Speed Senso
r
3
. ELECTROMAGNETIC PICKUP TYP
E
This sensor is fitted to the transmission and
detects the rotational speed of the transmission
output shaft
.
This sensor consists of a permanent magnet, a
coil, and a core
. A rotor with four teeth is
mounted on the transmission output shaft
.
Rotor
N S i Magne
t
OHP 3
0
+V
OHP 30
0
-
V
ELECTRICAL CIRCUITRY
OHP 3
0
Engine EC
U
OHP 3
0
OPERATION
When the transmission output shaft rotates, the
distance between the core of the coil and the
rotor increases and decreases because of the
teeth
.
The number of lines of magnetic force passing
through the core increases or decreases
accordingly, and AC (alternating current) voltage
is generated in the coil
.
Since the frequency of this AC voltage is
proportional to the rotational speed of the rotor,
it can be used to detect the vehicle speed
.
OHP 3
0
®
Coil Core Speed sensor
35