US3617836A
Expired / Lapsed
US
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Control circuit for synchronous motor
Assignee: EAGLE SIGNAL CONTROLS CORP A CORP OF DE
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Filing: 1968-07-18
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Granted: 1971-11-02
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Expires: 1988-07-18
Abstract
Abstract A control circuit is disclosed herein for applying signals to an inductive load, such as the winding of a synchronous motor. The circuit includes means for producing essentially a square wave signal together with a capacitor for coupling the signal to the inductive load. The average current impressed across and, hence, power consumed by the inductive load is limited by the capacitor in such a manner to prevent destruction of the inductive load at low frequencies.
Inventors
- 👤 Donald E Henry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:31
CPC Classifications
G; G08; G08G; G08G1/00; G08G1/07; G08G1/085; H; H02; H02P; H02P25/00; H02P25/02; H02P25/022; H02P25/024
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
238 words
A control circuit comprising: means for producing an essentially square wave signal of a frequency occuring within a range of frequencies defined by a lower frequency F1 and an upper frequency F2; the winding of a synchronous motor coupled to said signal producing means, said motor being operative in response to a waveform of alternating polarity pulses of said frequency occurring within said frequency range; and a capacitor coupling said signal producing means to said synchronous motor winding, said capacitor passing said waveform of alternating polarity pulses to operate said synchronous motor in response to said produced signal of said frequency, whereby the average current impresses across, and hence, the power consumed by, said winding when so operating is limited by said capacitor so as to prevent the destruction of said winding at the low values of frequency occurring within said range, the low values being essentially of a frequency F1, said signal-producing means including a nonlinear amplifying means, said amplifying means including a power switch means operative in response to said produced signal of said frequency; said signal-producing means also including: a sensing means responsive to a carrier signal input, said sensing means rectifying said carrier signal; a filtering means responsive to said rectified carrier signal, said filtering means demodulating said rectified cArrier signal so as to separate the modulating intelligence envelope therefrom, whereby the demodulated signal produced is an essentially square-wave intelligence envelope having said frequency.
Claim 2
Dependent Claim
238 words
A control circuit comprising: means for producing an essentially square wave signal of a frequency occuring within a range of frequencies defined by a lower frequency F1 and an upper frequency F2; the winding of a synchronous motor coupled to said signal producing means, said motor being operative in response to a waveform of alternating polarity pulses of said frequency occurring within said frequency range; and a capacitor coupling said signal producing means to said synchronous motor winding, said capacitor passing said waveform of alternating polarity pulses to operate said synchronous motor in response to said produced signal of said frequency, whereby the average current impresses across, and hence, the power consumed by, said winding when so operating is limited by said capacitor so as to prevent the destruction of said winding at the low values of frequency occurring within said range, the low values being essentially of a frequency F1, said signal-producing means including a nonlinear amplifying means, said amplifying means including a power switch means operative in response to said produced signal of said frequency; said signal-producing means also including: a sensing means responsive to a carrier signal input, said sensing means rectifying said carrier signal; a filtering means responsive to said rectified carrier signal, said filtering means demodulating said rectified cArrier signal so as to separate the modulating intelligence envelope therefrom, whereby the demodulated signal produced is an essentially square-wave intelligence envelope having said frequency.
Claim 3
Dependent Claim
110 words
A control circuit comprising: input connections for receiving a carrier signal; a sensing means responsive to said carrier signal input, said sensing means rectifying said carrier signal; a filtering means responsive to said rectified carrier signal, said filtering means demodulating said rectified carrier signal so as to separate the modulating intelligence envelope therefrom, whereby the demodulated signal produced is an essentially square-wave intelligence envelope having said frequency; a nonlinear amplifying means including a power switch means operative in response to said demodulated signal, an inductive load coupled to said power switch means, said inductive load being operative in response to a waveform of alternating polarity pulses of said envelope frequency.
Claim 4
Dependent Claim
110 words
A control circuit comprising: input connections for receiving a carrier signal; a sensing means responsive to said carrier signal input, said sensing means rectifying said carrier signal; a filtering means responsive to said rectified carrier signal, said filtering means demodulating said rectified carrier signal so as to separate the modulating intelligence envelope therefrom, whereby the demodulated signal produced is an essentially square-wave intelligence envelope having said frequency; a nonlinear amplifying means including a power switch means operative in response to said demodulated signal, an inductive load coupled to said power switch means, said inductive load being operative in response to a waveform of alternating polarity pulses of said envelope frequency.
Claim 5
Dependent Claim
38 words
The control circuit as set forth in claim 2 wherein said filtering means includes a Zener diode having a breakdown voltage such that only the essentially square-wave modulating intelligence envelope of said rectified carrier signal can feed therethrough.
Claim 6
Dependent Claim
51 words
The control circuit as set forth in claim 2 wherein said amplifying means also includes a wave squaring means responsive to said intelligence envelope signal, said wave squaring means producing an amplified square wave when so responsive so as to provide a fast-switching signal of said frequency to said amplifying means.
Claim 7
Dependent Claim
34 words
The control circuit as set forth in claim 4 wherein said carrier signal is a plurality of trains of mark-space pulses of said frequency, said mark and space portions being of equal time duration.
Claim 8
Dependent Claim
68 words
The control circuit as set forth in claim 5 wherein a monitoring circuit is connected to said capacitor and said motor winding, said monitoring circuit normally energizing a switching means, connected to said monitoring circuit, in the event the output power passed by said capacitor is maintained above a prescribed level, said switching means connecting said motor winding to said capacitor when said switching means is so energized.
Claim 9
Dependent Claim
125 words
In a motor control circuit of the type including a demodulator and an amplifier for demodulating a plurality of trains of mark-space pulses into a substantially square-wave intelligence signal of a frequency within a given range, with the intelligence signal frequency dependent upon the duration of each mark and the time lapse between successive marks and then amplifying said intelligence signal for application to a motor to cause operation of such motor, wherein the improvement comprises: a capacitor coupling said amplifier to a winding of said motor so as to limit the average current passes by said capacitor to said motor winding whereby destruction of said motor winding is prevented at low values of said frequency of said intelligence signal occurring within said frequency range.
Claim 10
Dependent Claim
125 words
In a motor control circuit of the type including a demodulator and an amplifier for demodulating a plurality of trains of mark-space pulses into a substantially square-wave intelligence signal of a frequency within a given range, with the intelligence signal frequency dependent upon the duration of each mark and the time lapse between successive marks and then amplifying said intelligence signal for application to a motor to cause operation of such motor, wherein the improvement comprises: a capacitor coupling said amplifier to a winding of said motor so as to limit the average current passes by said capacitor to said motor winding whereby destruction of said motor winding is prevented at low values of said frequency of said intelligence signal occurring within said frequency range.
Claim 11
Dependent Claim
40 words
In a motor control circuit as set forth in claim 7 wherein said motor is a synchronous motor, and said capacitor having a value so that said motor operates at a substantially unity power factor within said range of frequencies.
Claim 12
Dependent Claim
136 words
In a traffic control system including a master controller having means for developing one of a plurality of cycle length determining frequency signals each of a different frequency in the range from a low frequency F1 to a high frequency F2 and at least one local controller for receiving said frequency signals, said local controller including a synchronous motor which times one traffic signal cycle for each revolution of the motor, the improvement in said local controller comprising: means responsive to said frequency signal for providing an essentially square-wave signal of the same frequency, and capacitor means coupling said square-wave signal means to a winding of a said motor in such a manner to limit the average curreNt applied to said motor winding to prevent destruction of said motor windings at low frequencies approaching frequency F1.
Claim 13
Dependent Claim
136 words
In a traffic control system including a master controller having means for developing one of a plurality of cycle length determining frequency signals each of a different frequency in the range from a low frequency F1 to a high frequency F2 and at least one local controller for receiving said frequency signals, said local controller including a synchronous motor which times one traffic signal cycle for each revolution of the motor, the improvement in said local controller comprising: means responsive to said frequency signal for providing an essentially square-wave signal of the same frequency, and capacitor means coupling said square-wave signal means to a winding of a said motor in such a manner to limit the average curreNt applied to said motor winding to prevent destruction of said motor windings at low frequencies approaching frequency F1.
Claim 14
Dependent Claim
82 words
In a traffic control system as set forth square-wave claim 9 wherein said master controller has means for developing a mark-space train of carrier signals wherein the envelope of said train carrier signals exhibits the frequency of a desired cycle length determining signal, and said local controller further includes: means for demodulating said carrier signal to obtain a signal exhibiting the frequency of said envelope, and means for squaring said demodulated signal to develop a square wave signal of the same frequency.
Claim 15
Dependent Claim
45 words
In a traffic control system as set forth in claim 10 including power amplifier switching means for providing an amplified square-wave signal of the frequency of said envelope, said capacitor means directly coupling the output of said power amplifier switching means with said motor winding.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-01 | 1975-05-03 | 1975-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-01 | 1979-05-03 | 1979-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-01 | 1983-05-03 | 1983-11-02 | $7700.00 | Window Closed / Lapsed |