Patent US3638128A successfully refreshed from Google Patents.
US3638128A
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Pulse discriminator
Assignee: Advanced Technology Center Inc
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Filing: 1969-12-22
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Granted: 1972-01-25
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Expires: 1989-12-22
Abstract
Abstract Impulse noise effects on pulse-counting discriminators used for converting a frequency-modulated signal into a varying voltage are minimized by a feedback loop that controls the operation of a monostable multivibrator. In pulse-counting discriminators, voltage spikes are produced at a rate related to the frequency of a modulated signal. These spikes trigger the multivibrator that produces an output pulse of predetermined duration for each voltage spike. Output pulses from the multivibrator control the operation of a clamping circuit which, in turn, controls the operation of a ramp generator. A level detector compares the output of the ramp generator to a reference voltage signal and generates a voltage spike when the instantaneous value of the ramp generator output equals the reference signal. This voltage spike also connected to the multivibrator and triggers it to synthesize an output pulse. Operation of the clamping circuit, ramp generator and level detector in conjunction with the multivibrator synthesize an output pulse when one should appear. If the voltage spikes that trigger the multivibrator occur at a frequency in excess of an upper established limit, a second level detector compares the ramp generator output to a second reference signal. This second level detector generates a control signal to inhibit trigger pulses to the monostable multivibrator.
Inventors
- 👤 Robert F Downs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:43
CPC Classifications
G; G01; G01R; G01R29/00; G01R29/02; G01R29/027; G01R29/0273; H; H03; H03D; H03D3/00; H03D3/02; H03D3/04
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
39 words
A discriminator for converting a frequency-modulated signal into a varying voltage as set forth in claim 1 wherein said comparing means includes a level detector that produces a voltage when the reference voltage and the ramp voltage are equal.
Claim 2
Dependent Claim
39 words
A discriminator for converting a frequency-modulated signal into a varying voltage as set forth in claim 2 wherein said coupling means includes an OR gate that reproduces at an output terminal a signal appearing at either of two inputs.
Claim 3
Dependent Claim
40 words
A discriminator for converting a frequency-modulated signal into a varying voltage as set forth in claim 3 wherein said clamping means is a NAND gate having an input connected to said circuit means and an output to said ramp generator.
Claim 4
Dependent Claim
25 words
A discriminator for converting a frequency-modulated signal into a varying voltage as set forth in claim 4 wherein said circuit means is a monostable multivibrator.
Claim 5
Dependent Claim
149 words
A pulse-counting discriminator for converting a frequency-modulated signal into a varying voltage comprising: means for producing voltage spikes at a period related to the frequency of a modulated signal, circuit means for producing output pulses of predetermined duration for each voltage spike connected thereto, means for converting said pulses into a voltage that varies with the frequency of the modulated signal, a ramp generator having an output voltage that increases with time, clamping means responsive to the output pulses of said circuit means for clamping the output of said ramp generator at a fixed level during each output pulse, means for comparing the output of said ramp generator with a reference voltage and generating a voltage spike when said signals are in a predetermined relationship, and means for coupling the voltage spikes related to the frequency of the modulated signals and from said comparing means to said circuit means.
Claim 6
Dependent Claim
199 words
A pulse-counting discriminator for converting a frequency-modulated signal into a varying voltage comprising: means for producing voltage spikes at a period related to the frequency of a modulated signal, circuit means producing output pulses of predetermined duration for each voltage spike connected thereto, means for converting said pulses into a voltage that varies with the frequency of the modulated signal, a ramp generator having an output voltage that increases with time, clamping means responsive to the output pulses of said circuit means for clamping the output of said ramp generator at a fixed level during each output pulse, means for comparing the output of said ramp generator with a reference signal and generating a voltage spike when said signals are in a predetermined relationship, means for coupling the voltage spikes related to the frequency of the modulated signal and from said comparing means to said circuit means, means for comparing the output of said ramp generator with a second reference signal and generating a control signal when said voltages are in a predetermined relationship, and switching means responsive to the control signal for disconnecting the voltage spikes related to the frequency of the modulated signal from said coupling means.
Claim 7
Dependent Claim
70 words
A pulse-counting discriminator for converting a frequency-modulated signal into a varying voltage as set forth in claim 7 wherein said first comparing means includes a level detector that produces a voltage spike when the reference voltage and the ramp voltage are equal, and said second comparing means also includes a level detector that produces a control signal where the reference voltage and the ramp output are in a predetermined relationship.
Claim 8
Dependent Claim
41 words
A pulse-counting discriminator for converting a frequency-modulated signal into a varying voltage as set forth in claim 8 wHerein said clamping means is a NAND gate having an input connected to said circuit means and an output to said ramp generator.
Claim 9
Dependent Claim
27 words
A pulse counting discriminator for converting a frequency-modulated signal into a varying voltage as set forth in claim 9 wherein said circuit means is a monostable multivibrator.
Claim 10
Dependent Claim
222 words
A pulse-counting discriminator for converting a frequency-modulated signal into a varying voltage comprising: means for producing voltage spikes at a period related to the frequency of a modulated signal; an inverter pair having one input responsive to the voltage spikes related to the frequency of the modulated signal, a monostable multivibrator having an input connected to the output of said inverter pair for producing output pulses of predetermined duration for each voltage spike from said inverter pair, means for converting said pulses into a voltage that varies with the frequency of the modulated signal, a first transistor having a base electrode and an emitter electrode interconnected to a voltage source, and a collector electrode connected to a capacitor for generating a voltage at the collector electrode that increases with time, a second transistor having a base electrode connected to the output of said monostable multivibrator through a diode, a collector electrode connected to the collector electrode of said first transistor, and an emitter electrode connected to ground for clamping the output of said first transistor at a fixed level during each output pulse, means for comparing the output at the collector electrode of said first transistor with a reference signal and generating a voltage spike connected to the second input of said inverter pair when said voltages are in a predetermined relationship.
Claim 11
Dependent Claim
41 words
A pulse-counting discriminator for converting a frequency-modulated signal into a varying voltage as set forth in claim 11 wherein said inverter pair comprises two transistors having interconnected collector and emitter electrodes with the output of said pair of interconnected collector electrodes.
Claim 12
Dependent Claim
34 words
A pulse-counting discriminator for converting a frequency-modulated signal into a varying voltage as set forth in claim 11 wherein said converting means includes a low-pass filter connected to the input of an amplifier circuit.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-24 | 1975-07-26 | 1976-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-24 | 1979-07-26 | 1980-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-24 | 1983-07-26 | 1984-01-25 | $7700.00 | Window Closed / Lapsed |