Circuit arrangement for the wireless transmission of control signals to the control paths of controlled semiconductor valves

A circuit arrangement for the wireless transmission of control signals to the control paths of controlled semiconductor vavles such as thyristors used in a rectifier for high voltage, said semiconductor valves including a first group of controlled semiconductor valves arranged for simultaneous firing in response to a first control signal and a second group of control semiconductor valves similarly arranged to be simultaneously fired by in response to a second control signal occurring at a time different from said first control signal with first and second intermediate frequency modulation frequencies associated respectively with said first and second control signals, a high frequency common to both groups being provided for transmitting a signal having a high frequency carrier modulated by said first and second intermediate frequency modulation frequencies in dependent on said first and second control signals comprising:

• a. a first group of high frequency receivers disposed remotely from said high frequency transmitter each including a demodulator tuned to said first modulation frequency and providing an output to the control path of a semiconductor valve in said first group of controlled semiconductor valves;
• b. a second group of high frequency receivers similarly remotely located from said high frequency transmitter and each containing a demodulator tuned to said second modulation frequency providing an output signal to the control path of a semiconductor valve from said second group of controlled semiconductor valves;
• c. a high frequency transmitter including a transmitting antenna equipped with a reflector and means to train said reflector in the direction of said individual high frequency receivers, said high frequency transmitter being a frequency modulated high frequency transmitter having a carrier frequency in the range of 10 mhz to 50 ghz;
• and
• d. wherein the demodulators in each of said high frequency receiver comprises a filter tuned to demodulate the frequency associated with its control signal and to substantially block the passage of other frequencies.