rundsteuersendeanlage for exceeded 100 mg / l rundsteuerung

摘要

1,155,235. Converters. LANDIS & GYR AG. 13 March, 1967 [23 March, 1966], No. 11600/67. Heading H2F. [Also in Division H4] In a frequency changer of the A.C.-D.C.- A.C. type, employed as a ripple control signal transmitter, the inverter of each phase comprises a pair of series connected thyristors 13, 14, each shunted by a reverse diode 19, 20. The output filter 6 is connected across thyristor 14. When thyristor 13 is fired, the capacitor 20 charges through the primary of transformer 22 until the overswing current extinguishes thyristor 13. Thyristor 14 is now fired, and capacitor 20 discharges through it until the overswing circuit causes it in turn to be extinguished, ready to be fired again. In order to prevent both thyristors being fired at the same time, the firing signals to thyristor 14 are applied via a gate 25 which is only opened when diode 19 carries current, i.e. when thyratron 13 is off. A similar gate may be provided in the control circuit of thyristor 13. Transmission is controlled by a switch 30 which in its "off" position prevents thyristor 13 from firing, but allows thyristor 14 to fire to discharge capacitor 20. The filter may comprise series and parallel tuned circuits, Fig. 3 (not shown).