DETROIT DIESEL 53
Battery-Charging Generator Regulator 7.1.1
CONTROL RELAY
In addition to a circuit breaker and a voltage regulator, the three-unit regulator has a control relay unit. This unit has a
core with a single shunt winding connected from the "SW" terminal of' the regulator to ground. The winding and core are
assembled into a frame. A fiat steel armature supporting the upper one of two relay contacts is attached to the frame by
a hinge and is centered above the core. The lower contact point is supported by a detachable contact support insulated
from the frame. An armature stop is assembled above the upper contact.
Operation
When the ignition switch is "OFF", the contact points are held apart by the tension of a spiral spring acting on the
armature. When the ignition switch is turned "ON", battery current flows through the control relay winding to ground. The
magnetic field produced by the winding overcomes the armature spring tension and pulls the armature down causing the
contact points to close. This completes the circuit to ground for the circuit breaker relay winding so that it can operate
when the D.C. voltage from the power rectifier reaches the value for which the circuit breaker relay is adjusted. The
control relay contact points remain closed until the ignition switch is turned "OFF".
TRANSISTORIZED AND TRANSISTOR REGULATORS
In addition to the standard regulator, there are two other types of regulators being used with the self-rectifying A.C.
generators in the 'battery-charging circuit. One is a transistorized regulator which contains a vibrating voltage regulator
unit and a field relay unit. The other is a transistor regulator which contains no moving parts and is used with a
separately mounted field relay.
TRANSISTORIZED REGULATOR
The transistorized regulator (Fig. 3). for use on a negative ground circuit, contains a vibrating voltage regulator unit and
a field relay unit. The regulator uses a single transistor and two diodes. The transistor works in conjunction with the
conventional voltage unit having a vibrating contact point to limit the generator voltage to a pre-set value. A field
discharge diode reduces arcing at the voltage regulator contacts by dissipating the energy created in the generator field
windings when the contacts separate. A suppression diode prevents damage from transient voltages which may appear
in the system.
Certain transistorized regulators are equipped with a choke coil to permit the installation of a capacitor between the
regulator and the "BAT" terminal on installations experiencing radio interference. The capacitor suppresses the radio
noise and the choke coil
Fig. 3 - Transistorized Regulator
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