Abstract: A balanced voltage-to-current converter has two cells. Each cell has a first input terminal coupled to a first current source via a diode-connected first transistor and to an output terminal via the main current path of a third transistor, and a second input terminal coupled to a second (controllable) current source via the main current path of a second transistor. The control electrode of the third transistor is connected to the node between the second current source and the second transistor. The first input terminal of one of cell is connected to the second input terminal of the other cell and vice versa. The quiescent current through the third transistor is controlled by a differential amplifier which compares the voltage difference between the control electrode and a first main electrode of the third transistor with a reference voltage which is representative of the current through the third transistor.

Abstract: A motor drive circuit for driving an electromotor having a permanent magnet rotor and a stator comprising one or more stator windings. When the supply voltage of the motor drive circuit fails, an emergency signal is generated by a signal generator. This emergency control signal activates an auxiliary power supply circuit for extracting electric energy from the motor and supplying the extracted energy to an auxiliary circuit. The auxiliary power supply circuit comprises a rectifier circuit formed by the fly back diodes bridging the switches of an electronic commutation circuit. The drive circuit comprises short-circuit switches bridging the stator windings. In response to the emergency control signal a short-circuit apparatus causes the stator windings to be temporarily intermittently short-circuited. As a result, a capacitor is charged. The energy stored in the capacitor is used for temporarily energizing the auxiliary circuit once the power supply to the drive circuit has failed.

Abstract: The response rate of a liquid crystal display device is increased in that capacitive variations in the liquid crystal mixture caused by a different drive voltage or varying capacitances in drive transistors are taken into account in advance. If necessary, the required corrections are performed with a microprocessor, but they are preferably stored in advance in a look-up table.

Abstract: A circuit for converting samples of data received at a high sampling rate into data samples at a low sampling rate integrally related to the high sampling rate and with the low rate samples synchronized with the high rate samples without a complex phase control apparatus. A memory stores and transfers data under control of write and read address signals. The read address signals are derived by combining the write address signals with a difference address signal generated by a circuit including a modulo counter with a modulus corresponding to the integral ratio between the high and low sampling rates, a first sample-and-hold circuit for storing the count of the modulo counter and supplying its count to an allocating circuit which generates the difference address signal and supplies same to a combining circuit. A decoder controlled by the modulo counter supplies a clock signal at the low sampling rate to a second sample-and-hold circuit fed with data from the memory.

Abstract: A system for controlling the intensity of a lamp including a remote sensing device for detecting the presence of an occupant within an area. The device also transmits a signal based on the currently sensed presence of the occupant. After each transmission of an occupancy signal, the device is inhibited from further transmission for a first predetermined period of time to limit power consumption requirements by the battery powered device. The system also includes a light controller responsive to the transmitted occupancy signal for controlling the level of illumination by the lamp. In the absence of a transmitted occupancy signal within a second predetermined period of time, the light controller will instruct the ballast to reduce the level of illumination by the lamp. In the absence of an occupancy signal being transmitted within a third predetermined time period, the light controller will instruct the ballast to turn off the lamp.

Abstract: A television set includes a circuit for modulating the horizontal velocity of the beam scan as a function of the video content with the aid of an auxiliary line deflection coil. The beam scan velocity modulation circuit includes a video signal differentiator circuit followed by an amplifier provided at the output of a power stage of the current generator type, which has its output connected to one terminal of the auxiliary line deflection coil. A voltage amplifier is provided at the output of a power stage of the voltage generator type which has its input connected to the output of the differentiator circuit, and its voltage output connected to the other terminal of the auxiliary line deflection coil.

Abstract: A stabilized voltage generator circuit of the band-gap type for generating a reference voltage (Vref) which is independent of the supply voltage (Vcc) and the temperature comprises a cell whose transistors, having different emitter areas, supply a current (I.sub.pt) proportional to the absolute temperature. The circuit includes an amplifier having an input stage of the folded cascode type, and an output stage adapted to provide symmetrical operation in order to eliminate first and second-order errors in the accuracy and stability of the reference voltage produced by the generator circuit.

Abstract: A data decoder, for example, for decoding teletext and VPS data, comprises an input signal clamp and synchronizing signal separator circuit which receives a combined video and blanking signal and produces synchronizing pulses for a timing circuit and video signals which are applied to an ADC and a data slicer and clock regenerator (DSCR). Sliced data and clock signals feed an acquisition circuit which acquires selected data which is stored in a memory via a memory interface. A control circuit is arranged to modify the DSCR, acquisition circuit and memory interface dependence upon the type of data detected. The arrangement decoder is set to decode data of one type, for example, teletext, and if no valid teletext data is detected within a given period, for example, four television frames, the control circuit causes the decoder to attempt to decode data of the other type (VPS).

Abstract: An FM reciever which provides a rapid determination of the field strength of FM transmitters has a circuit arrangement which includes an FM demodulator and is characterized in that the output signal of the FM demodulator is applied to a comparator which, in response, produces an output signal that will assume a low or a high amplitude. The comparator precedes an integrator stage whose output signal has a high amplitude only when the output signal of the FM demodulator is suitable for field strength evaluation.

Abstract: An integrated circuit which includes a detection circuit for detecting the condition of saturation of an output transistor (Q.sub.0) whose collector-emitter path is intended to pass an output current. A threshold circuit (A) of the detection circuit is arranged to perform a switching operation when a representative parameter of the condition of saturation crosses a given threshold. A control transistor (Q) is arranged to supply at least a part of the base current of the output transistor (Q.sub.0) and the threshold circuit (A) performs its switching operation when the value of the current passing through the collector-emitter path of the control transistor exceeds a given level.

Abstract: A switched current bilinear integrator comprising interconnected current memory cells (M1, M2) in which, during a first phase of a clock cycle, an input current is fed to the inputs of the current memory cells and during a second phase of the clock cycle an inverted version (A1) of the input current is fed to the inputs of the current memory cells. The output of the integrator is obtained by combining the output (optionally scaled) of the first current memory cell (M1) with an inverted (A2) version of the output (optionally scaled) of the second memory cell (M2). A lossy integrator may be formed by feeding back to the input a scaled version of the current stored in the second current memory cell and an inverted, scaled version of the current stored in the first memoy cell.

Abstract: An audio or video apparatus has a housing, a loud-speaker and an acoustic channel. The loud-speaker acoustically cooperates with the channel. One end of the channel opens into an aperture in a side of the apparatus. The dimensions of the loud-speaker and acoustic channel and the positioning thereof within the housing are chosen so as to provide an apparatus that is compact and at the same time produces improved audio reproduction.

Abstract: A power supply system employs a control circuit to regulate the voltage across a load capacitor by monitoring the capacitor voltage by means of a differential voltage sensor and by monitoring the drain-source voltage of a switching power FET connected in series with the load capacitor across input terminals that supply a full wave rectified voltage derived from a commercial AC supply voltage. The control circuit controls the switching action of the power FET in a manner such that the load capacitor is charged at least once during each cycle of the rectified voltage (unfiltered). This method of voltage regulation by monitoring the load capacitor voltage and the FET voltage (V.sub.ds) provides significant advantages over other forms of voltage regulation.

Abstract: The time it takes for a liquid crystal display device picture to become homogeneous can be reduced to an acceptable extent by a suitable choice of the resistance and the capacitance of the orienting layers with respect to those of the liquid crystal layer. Possible DC voltages, which may occur in the case of a reset drive mode, can thus be rapidly eliminated.

Abstract: An interface circuit makes it possible, starting from an input signal varying between a reference level (VR) available on a first terminal and a first voltage level (V1), to deliver an output signal varying between this reference level (VR) and a second voltage level (V2) available on a second terminal. The circuit includes first and second branches each including first and second serially connected complementary transistors and a third branch with serially connected first and second transistors. First and second inverters couple the input terminal to respective control electrodes of the second transistors in the second and third branches. The inverters have response times chosen so that the two transistors of the third branch are never on simultaneously. Thus, short-circuiting the transistors of the second branch during the transient regime creates almost no current spike.

Abstract: A low noise charge-pump circuit with low power consumption and operating in a cyclic mode comprises two current sources connected in parallel, and a current mirror for transforming the current supplied by one of the current sources and coupling it to the output of the other current source. Each of the current sources essentially comprises a transistor controlled from the output (VB) of a reference voltage generator via a respective transistor switch. The reference voltage generator essentially comprises a third transistor similar to the two first-mentioned transistors and in series with a further current source supplying a current Io, and means for making the current through the third transistor equal to the current Io.

Abstract: A lighting system comprising lighting units each provided with a lamp and a control device for controlling the luminous fluxes of the lamps. The control device includes a first adjustment device (II) for selecting a lighting mode of the lighting system and a further adjustment device (III) for changing a desired luminous flux value in a chosen location illuminated by at least one lighting unit of a first group of the lighting units within a lighting mode. The system is also provided with a correction device (IV) for automatically changing the luminous fluxes of the lighting units of a second group of lighting units dependent upon a change in the desired luminous flux value at the chosen location. In the case of a change in the task lighting by the user (the luminous flux of a first group of lighting units), the surround lighting (the luminous flux of the second group of light units) is changed so that a good harmony between task lighting and surround lighting is maintained.

Abstract: An electro-optical measurement device for the sampling of an electric signal (SI) in an electronic component by means of a radiation beam. Special embodiments of the electro-optic measurement device are described. An electro-optic sensor element is provided with an electrically conductive tip at one side and with an electrode at the other side, so that an absolute and calibrated measurement is possible. The measurement beam can be high-frequency pulsed with a pulse (Lp) per period of the test signal (SI). The pulse series is low-frequency modulated and the pulses exhibit, relative to the test signal, a constant phase relationship during the first half periods of the modulation signal and a varying phase relationship during the second half periods so that accurate and reliable measurement is possible.

Abstract: In a method of manufacturing an in-the-ear hearing aid an auxiliary element, whose cross-section is larger than that of an auditory canal, is introduced into the auditory canal. As a result, the auditory canal is expanded. Subsequently, a hollow vent tube is inserted into the auditory canal, after which the auditory canal is filled with a viscous material. After the viscous material has solidified the mold is removed from the auditory canal. The vent tube insures that air is admitted to a space behind the mold. The mold thus formed has a cross-section larger than the cross-section of the auditory canal. Subsequently, a housing for the hearing aid is made, the mold being used as a template. Consequently, the heating aid will fit tightly in the auditory canal, which improves the wearing convenience.

Abstract: A magnetic resonance apparatus includes an RF coil tuned to a predetermined frequency and which is connected, via a connection circuit, to a transmission and/or receiving device for RF signals. A connection circuit is provided in order to increase the bandwidth of the RF coil without imposing restrictions on the design and the construction of the coil. Therefore, viewed from the RF, the connection circuit successively includes the following elements:a first matching network which is operative to transform an impedance connected to its output to a substantially lower value;a circuit which has the properties of a transmission line whose effective length is substantially equal to an integer number of times one half wavelength at the frequency to which the RF coil is tuned and whose characteristic impedance is substantially equal to the input impedance of the first matching network; anda second matching network which is operative to transform an impedance connected to its output to a substantially higher value.