emitter-base current stops. With no emitter-base
AMPLIFIER
current, the emitter-collector current stops. The
RESISTOR
emitter-collector is the primary circuit. The resistor
SWITCH
connected to the primary circuit establishes the proper
amount of primary current. The use of a capacitor in the
distributor is optional.
The contact-controlled system in figure 6-44 shows
the ignition switch resistor bypass, which functions
during cranking. On other systems, the resistor bypass
IGNITION
may be connected to a terminal on the starter solenoid
COIL
BATTERY
CONTACT
SET
TRANSISTOR-CONTROLLED MAGNETIC
PULSE SYSTEM.--A simplified wiring schematic
for a transistor-controlled magnetic pulse ignition
system is shown in figure 6-45. Many of the
RESISTOR
components in this system are essentially the same as
CAPACITOR
those used in the conventional and contact-controlled
VACUUM
systems. Note that in this type of ignition system, no
UNIT
ASf06044
contact points are used. The ignition coil is similar in
appearance to the conventional ignition coil, but is quite
Figure 6-44.--Contact controlled transistor battery ignition
different electrically. The ignition coil for the
system.
transistor-controlled magnetic pulse ignition system
has a different number of wire turns in its primary and
of current the breaker points can carry is limited, the
secondary windings. The two coils are not inter-
output that can be obtained from the coil is also limited.
changeable.
In the contact-controlled system (fig. 6-44), the
The magnetic pulse distributor is similar in external
breaker points carry only a very small emitter-base
appearance to the conventional distributor, and some
current of the transistor. The larger current of the coil
internal features are the same. The centrifugal advance
primary is carried through the emitter-collector of the
and vacuum advance mechanisms are the same in both
transistor. When the breaker points open, the
units. However, the breaker cam, contact points, and
AMPLIFIER
SPARK
PLUG
IGNITION
COIL
MAGNET
PULSE
RESISTOR
TIME
DISTRIBUTOR
CORE
RESISTOR
POLE
PIECE
PICK-UP
PERMANENT
COIL
MAGNET
BATTERY
SWITCH
ASf06045
Figure 6-45.--Transistor controlled magnetic pulse battery ignition system.
6-40