in the stator windings.
The voltages
Diode D5 prevents high transient volt-
across the six diodes cause current to
ages in the field coil when the field cur-
rent is decreasing.
flow to charge the battery.
Current from the stator flows through
Resistor R7, capacitor C3 and resistor
the three diodes to resistor R6 and the
R4 all act to cause transistor TR2 and
base-emitter of TR2 and TR1 to turn
TR1 to turn on and off more quickly.
these transistors on. Current also flows
from the stator through the diode trio
01, 02, and 03, the field coil and tran-
Troubleshooting
sistor TR1,
returning to the stator
through the other three diodes. All sta-
DEFINITIONS.
The
following
points
t o r c u r r e n t , except through the diode
should be kept in mind while trouble-
trio D1, D2, and D3, flows through the
s i x diodes c o n n e c t e d t o t h e s t a t o r .
The energizing speed is the RPM at
Current flow through R1, R2, and R3
which the regulator turns on to energize
c a u s e s a voltage to appear at zener diode
the field coil. This speed is higher than
D4.
some speeds at which output can be ob-
When the voltage becomes high
due to increasing alternator
enough
tained.
Therefore, when checking out-
put at low speeds, increase the speed
speed, D4 and the base-emitter or TR3
until the regulator turns on, then reduce
conduct current and TR3 turns on. TR2
the speed to check the output. No out-
and TR1 then turn off, decreasing the
put can be obtained until the regulator
field current and the system voltage de-
turns on. Once the regulator turns on,
crease.
The voltage at D4 decreases, D4
it will remain turned on until the engine
and TR3 turn off, TR2 and TR1 turn
is stopped.
back on
and
the
system
voltage
increases. This cycle then repeats many
The integral charging system output pre-
time per second to limit the system volt-
ferably should be checked at the "Rated
age as determined by the setting of the
Voltage" given.
potentiometer R2, R3.
However, it is permissible to check the
output in amperes at any voltage within
odes from high transient voltages and
the "Operating Range" listed, since the
current output will be quite close to the
value that would be obtained at "Rated
Resistor R5 prevents current leakage
Voltage".
The voltage should never be
through TR3 at high temperatures.
Electrical Components