Controlled-velocity drive

Claim 2

In a controlled-velocity drive having a DC motor the speed of which varies substantially as a function of the voltage applied to the armature thereof, a control for the motor comprising: a triggerable semiconductor current-switching device connected in a circuit, including an AC power source, for supplying a DC voltage to the motor armature when the switching device is triggered, shifting of the phase of triggering of the switching device causing variation of said DC voltage for varying the motor speed; a first feedback circuit sensing said DC voltage applied to the motor armature and producing a first degenerative feedback signal; a second feedback circuit sensing the rate of change of said DC voltage applied to the motor armature and producing a second degenerative feedback signal which varies as a function thereof; a summing junction for summing said first and second feedback signals; means for producing a reference voltage proportional to a preselected motor speed; and means, interconnecting said summing junction and said means for producing a reference voltage and responsive to the difference between said reference voltage and the sum of said feedback signals, for controlling the phase of triggering of said switching device to maintain the motor speed substantially equal to said preselected motor speed.

Claim 3

In a controlled-velocity drive as set forth in claim 1, said control further comprising a third feedback circuit, including a tachometer generator, for producing a third degenerative feedback signal varying according to the motor speed, said summing junction summing said third feedback signal with said first and second feedback signals.

Claim 4

In a controlled-velocity drive as set forth in claim 1, said control further comprising means, interconnected with said means for controlling the phase of triggering of said switching device for accelerating the motor at a substantially constant rate to said preselected motor speed.

Claim 5

In a controlled-velocity drive as set forth in claim 3, said means for accelerating the motor including a capacitor and means for charging the capacitor at a substantially constant current to said reference voltage.

Claim 6

In a controlled-velocity drive having a DC motor the speed of which varies substantially as a function of the voltage applied to the armature thereof, a control for the motor comprising: a triggerable semiconductor current-switching device connected in a circuit, including an AC power source, for supplying a DC voltage to the motor armature when the switching device is triggered, shifting of the phase of triggering of the switching device causing variation of said DC voltage for varying the motor speed; a feedback circuit sensing the motor speed and producing a first degenerative feedback signal which varies as a function thereof; said feedback circuit sensing the motor speed including means for sensing the DC voltage supplied to the motor armature and means for producing a degenerative feedback signal which varies as a function of the motor speed acceleration; means for producing a first reference voltage proportional to a preselected motor speed; a further feedback circuit sensing the motor armature current and producing a further feedback signal which varies as a function thereof; means for producing a second reference voltage proportional to a preselected maximum armature current; means, interconnecting said further feedback circuit and the means for producing said second reference voltage, for producing a degenerative control signal varying as a function of the voltage by which said further feedback signal exceeds said second reference voltage; and means, responsive to the algebraic sum of said first feedback signal, said first reference voltage and said degenerative control signal, for controlling the phase of triggering of said switching device for maintaining the motor speed substantially equal to said preselected motor speed while substantially preventing the motor armature current from exceeding said preselected maximum.

Claim 7

In a controlled-velocity drive having a DC motor the speed of which varies substantially as a function of the voltage applied to the armature thereof, a control for the motor comprising: a triggerable semiconductor current-switching device connected in a circuit, including an AC power source, for supplying a DC voltage to the motor armature when the switching device is triggered, shifting of the phase of triggering of the switching device causing variation of said DC voltage for varying the motor speed; a feedback circuit sensing the motor speed and producing a first degenerative feedback signal which varies as a function thereof; said feedback circuit sensing the motor speed including means for sensing the DC voltage supplied to the motor armature and means for producing a degenerative feedback signal which varies as a function of the motor speed acceleration; means for producing a first reference voltage proportional to a preselected motor speed; a further feedback circuit sensing the motor armature current and producing a further feedback signal which varies as a function thereof; means for producing a second reference voltage proportional to a preselected maximum armature current; means, interconnecting said further feedback circuit and the means for producing said second reference voltage, for producing a degenerative control signal varying as a function of the voltage by which said further feedback signal exceeds said second reference voltage; and means, responsive to the algebraic sum of said first feedback signal, said first reference voltage and said degenerative control signal, for controlling the phase of triggering of said switching device for maintaining the motor speed substantially equal to said preselected motor speed while substantially preventing the motor armature current from exceeding said preselected maximum.

Claim 8

In a controlled-velocity drive as set froth in claim 5, the last said means including a capacitor connected for differentiating the DC voltage supplied to the motor armature.

Claim 9

In a controlled-velocity drive having a DC motor the speed of which varies substantially as a function of the voltage applied to the armature thereof, a control for the motor comprising: a triggerable semiconductor current-switching device connected in a circuit, including an AC power source, for supplying a DC voltage to the motor armature when the switching device is triggered, shifting of the phase of triggering of the switching device causing variation of said DC voltage for varying the motor speed; a feedback circuit sensing the motor speed and producing a first-degenerative feedback signal which varies as a function thereof; means for producing a first reference voltage proportional to a preselected motor speed; a further feedback circuit sensing the motor armature current and producing a further feedback signal which varies as a function thereof; means for producing a second reference voltage proportional to a preselected maximum armature current; means, interconnecting said further feedback circuit and the means for producing said second reference voltage, for producing a degenerative control signal varying as a function of the voltage by which said further feedback signal exceeds said second reference voltage; means, responsive to the algebraic sum of said first feedback signal, said first reference voltage and said degenerative control signal, for controlling the phase of triggering of said switching device for maintaining the motor speed substantially equal to said preselected motor speed while substantially preventing the motor armature current from exceeding said preselected maximum; and an additional feedback circuit including a delay network responsive to the motor armature current and producing a regenerative feedback signal which varies as a function thereof, said means for controlling the phase of triggering of said switching device also being responsive to said regenerative feedback signal.

Claim 10

In a controlled-velocity drive having a DC motor the speed of which varies substantially as a function of the voltage applied to the armature thereof, a control for the motor comprising: a triggerable semiconductor current-switching device connected in a circuit, including an AC power source, for supplying a DC voltage to the motor armature when the switching device is triggered, shifting of the phase of triggering of the switching device causing variation of said DC voltage for varying the motor speed; a feedback circuit sensing the motor speed and producing a first-degenerative feedback signal which varies as a function thereof; means for producing a first reference voltage proportional to a preselected motor speed; a further feedback circuit sensing the motor armature current and producing a further feedback signal which varies as a function thereof; means for producing a second reference voltage proportional to a preselected maximum armature current; means, interconnecting said further feedback circuit and the means for producing said second reference voltage, for producing a degenerative control signal varying as a function of the voltage by which said further feedback signal exceeds said second reference voltage; means, responsive to the algebraic sum of said first feedback signal, said first reference voltage and said degenerative control signal, for controlling the phase of triggering of said switching device for maintaining the motor speed substantially equal to said preselected motor speed while substantially preventing the motor armature current from exceeding said preselected maximum; and an additional feedback circuit including a delay network responsive to the motor armature current and producing a regenerative feedback signal which varies as a function thereof, said means for controlling the phase of triggering of said switching device also being responsive to said regenerative feedback signal.

Claim 11

In a controlled-velocity drive having a DC motor the speed of which varies substantially as a function of the voltage applied to the armature thereof, a control for the motor comprising: a plurality of triggerable semiconductor current-switching devices interconnected with the motor armature and a multiphase AC power source for supplying a DC voltage to the motor armature when triggered in sequence, shifting of the phase of triggering of said devices causing variation of said DC voltage for varying the motor speed; a first feedback circuit sensing the DC voltage supplied to the motor armature and producing a first-degenerative feedback signal which varies as a function thereof; a second feedback circuit sensing the rate of change of the DC voltage supplied to the motor armature and producing a secoNd-degenerative feedback signal which varies as a function thereof; a third feedback circuit sensing the motor speed and including a tachometer generator having an output signal varying as a function of the motor speed; means for producing a first reference voltage proportional to a preselected motor speed; a further feedback circuit, including an impedance series-connected with the motor armature, the impedance developing a voltage thereacross which is a function of the motor armature current, said further feedback circuit producing a further feedback signal which varies as a function of the motor armature current; an additional feedback circuit including a delay network responsive to the voltage developed across said impedance and producing a regenerative delayed feedback signal which varies as a function of the motor armature current; a compensating feedback circuit sensing the voltage developed across said impedance and producing a compensating feedback signal which varies as a function of said developed voltage; means for producing a second reference voltage proportional to a preselected maximum armature current; means, interconnecting said further feedback circuit and said means for producing a second reference voltage, for producing a degenerative control signal varying as a function of the voltage by which said further feedback signal exceeds said second reference voltage; means for algebraically summing said first and second feedback signals, said tachometer output signal, said first reference voltage, said delayed feedback signal, said compensating feedback signal, and said degenerative control signal and for producing a triggering control signal varying as a function of the algebraic sum; and means for shifting the phase of triggering of said switching devices in response to said triggering control signal for maintaining the motor speed substantially equal to said preselected motor speed while substantially preventing the motor armature current from exceeding said preselected maximum.

Claim 12

In a controlled-velocity drive having a DC motor the speed of which varies substantially as a function of the voltage applied to the armature thereof, a control for the motor comprising: a plurality of triggerable semiconductor current-switching devices interconnected with the motor armature and a multiphase AC power source for supplying a DC voltage to the motor armature when triggered in sequence, shifting of the phase of triggering of said devices causing variation of said DC voltage for varying the motor speed; a first feedback circuit sensing the DC voltage supplied to the motor armature and producing a first-degenerative feedback signal which varies as a function thereof; a second feedback circuit sensing the rate of change of the DC voltage supplied to the motor armature and producing a secoNd-degenerative feedback signal which varies as a function thereof; a third feedback circuit sensing the motor speed and including a tachometer generator having an output signal varying as a function of the motor speed; means for producing a first reference voltage proportional to a preselected motor speed; a further feedback circuit, including an impedance series-connected with the motor armature, the impedance developing a voltage thereacross which is a function of the motor armature current, said further feedback circuit producing a further feedback signal which varies as a function of the motor armature current; an additional feedback circuit including a delay network responsive to the voltage developed across said impedance and producing a regenerative delayed feedback signal which varies as a function of the motor armature current; a compensating feedback circuit sensing the voltage developed across said impedance and producing a compensating feedback signal which varies as a function of said developed voltage; means for producing a second reference voltage proportional to a preselected maximum armature current; means, interconnecting said further feedback circuit and said means for producing a second reference voltage, for producing a degenerative control signal varying as a function of the voltage by which said further feedback signal exceeds said second reference voltage; means for algebraically summing said first and second feedback signals, said tachometer output signal, said first reference voltage, said delayed feedback signal, said compensating feedback signal, and said degenerative control signal and for producing a triggering control signal varying as a function of the algebraic sum; and means for shifting the phase of triggering of said switching devices in response to said triggering control signal for maintaining the motor speed substantially equal to said preselected motor speed while substantially preventing the motor armature current from exceeding said preselected maximum.