US3723765A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear frequency detector for analog to digital converter
Assignee: Bendix Corp
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Filing: 1971-05-25
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Granted: 1973-03-27
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Expires: 1991-05-25
Abstract
Abstract A device for converting an alternating current signal to a direct current voltage having an amplitude linearly proportional to the frequency of the signal in which the signal is converted to a square wave and the square wave is differentiated to provide pulses corresponding to the differential of the signal and the differentiated pulses are summed to provide the direct current voltage.
Inventors
- 👤 R Kautz
- 👤 L Bourgeault
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 00:24
CPC Classifications
G; G01; G01R; G01R23/00; G01R23/02; G01R23/06; G01R23/09; H; H03; H03D; H03D3/00; H03D3/02; H03D3/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
118 words
A frequency detector for converting an alternating current signal to a d.c. voltage having an amplitude corresponding to the frequency of the a.c. signal comprising: means for converting the a.c. signal to a square wave including a half-wave rectifier for producing a pulsating d.c. voltage and switching means connected to the half-wave rectifier for converting the pulsating d.c. voltage to a square wave, differentiating means connected to the converting means for differentiating the square wave and providing pulses corresponding to the differential of the alternating current input signal, and summing means connected to the differentiating means for summing the differentiated pulses and providing an output having an amplitude linearly proportional to the frequency of the a.c. input signal.
Claim 2
Dependent Claim
118 words
A frequency detector for converting an alternating current signal to a d.c. voltage having an amplitude corresponding to the frequency of the a.c. signal comprising: means for converting the a.c. signal to a square wave including a half-wave rectifier for producing a pulsating d.c. voltage and switching means connected to the half-wave rectifier for converting the pulsating d.c. voltage to a square wave, differentiating means connected to the converting means for differentiating the square wave and providing pulses corresponding to the differential of the alternating current input signal, and summing means connected to the differentiating means for summing the differentiated pulses and providing an output having an amplitude linearly proportional to the frequency of the a.c. input signal.
Claim 3
Dependent Claim
26 words
A device as described in claim 1 in which the means for converting the pulsating d.c. voltage to a square wave includes a pair of transistors.
Claim 4
Dependent Claim
18 words
A device as described in claim 1 in which the differentiating means includes a resistor and a capacitor.
Claim 5
Dependent Claim
112 words
A frequency detector for converting an alternating current signal to a d.c. voltage having an amplitude corresponding to the frequency of the a.c. signal comprising: means for converting the a.c. signal to a square wave, differentiating means connected to the converting means for differentiating the square wave and providing pulses corresponding to the differential of the alternating current input signal, and a Zener diode connected to the output of the differentiating means to provide a pulse width suitable for summing the pulses, and summing means connected to the differentiating means for summing the differentiated pulses and providing an output having an amplitude linearly proportional to the frequency of the a.c. input signal.
Claim 6
Dependent Claim
112 words
A frequency detector for converting an alternating current signal to a d.c. voltage having an amplitude corresponding to the frequency of the a.c. signal comprising: means for converting the a.c. signal to a square wave, differentiating means connected to the converting means for differentiating the square wave and providing pulses corresponding to the differential of the alternating current input signal, and a Zener diode connected to the output of the differentiating means to provide a pulse width suitable for summing the pulses, and summing means connected to the differentiating means for summing the differentiated pulses and providing an output having an amplitude linearly proportional to the frequency of the a.c. input signal.
Claim 7
Dependent Claim
28 words
A device as described in claim 4 in which the summing means includes a capacitor for summing the differentiated pulses and the output is taken across the capacitor.
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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) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |