b. The adjustable resistor is connected in series with the operating coil.
It reduces the line voltage to a suitable value for application to the operating
coil. The final adjustment of the voltage regulator operating voltage is made by
means of this resistor.
c. The rectifier and fixed resistor stabilize the operation of the
regulator by maintaining a minimum current flow through the field coil of the
generator. The rectifier permits current to flow only in one direction. This
means that a certain minimum current bypasses the carbon pile and flows during the
entire operational range of the generator.
d. The coil of the load relay assembly is connected to the left engine
ignition switch, and the contacts of the relay assembly are connected to the
battery positive line. When the ignition switch is turned ON, battery current
energizes the coil and the relay contacts close. This connects the generator
(alternator) to the vehicle electrical system.
e. The capacitor assembly consists of two capacitors mounted in a bracket.
The capacitors suppress radio interference. One capacitor is connected in the
battery positive (+) line, while the other is connected in the battery negative (-)
line.
4. SOLID-STATE REGULATOR. Today the solid-state voltage regulator is replacing
the mechanical type of regulators. The reason for this is minimum mechanical
parts, size, and maintenance. However, the solid-state regulator still contains
the line switch or load relay.
a. A screwdriver adjustment is provided for setting the voltage output of a
generator. Some will have two adjustments: one for current and one for voltage.
Normally, these adjustments are accessible by removing a screwplug in the regulator
cover. The screwplug incorporates an O-ring seal to keep out water and dirt.
b. Tests that are performed on the solid-state regulator are simple. There
is the line switch, or load relay test, and a test of voltage adjustment
regulation. Normally, if these tests are not satisfactory, the regulator is turned
in on a direct exchange basis or sent back to the manufacturer for repair. It will
not be your responsibility to repair this item.
c. Typical of a solid-state regulator is the 100-ampere regulator shown in
figure 8. Like the carbon pile regulator, the solid-state regulator contains a'
load relay which disconnects the charging system from the battery when the ignition
switch is opened. A polarity protection diode is included in the relay circuit to
prevent the relay from closing if reverse polarity is applied to the system.
d. This regulator also contains a transient suppression or snubber circuit
which consists of a transistor and other components. Transient suppression
capacitors and diodes are included for additional protection, and feed-through
capacitors are used in the output leads for RFI reduction. A suppression network
is also incorporated to reduce RFI caused by transistor switching action. These
circuits are mounted on printed circuit panels. Voltage transients created by the
relay coil or ignition system are bypassed by means of a diode shunted across the
relay coil (fig A, foldout 3).
5. TEST AND ADJUSTMENT OF THE 100-AMPERE REGULATOR. Bench testing of the
regulator requires a multimeter, such as the TS-352, and a 24-volt source, such as
a battery. The test stand could be used by connecting to J1 and J2 (fig 9).
a. Load relay. Connect the negative lead of a 24-volt battery to male pin
C of the regulator and the positive terminal to male pin F. The relay should
close. While the battery is connected and the relay is closed,
OS 010, 5-P8
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