Circuit Operation; Ignition Circuit - Textron Jacobsen InCommand PGM 22 Technical/Repair Manual

ELECTRICAL

Circuit Operation

Ignition Circuit

Operation
See Figure 4-4.
4
A magnet is mounted on the flywheel. When the flywheel
turns, the magnet passes by the ignition coil (T1). The
moving magnetic field provided by the magnet induces
voltage in the primary windings in the ignition coil. The
secondary windings provide high voltage to spark plug
(E1) by stepping up the voltage that is generated in the
primary windings.
When the E-stop switch (S1) or the engine on/off switch
(S2) is in the OFF position, the primary windings in the
ignition coil are grounded. With the primary windings
grounded, voltage induced in windings is shorted to
ground and the ignition coil does not produce high
voltage. Without high voltage at spark plug (E1), the
engine cannot operate.
4-8
S1
E-Stop
Switch
On
Off
X2 X3
Blk Red
X1
S2
Engine
On/Off
Switch
On
Off
X4
Blk
Figure 4-4: Ignition Circuit—Run Position
X5
Red Red Gry
Splice 1
X6
T1
Ignition
Coil
E1
Spark
Plug
4157082 First Edition