Motor voltage controller device

Claim 2

An improvement in a motor voltage control unit suitable for use with a motor and having a voltage sense unit for sensing motor voltage, a current sense unit for sensing motor current, a feedback error voltage unit operably connected to said voltage sense unit and said current sense unit for producing a signal related to the phase difference between the motor voltage and the motor current, a saw-tooth signal unit operably connected to said voltage sense unit for producing a cyclical signal, a comparator unit operably connected to said feedback error voltage unit and said saw-tooth signal unit for comparing those signals and a trigger unit responsive to said comparator unit for connecting said disconnecting the motor voltage from the motor, the improvement comprising a soft start unit operably connected to said comparator unit for gradually increasing the motor voltage during the motor starting cycle by initially separating the signal from the feedback error voltage unit from the cyclical signal of the saw-tooth signal unit, and then gradually allowing said signals to coincide.

Claim 3

An improvement in a motor voltage controller unit suitable for use with a motor and having a voltage sense unit for sensing motor voltage, a current sense unit for sensing motor current, a feedback error voltage unit operably connected to said voltage sense unit and said current sense unit for producing a signal related to the phase difference between the motor voltage and the motor current, a saw-tooth signal unit operably connected to said voltage sense unit for producing a cyclical signal, a comparator unit operably connected to said feedback error voltage unit and said saw-tooth signal unit for comparing those signals and a trigger unit responsive to said comparator unit for connecting and disconnecting the motor voltage from the motor, the improvement comprising fail detect means responsive to indicia of DC currents in the motor and operably connected to the trigger unit for locking the trigger unit on to continually apply motor voltage to the motor when said fail detect means senses indicia of DC currents in the motor.

Claim 4

An improvement in a motor voltage controller unit suitable for use with a motor and having a voltage sense unit for sensing motor voltage, a current sense unit for sensing motor current, a feedback error voltage unit operably connected to said voltage sense unit and said current sense unit for producing a signal related to the phase difference between the motor voltage and the motor current, a saw-tooth signal unit operably connected to said voltage sense unit for producing a cyclical signal, a comparator unit operably connected to said feedback error voltage unit and said saw-tooth signal unit for comparing those signals and a trigger unit responsive to said comparator unit for connecting and disconnecting the motor voltage from the motor, the improvement comprising fail detect means responsive to indicia of DC currents in the motor and operably connected to the trigger unit for locking the trigger unit on to continually apply motor voltage to the motor when said fail detect means senses indicia of DC currents in the motor.

Claim 5

A motor voltage control device for use with three-phase motors having no easily accessible ground path between phases, the device comprising: (a) first, second and third voltage sense means for sensing motor voltage in the first, second and third phases, respectively; (b) current sense means for sensing motor current in said first phase; (c) feedback error voltage means operably connected to said current sense means and to said first voltage sense means for producing a signal related to the phase difference between the motor voltage and motor current in the first phase; (d) first, second and third saw-tooth signal means operably connected to said first, second and third voltage sense means, respectively, for producing a cyclical signal; (e) first, second and third comparator means operably connected to said first, second and third saw-tooth signal means, respectively, and to said feedback error voltage means, for comparing such signals; and (f) first, second and third trigger means responsive to said first, second and third comparator means, respectively, and operably connected to the first, second and third phases, respectively, for selectively connecting and disconnecting the motor voltage from the motor during the positive half cycle of the motor voltage, but not during the negative half cycle of the motor voltage.

Claim 6

A motor voltage control device for use with three-phase motors having no easily accessible ground path between phases, the device comprising: (a) first, second and third voltage sense means for sensing motor voltage in the first, second and third phases, respectively; (b) current sense means for sensing motor current in said first phase; (c) feedback error voltage means operably connected to said current sense means and to said first voltage sense means for producing a signal related to the phase difference between the motor voltage and motor current in the first phase; (d) first, second and third saw-tooth signal means operably connected to said first, second and third voltage sense means, respectively, for producing a cyclical signal; (e) first, second and third comparator means operably connected to said first, second and third saw-tooth signal means, respectively, and to said feedback error voltage means, for comparing such signals; and (f) first, second and third trigger means responsive to said first, second and third comparator means, respectively, and operably connected to the first, second and third phases, respectively, for selectively connecting and disconnecting the motor voltage from the motor during the positive half cycle of the motor voltage, but not during the negative half cycle of the motor voltage.

Claim 7

A motor voltage control device for use with three-phase motors having no easily accessible ground path between phases, the device comprising: (a) first, second and third voltage sense means for sensing motor voltages in the first, second and third phases, respectively; (b) current sense means for sensing motor current in said first phase; (c) feedback error voltage means operably connected to said current sense means and to said first voltage sense means for producing a signal related to the phase difference between the motor voltage and motor current in the first phase; (d) first, second and third saw-tooth signal means operably connected to said first, second and third voltage sense means, respectively, for producing a cyclical signal; (e) first, second and third comparator means operably connected to said first, second and third saw-tooth signal means, respectively, and to said feedback error voltage means, for comparing such signals; and (f) first, second and third trigger means responsive to first, second and third comparator means, respectively, and operably connected to the first, second and third phases, respectively, for selectively connecting and disconnecting the motor voltage from the motor; and (g) first, second and third return path means operably connected to the first, second and third phases, respectively, for providing a path for motor current at all times during the negative half cycle of the motor current.

Claim 8

A motor voltage control device for use with three-phase motors having no easily accessible ground path between phases, the device comprising: (a) first, second and third voltage sense means for sensing motor voltages in the first, second and third phases, respectively; (b) current sense means for sensing motor current in said first phase; (c) feedback error voltage means operably connected to said current sense means and to said first voltage sense means for producing a signal related to the phase difference between the motor voltage and motor current in the first phase; (d) first, second and third saw-tooth signal means operably connected to said first, second and third voltage sense means, respectively, for producing a cyclical signal; (e) first, second and third comparator means operably connected to said first, second and third saw-tooth signal means, respectively, and to said feedback error voltage means, for comparing such signals; and (f) first, second and third trigger means responsive to first, second and third comparator means, respectively, and operably connected to the first, second and third phases, respectively, for selectively connecting and disconnecting the motor voltage from the motor; and (g) first, second and third return path means operably connected to the first, second and third phases, respectively, for providing a path for motor current at all times during the negative half cycle of the motor current.

Claim 9

A motor voltage control device for use with three-phase motors having no easily accessible ground path between phases, the device comprising: (a) first, second and third voltage sense means for sensing motor voltages in the first, second and third phases, respectively; (b) current sense means for sensing motor current in said first phase; (c) feedback error voltage means operably connected to said current sense means and to said first voltage sense means for producing a signal related to the phase difference between the motor voltage and motor current in the first phase; (d) first, second and third saw-tooth signal means operably connected to said first, second and third voltage sense means, respectively, for producing a cyclical signal; (e) first, second and third comparator means operably connected to said first, second and third saw-tooth signal means, respectively and to said feedback error voltage means, for comparing such signals; and (f) first, second and third trigger means responsive to said first, second and third comparator means, respectively, and operably connected to the first, second and third phases, respectively, for selectively connecting and disconnecting the motor voltage from the motor during the positive half cycle of the motor voltage, but not during the negative half cycle of the motor voltage; and (g) first, second and third return path means operably connected to the first, second and third phases, respectively, for providing a path at all times for motor current during the negative half cycle of the motor current.

Claim 10

A motor voltage control device for use with three-phase motors having no easily accessible ground path between phases, the device comprising: (a) first, second and third voltage sense means for sensing motor voltages in the first, second and third phases, respectively; (b) current sense means for sensing motor current in said first phase; (c) feedback error voltage means operably connected to said current sense means and to said first voltage sense means for producing a signal related to the phase difference between the motor voltage and motor current in the first phase; (d) first, second and third saw-tooth signal means operably connected to said first, second and third voltage sense means, respectively, for producing a cyclical signal; (e) first, second and third comparator means operably connected to said first, second and third saw-tooth signal means, respectively and to said feedback error voltage means, for comparing such signals; and (f) first, second and third trigger means responsive to said first, second and third comparator means, respectively, and operably connected to the first, second and third phases, respectively, for selectively connecting and disconnecting the motor voltage from the motor during the positive half cycle of the motor voltage, but not during the negative half cycle of the motor voltage; and (g) first, second and third return path means operably connected to the first, second and third phases, respectively, for providing a path at all times for motor current during the negative half cycle of the motor current.

Claim 11

The improvement of claims 3 or 4, and further including soft start means operably connected to said first, second and third comparator means for gradually increasing the motor voltage during the motor starting cycle.

Claim 12

The improvements of claims 3 or 4, and further including fail detect means responsive to indicia of DC currents in the motor and operably connected to said first, second and third trigger means for locking said trigger units on to continually apply motor voltage to the motor when said fail detect means senses indicia of DC currents in any of said first, second and third phases.

Claim 13

The improvements of claims 3 or 4, and further including sensitivity control means operably connected to said feedback error voltage means for varying the sensitivity of said feedback error voltage means to phase differences between the current in said first phase and the voltage in said first phase.

Claim 14

A motor voltage control device for use with three-phase motors having no easily accessible ground path between phases, the device comprising: (a) first, second and third voltage sense means for sensing motor voltage in the first, second and third phases, respectively; (b) current sense means for sensing motor current in said first phase; (c) feedback error voltage means operably connected to said current sense means and to said first voltage sense means for producing a signal related to the phase difference between the motor voltage and motor current in the first phase; (d) first, second and third saw-tooth signal means operably connected to said first, second and third voltage sense means, respectively, for producing a cyclical signal; (e) first, second and third comparator means operably connected to said first, second and third saw-tooth signal means, respectively, and to said feedback error voltage means, for comparing such signals; and (f) first, second and third trigger means responsive to said first, second and third comparator means, respectively, and operably connected to the first, second and third phases, respectively, for selectively connecting and disconnecting the motor voltage from the motor during one-half cycle of the motor voltage, but not during the remaining half cycle of the motor voltage.

Claim 15

A motor voltage control device for use with three-phase motors having no easily accessible ground path between phases, the device comprising: (a) first, second and third voltage sense means for sensing motor voltage in the first, second and third phases, respectively; (b) current sense means for sensing motor current in said first phase; (c) feedback error voltage means operably connected to said current sense means and to said first voltage sense means for producing a signal related to the phase difference between the motor voltage and motor current in the first phase; (d) first, second and third saw-tooth signal means operably connected to said first, second and third voltage sense means, respectively, for producing a cyclical signal; (e) first, second and third comparator means operably connected to said first, second and third saw-tooth signal means, respectively, and to said feedback error voltage means, for comparing such signals; and (f) first, second and third trigger means responsive to said first, second and third comparator means, respectively, and operably connected to the first, second and third phases, respectively, for selectively connecting and disconnecting the motor voltage from the motor during one-half cycle of the motor voltage, but not during the remaining half cycle of the motor voltage.