Figure 4-33.--Block diagram of the data correction system.

Figure 4-33.--Block diagram of the data correction system.

follow-up system, as mentioned previously. The

reference. The demodulator output (a dc voltage propor-

meridian gyro roll-pitch pickoff signal is fed to one

tional to the pickoff signal) is modulated using the

resolver rotor winding, and the slave gyro roll-pitch

synchro excitation voltage as a reference (as shown in

pickoff signal is fed to the other rotor winding. The

fig. 4-34). The output of the amplifier to the quadrature

resolver functions to resolve its own ship's course and

synchro rotor winding is a voltage proportional to the

roll-pitch pickoff input signals into output signals of

follow-up error; thus the transmitted data is corrected

proper proportions to the follow-up amplifiers. The

by an amount equal to the follow-up error. The

follow-up motors position the roll-pitch phantom until

transmitted data then indicates the true attitude of the

the pickoffs are restored to their neutral position and, at

gyros rather than the phantom ring assembly.

the same time, position 2- and 36-speed roll and pitch

Alarm System

synchro data transmitters. Figure 4-32 shows a block

diagram of the roll-pitch follow-up sequence.

An alarm system is incorporated in the Mk 19 Mod

3A gyrocompass system to the extent that each loop in

Due to backlash, spring in gearing, and other effects,

follow-up motors may have errors up to 0.05. These

errors are compensated for in the Mk 19 gyrocompass

by a data correction system (shown only in fig. 4-33).

Three special type synchro transmitters are used with

three transistor data correction amplifiers in

transmitting the 36-speed heading, roll, and pitch data.

Each 36-speed synchro transmitter has an additional

rotor winding displaced 90 electrical degrees from the

normal rotor winding. When this additional, or

quadrature, rotor winding (W1) is excited by a variable

voltage, the magnetic field produced reacts with the

magnetic field of the normal rotor winding (W2), and

thus produces a resultant rotor field that is displaced

from the normal rotor winding field. The angle of this

displacement is proportional to the magnitude and phase

of the voltage applied to the additional rotor winding.

The three transistor data correction amplifiers are

sealed and mounted in the bottom of the master

compass. The input signals to the amplifier area portion

of the azimuth follow-up signal, roll follow-up signal,

Figure 4-34.--Simplified schematic diagram of an amplifier

and pitch follow-up signal. The signal is amplified and

alarm relay.

demodulated using the pickoff excitation voltage as a

4-31