US3914619A
Expired / Lapsed
US
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Frequency responsive switching circuit
Assignee: Ford Motor Co
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Filing: 1975-01-08
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Granted: 1975-10-21
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Expires: 1995-01-08
Abstract
Abstract A frequency responsive switching circuit particularly suitable for use with apparatus for limiting the position of the throttle of an internal combustion engine at a predetermined engine speed. The circuit includes first and second retriggerable monostable multivibrators, each having a different timing circuit, which cooperate with one another to produce a switched output signal when the frequency level of the circuit input signal has reached a predetermined magnitude. The frequency responsive switching circuit is designed for use in a motor vehicle environment and may derive its input signal from the primary winding of an ignition coil conventionally included in motor vehicles.
Inventors
- 👤 Dennis D Talmage
- 👤 Paul D Stokes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:14
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/42; G01P3/44; G01P3/48; G01P3/4802; G01P3/4807; F; F02; F02D; F02D31/00; F02D31/001; F02D31/002; F02D31/006; F02M; F02M3/00; F02M3/06; F02M3/07; G01P1/00; G01P1/07; G01P1/08; G01P1/10; G01P1/106
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
106 words
A frequency responsive switching circuit, which comprises, in combination: an integrated circuit dual timer comprising first and second retriggerable monostable multivibrators; circuit means coupling the output of said first multivibrator to the input of said second multivibrator; timing circuits for each of said multivibrators, the timing circuit for said first multivibrator being set to produce an output pulse duration less than the output pulse duration set by the timing circuit for said second multivibrator; and circuit means for modifying the timing characteristic of said timing circuit for said first multivibrator in response to the occurrence of a signal condition at the output of said second multivibrator.
Claim 2
Dependent Claim
106 words
A frequency responsive switching circuit, which comprises, in combination: an integrated circuit dual timer comprising first and second retriggerable monostable multivibrators; circuit means coupling the output of said first multivibrator to the input of said second multivibrator; timing circuits for each of said multivibrators, the timing circuit for said first multivibrator being set to produce an output pulse duration less than the output pulse duration set by the timing circuit for said second multivibrator; and circuit means for modifying the timing characteristic of said timing circuit for said first multivibrator in response to the occurrence of a signal condition at the output of said second multivibrator.
Claim 3
Dependent Claim
45 words
A frequency responsive switching circuit according to claim 1 wherein said first multivibrator includes a trigger input and a reset input and wherein said frequency responsive switching circuit further includes a capacitor for coupling a signal applied to said trigger input to said reset input.
Claim 4
Dependent Claim
158 words
A frequency responsive switching circuit, which comprises, in combination: first and second retriggerable monostable multivibrators; a first timing circuit, associated with said first multivibrator, said first timing circuit determining the maximum frequency of an input signal applied to said first multivibrator that will permit said first multivibrator to complete its timing cycle before being retriggered; a second timing circuit, associated with said second multivibrator, said second timing circuit determining the maximum Frequency of an input signal applied to said second multivibrator that will permit said second multivibrator to complete its timing cycle before being retriggered, said maximum frequency determined by said second timing circuit being lower than said maximum frequency determined by said first timing circuit; and circuit means coupling said first timing circuit to the output of said second multivibrator, said maximum frequency determined by said first timing circuit being capable of being modified by a change in voltage level at said output of said second multivibrator.
Claim 5
Dependent Claim
158 words
A frequency responsive switching circuit, which comprises, in combination: first and second retriggerable monostable multivibrators; a first timing circuit, associated with said first multivibrator, said first timing circuit determining the maximum frequency of an input signal applied to said first multivibrator that will permit said first multivibrator to complete its timing cycle before being retriggered; a second timing circuit, associated with said second multivibrator, said second timing circuit determining the maximum Frequency of an input signal applied to said second multivibrator that will permit said second multivibrator to complete its timing cycle before being retriggered, said maximum frequency determined by said second timing circuit being lower than said maximum frequency determined by said first timing circuit; and circuit means coupling said first timing circuit to the output of said second multivibrator, said maximum frequency determined by said first timing circuit being capable of being modified by a change in voltage level at said output of said second multivibrator.
Claim 6
Dependent Claim
199 words
A frequency responsive switching circuit, which comprises, in combination: first and second retriggerable monostable multivibrators, each of said multivibrators having a trigger input and an output, said multivibrators being capable of producing pulse output signals in response to trigger input signals, the output of said first multivibrator being coupled to the input of said second multivibrator, first timing circuit means, associated with said first multivibrator, for determining the time duration of pulses occurring at said output of said first multivibrator; second timing circuit means, associated with said second multivibrator, for determining the time duration of pulses occurring at said output of said second multivibrator; circuit means for resetting said first timing circuit means as a function of the frequency of the signal applied to said trigger input of said first multivibrator; circuit means for resetting said second timing circuit means as a function of the frequency of the signal applied to said trigger input of said second multivibrator; and circuit means, coupled to said output of said second multivibrator and to said first timing circuit means, for modifying the timing characteristic of said first timing circuit means in response to a change in the output of said second multivibrator.
Claim 7
Dependent Claim
199 words
A frequency responsive switching circuit, which comprises, in combination: first and second retriggerable monostable multivibrators, each of said multivibrators having a trigger input and an output, said multivibrators being capable of producing pulse output signals in response to trigger input signals, the output of said first multivibrator being coupled to the input of said second multivibrator, first timing circuit means, associated with said first multivibrator, for determining the time duration of pulses occurring at said output of said first multivibrator; second timing circuit means, associated with said second multivibrator, for determining the time duration of pulses occurring at said output of said second multivibrator; circuit means for resetting said first timing circuit means as a function of the frequency of the signal applied to said trigger input of said first multivibrator; circuit means for resetting said second timing circuit means as a function of the frequency of the signal applied to said trigger input of said second multivibrator; and circuit means, coupled to said output of said second multivibrator and to said first timing circuit means, for modifying the timing characteristic of said first timing circuit means in response to a change in the output of said second multivibrator.
Claim 8
Dependent Claim
35 words
A frequency responsive switching circuit according to claim 4 which further includes circuit means for retriggering said first multivibrator during each period of an alternating signal applied to said trigger input of said first multivibrator.
Claim 9
Dependent Claim
34 words
A frequency responsive switching circuit according to claim 5 which further includes circuit means for retriggering said second multivibrator in response to a change in voltage level at said output of said first multivibrator.
Claim 10
Dependent Claim
58 words
A frequency responsive switching circuit according to claim 5 wherein said circuit means for retriggering said first multivibrator includes a voltage divider, said first multivibrator having a reset input coupled to said voltage divider, and wherein said frequency responsive switching circuit further includes a capacitor coupled between said voltage divider and said trigger input of said first multivibrator.
Claim 11
Dependent Claim
79 words
A frequency responsive switching circuit according to claim 5 wherein said first multivibrator has a reset input and wherein said frequency responsive switching circuit further includes circuit means for establishing a quiescent voltage level at said reset input and a capacitor coupled to said reset input and to said trigger input of said first multivibrator to retrigger said first multivibrator at a frequency corresponding to the frequency of the signal applied to said trigger input of said first multivibrator.
Claim 12
Dependent Claim
40 words
A frequency responsive switching circuit according to claim 5 which further includes circuit means for rendering the output response of said first multivibrator independent of the duty cycle of the signal applied to said trigger input of said first multivibrator.
Claim 13
Dependent Claim
54 words
A frequency responsive switching circuit according to claim 5 wherein said first timing circuit means comprises an RC timing circuit including a carbon film resistor and a mylar capacitor, said resistor and capacitor having temperature characteristics rendering said first timing circuit means substantially independent of temperature in the range from about -40*F. to 185*F.
References Cited (Backward Citations)
US3645241A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |