Abstract: A percussive digging tool attachment for a small robotic platform employs a percussor module for applying percussive impulses of relatively low impact at relatively high frequency to an attached digging tool to dig into or break up soil and rocks. By using low-impact, high-frequency percussive forces, it reduces the reaction loads on the small robotic platform while providing increased capability.

Abstract: A percussive digging tool attachment for a small robotic platform employs a percussor module for applying percussive impulses of relatively low impact at relatively high frequency to an attached digging tool to dig into or break up soil and rocks. By using low-impact, high-frequency percussive forces, it reduces the reaction loads on the small robotic platform while providing increased capability.

Abstract: A clipper includes an amplifier having a non-inverting input node, an inverting input node, and an output node. A feedback transistor has its base connected to the amplifier output node and its emitter connected to the inverting input node for providing unilaterally conductive degenerative current feedback between the output node and the inverting input node. A resistor is connected between the inverting input node and an input terminal for conducting a current supplied via the collector-to-emitter path of the feedback transistor which is proportional to the amplitude of an unclipped portion of the signal applied between the input terminal and the non-inverting input node. When a reference potential is applied to the non-inverting input node and an AC input signal varying about the reference potential is applied to the input terminal, the stage functions as a negative half-wave rectifier.

Abstract: A video cassette recording (VCR) playback system includes circuitry for separating the components of a video signal to produce luminance information and color-under information. The separated color-under information is applied to the input of a variable gain control amplifier the output signal from which includes burst information at color-under carrier frequency during burst intervals. The output signal from the variable gain amplifier is applied to a rectifying circuit which is enabled during the burst interval. The burst information at color-under carrier frequency is rectified during the burst interval and peak detected to produce a control voltage which is applied to the variable gain control amplifier for controlling its gain.

Abstract: Signal phase reversal as well as DC shift is avoided in the load current of a controlled-gain transistor amplifier of a type including: first and second transistors connected as a first emitter-coupled differential amplifier; means for applying an input signal voltage between the base electrodes of the first and second transistors; third and fourth transistors connected as a first current splitter, including an interconnection between the emitter electrodes of the third and fourth transistors to which the collector electrode of the first transistor connects; fifth and sixth transistors as a second current splitter, including an interconnection between the emitter electrodes of the fifth and sixth transistors to which the collector electrode of the second transistor connects; means for applying a control signal voltage between the base electrodes of the third and fourth transistors and between the base electrodes of the fifth and sixth transistors; means for applying an operating potential to a first interconn

Abstract: A first pair of transistors, Q721 and Q723, operating, each, as an emitter follower, has a relatively low emitter current. The emitter followers drive corresponding base electrodes of transistors of a second pair of transistors, Q148 and Q149, coupled as a differential amplifier. A current gain compensating transistor Q726 has a current gain that tracks current gain variations of each of the transistors of the second pair. A base electrode current of the compensating transistor and a second current i.sub.Q727 that is unaffected by current gain variations are summed. The summed current is coupled via transistors Q722 and Q724 of a current mirror arrangement to first and second junction terminals, 610e and 610f. The junction terminals are coupled between the respective emitter electrodes of the emitter followers and the base electrodes of the second pair.

Abstract: A control circuit of a television receiver power supply is constructed using a plurality of transistors operating in a common base configuration. The base electrodes of each of the transistors is coupled to a common conductor rail line that maintains the collector currents in the transistors temperature compensated over a wide range of operating temperatures during normal operation power-up mode of the receiver. In a standby mode of the receiver, power dissipation in the transistors is reduced by applying an on/off control signal to the common conductor rail line that prevents the flow of the collector currents in each of the transistors. Consequently, the supply current requirement of the control circuit is reduced during the standby mode.

Abstract: A supply voltage is developed in accordance with an on/off control signal of a remote receiver during a start-up interval and during a power-up mode of operation of a television power supply. During a standby mode of operation, the supply voltage is switched off. The supply voltage produces a supply current in an oscillator that produces a signal at a horizontal rate related frequency. The supply voltage also produces a base drive current in a switching transistor of a horizontal driver only during the start-up interval. During a power-up mode, a run supply voltage is coupled to the oscillator and to the driver.

Abstract: A level shifter receives a variable input voltage such as a beam current representative voltage of a cathode ray tube and produces an output voltage that changes when the input voltage changes such that the output voltage is level shifted relative to the input voltage. The output voltage is coupled to an input terminal of an error amplifier of a power supply voltage regulator of a television receiver. The level shifter includes a current mirror arrangement responsive to the input voltage. A band gap type voltage source determines the amount of level shifting that is produced by the level shifter.

Abstract: Odd harmonic generator includes two amplitude limiting amplifiers and a frequency selective signal combining network. Sinusoidal signal at frequency of chrominance subcarrier is applied to inputs of both amplifiers. The first amplifier provides signal comprising fundamental and odd harmonic frequency components. The second amplifier provides signal comprising a fundamental frequency component and odd harmonic frequency components that are comparatively much smaller than the odd harmonic frequency components of the first amplifier's output signal. Signals are combined so that fundamental frequency components offset. Output signal at third harmonic of chrominance subcarrier frequency is used as clock signal for CCD comb filter in a color TV receiver.

Abstract: An amplifier, including a pair of emitter coupled non-complementary transistors operated at constant emitter, base and collector potentials, provides a bidirectional output current proportional to an AC signal to be rectified. The output current is applied to a common base connection of a pair of complementary emitter-coupled base-coupled transistors having a common emitter connection coupled via a linearizing feedback resistor to the base electrode of one of the amplifier transistors and via a load to a source of reference potential.

Abstract: Color reference oscillator in a color television receiver comprises a non-inverting amplifier, with positive feedback from its output conveyed via a crystal filter to its input. A quadrature phase shift network, coupled to the filter output, develops phase shifted signals which are matrixed with signals derived directly from the non-inverting amplifier to form resultant signals with a phase intermediate the phases of the matrix inputs. Control voltage outputs of a phase comparator, responsive to oscillator signals and to received synchronizing bursts, determine the magnitude and polarity of the output of a controlled amplifier which has at its input the resultant signals produced by said matrixing. The controlled amplifier output, and the output of an inverting amplifier also responsive to said resultant signals, share the load resistor of the non-inverting amplifier.

Abstract: An automatic fine tuning (AFT) circuit is provided which generates an AFT control signal in response to a video intermediate frequency (I.F.) signal. The I.F. signal is supplied to the inputs of two buffer amplifiers, which couple signals of like phase relationship to two inputs of a discriminator network. The discriminator network is tuned to the desired frequency of the video I.F. signal, and is responsive to the buffered I.F. signals for causing respective signal voltages to be developed at its inputs which vary differentially in magnitude in response to the frequency deviation of the I.F. signals from the desired I.F. frequency. The differentially related signals are detected by two peak detector networks for use as AFT control signals. The buffer amplifiers and peak detectors may be conveniently fabricated on a single I.C. chip. The discriminator network is coupled to the buffer amplifiers by two external I.C. terminals.

Abstract: An intercarrier sound system is provided in which a single transistor is used as both the intercarrier sound mixer and a sound I.F. amplifier. The transistor has an input circuit which includes its base-to-emitter junction, and an output circuit including its collector electrode and one of its base and emitter electrodes. Picture and sound carrier signals are applied to the transistor by way of the input circuit and are mixed across the base-to-emitter junction of the transistor. Means are provided at an electrode of the transistor common to the input and output circuits having an impedance which varies inversely with frequency. The variable impedance means causes the amplification provided by the transistor to vary directly with frequency over a band of frequencies including the video signal and the intercarrier sound signal frequencies.