GB389838A - Improvements in or relating to electric telegraphic systems - Google Patents

Abstract

389,838. Code telegraphy. ELECTRICAL RESEARCH PRODUCTS, Inc., 195, Broadway, New York, U.S.A.-(Assignees of Knoop, W. A.; 36, St. Paul Road South, Hempstead, New York, U.S.A.) Sept. 24, 1931, No. 26684. Convention date, Oct. 8, 1930. [Class 40 (iii).] In a system for interpolating lost impulses a polarized relay is controlled by a pair of valves, and impulses are stored in a condenser of small capacity. In the absence of effective signals from the line 28 a succession of unit impulses is registered under control of the valve 2 as follows. Whenever the brush 31 passes over an even segment 16 of the interpolating distributer 14, a charge of positive or negative polarity, as the case may be, is drawn through armature 5a and stored on condenser 4. When the brush reaches the succeeding odd segment 17, a small portion of the charge is discharged through resistance 11 and charges the grid of valve 2 positively' or negatively as the case may be. The balance between valves 1, 2 is thus upset in such a direction that the armature 5a is reversed, so that when brush 31 reaches another even segment 16 the polarity of the charge on condenser 4 is reversed also. In this manner the armature 5a and consequently the printer-relay armature 18a are caused to vibrate. Reversal of armature 18a is effected at an instant when brush 30 is on a dead segment of distributer 15, but an impulse of the resulting polarity is passed to a printer magnet 32 when brush 30 reaches the corresponding segment. Thus, in the absence of effective line signals, a succession of impulses of opposite polarity is registered by magnets 32. When, however, a signal comprises two or more successive impulses of the same polarity the line signal is strong enough to act through valve 1 so as to overpower the effect of valve 2 on magnet 5, so that the vibration of armature 5a is prevented for as long as the signal lasts. The Specification refers to a known system in which the impedance of one of the valves is balanced against a linear impedance instead of against a second valve. The capacity of condenser 4 may be small and the resistance 11 may be such that only a small fraction of the charge on the condenser is discharged during the passage of brush 31 over a segment 17. The network comprising meter 6 and resistances 7, 8 regulates the sensitivity of the relay 5.