Wacker Neuson WM 170 Repair Manual

WM 130/170/270 Repair Electrical
wc_tx000381gb.fm 91
11.3 WM 130/WM170 Ignition Coil Internal Circuit
11.4 Basic Theory
See Graphic: wc_gr001823
11.4.1 Revolution of the flywheel generates electricity on the primary side of
the ignition coil, and the electric current I
1
flows to the power transistor
(4). Current I
1
turns the power transistor “ON” and electric current I
2
flows.
11.4.2 When the revolution of the flywheel reaches the ignition point, the
electric current I
3
flows to turn the signal transistor (3) “ON”, thus the
current I
1
bypasses the signal transistor as current I
4.
At this moment,
the power transistor turns “OFF” and the current I
2
is shut off abruptly.
As a result, the high voltage electricity is generated on the secondary
side of the ignition coil and it sparks at the spark plug (7).
Ref. Description Ref. Description
1 Ignition timing detective circuit 5 Primary coil
2 Resistor 6 Secondary coil
3 Signal transistor 7 Spark plug
4 Power transistor

Wacker Neuson WM 170 Specifications

General

Brand	Wacker Neuson
Model	WM 170
Category	Engine
Language	English