Abstract: An electric motor with permanent-magnet excitation, particularly an internal-rotor or external-rotor motor, having motor parts which are movable relative to one another. One motor part forms a multi-pole excitation field in an air gap by means of permanent magnets and the other motor part comprises a coil configuration situated in the air gap. The coil configuration is free of soft-magnetic material. The permanent-magnetically excited motor part includes a cylindrical yoke having substantially radial slots which are uniformly spaced about the circumference and in which the permanent magnets are mounted. The permanent magnets are magnetized in a circumferential direction with directions of magnetization which change from magnet to magnet.

Abstract: A control section for a radio receiver receives and decodes information transmitted in coded form in the Radio Data System (RDS) in its Traffic Message Channel (TMC). The control section, which should simplify access to the transmitted information, has an information key and/or an area key and/or storage keys. The information key can activate a plurality of functions. The area key and the storage keys provide access to information about selected areas.

Abstract: A circuit arrangement for charging batteries comprises a charging current source for supplying charging current pulse trains. The circuit arrangement comprises a first detection device for determining an actual voltage dependent upon a variable reference voltage, which actual voltage is proportional to the average sum voltage of a battery. The first detection device supplies a detection signal corresponding to the detection result and which controls the duty cycle of the pulse-shaped control signal which can be generated by a control pulse generator. The control pulse generator varies the duty cycle dependent on the detection signal when the actual voltage increases or the reference voltage decreases, in a manner such that the ratio between the charging period and the charging pause in a charging pulse train is reduced. A device is provided which enable the reference voltage to be varied in the same sense as the duty cycle depending on this duty cycle.

Abstract: A high frequency AC/AC converter apparatus with power factor correction includes an AC/DC converter circuit part to provide power factor correction and a DC/AC inverter circuit part to produce a high frequency AC signal for operation of a load, for example, a discharge lamp. The AC/DC converter circuit part includes a diode and an inductor. The converter apparatus utilizes first and second semiconductor controlled switching devices, one of which is common to each part of the overall converter apparatus. A single control circuit controls both parts of the converter apparatus by controlling the switching of the first and second semiconductor switching devices. There are two possible control techniques, constant duty ratio control or duty ratio sweeping control. A voltage clamp circuit inhibits undesired oscillation of the diode voltage.

Abstract: In a multiphase output oscillator a number of serially coupled oscillator circuits is organized in a loop. Each particular oscillator circuit is coupled to its serial successor in the loop, to provide adjustment of the phase of an oscillation signal of the successor oscillator circuit dependent upon a difference between the phase of the oscillation signal in the successor and the phase of an oscillation signal in the particular oscillator circuit. None of the oscillator circuits will oscillate freely: as each oscillator will adjust its successor all the way around the loop. Indirectly, each oscillator circuit thus influences all of the other oscillator circuits and ultimately over itself. The multiphase output oscillator as a whole will oscillate in a collective mode of oscillation wherein all oscillator circuits oscillate at the same frequency. Successive oscillator circuits along the loop will oscillate at respective fractions of the full oscillation period delayed from each other.

Abstract: In a frequency modulator (1) having an adjusting circuit by which frequency modulator an applied luminance signal of a color video signal that contains synchronization pulses is frequency modulated, while the chrominance signal of the color video signal is modulated on a carrier, that has a quiescent frequency if no color information is available. A capacitor is provided for an automatic mode of operation, and is charged or discharged, respectively, in dependence on the period duration of the modulator output signal and in dependence on the period duration of the quiescent frequency of the chrominance carrier.

Abstract: A circuit for operating a discharge lamp includes input terminals for connection to a supply voltage source and a first apparatus coupled to the input terminals for generating a low-frequency alternating current from a supply voltage delivered by the supply voltage source. A second apparatus is coupled to the input terminals for generating from the supply voltage a further current which is superimposed on the low-frequency alternating current. The polarity of the further current is the same as that of the low-frequency alternating current. As a result, instabilities do not arise in the discharge arc of a high-pressure discharge lamp operated by the circuit.

Abstract: A converter with which an extended definition (ED) video signal may be converted into a signal that may be recorded by a video recorder and with which a signal read out by a video reorder may be converted to an ED video signal. The ED video signal includes first lines having a first luminance signal (Y.sub.1) and a chrominance signal (C), and second lines having no chrominance signal but a second luminance signal (Y.sub.2) in the form of a modulated luminance signal with suppressed carrier. The converter includes a separation unit which receives the ED video signal from an input terminal and has three outputs. A first output couples the first luminance signal to a first output terminal via a first signal combination unit. A second output couples the chrominance signal to a second output terminal via a second combination unit. The third output is coupled to the first output terminal via a mixer circuit and the first combination unit.

Abstract: A circuit arrangement for converting of a stereo signal having a mid-plane signal and a side signal into an output signal for each of two audio signal channels. By this circuit arrangement, a simplified and also automatic crosstalk cancellation is possible.

Abstract: A circuit supplying a stabilised voltage (Vref) which is insensitive to variations of the supply voltage (Vcc) and of the temperature, comprises a cell of four transistors. The first two transistors have their bases and collectors cross-coupled, and the first transistor has its emitter coupled to the reference voltage (VEE) by a resistor and has an emitter area larger than the emitter area of the third transistor. A fifth transistor has an emitter connected to the collector of the fourth transistor and a base which is driven by a line via a resistor. This line is coupled to the supply voltage via a current source. This resistor has a value between 2 and 4 times that of a compensation resistor coupled between the third transistor and the line. Preferably, a capacitance is connected between the bases of the second and the fifth transistor. The circuit is useful as a reference voltage source in integrated circuits where the supply voltage is afflicted with noise.

Abstract: A power supply which serves to convert an alternating voltage supplied by an electric mains, into a DC voltage, having a rectifier with input terminals for receiving the alternating voltage and output terminals for supplying a pulsating direct voltage. A first capacitor is connected parallel to the output terminals. An inverter has input terminals connected to the first capacitor. A current limiting circuit is connected between one of the rectifier output terminals and an electrode of the first capacitor in order to limit the inrush current occurring when the power supply is switched on. The current limiting circuit includes a parallel connection of a first resistor and a first switching element, with the first switching element being operative to be in an electrically non-conductive state upon switching on of the power supply and to change over to an electrically conductive state some time after the power supply is switched on.

Abstract: A differential amplifier with common-mode rejection for low supply voltages has a first and a second differential pair without transistors in the tails of the differential pairs and with proportional common-mode currents flowing through the first and the second differential pair. The differential amplifier includes a current mirror which feeds the common-mode current of the second differential pair (3, 4) back to the output terminals of the first differential pair for the rejection of common-mode currents at the output terminals. The voltage at the output terminals of the current mirror has a d.c. level which can be established by means of a first reference voltage source independently of the common-mode voltage at the input terminals of the differential amplifier.

Abstract: Apparatus for the time controlled charge of a battery includes a switching device to control the supply of charge current to the battery. The switching device is in turn controlled by a control device including a time signal generation stage having a temperature sensitive device responsive to the ambient temperature of the apparatus so as to adjust the time signal generation stage to alter the battery charge time in a sense to prevent overcharging of the battery.

Abstract: Integrated circuits which process analog signals and consist of a plurality of separate functional blocks are difficult to test because the terminals of, internally interconnected functional blocks cannot be simply fed out in view of the limited number of external terminals. In order to test the integrated circuit by testing individual functional blocks separately, it is proposed to connect inputs and outputs of functional blocks are connected to switches enabling connection of these functional blocks to external terminals. The switches are controlled by storage stages which are loaded via a test input which is connected to comparators. These comparators compare the input signal with various reference voltages, the voltage ranges between the reference signals being associated with the logic values "0" and "1" as well as with a clock signal value.

Abstract: A temperature sensing circuit (100) for sensing the temperature of an active semiconductor device, for example, a power MOSFET (11) of a semiconductor body (10). The circuit has a first temperature sensing device (R1R2) provided on the semiconductor body at a first position (P.sub.1) adjacent a periphery (12) of the active semiconductor device (11), a second temperature sensing device (R3,R4) provided on the semiconductor body at a second position (P.sub.2) further from the periphery of the active semiconductor device than the first position. An arrangement, for example, a comparator responsive to the first and second temperature sensing devices provides a control signal to switch off the active semiconductor device (11) when the difference in the temperature sensed by the first and second sensing devices reaches a predetermined value.

Abstract: A ballast filter in which the ballast can operate at a total harmonic distortion of power line current of less than 10%. Power dissipated by the filter when at a THD of less than 10% is relatively low. The input impedance of the ballast is chosen to be no greater than twice the equivalent filter impedance of a front end filter and no less than the equivalent filter impedance/1.5. The filter includes a transformer having a core which at times operates within the non-linear region of its B-H curve under nominally rated ballast load conditions.

Abstract: Encoder for the conversion of a signal of thermometric or cyclic type including a set of n Exclusive OR gates (X1, Xi, . . . , Xn) and an encoding matrix with n rows (1 . . . n) and a plurality of pairs of columns for a differential output of one bit of the binary signal, a matrix in which a row/column coupling is produced by a transistor (T). A pair of pseudo-columns of order zero is coupled to the rows in a way comparable to the coupling of the pair of columns of order 1, but by applying a cyclic shift in respect of the rank of the rows (rows of rank i of the pseudo-columns of order zero, coupled like the rows of rank (i modulo n)+1 of the columns of order 1). The bit of order zero [Bo] is obtained at the output of an additional Exclusive OR gate the inputs of which respectively receive the logic signal [Bo*] output by the pair of pseudo-columns of order zero, and the logic signal [B1] output by the pair of columns of order one.

Abstract: A device and method for insulating a dry film capacitor includes a pair of electrically non-conductive discs having knurled protrusions extending therefrom. The dry film capacitor includes a core for receivingly engaging the protrusions to thereby secure the discs to the capacitor. The discs are dimensioned such that the discs when placed on the interior surface of a ballast can serve as supports for the capacitor by raising the capacitor away from contact with the ballast can. In connecting the discs to the capacitor, the protrusions are twistingly pushed into the core of the capacitor.

Abstract: Current in a line is measured by passing it through a coil, having at least one turn, linking a small high permeability core; passing a measuring current through a bucking winding around the same core; and controlling the measuring current to buck the magnetomotive force of the line current so that the core flux stays below the saturation level. The measuring current may flow through a precision resistor so that a voltage across the resistor is an accurate measure of the line current. The measuring current is obtained from a high frequency switching circuit which senses the change of flux in the core. In normal operation the circuit switches when the core flux has risen to a predetermined value, such as 60% or 80% of the saturation value. If drift or extreme transients cause the flux to reach the saturation level, a sensing and correction circuit re-establishes operation between the desired points.

Abstract: A power supply comprising a coil a switching transistor for establishing a conduction path between the input terminal and the coil during an on-time and for interrupting the conduction path between the input terminal and the coil during an off-time. A diode is provided for sustaining a conduction path for the current through the coil (20) upon interruption of the conduction path between the input terminal (20) and the coil and an apparatus is provided for varying the ratio between the on-time and the off-time of the switching transistor in response to a difference between an output voltage across the load and a first reference voltage (VI). The power supply exhibits an improved efficiency by maintaining the ratio constant if the output voltage lies between two reference values. Within this voltage window defined by the two reference values the power supply is self-regulating, as a result of which the control may be disabled so that the efficiency is improved.