US3634618A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit for connecting a television set to a recording instrument
Assignee: Telefunken Patentverwertungs GmbH
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Filing: 1969-02-27
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Granted: 1972-01-11
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Expires: 1989-02-27
Abstract
Abstract A circuit for connecting a television set to a video recording set includes a terminal connectable to a video signal output terminal of an FM modulating means connected to the television receiver terminal impressing a video signal on a carrier, a transformer having a primary winding DC connected to the output of the modulating means, and a secondary winding which is AC connected to the primary winding to pass the modulated signal, but is DC isolated therefrom. The secondary winding is DC connected to a terminal which may be connected to the recording head of the recorder. The circuit is arranged so that there is no DC electrical connection between the television receiver and the recorder chassis so as to reduce interference therebetween. A further transformer is similarly arranged between the reading head of the recorder and an FM demodulator for use during playback.
Inventors
- 👤 Wilfried Von Der Ohe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:22
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/76; H04N5/765; H04N5/775
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
212 words
In a recorder for recording a video signal received from the television receiver having an AC/DC chassis connection and for playing back such video signal having: an FM modulator whose input is connectable to a video signal output of the television receiver and an FM demodulator whose output is connectable to a video signal input of the television receiver; recording and playback head means; a first transformer having its primary winding connected to the output of said modulator and its secondary winding connected to said head means for feeding said video signal to said head means for recording same; a second transformer having its primary winding connected to said head means and its secondary winding connected to the input of said demodulator for feeding the recorded video signal to said demodulator during playback; said secondary winding of said first transformer and said primary winding of said second transformer being DC connected to said recorder; the improvement wherein said primary winding of said first transformer, said secondary winding of said second transformer and the components, including said modulator and said demodulator, connected thereto in the signal paths from and to the television receiver are DC isolated from said recorder and DC connected to only said television receiver when said recorder is connected thereto.
Claim 2
Dependent Claim
212 words
In a recorder for recording a video signal received from the television receiver having an AC/DC chassis connection and for playing back such video signal having: an FM modulator whose input is connectable to a video signal output of the television receiver and an FM demodulator whose output is connectable to a video signal input of the television receiver; recording and playback head means; a first transformer having its primary winding connected to the output of said modulator and its secondary winding connected to said head means for feeding said video signal to said head means for recording same; a second transformer having its primary winding connected to said head means and its secondary winding connected to the input of said demodulator for feeding the recorded video signal to said demodulator during playback; said secondary winding of said first transformer and said primary winding of said second transformer being DC connected to said recorder; the improvement wherein said primary winding of said first transformer, said secondary winding of said second transformer and the components, including said modulator and said demodulator, connected thereto in the signal paths from and to the television receiver are DC isolated from said recorder and DC connected to only said television receiver when said recorder is connected thereto.
Claim 3
Dependent Claim
20 words
The combination of claim 1 including means for supplying said modulator and demodulator with operating voltage from the television set.
Claim 4
Dependent Claim
44 words
The combination of claim 1 in which said head means is a rotating head wheel bearing recording and playback head means and said transformers are rotating transformers which transmit the modulated signal from a stationary portion of the recorder to said rotating head wheel.
Claim 5
Dependent Claim
24 words
The combination of claim 1 including amplifier means which are DC isolated from said recorder between said transformers and said modulator and demodulator respectively.
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) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |