US3769596A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oscillation detection circuit
Assignee: Bendix Corp
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Filing: 1972-03-02
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Granted: 1973-10-30
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Expires: 1992-03-02
Abstract
Abstract A circuit detects those oscillations of an input signal that fall within a predetermined frequency band. An output is provided in the form of a logic signal commensurate with the detected oscillations.
Inventors
- 👤 G Peersch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:20
CPC Classifications
H; H03; H03D; H03D3/00; H03D3/02; H03D3/04
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
248 words
A circuit for detecting oscillations of an input signal provided by an input signal means and which fall within a predetermined frequency band, comprising: means connected to the input signal means and responsive to the input signal therefrom for providing a signal having a predetermined wave form and oscillating at the same frequency as the input signal, and including a high pass filter connected to the input signal means for filtering the input signal and an operational amplifier connected to the filter and responsive to the filtered signal for providing the predetermined wave form signal oscillating at the same frequency as the input signal; means connected to the predetermined wave form signal means for converting the signal therefrom to pulses of a predetermined sense, and including a capacitor connected to the operational amplifier, a current flow control device connected to the capacitor and another current flow control device connected between the capacitor and the first mentioned current flow control device at a point at which the pulses are provided; means connected to the converting means for counting the pulses therefrom and for providing a signal corresponding to the number of said pulses; means connected to the predetermined wave form signal means for setting the maximum frequency of the predetermined frequency band; means connected to the pulse counting means for setting the minimum frequency of the predetermined frequency band; and means connected to the maximum and minimum frequency setting means for providing an output commensurate with the detected oscillations.
Claim 2
Dependent Claim
248 words
A circuit for detecting oscillations of an input signal provided by an input signal means and which fall within a predetermined frequency band, comprising: means connected to the input signal means and responsive to the input signal therefrom for providing a signal having a predetermined wave form and oscillating at the same frequency as the input signal, and including a high pass filter connected to the input signal means for filtering the input signal and an operational amplifier connected to the filter and responsive to the filtered signal for providing the predetermined wave form signal oscillating at the same frequency as the input signal; means connected to the predetermined wave form signal means for converting the signal therefrom to pulses of a predetermined sense, and including a capacitor connected to the operational amplifier, a current flow control device connected to the capacitor and another current flow control device connected between the capacitor and the first mentioned current flow control device at a point at which the pulses are provided; means connected to the converting means for counting the pulses therefrom and for providing a signal corresponding to the number of said pulses; means connected to the predetermined wave form signal means for setting the maximum frequency of the predetermined frequency band; means connected to the pulse counting means for setting the minimum frequency of the predetermined frequency band; and means connected to the maximum and minimum frequency setting means for providing an output commensurate with the detected oscillations.
Claim 3
Dependent Claim
69 words
A circuit as described by claim 4, wherein the means connected to the converting means for counting the pulses therefrom and for providing a signal corresponding to the number of said pulses includes: integrating means having a resistor connected to the second mentioned current flow control device and a capacitor connected to the resistor at a point at which the signal corresponding to the number of pulses is provided.
Claim 4
Dependent Claim
106 words
A circuit as described by claim 2, wherein the means connected to the pulse counting means for setting the minimum frequency of the predetermined frequency band includes: a resistor connected in parallel with the integrator capacitor and cooperating with said capacitor to provide a predetermined circuit time constant; an operational amplifier connected to the integrating means and to the resistor, said operational amplifier being initially saturated in one sense and affected by a threshold signal applied thereto from the integrating means for switching to saturation in the opposite sense; and the time constant affecting the circuit to determine whether or not the threshold voLtage is reached.
Claim 5
Dependent Claim
86 words
A circuit as described by claim 1, wherein the means connected to the predetermined wave form signal means for setting the maximum frequency of the predetermined frequency band includes: a capacitor connected in feedback relation to the operational amplifier for controlling the amplifier to ramp in one sense at a predetermined rate; current flow control means connected to the capacitor for affecting the amplifier to instantaneously reach its output limit in the opposite sense; and a voltage divider network connected to the current flow control means.
Claim 6
Dependent Claim
22 words
A circuit as described by claim 3, including: a voltage divider network connected to the operational amplifier for controlling the threshold voltage.
Claim 7
Dependent Claim
86 words
A circuit as described by claim 3, wherein the means connected to the predetermined wave form signal means for setting the maximum frequency of the predetermined frequency band includes: a capacitor connected in feedback relation to the operational amplifier for controlling the amplifier to ramp in one sense at a predetermined rate; current flow control means connected to the capacitor for affecting the amplifier to instantaneously reach its output limit in the opposite sense; and a voltage divider network connected to the current flow control means.
Claim 8
Dependent Claim
105 words
A circuit as described by claim 6, wherein the means connected to the maximum and minimum frequency setting means for providing an output includes: a circuit connected to the feedback capacitor and including a capacitor, a current flow control device and a resistor connected in parallel and connected to the capacitor, said circuit providing an output pulse with each zero crossing of the input signal; and a gate connected to said circuit and connected to the operational amplifier connected to the integrator and responsive to the output pulse and the amplifier output for providing an output for each cycle of oscillation above a given number.
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) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |