7.1.1 Battery-Charging Generator Regulator
DETROIT DIESEL 53
Fig. 5 - Transistor Regulator with Plug-In Connections
changed, or rectified. to a D.C. voltage which appears
The voltage regulator illustrated in Fig. 4 is designed for
at the output, or "BAT", terminal on the generator The
negative ground battery-charging circuits only. It has
generator then supplies current to charge the battery
two exposed terminals. The voltage setting may be
and operate vehicle accessories.
adjusted by relocating a screw in the base of the
regulator.
As generator speed increases, the voltage reaches the
pre-set value and the components in the regulator cause
The voltage regulator shown in Fig. 5 has shielded
transistor TR-I to alternately "turn off"' and "turn on" the
plug-in connections and requires a cable and plug
generator field voltage. The regulator thus operates to
assembly to connect the regulator into the battery-
limit the generator output voltage to the pre-set value.
charging circuit. This type of regulator may be used in
negative ground.
positive ground and insulated
charging circuits. The voltage setting may be adjusted
In the positive ground circuit , when the switch is
by removing a plug in the cover and turning a slotted
closed and the engine is not running, the field current
adjusting button inside the regulator.
can be traced from the battery positive ground to
generator ground, and then to the regulator "POS"
Operation
terminal. The current continues through diode Dl and
transistor TRI to the regulator "FLD" terminal, and then
through the field winding and field relay contacts back to
When the engine starting switch is closed, the field relay
the battery, thus completing the circuit. Except for this
winding is energized, which causes the relay contacts to
primary difference, this circuit operates in the same
close.
manner as that described for the negative ground
circuit.
In the negative ground circuit with the field relay
contacts closed and the engine not running, generator
REGULATOR PRECAUTIONS
field current can be traced from the battery through the
Never short or ground the regulator terminals; do not
relay contacts to the regulator "POS" terminal. Current
attempt to polarize the circuit.
then continues through the back-bias diode (Dl) and
power transistor (TRI) to the regulator "FLID" terminal,
Make sure all connections in the charging circuit are
and then through the generator field winding to ground,
tight to minimize resistance.
completing the circuit back to the battery.
Refer to "A.C. Generator Precautions" in Section 7 1
When the generator begins to operate, A.C. voltages
are induced in the stator windings. These voltages are
1971 General Motors Corp
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