Chapter 7 — BASIC FIRE CONTROL 



When the resolver is zeroed electrically, 

 the rotor coll clamped to the stator coil is 

 called the cosine coil. The other rotor coil, 

 at right angles to it, is called the sine coil. 

 As the rotor rotates from 0° to 360°, the voltage 

 induced across the cosine coil follows the cosine 

 function of the excitation voltage. Similarly, the 

 voltage induced across the sine coil follows the 

 sine function of the excitation voltage. 



Schematic Identification of System 

 Components 



In the maintenance publications for fire control 

 systems, the devices described in this section 

 are identified by standardized symbols. The 

 identifying symbols and their abbreviations for 

 system components are reproduced in figure 

 7-12. Usage of some of the component symbols 

 in a sectional diagram may be seen in figure 

 7-13. 



UNDERWATER FIRE CONTROL SYSTEMS 



HC2 7 



I INPUT 

 fiLL MANUAL K^imiS^ 

 So MANUAL 9 

 AUTOMATIC 6 



,X 



POSITION 

 KEEPING 



I ON 



^xja- 



OWN SHIP OPERATIONAL SCT I 



INPUT SWITCH 



MUL?5 



HC12 V SL 



A modern fire control system, as mentioned 

 earlier, is tailored to the requirements of a 

 particular weapon system. Aboard submarines, 

 the weapon is the torpedo. Aboard ships, the 

 weapon system usually consists of several types, 

 such as A/S torpedoes, DASH, hedgehogs, and 

 depth charges. Despite the type of fire control 



71.61 

 Figure 7-13. — Use of symbols in a sectional 

 diagram. 



POSITION 

 KEEPER 



RELATIVE 

 TARGET 

 MOTION 



ANALYZER 



TARGET 

 SPEED 



BEARING 



DEPTH 



SONAR 

 EQUIPMENT 



RANGE 



Y *■ 



TARGET 

 COURSE 



BALLISTIC 

 COMPUTER 



TIME TO FIRE 



RANGE 



FIRING 

 PANEL 



FIRE 



WEAPON CONTROL CIRCUITS 



"Y" 



(BEARING ORDER, TILT ORDER, ETC. 



ROLL 



WEAPONS 



(TORPEDOES, 

 HEDGEHOGS.WEAPON A 

 DEPTH CHARGES) 



STABILIZATION 

 COMPUTER 



LEVEL 



CROSS LEVEL 



STABLE 

 ELEMENT 



■B'r 



51.101 

 Figure 7-14. — T3T)ical underwater fire control system. 



123 



