| 摘要 |
ZPHM 8777 In a teleprinter equipment, a method and arrangement to transmit messages between a station and a teleprinter apparatus by feeding D.C.-pulses, representing binary coded characters in the message, through a line interconnecting the station and the teleprinter apparatus. The line has a capacitance dependent upon the length of the line. The method is characterized in that the current is regulated, at least in an interval following the closing of the line path at the beginning of a current pulse, by means of a variable impedance element included in series with the line path on the transmitter side. The variable impedance element is controlled such that the impedance value of the impedance element assumes a high value immediately after the commencement of current flow due to the closing of the line path and thereafter rapidly decreases to a low value, which is maintained during the pulse. The variable impedance may be a controllable semi-conductive element included in a constant current generator. This semi-conductive element is brought to a high impedance value in the transient intervals immediately after commencement of current flow and then its impedance value is decreased. |
