Chevrolet 30 Series 1967 Service Manual page 356

ENGINE-ELECTRICAL 6Y-8
FIELD RELAY
" LA TC H "
" F" TERM IN A L
N O . 2 TERM IN A L
N O . 3 T ERM IN A L
N O . 4 T E R M IN A L
double contact two unit type, a transistor unit with an in­
ternal field relay and a completely static full transistor
regulator (130 amp generator only). The function of these
regulators in the charging system is to limit the genera­
tor voltage to a pre-set value by controlling the generator
field current.
The two unit double contact unit and the junior tran­
sistor regulator (when applicable) use the field relay to
turn out the indicator lamp.
lamp to light (as a bulb check) with the ignition key on
and engine not running. When the engine is started and
the generator begins to charge, the indicator light goes
out indicating that the system is operating normally.
The double-contact regulator assembly (fig. 2c) con­
sists of a double-contact voltage regulator unit and a
field relay unit. This unit uses two sets of contact points
on the voltage regulator unit to obtain desired field
excitation under variable conditions.
when used with the special 63 amp air conditioning model
generator (4 ohm field coil), uses a field discharge diode
"F" TERMINAL
No. 2 TERMINAL
No. 3 TERMINAL
No. 4 TERMINAL
V O LT A G E
R EG U LA TO R
Fig. 2 c — Double C ontact Regulator
The relay unit allows the
This regulator,
ACCESS PLUG TO
VOLTAGE ADJUSTMENT
Fig . 3 c—Transistor V oltage Regulator Assembly
DEICOTRON ' R. 6 3 AMP
MODELS ONLY
DOUBLE CONTACT
internally in the field circuit (fig. 2c).
adapts the regulator to handle the higher field current and
enables it to absorb the increased inductive voltages of
the field coil with satisfactory contact point life. A wir­
ing diagram of the regulator internal circuit is illuatrated
in Figure 2c.
The light duty transistor regulator (fig. 3c) is an
assembly composed principally of transistors, diodes,
resistors, a capacitor, and a thermistor to form a com­
pletely static voltage regulating unit in combination with
a conventional vibrating type field relay.
The transistor is an electrical device which limits the
generator voltage to a preset value by controlling the
generator field current.
sistors act together to aid the transistors in controlling
the generator voltage. This is the only function that the
regulator performs in the charging circuit.
mistor provides a temperature-compensated voltage set­
ting. A wiring diagram of this regulator's internal circuit
is shown in Figure 3c.
JUNCTION BLOCK
Q
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TRANSISTOR
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The added diode
The diodes, capacitor and re ­
The ther­
IN D IC A TO R
LAMP
CHEVROLET TRUCK SERVICE M ANUAL