| GENE SLOVER'S US NAVY PAGES NAVAL ORDNANCE AND GUNNERY, VOLUME 1 CHAPTER 10 AUTOMATIC CONTROL EQUIPMENT |
| HOME INDEX Chapter 10 Automatic Control Equipment A. Introduction B. Synchros C. Electric-hydraulic systems D. Amplidyne follow-up system E. Other types F. Shipboard tests of automatic control equipment |
| E. Other Types 10E1. Thyratron system Thyratron systems are found on stable elements and stable verticals which require a simple and accurate low-power automatic control system. In this system the electrical (AC) signal is amplified by electronic tubes. The amplified signal is then changed to DC by 1 of 2 half-wave rectifier tubes. A signal in 1 direction utilizes 1 rectifier tube, while a signal in the other direction utilizes the other rectifier tube. The DC output of the rectifier tubes is led to a DC motor, the direction of rotation of which depends upon which of the rectifier tubes furnishes the voltage. This DC motor furnishes the working power for the system. 10E2. York Safe and Lock Company drive This drive, used extensively as the train and elevation units on 40-mm mounts, is an electric-hydraulic drive using both electronic and hydraulic amplification. Figure 10E1 is a simplified schematic drawing of the drive. |
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| The main parts of this system consist of an electric power motor, a hydraulic A-end pump and B-end motor, and a receiver-regulator control system. The electric motor drives the A-end pump. Fluid from the A-end drives the B-end in the proper direction and amount. The B-end is directly geared to the mount to drive it in train (elevation). The receiver-regulator controls the position of the tilt box of the A-end in the following manner: The receiver-regulator has a control transformer which sends an electrical error signal to an electronic amplifier. The amplified signal drives a stroke motor which controls a hydraulic pilot valve. This pilot valve positions the booster piston directly connected to the A-end tilt box, thereby providing the necessary control of the mount. As the stroke motor rotates, it drives the stroke generator, which sends a pre-response signal back to the amplifier, thus smoothing out the operation of the system. This mount is equipped with a three-position selector lever whose settings are: MANUAL, LOCAL, and AUTO. In MANUAL control the pointer’s and trainer’s handwheels drive the mount and the power motors are not energized; however, the lag meter may be used to match a signal from the director. The lag meter is a voltmeter indication of the error signal. In LOCAL power control, the pointer controls the mount in train and elevation through use of the handle control (joy stick). In AUTO, the mount is positioned by the power drives using remote signals from a director. |
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| 10E3. 16”/50 turret train drive The automatic control equipment used to train the 16”/50 caliber turret is an electric-hydraulic drive designed by the General Electric Company. See figure 10E2. The main units of this system are the electric drive motor, the variable-speed gear ‘consisting of 1 A-end and 2 B-ends, a servo stroking system, and a receiver-regulator. Turret train movement is controlled by positioning the A-end tilt box. Such tilt-box movement is performed by a servo stroking cylinder and piston under hydraulic pressure from a control pressure pump. Opening of servo pressure to the stroking cylinder is controlled by two methods: HAND and AUTO. In HAND control, movement of the trainer’s hand-wheels rotates a nut on the control screw, causing the screw to move axially within the nut. This movement of the screw through linkages and valves controls the flow of fluid into the servo cylinder, moving the servo piston. The servo piston, being directly connected to the A-end tilt box, tilts it the amount ordered. As the turret trains, response turns the control screw, moving it axially and thereby repositioning the tilt box back to its neutral position. Handwheel motion, as can be seen from figure 10E2, may come from the train layer’s station or from either the left or the right sight trainer’s stations, depending on the positions of the clutches. In AUTO control, the remote signal is received at the receiver-regulator by a synchro. The rotor of the synchro positions a small hydraulic valve. This signal is amplified hydraulically and controls the flow of fluid into the servo cylinder. This positions the servo piston and, hence, the A-end tilt box. Response, as the turret trains, rotates the stator of the synchro and returns the synchro rotor and the A-end tilt box to neutral. 10E4. Fuze-setting drives An all-electric type of drive is used on automatic fuze setters. This drive may be considered nothing more than a two-stage servo-motor drive. Movement of the synchro receiver rotor, in response to the remote signal, closes contacts to a 115-volt AC pilot motor. Rotation of this pilot motor shaft closes silver contacts which sends 115-volt alternating current to the power motor, and causes it to drive the load in the proper direction. Rotation of this pilot-motor shaft also rotates the synchro receiver stator, returning it to neutral and opening the first set of contacts. Response from the load drives back to the power-control head of the pilot motor, opening the second set of silver contacts and stopping the power motor when the load is positioned in response to the original signal. |