Patent GB-676253-A (GB)
Title: Improvements in or relating to pulse-synchronising circuits
IPC: H03K5/00
Filed: 1950-02-16
Abstract: 676,253. Phase measurement. RUSH, D. A. U., BAKER, M. W., and SPERRY GYROSCOPE CO., Ltd. Feb. 16, 1951 [Feb. 16, 1950], No. 3995/50. Class 37. [Also in Group XXXV] Apparatus shown schematically in Fig. 1 for producing recurrent high-power pulses O in predetermined time relation with recurrent low-power primary signals A, of the kind in which a relay device 4 (e.g. a sparkgap or a gas discharge tube) is used for releasing the high-power pulses O ; wherein in order to compensate for variable delays at the relay device 4, (a) the primary signals A from the source 1 are applied to the relay 4 through a controllable time-delay device 2; (b) reference signals B are produced at 1 which are delayed a fixed time interval after the primary signals A ; (c) the reference signals B are compared in a time comparator 3 with signals D synchronous with the output pulses O to derive an error voltage V ; and (d) the controllable time-delay device 2 is actuated by the error voltage V to bring the output pulses O into synchron. ism with the reference signals B. Fig. 2 shows the pulse forms at various points in the circuits, Fig. 3 the controllable time-delay device 2, and Fig. 4 the time comparator 3. Pulses A from the source 1 are inverted in polarity to A<SP>1</SP> at 201 and applied to the.input grid of a cathode-coupled flip-flop pair of valves 205 giving a lengthened negative pulse at F, the duration of which is dependent on circuit constants and on the controllable bias V applied to the input grid. This pulse is differentiated by the network 211, 212 to provide spaced pulses G, H of which H occurs at a controllable delay after A, and is used to unblock one valve of a cathode-coupled valve pair 213 arranged as a blocking oscillator. The rise of anode current operating through a transformer 217 drives the grid of the right-hand valve positive and further increases the anode current. Owing to the passage of grid current, the grid voltage then falls and blocks the valve. The positive pulse occurring at 221 is fed to a cathode-follower 223 whose output C is applied to the relay 4 to release the high-power pulse O. The time comparator, Fig. 4, receives a reference pulse B from the primary signal source 1 at a fixed delay time To after the primary pulse A. The pulse B is lengthened by a flip-flop pair 313 into a positive-going pulse B<SP>1</SP> which is applied to the grid of a blocked valve 322. A pulse D synchronous with the high-power output pulse O, and derived therefrom, is also lengthened to the form D<SP>1</SP> at 301, is inverted to negative polarity D" by the valve 305, and is also applied to the grid of the valve 322. This valve thus passes current for a time equal to the interval between the pulses B, D, and enables an error voltage V to be taken from its cathode across a resistor 324, which after averaging by the shunt condenser 323 and smoothing by the network 325, 326 is applied to the input grid of the delay device 205 to control the timing of the pulse C and the high-power pulse O. In this manner the high-power pulses O, which may be used to energize a magnetron, are produced at a fixed time interval To after the primary pulses A despite changes in the delay occurring in the gas discharge tube or other relay 4.