TM 5-3810-300-24&P-3
REGUL.ATOR FOR BATTERY-CHARGING GENERATOR
The voltage at which the generator operates is
contacts closed and the engine not running, generator
determined by the regulator adjustment. Once adjusted,
field current can be traced from the battery through the
the generator voltage remains almost constant, since the
relay contacts to the regulator "POS" terminal. Current
regulator is unaffected by length of service, changes in
then continues through the output transistor of the
temperature, or changes in generator output and speed.
regulator, to the "FLD" terminal, and then through the
generator field winding to ground, completing the circuit
The voltage regulator illustrated in Fig. 4 is designed for
back to the battery.
negative ground battery-charging circuits only. It has two
exposed terminals. The voltage setting may be adjusted
When the generator begins to operate, AC voltages are
by relocating a screw in the base of the regulator.
induced in the stator windings. These voltages are
changed, or rectified, to a DC voltage which appears at
The voltage regulator shown in Fig. 5 has shielded plug-
the output, or "BAT," terminal on the generator. The
in connections and .requires a cable and plug assembly
generator then supplies current to charge the battery and
to connect the regulator into the battery-charging circuit.
operate vehicle accessories.
This type of regulator may be used in negative ground,
positive ground and insulated charging circuits. The
As generator speed increases, the voltage reaches the
voltage setting may be adjusted by removing a plug in
pre-set value and the components in the regulator cause
the cover and turning a slotted adjusting button inside the
the output transistor to alternately "turn off" and "turn on"
regulator.
the generator field voltage. The regulator thus operates
to limit the generator output voltage to the pre-set value.
Operation
In the positive ground circuit, when the switch is closed
and the engine is not running, field current can be traced
A separately mounted field relay connects the regulator
from the battery positive ground to generator ground, and
"POPS" terminal and the generator field windings to the
then to the regulator "POS" terminal. The current
battery when the engine starting switch is closed.
continues through the output transistor, to the regulator
"FLD" terminal, and then through the field winding and
In the negative ground circuit, with the field relay
field relay contacts back to the battery, thus completing
the circuit. Except - for this primary difference this
Fig. 4 - Former Transistor Regulator (Negative Ground Circuits Only)
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