| 摘要 |
436,462. Calculating - machines. BRITISH TABULATING MACHINE CO., Ltd., Victoria House, Vernon Place, Southampton Row, London. April 11, 1934, No. 10977. Convention date, April 12, 1933. [Class 106 (i)] In an electromagnetically controlled calculating-machine, a method of, and apparatus for, energizing an electromagnet by the momentary closure of a circuit-maker (e.g. card reading brush contacts 10, 11) includes a condenser 22 in series with the electromagnet (SM) and with the circuit-maker so that an initially high current through the magnet is reduced to a low value before the circuit-maker re-opens. This prevents sparking at the circuit-maker (10, 11). The invention is illustrated as applied to the perforated-card sorting-machine of Specification 242,654, [Class 106 (i)], wherein differentially-timed energization of sorting magnet SM lowers all the horizontal deflecting blades ahead of the card, so that the latter is sorted into the correct card channel. The commutator 14 constitutes a single-column selector as in the prior Specification, slides 14a being connectible at will to common ring 17 so that sorting is only effective for hole positions thus selected. Rigid with commutator 14 is a commutator 21 with sector 19. Brushes 18, 20 are only bridged by parts 19, 21 to charge the condenser 22 (of about 4 microfarads) between the reading of the last hole-position on one card and the reading of the first hole-position on the next card. Condenser 30 (of about ¢ microfarad) is for smoothing. Resistances R1 (about 2,000 ohms) and R2 (about 15,000 ohms) are connected as shown to a full-wave thermionic rectifier 23, the two plates 24 being connected together to give half-wave rectification. The condenser 22 in thus charged through brushes 18, 20 between successive cards, and, when a hole is read by brush 10, discharges rapidly through line 16, commutation 14 and magnet SM. During the charging of condenser 22, brush 13 rests one insulation and breaks the circuit 13, 15 to the magnet SM. When the low resistance charging circuit is interrupted at 18, 20 the condenser is still charged through resistance R2 : this, however, is high and allows just sufficient charging of condenser 22 to compensate for losses due to leaky insulation in the condenser. Statistical cards.-The rapid discharge of condenser 22 through magnet SM permits the machine to be operated at a higher speed than usual ; or smaller holes may be used in the cards so that more hole-positions may be accommodated in a standard card.
|
