DETROIT DIESEL 53
7.1.1
BATTERY-CHARGING GENERATOR REGULATOR
A.C. CHARGING CIRCUIT
The relay contact points remain closed as long as the
The alternating current generator regulator is similar in
D.C. voltage is enough to hold the relay armature
outward appearance to the regulator used with the D.C.
against the core.
They open when the voltage
generator. The D.C. and A.C. regulators are NOT
decreases to a value at which the magnetic pull of the
interchangeable.
core can no longer overcome the armature spring
tension.
The internal wiring circuits of all standard A.C. generator
regulators are similar, but the internal connections vary
somewhat according to the method used to control the
VOLTAGE REGULATOR
circuit breaker relay.
The voltage regulator unit has a core with a single shunt
There are two and three unit standard A.C. generator
winding. This winding also consists of fine wire and is
regulators: the two unit regulators have a circuit breaker
connected across the D.C. side of the power rectifier.
relay controlled by a relay rectifier or by an oil pressure
The assembly and parts are similar to the circuit breaker
switch and the three-unit regulators have a circuit
breaker relay controlled by a built-in control relay.
a detachable contact support insulated from the frame.
The generator field circuit is insulated in the generator
Operation
and grounded in the regulator. This type of connection
If the voltage regulator unit is not operating, the
is designated as Circuit "A".
generator field circuit is completed to ground through
the contact points which are held closed by the tension
NOTE: Each type of regulator is used with a
of a spiral spring acting on the armature.
certain circuit. Do not attempt to interchange
When the D.C. voltage of the A.C. D.C. system
regulators.
reaches the value for which the voltage regulator is
adjusted, the magnetic field produced by the shunt
The two unit A.C. generator regulator has a circuit
winding overcomes the armature spring tension and
breaker relay and a voltage regulator unit while the three
pulls the armature down, causing the contact points to
unit regulator is also equipped with a control relay in
separate. When the contact points separate, resistance
addition to the other two units.
is introduced into the field circuit. The resistance
decreases the field current causing a corresponding
CIRCUIT BREAKER RELAY
decrease in generator voltage and magnetic pull on the
regulator armature. This allows the armature spring
The circuit breaker relay has a core with the winding
tension to reclose the contact points. When the voltage
made up of many turns of fine wire. This core and
again reaches the value for which the voltage regulator
winding are assembled into a frame. A flat steel
is adjusted, this cycle repeats and continues to repeat
armature is attached to the frame by a hinge and is
many times a second, thus limiting the voltage to the
centered above the core. Two contact points, supported
value for which the regulator is set.
by two flat springs on the armature, are located above
two stationary contact points. The upper and lower
With the voltage limited in this manner, the generator
contact points are held apart by the tension of a flat
supplies varying amounts of current to meet the various
spring riveted to the top side of the armature.
states of battery charge and electrical load.
Operation
Voltage regulators are compensated for variations in
When the D.C. voltage reaches the value for which the
temperature by means of a bimetal thermostatic hinge
circuit breaker relay is adjusted, the magnetism Induced
on the armature. The effect of this hinge causes the
in the core by current flow in the winding is sufficient to
regulator to adjust at a higher voltage when cold, which
overcome the armature spring tension and the relay
partly compensates for the fact that a high voltage is
points close. Closing of the contact points connects the
required to charge a cold battery.
D.C. side of the power rectifier to the battery so that
current will flow to the battery whenever the generator is
driven at sufficient speed.
1971 General Motors Corp.
May, 1971
SEC. 7.1.1 Page 3
