GB716226A - Improvements in or relating to the correction of coded electric signals - Google Patents

Abstract

716,226. Digital electric calculating apparatus. SOC. D'ELECTRONIQUE ET D'AUTOMATISME. Jan. 18, 1950 [Jan. 19, 1949; Feb. 17, 1949], No. 171/53. Divided out of 716,172. Class 106 (1) A component for an electric carry-over operator for correcting incorrectly coded pulse trains, comprises, in a transmission channel between input 1 and output 2 terminals, first means 9 adapted to respond to a pulse of amplitude smaller than the radix B with a pulse of the same amplitude and to a pulse of amplitude equal or greater than radix value B with a pulse of predetermined amplitude not less than (B-1), in a channel branched off the transmission channel before the first means, second means 4 adapted to respond to pulses of amplitude equal to or greater than radix value, with unit amplitude pulses delivered to a carry channel and with pulses of predetermined amplitude to a cancellation channel, means 7 for applying the carry pulses to the input terminal 1 with the same polarity but a phase lag of one digit period relative to the incoming train, and means 5 for applying the cancellation pulses to the output terminal 2 in phase with but with opposite polarity to the pulses delivered thereto by the first means. In an embodiment for correcting incorrectly coded binary pulse trains which may include negative-going as well as positive-going pulses, the pulse train which may contain negative pulses is fed to the grid of a valve 19, Fig. 3, and another positive pulse train may be fed to the grid of a valve 18. A resulting train, with negative pulses inverted, appears at the point 3 (of Fig. 1), together with the carry train from a delay device 7, and is applied to the grids of amplitude-responsive valves 9, 4, 9<SP>1</SP>, 4<SP>1</SP>. Valve 9 has a threshold "0"; valve 4 has a threshold "1"; valve 9' has a threshold "2" and valve 4<SP>1</SP> has a threshold " 3.". The valves have amplitude-limiting characteristics and resistors 10, 10', 6, 6' limit any output impulses to unit amplitude. Valves 15, 15<SP>1</SP> and resistors 5, 5<SP>1</SP>, provide inverted unit-amplitude output pulses to the point 2 when the associated valves 4, 4' respond. Also carry impulses derived from these valves are inverted by a valve 16 and fed into the one-unit delay device 7. In this manner the network, formed from components in accordance with the invention, produces from the incorrectly-coded input, a correctly-coded series-mode pulse train at a cathode-follower output valve 17. An arrangement for correcting incorrectly-coded decimal pulse trains is also described. Specification 716,172 and U.S.A. Specification 2,429,227 are referred to.