Patent US3767993A successfully refreshed from Google Patents.
US3767993A
Expired / Lapsed
US
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Stepping motor control circuit
Assignee: EECO Inc
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Filing: 1971-08-25
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Granted: 1973-10-23
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Expires: 1991-08-25
Abstract
Abstract A stepping motor circuit in which the electrical damping period for locking the rotor is automatically inversely variable according to the speed of operation. Three monostable relaxation devices provide required timing for effective stepper motor drive. A differentiating circuit resets either one or two of these devices to decrease the period of damping at high stepping rates. Typically, for high stepping rates, the motor supply voltage is increased to rapidly accelerate the rotor and Zener semiconductor breakdown is used to subsequently dissipate energy from the motor coils.
Inventors
- 👤 R Yablonski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:19
CPC Classifications
H; H02; H02P; H02P8/00; H02P8/32
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
164 words
A stepper motor drive circuit comprising; a. a source (1) of step command pulses, b. a first relaxation device (4) connected to said source for actuation by step command pulses, c. a second relaxation device (5) connected to said first relaxation device for subsequent actuation thereby, d. a third relaxation device (6) connected to said second relaxation device for subsequent actuation thereby, e. logic means (3) connected to said first relaxation device to provide plural-phase excitation to said stepper motor, and f. electric differentiating means (7) connected to said first relaxation device and to said second and third relaxation devices to selectively reset said third and second relaxation devices on each step command pulse, whereby said third relaxation device and selectively said second relaxation device are reset prior to the expiration of their normal cycle of actuation when said command pulses occur more rapidly than the full period of the normal cycle of actuation of said third and selectively also said second relaxation devices.
Claim 2
Dependent Claim
164 words
A stepper motor drive circuit comprising; a. a source (1) of step command pulses, b. a first relaxation device (4) connected to said source for actuation by step command pulses, c. a second relaxation device (5) connected to said first relaxation device for subsequent actuation thereby, d. a third relaxation device (6) connected to said second relaxation device for subsequent actuation thereby, e. logic means (3) connected to said first relaxation device to provide plural-phase excitation to said stepper motor, and f. electric differentiating means (7) connected to said first relaxation device and to said second and third relaxation devices to selectively reset said third and second relaxation devices on each step command pulse, whereby said third relaxation device and selectively said second relaxation device are reset prior to the expiration of their normal cycle of actuation when said command pulses occur more rapidly than the full period of the normal cycle of actuation of said third and selectively also said second relaxation devices.
Claim 3
Dependent Claim
36 words
The circuit of claim 1 in which the logic means (3) includes; a. a semiconductor device (as 41) connected in the circuit of each of the plural phases (as phi A) exciting said stepper motor to,
Claim 4
Dependent Claim
21 words
rapidly dissipate residual electrical energy remaining in the electrical circuit of said stepper motor by Zener breakdown of said semiconductor device.
Claim 5
Dependent Claim
21 words
rapidly dissipate residual electrical energy remaining in the electrical circuit of said stepper motor by Zener breakdown of said semiconductor device.
Claim 6
Dependent Claim
26 words
The circuit of claim 2, in which; a. said semiconductor device is a power transistor (as 41), and b. the collector-base diode thereof suffers Zener breakdown.
Claim 7
Dependent Claim
32 words
The circuit of claim 1 in which said differentiating means (7) includes; a. input isolation means (65), b. a resistor (67) - capacitor (66) differentiating circuit, and c. output isolation means (68).
Claim 8
Dependent Claim
55 words
The circuit of claim 1 in which; a. said differentiating means (7) produces an output pulse simultaneously with the leading edge of each said command pulse, whereby damping of said stepper motor by the output of at least said third relaxation device is reduced in duration near and at the maximum command pulse repetition rate.
Claim 9
Dependent Claim
39 words
The circuit of claim 5 in which; a. said damping of the stepper motor is further reduced in duration at said maximum command pulse repetition rate by the output of said differentiating means resetting said second relaxation device (5).
Claim 10
Dependent Claim
96 words
The circuit of claim 1, which additionally includes high voltage - low voltage means (8) having; a. a triggerable relaxation device (52) connected to said source of step command pulses, b. a source of high voltage (58), c. impedance means (63) connected between said source of high voltage and the plural phases ( phi A, phi B & phi C) of said stepper motor, and d. saturable semiconductor means (62) connected for actuation by said triggerable relaxation device and connected across said impedance means (63) for essentially bypassing said impedance means when in the saturated state.
Claim 11
Dependent Claim
108 words
The circuit of claim 1 in which said logic means (3) includes; a. a gate (36, 43 or 46) for each of the plural phases, b. a connection (23) from said first relaxation device (4) to the input of said logic means, c. a connection from each phase of the output of said logic means to one of said gates, and d. a connection from said thiRd relaxation device (6) to each of said gates, whereby a said energizing pulse is passed on from said logic means for energizing said motor, and a damping pulse is passed on from said third relaxation device for subsequently damping said motor.
Claim 12
Dependent Claim
65 words
The circuit of claim 1, in which; a. said electrical differentiating means (7) is connected only to said first and third relaxation devices, and b. only said third relaxation device (6) is reset prior to the expiration of its normal cycle of actuation when said command pulses occur more rapidly than the full period of the normal cycle of actuation of said third relaxation device.
Claim 13
Independent Claim
68 words
The method of operating a stepper motor in which each step is initiated by a drive pulse and thereafter is damped by an electrical damping pulse (19) applied to stop rotation thereof at low stepping rates, and the damping effectiveness of the damping pulse is progressively reduced (19'') at higher stepping rates by altering the duration of the damping pulse as an inverse function of the stepping rate.
Claim 14
Independent Claim
68 words
The method of operating a stepper motor in which each step is initiated by a drive pulse and thereafter is damped by an electrical damping pulse (19) applied to stop rotation thereof at low stepping rates, and the damping effectiveness of the damping pulse is progressively reduced (19'') at higher stepping rates by altering the duration of the damping pulse as an inverse function of the stepping rate.
Claim 15
Dependent Claim
22 words
The method of claim 10 in which the damping pulse is eliminated while the stepper motor steps at a high stepping rate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |