Chapter 25. -NEW DEVELOPMENTS IN NAVAL ENGINEERING 



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Figure 25-23.— Block diagram of throttle control system. 



motor to drive in a direction to open the throttle 

 valve. A negative input will close the throttle 

 valve. The SCR power package will be inhibited 

 by limit switches if the motor travel exceeds a 

 predetermined point of travel. 



The pilot motor positions a pilot valve in the 

 hydraulic actuator which ports oil in the proper 

 direction to correctly position the throttle valve. 



A reference signal for throttle position, which 

 is controlled by the pilot motor, is fed back to the 

 summing junction. This section cancels the input 

 signal when the desired valve opening is reached. 



During direct electrical control of the throt- 

 tle, the contacts in the throttle location switch 

 change the circuitry eliminating the regulated 

 signal and setting up the circuitry for signals 

 from the direct throttle switches. 



During manual operation, the manual clutch is 

 engaged and the hydraulic actuator is inhibited. In 

 addition, the hydraulic system is vented to pre- 

 vent a hydraulic lock and permit the movement 

 of the handwheel for manual throttle control. 



A tachometer generator on the shaft produces 

 an output signal that is fed back as the speed 



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