Abstract: 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, a first series resistor coupled between the resistive divider and the input of the voltage follower and a second resistor coupled between the output of the follower 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.

Abstract: Hue correction apparatus of the general type described in U.S. Pat. No. 3,663,744 is provided. Chrominance signals are monitored on a dynamic basis and the phase of a color subcarrier reference signal is automatically altered when the chrominance signals are in the vicinity of the flesh tone (+I) axis. The phase of the reference subcarrier is altered, making use of a wide bandwidth phase detector, by controllably adding a portion of an amplitude limited chrominance signal to the subcarrier so as to shift the subcarrier phase towards the phase of the chrominance signal. The range of angles and response of the apparatus is restricted by means of an offset bias control coupled to the chrominance signal adder circuits. Green and blue tones are relatively unaffected by the system operation. Good transient response of the correction apparatus is provided at sharp color transitions.

Abstract: A digital remote control system provides substantially simultaneous actuation of remote functions. Repetitive transmissions of a plurality of remote control instructions and an identifier pattern are compared in an associated remote control receiver to verify authenticity of received signals. Transmitted signals are digitally encoded to contain both message information and encoded clock signals.

Abstract: Switching apparatus is included in a color television receiver for changing the threshold of a saturation overload detector and simultaneously changing the gain characteristics of an associated chrominance signal amplifier. The overload detector is operative to limit chrominance signals at a lower level when noisy signals are present and at a higher level when relatively noise-free signals are present. The switching apparatus is arranged to avoid annoying large shifts in picture saturation upon its operation. An associated flesh tone correction circuit is enabled by the switching apparatus when the lower overload limit is employed and is disabled when the higher limit is employed.

Abstract: A remote control receiver for processing signals representative of a plurality of commands, each command being identified by a control signal lying in a respective band of frequencies. The command-representative control signals are supplied to a counter which is also supplied with regularly recurring timing or clock signals. The clock signals provide recurring counting intervals of fixed duration during which the frequency of an incoming signal is measured and divided. The counter provides an output count, the magnitude of which is representative of a particular command. The divided output signals are compared during successive time intervals for identifying continued reception of like signals. Apparatus which is to be controlled by the received command signals is supplied with the divided output signals only after a predetermined number of successive like output signals are sensed.

Abstract: A tuner bandswitching system for a television receiver tuning system wherein a reset pulse generated at the completion of the selection of a channel to be received is utilized to determine the initial stable state of a series of bistable circuits and to provide a bandswitch reset pulse for use in establishing an initial voltage output from a voltage sweep generator utilized to scan a varactor tuned VHF tuner or a varactor tuner through one or more bands of frequencies. The bistable circuits control switching voltages supplied to the VHF tuner and the UHF tuner to provide for sequencing of the tuning system serially through, for example, the low VHF band, the high VHF band, and the UHF band until the appropriate band has been selected wherein the selected channel can be tuned. When the selected channel is tuned, a hold signal is developed. Data identifying the channel being received during a sweep through a given band is accumulated in a counter. At a predetermined output of the counter (e.g.

Abstract: 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.

Abstract: A bandstart detector system for a television receiver tuning system wherein a sample of oscillator signals utilized for conversion of radio frequencies into intermediate frequencies is coupled to a plurality of tuned circuits. Detecting means are coupled to each of the tuned circuits to produce control signals having an amplitude inversely related to the difference between the oscillator signal frequency and the resonant freqency of each of the tuned circuits. The amplitude of the control signal will vary as the oscillator signal frequency is swept in a regular manner through a predetermined band of frequencies corresponding to television channel frequency allocations. The control signals are coupled to a sensing circuit which produces one output signal when the control signal is below a predetermined level and a second output signal when the control signal is above a predetermined level.

Abstract: A low output impedance precision dynamic voltage divider network having low power dissipation and particularly suited for fabrication on a monolithic integrated circuit chip.

Abstract: A timed alarm system having an audio signal source coupled to a sound reproducing system by means of a field effect transistor which yields increasing output as its control electrode is biased by a capacitive network thus producing an alarm signal of gradually increasing amplitude. Apparatus for delayed alarm and drowse capabilities is also described.