TM 5-3895-373-20
1.18.3. Alternator/Charqinq Circuits. The
alternator/charging circuits consist of the alternator,
voltage transformer, and the storage batteries.
The alternator is belt driven from the crankshaft pulley on
the paving machine engine. Alternating current (AC) is
generated as the coils of the rotor pass a pair of
magnetic poles in the stator. The AC is rectified to direct
current (DC) through a series of diodes, which form a
rectifier circuit.
Batteries A and B are connected in series to supply 24 V
to the 24 V post on the voltage transformer. When the
ignition switch is turned on, the field relay closes sending
24 VDC excitation voltage to the alternator D+ terminal
for engine initial startup. The 24 V output charging
voltage of alternator B+ terminal is directly connected to
the 24 V post on the voltage transformer. The 24 VDC
output of the voltage transformer is applied to the POS
terminal of battery B. Because 12 VDC is applied to the
NEG terminal and 24 VDC is sent to the POS terminal,
the batteries are charged with a difference of 12 VDC.
The voltage transformer simply converts the 24 VDC into
12 VDC to charge the batteries.
1.18.4. Paving Liqhtinq Circuits. Operator control
panel lights, instrument lights, and work lights are
controlled from the operator gauge panel. Screed
control panel lights are controlled from the screed control
panels. All paving machine lights are operated by toggle
switches.
The ignition switch receives power from CB8 through the
three emergency stop switches. When in the ON
position, the ignition switch supplies 12 VDC power to
the panel light switch. Where the panel light switch is in
the up, ON position, the operator gauge panel and
operator switch panel lights are lit. The gauges on the
operator gauge panel also have internal lights that are lit
when the panel light switch is ON.
12 VDC from the 80 amp circuit breaker feeds power to
the rear work lights through CB9, the auger work lights
through CB 10, and the forward work lights through CB
11. Each circuit breaker feeds a toggle switch on the
operator gauge panel for independent control of each
light.
CB6 supplies 12 VDC to the left and right screed control
panels for panel lights. The 12 VDC is applied to a
toggle switch that controls the panel lights.
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