| 摘要 |
1,214,337. Card readers. NETHERLANDS POSTAL & TELECOMMUNICATION SERVICE, DIRECTOR GENERAL OF. 9 July, 1968 [26 July, 1967], No. 32765/68. Heading G4M. [Also in Division H4] An automatic dialler has a slot for the reception of a dialling card and an electromagnet which is energized when the card is inserted and makes contact with electric terminals on the card. As shown, the card is of insulating material and has orthogonal sets of conductive strips 28 and 29 on opposite faces. The strips may be selectively interconnected at the crossing points by inserting fixed or removable connecting elements in perforations at those crossing points. In the particular card shown and working from the left of the Figure, the first three strips 29 store digits 0, 2 and 0, respectively, the next strip does not have a connecting point and is used to stop the apparatus until dial tone is again returned after the first three digits have been dialled, the next six strips store the digits 2, 0, 3, 0, 4 and 0, respectively, and the next strip connects to an end of dialling code strip E of the set 28. The last eleven strips 29 connect along a diagonal line as indicated with the strips 28 in the same manner for each card and act as output conductors with terminals in line (along the bottom of the figure) with input terminals on earlier mentioned strips 29. The dialler has a microswitch in the bottom of the slot positioned to be energized when a card is inserted and is arranged to energize the electromagnet bringing a bank of contacts into engagement with the terminals on the card. The input terminals are then selected in succession by the wiper of a stepping switch and at each step a capacitor charged to a predetermined level is discharged into that input terminal. It re-appears at that one of the output terminals which is associated with the corresponding digit. It is attenuated to a level characteristic of that digit by a corresponding value resistor 30 connected to that output and is used to partially saturate a magnetic core of square loop material. Between each step of the wiper the core is driven back to its original state of magnetization by pulses from a generator. The pulses are simultaneously transmitted to line as dialling pulses. The device does not normally respond until it recognizes dialling tone from the exchange. The dial tone detector includes an integrator to distinguish between dial tone and a busy signal. Two lamps one of which lights when the device is activated and the other of which lights continuously while it receives dial tone and intermittently while it receives busy tone are included. Two push-buttons are provided. One may be pressed if dial tone is present but too weak to operate the detector and the other may be pressed to re-initiate dialling, e.g. after reception of a busy tone. |
