TM 11-6125-240-34
CHAPTER 2
FUNCTIONING OF EQUIPMENT
Section I. BLOCK DIAGRAM ANALYSIS
2-1. General
components.
(2) The reaction of the magnetic field established
a. The inverter is divided into two sections: an
by the current flowing through motor B1 causes the ar-
electromecanical section, consisting of motor B1 and
mature to rotate. The exciter of G1 is mechanically
generator G1, and an electronic section, consisting of
coupled to the armature of motor B1 by a common
one of several types of voltage and frequency regula-
shaft; therefore, the exciter also rotates.
tors.
(3) An ac voltage is induced in the ac field coils of
(1) Electronic Regulator CSV1186-1, installed in
G1 by the sweep of the exciter. The induced voltage is
earlier units, consists of three circuit boards designated
applied through filter FL1 to ac power connector J3. In
Al, A2, and A3.
addition, a sample of the ac output is applied to the
(2) The CSV2215-2 regulator, installed in later
voltage and frequency regulator.
production units identified by Manufacturer Part No.
b. Electronic Section. The regulator controls the in-
07639-MGE23-400A and marked with serial number
verter frequency output by controlling the strength of
suffix C, consists of a single circuit assembly mounted
the motor field and thus governing the speed of the
on a base. The CSV2215-3 regulator, installed in late'r
rotating section. The voltage output is regulated
production units identified by Manufacture'r Part No.
through control of the current in the ac generator ex-
07639-MGEZ3-500A and marked with serial number
citer.
suffix D, consists of a single circuit assembly but is fur-
(1) As the mechanical speed of the inverter in-
nished separately from the base. Both these regulators
creases, the output frequency also increases. To control
provide, on one card, all the functions provided by
the frequency, the regulator controls the amount of
several cards on the earlier regulator.
current flow through the motor shunt coils. The speed
(3) The 4B93-1 -A regulator, installed in the latest
of the motor may be reduced by increasing the strength
production units consists of a single circuit board as-
of the motor shunt field.
sembly.
b. The purpose, operation, and inter-operation of the
(2) The current level in the generator exciter
two sections (electronic and electromechanica]) of the
determine the magnitude of output voltage. Reducing
inverter are explained in this chapter. Familiarity with
the exciter current causes a reduction of ac output
the equipment and its functioning is a valuable tool in
voltage. Output voltage is controlled by regulating the
troubleshooting rapidly and effectively.
average current in the exciter.
2-2. Block Diagram
(3) The regulator performs the function of a
rapidly operating switch which interrupts the current
flow in both motor and generator field windings at a
a. Electromechanical Section.
rate of 800 Hertz (Hz). Control is accomplished with
(1) The 28 vdc input is applied to the
voltage- and frequency-sensing circuits in the voltage
electromechanical section of the inverter through ter-
and frequency regulator that establish the magnitude
minal board TB1 to motor B1 and the exciter of
of current required to produce the desired output.
generator G1, causing current to flow in each of the
2-1
