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公开(公告)号：CA1038048A
公开(公告)日：1978-09-05
申请号：CA240523
申请日：1975-11-26
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A , WITTMANN ERWIN J
Abstract: CONTROLLABLE GAIN SIGNAL AMPLIFIER A signal amplifier is supplied with input signals at its base electrode and also is supplied at its emitter with quiescent operating current from a current source. Amplified output signals developed at the collector of the amplifier are coupled to a transistor-diode current splitter. The relative division of current in the splitter is controlled by coupling a variable direct current supply to the diode. The latter supply comprises a source of direct voltage, a variable, resistive voltage divider coupled across the voltage source, and the combination of a voltage follower stage and a series resistor coupled between the resistive divider and the diode. Gain controlled push-pull output signals may be provided by differentially coupling a second amplifier device to the first and coupling the output of a second current splitter to the second amplifier. The second current splitter is then also controlled by the same current source as the first.
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公开(公告)号：CA1219339A
公开(公告)日：1987-03-17
申请号：CA469208
申请日：1984-12-03
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A , SHANLEY ROBERT L II
IPC: H04N5/18 , H03K5/153 , H04N3/24 , H04N9/44 , H04N9/64 , H04N9/72 , H04N9/73 , H04N9/77 , H04N9/12
Abstract: RCA 76,343 Trilevel sandcastle pulse decoder includes a trio of voltage comparison means for comparing incoming sandcastle pulses with reference potentials of respectively different levels. One of the voltage comparison means, which is subject to change in operating state in response to appearance of a given level of the sandcastle pulse, is precluded from operating state change in response to the appearance of the next higher level of the sandcastle pulse by control circuitry responsive to the output of a second of the voltage comparison means. One of the decoder outputs is developed by logic circuitry responsive to outputs of two of the comparison means.
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公开(公告)号：DD238144A5
公开(公告)日：1986-08-06
申请号：DD28134985
申请日：1985-10-02
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A , WARGO ROBERT A
Abstract: An adaptive filtering system is disclosed, which may be used in a digital television receiver to extract low frequency vertical detail information from a comb filtered chrominance signal. This system provides wide bandwidth vertical detail information when the amplitude of the chrominance component of the composite video signal is low and narrower bandwidth vertical detail signals as the amplitude of the chrominance component increases. Adaptive filtering is accomplished by passing the comb filtered chrominance signal through a first low-pass filter (14) and developing two reduced amplitude replicas (21,21) of the filtered signal which are mutually supplementary. The ratio of the amplitudes of these two replicas is variable with a control signal.One replica is passed through a second low-pass filter (22) and combined (26) with the other replica to produce a vertical detail signal. The embodiment of the system that is disclosed includes means (41-46) for developing a control signal that is dependent on the instantaneous amplitude of the chrominance component of the composite video signal.
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Patent Agency Ranking46.发明专利
公开(公告)号：CA1185355A
公开(公告)日：1985-04-09
申请号：CA413038
申请日：1982-10-07
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A , SHANLEY ROBERT L II , HETTIGER JAMES
Abstract: A DC coupled system for automatically controlling the high frequency peaking content of a video signal is disclosed. The system includes a DC coupled control path comprising a peak detector for developing a control voltage representative of the high frequency content of the video signal exclusive of video signal DC components. The detector is preceded in the control path by a frequency selective network comprising an amplifier and a filter for shaping the frequency response of the control path such that high frequency video signal components exclusive of DC video signal components are passed to the peak detector. The frequency selective network comprises the cascode combination of a video signal amplifier transistor and a current source transistor which provides quiescent operating currents for the amplifier transistor. The filter is coupled to the junction of the amplifier and current source transistors, and includes a DC blocking network coupled between the junction and a point of reference potential.
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公开(公告)号：CA1180106A
公开(公告)日：1984-12-27
申请号：CA411580
申请日：1982-09-16
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A , SHANLEY ROBERT L II
Abstract: RCA 77,259 In a video signal processing system, an input capacitor AC couples video signals to a DC coupled video signal path, and to a DC coupled peaking signal path for generating a peaking component which is combined with video signals from the video path to develop a peaked video signal. A feedback control voltage for controlling the DC level of the video signal is stored by the input coupling capacitor, and is DC coupled to both the video path and the peaking path in a manner to reduce the likelihood of a DC offset error when the video signal and peaking component are combined. In an embodiment, the control voltage is coupled to the storage capacitor via a delay line included in the video path and which is coupled across the differential inputs of a differential amplifier with which the delay line coacts to generate the peaking component.
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公开(公告)号：CA1142640A
公开(公告)日：1983-03-08
申请号：CA361234
申请日：1980-09-30
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A , WITTMANN ERWIN J
Abstract: RCA 72,790 A controlled oscillator comprises an amplifier including an active device, a filter network arranged in a feedback loop of the amplifier for providing regenerative feedback to sustain oscillation of the amplifier, and a source of control signals. Output oscillatory signals from the amplifier and output control signals from the control source are summed by a combining network to produce a resultant controlled signal, which is coupled to the filter network. Parasitic capacitances associated with output terminals of the amplifier and control source impart an unwanted phase shift to the controlled signal. A compensation signal derived from the oscillator is supplied to the combining network with a magnitude and phase to offset the unwanted phase shift, to thereby produce a phase compensated resultant controlled signal.
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公开(公告)号：CA1142608A
公开(公告)日：1983-03-08
申请号：CA368436
申请日：1981-01-13
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A , WITTMANN ERWIN J
Abstract: RCA 72,789 An arrangement for symmetrically gain controlling a differential amplifier is disclosed. A control circuit including first and second similarly arranged transistors coupled between points of operating potential develops first and second control voltages of prescribed magnitude at collector outputs of the transistors. The first transistor is biased to provide the first control voltage at a fixed, prescribed level related to the gain control bias requirements of the amplifier. The second control voltage varies symmetrically with respect to the first control voltage in response to the setting of a potentiometer coupled to a bias circuit of the second transistor. The potentiometer is connected directly between points of operating potential such that the control voltages are equal for a center potentiometer setting, and the second control voltage varies symmetrically with respect to the first control voltage as the potentiometer is adjusted between minimum and maximum extremes to thereby produce symmetrical amplifier gain control. Symmetrical gain control is predictable and independent of potentiometer tolerance effects and variations of the operating potentials associated with the control circuit.
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公开(公告)号：CA1078029A
公开(公告)日：1980-05-20
申请号：CA274299
申请日：1977-03-18
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A
Abstract: THIRD HARMONIC SIGNAL GENERATOR An integratable third harmonic signal generator includes a signal multiplier coupled to a source of alternating input signal, for providing a first output signal proportional to the input signal raised to the third power. The first output signal includes a first harmonic component and a third harmonic component each proportional to the input signal. Means are also included for deriving, from the input signal, a second output signal in predetermined magnitude and polarity relation with the first harmonic component. The first and second output signals are combined to cancel the first harmonic component and thereby provide a third output signal proportional to the third harmonic component of the input signal substantially devoid of any first harmonic component.
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