Abstract: An audio control system for altering the frequency content of an audio signal with a d.c. control voltage. An audio signal is divided into a plurality of signal channels representing different portions of the audio signal frequency spectrum. Each signal channel is terminated by an attenuator which is responsive to a d.c. control voltage. The attenuated signals are then combined. By changing a d.c. control voltage a change in tone, volume, balance or loudness of an audio signal in a stereoamplifier or the like may be achieved.

Abstract: An A.C. powered amplifier for converting low power information input signals to corresponding signals of a substantially increased power level without requiring a power transformer. A signal processor having a low power information signal input and a feedback signal input controls the state of a controllable switch. The switch power input is coupled to a source of relatively high A.C. voltage via a rectifier circuit and a first low pass filter circuit, and the switch output is coupled to the amplifier output terminal via a second low pass filter circuit. A feedback path is provided from either the switch output or the amplifier output terminal to the feedback signal input of the signal processor. The signal processor may comprise a pulse width, or pulse frequency modulation circuit.The amplifier provides high efficiency, low power loss, and has a band width limited only by the maximum switching frequency of the controllable switch.

Abstract: A zeroing circuit for use in conjunction with devices that produce output signals in response to input data signals feeds a compensating signal into such a device to produce a zero output signal when there is a zero input signal. The device being compensated is intermittently tested for the zero condition, and an aspect of the compensating signal is altered to produce the zero condition.

Abstract: An output stage and feedback circuit for a buffer amplifier are disclosed. The output stage protects an operational-amplifier circuit preceding it from overvoltages appearing at the load. The circuit includes a pair of complementary transistors in a push-pull arrangement that sources and sinks current to and from the load. Both the transistors are in common-emitter configurations, and each one has a corresponding diode connected between its collector and the load in an orientation opposite that of the collector-base junction. The diodes prevent the reverse current that would otherwise flow in response to an output overvoltage of the polarity that forward biases the collector-base junction of the transistor, and the over-voltage is thereby prevented from being seen at the operational-amplifier output terminal. Overvoltages of the other polarity are not seen because they reverse bias the base-collector junction.

Abstract: Disclosed is a broad band amplifier for use as a preamplifier in TV receiving systems and in other applications where broad band amplification is desired. A ferrite directional coupler is used to negatively feed back a portion of the output of an amplifying stage to its input.

Abstract: A cathode-ray tube having a conductive internal coating comprised of carbon, optionally iron oxide, lithium silicate and at least one of sodium and potassium silicates on the interior walls of the tube.

Abstract: A circuit for detecting the amplitude of a RF signal propagating along a transmission line. A plurality of rectification circuits, each including a diode and a filter capacitor, are located at different positions along the line. The signal electrodes of the capacitors are connected together to thereby non-additively combine the signals seen at each rectifier.The spacing between the rectifier circuits is carefully selected and will vary with the number of rectifier circuits used. If two rectifiers are employed, the distance therebetween may conveniently be equal to an odd multiple of one-quarter of the wavelength of the driving signal. For this spacing, the combined signal will never fall below the amplitude of the signal produced when the transmission line is terminated with a perfectly matched load. Additionally, the output of the detector will be generally responsive to VSWR. Other RF level detectors having greater numbers of rectifier circuits are also described.

Abstract: A system for phase control of multiple high power microwave frequency amplifiers. A pilot frequency lower than the frequency to be amplified is used to modulate the microwave signal. The pilot frequency is detected at the output of the amplifier stage and phase compared with the original pilot frequency. Any difference is used to produce a phase correction signal applied to the amplifier. Phase modulatable traveling wave tubes are the power amplifiers. One alternate embodiment involves a steerable array employing an additional pilot frequency correction introduced into the pilot signal. In another embodiment a cross field amplifier is placed in series with a traveling wave tube amplifier in the phase correction loop.

Abstract: An electronic photographic flash apparatus which is useful as an artificial light source for taking photographs. The apparatus of this invention does not use an AC charger or the like as its power source, but it uses a plurality of secondary batteries normally held in a charged state by a primary battery, whereby when the flash apparatus is to be used, the connection of the plurality of the secondary batteries is changed to quickly charge a main discharge capacitor of the flash apparatus. By virtue of the ability of the apparatus to quickly charge its main discharge capacitor, the electronic flash apparatus in accordance with the present invention can effectively associate its operation with the operation of the shutter release of a photographic camera when it is incorporated in the latter.

Abstract: The output of an amplification assembly is coupled with the input of an integrating circuit by means of a first controlled switch. The output of the integrating circuit is coupled with the input of an intermediate stage and subtracted from the amplifier input signal during quiescence of the amplifier. The signal delivered by the amplification assembly is also applied to the input of a logical detection circuit which opens the first switch and closes a second switch discharging the integrating circuit in response to any rapid-variation pulse applied to its input, thus disabling the integration-subtraction operation, but closes the first switch and opens the second to enable integration and subtraction when the signal applied to the input of the detection circuit is steady or is subject only to slow variations.

Abstract: A low-noise, small-signal transistor amplifier particularly suited for use as a preamplifier in an acoustic or audio apparatus employs a field effect transistor having triode-type characteristics in a common source type amplification circuit, with the gate of the field effect transistor being connected directly to an input terminal which receives the audio signals to be amplified, the drain of the field effect transistor being connected to an output terminal, preferably through a capacitor for DC cutting, and the source of the field effect transistor being connected to a point of reference potential, such as the ground, through a parallel circuit of a resistor and a capacitor.

Abstract: An AM converter and AGC amplifier are described for use either separately or in combination in a radio receiver. The AGC amplifier includes a semiconductor device directly coupled to the amplifier input for receiving automatic gain control signals. The AM converter includes a single mixer transistor directly coupled to both an RF amplifier and local oscillator. The converter circuit provides attenuation of the oscillator signal by up to 60 d.b. relative to the R.F. signal, greatly reducing the necessary I.F. filtering. Both the converter and AGC circuits are fabricated on integrated circuit chips.

Abstract: A difference amplifier, the construction of which includes operational amplifier, has an extended amplitude range of common mode signal. The input of the circuit which is applied to the inversion input of the operating amplifier is applied to the latter through an attenuation network. An adjustment of the other resistor values in the circuit is made to appropriately retain the desirable characteristics of keeping common mode rejection.

Abstract: A low-noise, stage-stabilized, direct-coupled, single-ended amplifier cirt is disclosed which has a unique feedback network combined therewith in such manner that degenerative alternating current and substantially constant direct current feedback signals are supplied thereto, so as to effect an exceptionally steady amplification factor therefor over a very broad frequency response band.

Abstract: A lens cap, for use with a light emitting diode, comprises:A. an end wall and a side wall defining a skirt integral with said end wall,B. the skirt being polygonal and defining interior corners,C. the skirt interior surface defining serrations extending lengthwise toward said end wall, andD. the skirt side wall thickness at the corners being substantially the same as the skirt side wall thickness between said corners.

Abstract: A low noise amplifier for amplifying a signal from a moving coil phono cartridge which comprises a plurality of pairs of complimentary first and second transistors in push-pull and each pair in parallel, with a resistance of relatively low-value in the emitter circuit of each transistor and all collectors connected to an output terminal.

Abstract: A display device comrising a panel structure including a plurality of gas-filled cells and including, within the body of the panel, gas communication channels extending between selected cells to provide a selective flow of excited gaseous particles from certain cells to others to prime the receiving cells and thereby control the transfer of glow between the cells.

Abstract: An amplifier circuit whose gain bears a desired relation to a control voltage, including a differential amplifier, a plurality of impedances interconnected between the amplifier terminals and switches interconnected with the impedances and switchable between two states which create two impedance configurations that give the circuit mutually complementary gain vs. control voltage control characteristics.

Abstract: Color correction is provided in a high-pressure mercury vapor discharge lamp with a particular combination of two different phosphor materials producing an efficient composite emission. A blend of said phospor materials can improve color rendition without effecting any significant reduction in the lamp lumen output.

Abstract: A current amplifier (CMA) having plurality of input terminals and an output terminal. Each input circuit and the output circuit of the CMA includes the conduction path of a separate one of a plurality of transistors. Means are provided for applying substantially the same potential to the control electrode of each of these transistors, which means includes an input-terminal-to-control-electrode degenerative feedback connection for each of the transistors having its conduction path in an input circuit. By including a unilaterally conductive device in such an input-terminal-to-control-electrode feedback connection, saturation of the transistor associated therewith caused by certain input current conditions is forestalled.