Motor control circuit

Claim 2

A motor control circuit whereby a bifilar stepping motor is adapted for operation through a large speed range without resonance, comprising A. means for monitoring a load which is driven by said bifilar stepping motor; B. means for continuously supplying drivin current to said motor; and C. control means responsive to said monitoring means for limiting the continuous driving current in accordance with the load being monitored; and wherein said circuit also comprises A. means for sensing the current supplied to said motor; B. means associated with said monitoring means for providing an output current proportional to the load being monitored; anad C. current summing means providing an output dependent on the difference between the motor current and the monitor current for controlling the driving current supply means.

Claim 3

A motor control circuit according to claim 1 in which the current summing means includes an integrator whereby the driving current supply means responds to the difference between the motor current and the monitor current over a time interval corresponding to the integration time of the integrator.

Claim 4

having a control gate connected to said control means, and

Claim 5

having a control gate connected to said control means, and

Claim 6

responsive to said control means to control the duration which the controlled rectifier connects the output of the first rectifier to the filter circuit; and D. means associated with the controlled rectifier for assisting in turning on said rectifier.

Claim 7

responsive to said control means to control the duration which the controlled rectifier connects the output of the first rectifier to the filter circuit; and D. means associated with the controlled rectifier for assisting in turning on said rectifier.

Claim 8

A motor control circuit according to claim 2 which includes means for discharging the integrator from time to time.

Claim 9

A motor control circuit according to claim 1 in which the control means includes: A. an integrator having applied as inputs thereto a first current proportional to the current through the motor and a second current of opposite polarity to the first current and proportional to the output of the monitoring means; B. a capacitor connected to the output of the integrator; and C. a switch interposed between said capacitor and the driving current supply means.

Claim 10

A motor control circuit according to claim 4 in which said capacitor controls the firing point of a controlled rectifier in the driving current supply means whereby the current applied to the motor is dependent on the change on said capacitor.

Claim 11

A motor control circuit according to claim 1 in which the motor is a stepping motor having a pluralitY of control windings for driving said motor and having a plurality of switches associated with the control windings for distributing current to said windings in accordance with a predetermined schedule, and which includes a rate control circuit for energizing said switches at a controlled rate.

Claim 12

A motor control circuit according to claim 1 in which said motor is a stepping motor having a plurality of control windings and a switch in each winding for selectively energizing said windings and which includes auxiliary switching means in series with each winding and each switch to allow current to flow through said windings in a first direction only.

Claim 13

A motor control circuit according to claim 7 in which said auxiliary switching means comprises a diode.

Claim 14

A motor control circuit for continuously controlling a stepping motor while minimizing heat generation of said motor, said circuit comprising a stepping motor and A. means for monitoring a load being driven by said stepping motor; B. means for supplying driving current to said stepping motor; and C. a pulse generator responsive to the load-monitoring means for supplying driving pulses to the motor to drive it at a rate dependent at least in part on the load driven by said motor; and in which said pulse generator comprises A. a multi-stable device providing at least one distinct output for each control winding in said motor; and B. an oscillator having a selectively variable repetition rate for driving said device.

Claim 15

A motor control circuit for continuously controlling a stepping motor while minimizing heat generation of said motor, said circuit comprising a stepping motor and A. means for monitoring a load being driven by said stepping motor; B. means for supplying driving current to said stepping motor; and C. a pulse generator responsive to the load-monitoring means for supplying driving pulses to the motor to drive it at a rate dependent at least in part on the load driven by said motor; and in which said pulse generator comprises A. a multi-stable device providing at least one distinct output for each control winding in said motor; and B. an oscillator having a selectively variable repetition rate for driving said device.

Claim 16

A motor control circuit according to claim 9 in which said motor is a stepping motor having a plurality of control windings and a switch in each winding for selectively energizing said windings and which includes auxiliary switching means in series with each winding and each switch to allow current to flow through said windings in a first direction only.

Claim 17

A motor control circuit according to claim 10 in which said auxiliary switching means comprises a diode.

Claim 18

A motor control circuit, whereby a bifilar stepping motor is adapted for operation through a large speed range, without resonance, comprising A. means for monitoring a load which is driven by a bifilar stepping motor; B. means for continuously supplying driving current to said motor; and C. control means responsive to said monitoring means for limiting the continuous driving current in accordance with the load being monitored which circuit further includes: D. means for sensing the current supplied to said motor; E. means associated with said monitoring means for providing an output current proportional to the load being monitored; and F. current summing means providing an output dependent on the difference between the motor current and the monitor current for controlling the driving current supply means and wherein the current summing means includes an integrator whereby the driving current supply means responds to the difference between the motor current and the monitor current over a time interval corresponding to the integration time of the integrator; and also means for discharging the integrator from time to time; and in which the driving current supply means includes a converter for converting an AC voltage to a DC voltage in which the discharge of said integrator is synchronized with the zero crossings of the AC voltage.

Claim 19

A motor control circuit, whereby a bifilar stepping motor is adapted for operation through a large speed range, without resonance, comprising A. means for monitoring a load which is driven by a bifilar stepping motor; B. means for continuously supplying driving current to said motor; and C. control means responsive to said monitoring means for limiting the continuous driving current in accordance with the load being monitored which circuit further includes: D. means for sensing the current supplied to said motor; E. means associated with said monitoring means for providing an output current proportional to the load being monitored; and F. current summing means providing an output dependent on the difference between the motor current and the monitor current for controlling the driving current supply means and wherein the current summing means includes an integrator whereby the driving current supply means responds to the difference between the motor current and the monitor current over a time interval corresponding to the integration time of the integrator; and also means for discharging the integrator from time to time; and in which the driving current supply means includes a converter for converting an AC voltage to a DC voltage in which the discharge of said integrator is synchronized with the zero crossings of the AC voltage.

Claim 20

A motor circuit, whereby a bifilar stepping motor is adapted for operation through a large speed range without resonance comprising A. means for monitoring a load which is driven by a bifilar stepping motor; B. means for continuously supplying driving current to said motor; and C. control means responsive to said monitoring means for limiting the continuous driving current in accordance with the load being monitored and in which the driving current supply means comprises: A. a first rectifier for converting an AC voltage into a pulsating DC voltage; B. a filter for filtering the pulsating DC voltage; C. a controlled rectifier

Claim 21

A motor circuit, whereby a bifilar stepping motor is adapted for operation through a large speed range without resonance comprising A. means for monitoring a load which is driven by a bifilar stepping motor; B. means for continuously supplying driving current to said motor; and C. control means responsive to said monitoring means for limiting the continuous driving current in accordance with the load being monitored and in which the driving current supply means comprises: A. a first rectifier for converting an AC voltage into a pulsating DC voltage; B. a filter for filtering the pulsating DC voltage; C. a controlled rectifier

Claim 22

A motor control circuit, whereby a bifilar stepping motor is adapted for operation through a large speed range without resonance comprising A. means for monitoring a load which is driven by a bifilar stepping motor; B. means for continuously supplying driving current to said motor; and C. control means responsive to said monitoring means for limiting the continuous driving current in accordance with the load being monitored; and in which the control means includes: A. an integrator having applied as inputs thereto a first current proportional to the current through the motor and a second current of opposite polarity to the first current and proportional to the output of the monitoring means; B. a capacitor connected to the output of the integrator and C. a switch interposed between said capacitor and the driving current supply means; and in which said capacitor controls the firing point of a controlled rectifier in the driving current supply means whereby the current applied to the motor is dependent on the charge on said capacitor; and wherein said motor control circuit includes means for discharging said capacitor from time to time in accordance with an AC voltage applied to the driving current supply means.

Claim 23

A motor control circuit, whereby a bifilar stepping motor is adapted for operation through a large speed range without resonance comprising A. means for monitoring a load which is driven by a bifilar stepping motor; B. means for continuously supplying driving current to said motor; and C. control means responsive to said monitoring means for limiting the continuous driving current in accordance with the load being monitored; and in which the control means includes: A. an integrator having applied as inputs thereto a first current proportional to the current through the motor and a second current of opposite polarity to the first current and proportional to the output of the monitoring means; B. a capacitor connected to the output of the integrator and C. a switch interposed between said capacitor and the driving current supply means; and in which said capacitor controls the firing point of a controlled rectifier in the driving current supply means whereby the current applied to the motor is dependent on the charge on said capacitor; and wherein said motor control circuit includes means for discharging said capacitor from time to time in accordance with an AC voltage applied to the driving current supply means.

Claim 24

A motor control circuit according to claim 14 in which the means for assisting the turn-on of the controlled rectifier includes a capacitor connected between the output of the controlled rectifier and a terminal common to the first rectifier, said capacitor initially presenting a low impedance to the output of the controlled rectifier whereby turn on is assisted.

Claim 25

A motor control circuit according to claim 14 in which the means associated with the controlled rectifier includes a resistor connected between the output of said rectifier and terminal commo to the first rectifier for maintaining a small current through the resistor and through the controlled rectifier to maintain said rectifier in the ''''on'''' condition when the output of the filter is at a higher potential than the input thereto.

Claim 26

A motor control circuit, whereby a bifilar stepping motor is adapted for operation through a large speed range without resonance comprising A. means for monitoring a load which is driven by a bifilar stepping motor; B. means for continuously supplying driving current to said motor; and C. control means responsive to said monitoring means for limiting the continuous driving current in accordance with the load being monitored; and in which the motor is bifilar stepping motor having a plurality of control windings for driving said motor and having a plurality of switches associated with the control windings for distributing current to said windings in accordance with a predetermined schedule, and which includes a rate control circuit for energizing said switches at a controlled rate and wherein said rate control circuit includes an oscillator comprising: A. an integrator having an input and an output; B. means connecting the output to the motor winding control switches for driving said motor; and C. switching means having a control gate for discharging the integrator when the integrator output reaches a magnitude determined by the potential applied to said control gate.

Claim 27

A motor control circuit, whereby a bifilar stepping motor is adapted for operation through a large speed range without resonance comprising A. means for monitoring a load which is driven by a bifilar stepping motor; B. means for continuously supplying driving current to said motor; and C. control means responsive to said monitoring means for limiting the continuous driving current in accordance with the load being monitored; and in which the motor is bifilar stepping motor having a plurality of control windings for driving said motor and having a plurality of switches associated with the control windings for distributing current to said windings in accordance with a predetermined schedule, and which includes a rate control circuit for energizing said switches at a controlled rate and wherein said rate control circuit includes an oscillator comprising: A. an integrator having an input and an output; B. means connecting the output to the motor winding control switches for driving said motor; and C. switching means having a control gate for discharging the integrator when the integrator output reaches a magnitude determined by the potential applied to said control gate.

Claim 28

A motor control circuit according to claim 17 in which the control gate is connected to the load monitoring means whereby the repetition rate of said oscillator is dependent on the load.

Claim 29

A motor control circuit according to claim 17 which includes means for connecting thte integrator input to a potential source of selectable magnitude whereby the integration time of said integrator may be controlled.

Claim 30

A motor control circuit for controlling a bifilar stepping motor, whereby a bifilar stepping motor is adapted for operation through a large speed range without resonance comprising A. means for continuously monitoring a load being driven by said motor; B. means for continuously supplying driving current to said motor; and C. a pulse generator responsive to the monitoring means for supplying driving pulses to the motor to drive it at a rate dependent at least in part on the load driven by said motor; and in which said pulse generator comprises: A. a multi-stable device providing at least one distinct output for each control winding in said motor; and B. an oscillator having a selectively variable repetition rate for driving said device; and in qhich said oscillator comprises an amplifier, a capacitor connected between the input and output of said amplifier and forming an integrator with said amplifier, and means for discharging said capacitor from time to time to control the integration time of said integrator.

Claim 31

A motor control circuit for controlling a bifilar stepping motor, whereby a bifilar stepping motor is adapted for operation through a large speed range without resonance comprising A. means for continuously monitoring a load being driven by said motor; B. means for continuously supplying driving current to said motor; and C. a pulse generator responsive to the monitoring means for supplying driving pulses to the motor to drive it at a rate dependent at least in part on the load driven by said motor; and in which said pulse generator comprises: A. a multi-stable device providing at least one distinct output for each control winding in said motor; and B. an oscillator having a selectively variable repetition rate for driving said device; and in qhich said oscillator comprises an amplifier, a capacitor connected between the input and output of said amplifier and forming an integrator with said amplifier, and means for discharging said capacitor from time to time to control the integration time of said integrator.

Claim 32

A control circuit according to claim 20 in which the discharge means has a control terminal to which a control potential is applied to discharge said capacitor when the integrator output bears a predetermined relation to the control input.

Claim 33

A control circuit according to claim 21 in which the control input is connected to the said load monitoring means whereby the repetition rate of said oscillator is dependent on the load being driven.