Antenna positioning system

Claim 2

An antenna positioning system, comprising: a motor for driving said antenna; a source of power for providing current for driving said motor, said source of power being connected to said motor by a pair of conductors, a voltage being developed across said pair of conductors; said system including means for measuring and controlling the speed of said antenna, comprising: means for interrupting said current for a current interruption period, said current interruption period being adjustable whereby to adjust the speed of said motor to thereby adjust the speed of said antenna; and means for measuring said voltage during said current interruption period; said voltage measured during said current interruption period being proportional to the speed of said motor and therefore to the speed of said antenna.

Claim 3

A system as defined in claim 1 and including comparator means for comparing said measured voltage with a reference representative of desired speed; the output of said comparator being fed to said means for interrupting said current to adjust said current interruption period whereby to adjust the speed of said motor, and thereby said antenna, such that it approaches said desired speed.

Claim 4

A system as defined in claim 2 wherein said means for interrupting said current comprises a blocking arrangement for blocking current in one position thereof and for permitting current flow in the other position thereof, and having a control terminal; said means for measuring and controlling further including sample and hold means connected across said pair of conductors and having an output terminal and a control terminal; the comparator means comprising error amplifier/compensator means having a first input terminal connected to said first output terminal of said sample and hold means and a second input terminal connected to said source of reference voltage, and an output terminal; and a control pulse generator means having an input terminal and a first output terminal and a second output terminal, said input terminal of said control pulse generator means being connected to said output terminal of said sample and hold means, said first output terminal of said control pulse generator means being connected to the control terminal of said blocking arrangement and said second output terminal of said control pulse generator means being connected to the control terminal of said sample and hold means.

Claim 5

A system as defined in claim 3 wherein said source of power comprises a source of AC power; said blocking arrangement comprising a rectifier bridge having controlled elements; said control pulse generator means generating a first pulse for activating said sample and hold means and a second pulse for activating said blocking arrangement; the position of said first pulse being a function of the output of said comparator means.

Claim 6

A system as defined in claim 3 wherein said source of power comprises a DC source of power; said blocking arrangement comprising switch means; said control pulse generator means generating a first pulse for activating said blocking arrangement and a second pulse for activating said sample and hold means; the position of said first pulse being a function of the output of said comparator means.

Claim 9

A method as defined in claim 6 wherein said system further comprises comparator means for comparing said measured voltage with a reference voltage; and including the steps of comparing said measured voltage with a reference voltage representative of desired speed; the output of said comparator means being fed to said means for interrupting said current to adjust said current interruption period whereby to adjust the speed of said motor and thereby said antenna such that it approaches said desired speed.