Patent GB-823622-A (GB)
Title: Comparator for comparing encoded information
IPC: G06F7/02
Filed: 1958-01-16
Abstract: 823,622. Data-comparators. ADDRESSOGRAPH - MULTIGRAPH CORPORATION. Jan. 16, 1958 [Jan. 28, 1957], No. 1556/58. Class 106 (1). A comparator adapted to compare primary decimal information in a one-out-of-ten code with secondary information in a different code comprises a magnetic core matrix having a column of ten cores for each digit, each core having a winding for setting the core representing the primary digit and one or more windings connected in a network so as to re-code the secondary information to one-out-of-ten form, a core being first set by the primary information and reset to give an output signal by the secondary information if it is the same. In Fig. 1, the comparator 25 is used to compare serial numbers on corresponding pairs from a series of documents 15 and a series of printing plates 10. The documents 15 which are sensed at 21 are cheques or record cards and have a serial number punched therein by a hole in one of ten positions in a number of columns. The printing plates which are sensed at 26 have a punched insert in which the digits of the serial number are recorded by one or two holes in a column. Upon agreement the comparator signals cause AND circuits 33 to control the printer so that the address is printed on the document 15 which is then mailed. Disagreement prevents printing and the control is energized to reject the document 15 and feed the next to the sensing station, this being repeated until agreement is reached. In the sensing stations all record positions are sensed simultaneously. The comparator.-One column or stage of the core matrix is shown in Fig. 4. The ten sensing contacts of the documents 15 are shown at 220-229, the one corresponding to the digit sensed being connected to earth through the hole in the card column to energize the appropriate winding 50-59 and set the associated core 40-49. The other end of these windings are connected in parallel to a switch contact 61 and thence to power source 24. The sensing contacts for the printing plates 10 are shown at 272-279; those passing through holes in the record insert are earthed. Between contacts 272-279 and switch contact 62 are connected twenty weighted windings, two on each core (70L, 70R, &c.), the weighting and connection being such that a resetting M.M.F. is produced only in the core corresponding to the digit sensed. These connections are shown in Fig. 6, together with the weightings, this circuit being in effect a code converting arrangement, the theory of which is described in detail in the Specification. Another circuit arrangement is described for converting data in a 1,2,4,8 code to decimal form. Each core is also provided with a resetting winding 80-89 and an output winding 90-99 connected to contacts 63 and 67 of switch 60. Operation.-Data sensed from the document 15 is entered into the columns of the core matrix as described above, switch 60 being in the position shown to apply the source voltage to terminal 61. The switch is then moved to the second position 62 so that the appropriate ones of the second set of windings 70L-79L and 70R-79R are energized to apply a resetting M.M.F. to the cores corresponding to the digits sensed. If, in any column of cores, this digit is the same as that sensed on document 15 the set core will be reset and provide an output on the associated winding 90-99. This passes via the arm 65 of ganged switch 60 to contact 67 and thence to the AND circuit 33. If the digits are different the core set up from document 15 is not reset; the resetting M.M.F., being applied to an unset core, makes no change in its condition so that no output is generated. Where the numbers sensed are identical each column of cores passes an output to the AND circuit 33 which produces a control signal for the purpose described above. In the third position of switch 60 the source is connected via contact 63 to resetting windings 80-89 so that all cores are returned. to their initial condition. The switches for all columns of the matrix may be ganged together. Specification 489,390, [Group XVI], is referred to.