Synchronisiervorrichtung fuer elektronische Rechenmaschinen u. dgl.

摘要

802,312. Automatic-phase control systems. COMPAGNIE DES MACHINES BULL. Feb. 15, 1957 [Feb. 24, 1956], No. 5259/57. Class 38 (4). [Also in Group XIX] A pulse train is synchronized with the rotation of a magnetic drum by equidistant control marks on the drum. A magnetic drum 1, Fig. 5, comprises a control track 2 with equidistant marks 3 read by the head 4 to produce pulses 15a, Fig. 2. The frequency of the pulses generated from the sinusoidal oscillator 5 is controlled by a reactance tube 7. Square pulses 10, Fig. 2, are derived from the oscillator 5 by a clipper stage 6, and a selector 8 generates the pulse trains 11, 12 therefrom which are applied to the flip-flop 20 to give the output 14 or I2. The pulse trains 12, 15a are fed to the flip-flop 21 to give an output 13 or I1. These outputs are fed to the " and " gate 15 and the " or " gate 16, The detected output which, if synchronism is lacking is represented by 26 or 271 passes to a Miller integrating circuit 19 which provides a control voltage output depending on the time difference desired to be eliminated and this controls the reactance tube 7. To ensure correct synchronization when the drum commences rotation a second track 211, Fig. 7, may be provided having a single mark Mto thereon. The pulse selector stage 8 then selects also a train of " zero " pulses the period of which is equal to the theoretical period of rotation of the drum. An additional control circuit 2011 , 2111 , 3911 , 1911 is provided and an arrangement is described whereby the flip-flop 37 supplies control waveforms so that the first control voltage is blocked as long as the single mark does not coincide with the required origin time: When coincidence is effected the second control voltage is blocked and " fine synchronization is completed as described above. In a third embodiment (Fig. 8, not shown), one control voltage is generated by a single circuit. The reactance tube does not respond to the release signals generated by coincidence between a " zero " pulse and a pulse corresponding to the mark Mto by reason of its frequency response, but when normal operating speed is reached, a further coincidence caused by normal drum speed fluctuations releases the reactance tube to control the frequency of the pulse generator. The isolated mark Mto may be engraved on the same track and read by the same head as the equidistant control marks.