Coil driver with high voltage switch

Claim 2

A circuit for controlling current in a coil comprising: A first switching means and a first source of power serially connected with the coil for energizing the coil with an electric current; A second source of power connected to the first switching means; and Sensing means responsive to the rate of change of current in the coil, the sensing means operating the first switching means to provide alternate states of conduction such that when a positive rate of change of current in the coil is less than a first predetermined value, the coil is energized with power from the first source of power and when the positive rate of change of current in the coil is greater than the first predetermined value, the coil is energized with power from the second source of power.

Claim 3

The cIrcuit as defined by claim 1 wherein the sensing means comprises: transistor circuit means providing a switching control signal for the first switching means; and a diode in circuit between the coil and the transistor circuit means, the diode being in a state of conduction when the rate of change of current in the coil is greater than the first predetermined value.

Claim 4

The circuit as defined by claim 1 wherein the first source of power has a first voltage and the second source of power has a second voltage greater than the first voltage, the circuit further comprising a second switching means interconnecting the coil and the second source of power, the second switching means being operative in response to the rate of change of current in the coil such that when a negative rate of change of current in the coil attains a second predetermined value, stored energy within the coil is discharged through the second switching means into the second source of power.

Claim 5

The circuit as defined by claim 3 wherein the sensing means comprises: transistor circuit means providing a switching control signal for the first switching means; and a diode in circuit between the coil and the transistor circuit means, the diode being in a state of conduction when the rate of change of current in the coil is greater than the first predetermined value.

Claim 6

In a phased array antenna utilizing a plurality of phase shifting elements, each of which incorporates a coil and provides a phase shift in accordance with computer commands, an improved coil driving circuit for the coils responsive to independent input signals from the computer for individual control of the current in each of the coils comprising: current controller means responsive to the input signals from the computer: a first switching means and a first source of power: the current controller means, the first switching means and the first source of power being serially connected with the coils for energizing the coils with electric currents: a second source of power connected to the first switching means; and SENSING MEANS RESPONSIVE TO THE RATES OF CHANGE OF CURRENTS IN THE COILS, THE SENSING MEANS OPERATING THE FIRST SWITCHING MEANS TO PROVIDE ALTERNATE STATES OF CONDUCTION SUCH THAT WHEN A POSITIVE RATE OF CHANGE OF CURRENT IN THE COIL IS LESS THAN A FIRST PREDETERMINED VALUE, THE COIL IS ENERGIZED WITH POWER FROM THE FIRST SOURCE OF POWER AND WHEN THE POSITIVE RATE OF CHANGE OF CURRENT IN THE COIL IS GREATER THAN THE FIRST PREDETERMINED VALUE, THE COIL IS ENERGIZED WITH POWER FROM THE SECOND SOURCE OF POWER.

Claim 7

In a phased array antenna utilizing a plurality of phase shifting elements, each of which incorporates a coil and provides a phase shift in accordance with computer commands, an improved coil driving circuit for the coils responsive to independent input signals from the computer for individual control of the current in each of the coils comprising: current controller means responsive to the input signals from the computer: a first switching means and a first source of power: the current controller means, the first switching means and the first source of power being serially connected with the coils for energizing the coils with electric currents: a second source of power connected to the first switching means; and SENSING MEANS RESPONSIVE TO THE RATES OF CHANGE OF CURRENTS IN THE COILS, THE SENSING MEANS OPERATING THE FIRST SWITCHING MEANS TO PROVIDE ALTERNATE STATES OF CONDUCTION SUCH THAT WHEN A POSITIVE RATE OF CHANGE OF CURRENT IN THE COIL IS LESS THAN A FIRST PREDETERMINED VALUE, THE COIL IS ENERGIZED WITH POWER FROM THE FIRST SOURCE OF POWER AND WHEN THE POSITIVE RATE OF CHANGE OF CURRENT IN THE COIL IS GREATER THAN THE FIRST PREDETERMINED VALUE, THE COIL IS ENERGIZED WITH POWER FROM THE SECOND SOURCE OF POWER.

Claim 8

The circuit as defined by claim 5 wherein the first source of power has a first voltage and the second source of power has a second voltage greater than the first voltage, the circuit further comprising a second switching means interconnecting the coils and the second source of power, the second switching means being operative in response to the rates of change of currents in the coils such that when the negative rates of change of currents in the coils attain a second predetermined value, stored energy within the coils is discharged through the second switching means into the second source of power.