| 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 |
| F. Shipboard Tests of Automatic Control Equipment 10F1. General Frequently, errors made by automatic control equipment in following a remote signal are obvious and may be readily determined without special apparatus. A mount matching a fixed signal may be in error by a constant amount such as 10 or 120 degrees. This type of error may be only a mistake in wiring, which is easily corrected. In certain types of drives, such as 40-mm, matching 180 degrees out may occur because the error voltage for 180 degrees error is zero, since the coarse synchro is 2-speed (i. e., 1 revolution of the synchro causes 180° revolution of the mount). Excessive oscillation of the mount or sluggishness in following a signal indicates that the drive needs adjustment. In order to determine whether a drive is following a signal accurately, instruments such as the dummy director with its accompanying error recorder are used. See the next article. 10F2. Dummy-director tests Using a dummy director and error recorder, the dynamic accuracy (error in following a remote signal) of automatic control equipment may be determined. The dummy director is an instrument which transmits an electrical order signal to the control equipment of the unit under test. The motion introduced may be either constant or simple harmonic. The error recorder (spark recorder) measures and makes a permanent record of the error on a strip of paper. Figure 10F2 shows sample recordings. If no error exists, the recording shows a straight horizontal line. The amount of variation of the plot from the zero error line, therefore, is a measure of the error in minutes. Such tests are made whenever equipment does not seem to be functioning properly, as well as periodically each quarter and during shipyard overhaul. |
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