Chapter 25. -NEW DEVELOPMENTS IN NAVAL ENGINEERING 



(1) Stem Sensitive RTD 



(2) Thermowell with Adapter 



(3) Tip Sensitive RTD 



(4) Thermowell with Holder 



Figure 25-21.— Resistance Temperature Detectors. 



140.93 



Information leaving the scaling module for 

 display is sent directly to the Digital Display Buf- 

 fers and Readouts (44) and appear at the readout 

 units on the console face. 



The entire operation from pick-up of the input 

 address to activation of the printout units 

 requires a time span of .0376 milliseconds. The 

 assembly will monitor the complete bank of 273 

 inputs in approximately two seconds providing 

 there are no requests or alarms conditions pre- 

 sented to the system during that time period. 



THROTTLE CONTROL 



Figure 25-23 is a block diagram of the 

 throttle control system. A reference input signal 

 may be taken from either the bridge or engine 

 room reference handwheel potentiometer and fed 

 to the system. Negative voltages are used for 

 ahead speeds and positive for astern. The signal 

 then passes through a common operational am- 

 plifier where it is inverted and then goes to the 

 common circuit for both the ahead and astern tur- 

 bines. The function generators will accept only 



a signal of a given polarity. The ahead function 

 generator accepts positive signals and the astern 

 function generator negative signals. The signal 

 to the function generator is also used as a refer- 

 ence signal for the speed feedback system. This 

 circuit compares the reference and speed feed- 

 back signals and uses the algebraic sum as the 

 input to the speed error amplifier. 



The signal to the function generator is ad- 

 justed within the amplifier so that the output is 

 equivalent to the cube of the input. This is done 

 to change the linear movement of the reference 

 to the non-linear characteristics of the throttle 

 valve. Inversion once again takes place in the 

 function generator. 



The output of the function generator is 

 matched with the speed error signal and the 

 throttle position signal at the summing junction 

 and the algebraic sum is fed to the summing am- 

 plifier. Inversion takes place and the output con- 

 trols the action of the SCR power package. 



The SCR power package will cause the pilot 

 motor to drive in either direction depending upon 

 the input. A positive input will cause the pilot 



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