Device for deriving from a control a.c.-voltage of relatively high frequency an a.c.-voltage of lower frequency and with a predetermined phase position in time

Claim 1

A DIGITAL FREQUENCY SYNTHESIS DEVICE FOR PRODUCING AN OUTPUT VOLTAGE OF ADJUSTABLE FREQUENCY, COMPRISING MEANS FOR GENERATING A SERIES OF INPUT PULSES, A FIRST PULSE COUNTER CONNECTED TO SAID MEANS FOR RECEIVING SAID INPUT PULSES, SAID FIRST PULSE COUNTER COMPRISING A PLURALITY F BISTABLE STAGES CONNECTED IN CASCADE, MEANS CONNECTED TO EACH OF SAID STAGES FOR DERIVING AN INTERMEDIATE PULSE INDICATIVE OF A CHANGE OF STATE OF EACH OF SAID STAGES, SELECTIVELY OPERABLE CONNECTING MEANS HAVING PROVISION FOR INPUT AND OUTPUT, MEANS CONNECTED TO THE INPUT OF SAID SELECTIVELY OPERABLE CONNECTING MEANS FOR SUPPLYING THERTO SAID INTERMEDIATE PULSES FROM SAID FIRST PULSE COUNTER, A SECOND PULSE COUNTER COMPRISING A PLURALITY OF CASCADED BISTABLE STAGES INCLUDING AN INPUT STAGE AND AN OUTPUT STAGE, MEANS CONNECTING THE OUTPUT OF SAID SELECTIVELY OPERABLE CONNECTING MEANS TO THE INPUT STAGE OF SAID SECOND PULSE COUNTER, THE OUTPUT STAGE OF SAID SECOND PULSE COUNTER ALTERNATING STATES AT THE END OF EACH CYCLE OF SAID SECOND COUNTER THEREBY GENERATING THE OUTPUT VOLTAGE OF ADJUSTABLE FREQUENCY, A CYCLICALLY OPERATING PHASE CHECMING PULSE COUNTER CHAIN COMPRISING THE SAID FIRST PULSE COUNTER SERIALLY CONNECTED TO A FURTHER PULSE COUNTER, SAID FURTHER PULSE COUNTER HAVING THE SAME NUMBER OF COUNTING STAGS AS THE SAID SECOND PULSE COUNTER, MEANS CONNECTING TO SAID FURTHER PULSE COUNTER FOR DERIVING A FURTHER PULSE AT EACH OPERATION CYCLE OF THE SAID COUNTER CHAIN, AND MEANS CONNECTING SAID MEANS FOR DERIVING TO SAID SECOND PULSE COUNTER FOR RESTORING ALL STAGES OF SAID SECOND COUNTER TO A STARTING POSITION UPON THE INTRODUCTION OF SAID FURTHER PULSE THERETO IN ORDER TO MAINTAIN PREDETERMINED PHASE CONDITIONS FOR VARIOUS OUTPUT FREQUENCIES.