Patent US3866129A successfully refreshed from Google Patents.
US3866129A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for the digital subtraction of frequencies
Assignee: US Philips Corp
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Filing: 1973-05-29
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Granted: 1975-02-11
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Expires: 1993-05-29
Abstract
Abstract A device for the digital substraction of two different frequencies includes means which reverse the phase of a wave-form of the signal of higher-frequency about 180* during its coincidence with one half-wave form of the signal of lower frequency and, subsequently, reverses the phase of another wave form of that signal about further 180* during its coincidence with the other half-wave of the lower frequency signal.
Inventors
- 👤 Berdnardus Henricu Cornelissen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:35
CPC Classifications
H; H03; H03K; H03K5/00; H03B; H03B21/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
195 words
A device for the digital subtraction of first periodic waveforms of a higher frequency and second periodic waveforms of a lower frequency, comprising means for deriving a first trigger pulse extending between the instant of coincidence of a steep portion of a first waveform with the top portion of a second waveform, and the instant of coincidence of the steep portion of a subsequent first waveform with the bottom portion of said second waveform, means for producing a first command pulse corresponding in length to said trigger pulse and delayed about the half-period of said first waveforms with respect to said trigger pulse, means for producing a second command pulse corresponding in length to said trigger pulse and delayed about the half-period of said first waveforms with respect to said first command pulse, means for producing an output train of waveforms corresponding to said first waveforms, means for suppressing an output waveform during the time interval between the leading edges and, respectively, during the interval between the trailing edges of said first and second command pulses, and means for inverting the phase of said ouput waveforms during the time interval of said second command pulse.
Claim 2
Independent Claim
195 words
A device for the digital subtraction of first periodic waveforms of a higher frequency and second periodic waveforms of a lower frequency, comprising means for deriving a first trigger pulse extending between the instant of coincidence of a steep portion of a first waveform with the top portion of a second waveform, and the instant of coincidence of the steep portion of a subsequent first waveform with the bottom portion of said second waveform, means for producing a first command pulse corresponding in length to said trigger pulse and delayed about the half-period of said first waveforms with respect to said trigger pulse, means for producing a second command pulse corresponding in length to said trigger pulse and delayed about the half-period of said first waveforms with respect to said first command pulse, means for producing an output train of waveforms corresponding to said first waveforms, means for suppressing an output waveform during the time interval between the leading edges and, respectively, during the interval between the trailing edges of said first and second command pulses, and means for inverting the phase of said ouput waveforms during the time interval of said second command pulse.
Claim 3
Dependent Claim
79 words
A device as claimed in claim 1, wherein said means for producing said first and second command pulses include bistable elements responsive to the coincidence of waveforms of higher frequency with waveforms of lower frequency, said output waveforms providing means being blocking means connected to the input of the waveforms of higher frequency and controlled by outputs of said bistable elements to introduce a time delay which corresponds substantially to the half period of the waveforms of higher frequency.
Claim 4
Dependent Claim
79 words
A device as claimed in claim 1, wherein said first and second command pulses are output signals from two differentiating circuits operable for receiving said input waveforms, respectively, and said output waveforms providing means including a binary counter operable for counting up in response to the differentiated signals of higher frequency and, respectively, for counting down in response to the differentiated signals of lower frequency, and means for providing an output signal corresponding to the resetting of said counter.
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) | 1978-02-10 | 1978-08-12 | 1979-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-10 | 1982-08-12 | 1983-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-10 | 1986-08-12 | 1987-02-11 | $7700.00 | Window Closed / Lapsed |