Digitally controlled analog flux sensing ferrite phase shifter driver

Claim 1

A digitally controlled phase shift network comprising: a. an analog phase shifter having a magnetizable core exhibiting plural magnetic states and differential phase shift varying correspondingly with the integral of an applied magnetic flux drive; b. magnetization current supply means for said phase shifter including a magnetizing current source and switch means operable to control flow of magnetizing current from said source to said phase shifter; c. digital counter means connected to receive a digital input signal for entry of an initial count therein, said counter means being operative upon application of each count input pulse to effect a unit change in a running count therein and operative upon said running count reaching a magnitude determined by said initial count to generate an output pulse; d. input means for generating a digital input signal representing a called-for value of phase shifter differential phase shift and applying such signal to said digital counter means for entry therein as said initial count; e. voltage responsive means connected to said phase shifter for response to an operating voltage having predetermined relationship to phase shifter magnetic flux, said voltage responsive means including means for integrating such voltage with respect to time to thereby provide a volt-time integral indicative of the differential phase shift effectuated by said magnetizing current; f. control means connected to said volt-time integration means and operative to zero the volt-time integral each time it reaches a predetermined value representative of a differential phase shift increment of predetermined unit magnitude, and operative simultaneously to apply a phase shift increment count pulse input to said digital counter means thereby to effect a unit change in the running count in said counter; and g. means responsive to said digital counter output pulse to open said switch means to thereby cut off current flow to said phase shifter when the running count in said digital counter reaches said predetermined magnitude indicating that the called-for value of differential phase shift has been achieved.