Abstract: A method for installing a wireless network, which includes the steps of physically installing a plurality of nodes in respective different locations in a building, connecting the nodes to a power supply and powering up the nodes, using a wireless installation device to program a respective address into the nodes, using the wireless installation device to program one or more default settings into the nodes, using the wireless installation device to verify operation of the nodes, and, using the wireless installation device to dump at least information regarding the physical location and associated address of the nodes to a building computer. In a presently preferred embodiment, the wireless installation device is preferably an RF portable computer which has an RF transmitter which has a variable power setting, and an RF receiver which also has a variable power setting.

Abstract: An AC-AC ballast system for a discharge lamp (e.g., a fluorescent lamp), which includes a PFC converter which incorporates an isolation transformer, and a DC-AC inverter provided on the secondary side of the isolation transformer. Because the AC line input is isolated from the lamp load by the transformer in the PFC converter, the switching frequency of the PFC converter can be advantageously significantly higher than the lamp current frequency (and the switching frequency of the DC-AC inverter), to thereby enable a significant reduction in the size and weight of the ballast system, without an increase in the emission of EMI radiation from the lamp. In this regard, the ballast system of the present invention can be thought of as a two-frequency ballast system having an isolated PFC converter.

Abstract: A system for controlling the playing of rented compact discs on an end-user's compact disc player. The end-user obtains a validation disc on which is stored a control program and an expiry date. When the validation disc is inserted into the user's player, the player downloads the control program into its memory and runs the program. This causes the expiry date to be read from the disc and stored in the player's memory. Discs to be played on the player have stored thereon a second control program which is downloaded into the player's memory when they are inserted into the player. This second control program causes the player to check whether or not the current date, as maintained by the player, is later than the stored expiry date. If the current date is later, playing of the disc is prevented, while if it is earlier, playing of the disc is allowed.

Abstract: A circuit arrangement according to the invention for operating a discharge lamp (I) comprises a DC/AC converter (II) provided with a series circuit with a first and a second switching element, (1, 1', respectively) between a first and a second input terminal (5, 5', respectively) for connection to a DC voltage source, and with a starting circuit (F) with a first resistive means (R1) between the first input terminal (5) and the control electrode (2) of the first switching element (1). The DC/AC converter is also provided with a second resistive element (R2) which together with the first resistive element (R1) form a voltage divider between the input terminals (5, 5'). The power dissipation in the DC/AC converter is reduced thereby.

Abstract: Filing system for managing recording and retrieving of information files on a record carrier of a rewritable type, which have a limited number of overwrites, such as CD-Erasable having a phase-change recording layer. The system includes a unit for generating non-file and file items having management information and a unit for assigning areas on the record carrier for recording the items. The management information includes references indicative of the areas, and the items include at least one item of a first type to be recorded at a predetermined area (e.g., a Primary Volume Descriptor as in ISO 9660) and items of a second type to be recorded at variable areas (e.g., a Path Table and Directory Files). To restrict the number of overwrites, the unit for assigning areas is arranged for assigning areas for items of the second type in such a way that in operational use updated versions of items of the second type are preferably assigned the same area as the original version of the respective item.

Abstract: A communication method particularly suited for lighting control employs encoding of perturbations in a voltage signal having a fundamental period with a nominal waveform. A control period includes a pre-selected number of fundamental periods of the voltage signal. Different control commands are indicated by imposing a selected perturbation, such as a phase cut, on the nominal waveform with a respective occurrence signature within the control period. The control commands are decoded from the voltage signal by detecting the occurrence signature of the perturbations within each control period. Decoding is accomplished by differentiating the nominal waveform to detect encoded perturbations.

Abstract: An electrical drive arrangement for an electric motor including a stator having a plurality of phase windings, and a rotor. The drive arrangement includes an electronic commutation circuit to supply electric power to the phase windings of the electric motor, a position sensor device, a phase control circuit coupled to receive the sensor signals and provide resultant sensor signals with a phase shift relative to the phase relationship of the sensor signals, a waveform generator coupled to receive the resultant sensor signals and provide commutation signals, and a control circuit coupled at least to the waveform generator for setting the amplitude and the phase shift of the electric power to be supplied to the motor. The phase control circuit includes a control signal generation circuit, a sensor signal allocation circuit, a delay time determining circuit, a sensor signal output circuit, and a load signal generating circuit. The drive arrangement enables the torque angle, i.e.

Abstract: Apparatus and method for use in recording and reading edit data pertaining to reproduction of information signals and/or portions thereof recorded on a record carrier. Edit data includes skip information (identifying information signals and/or portion thereof for which reproduction is undesired) and/or restore information (denoting invalid skip information). The edit data enables determination as to which information signals and/or portions thereof should be inhibited during reproduction.

Abstract: An information storage system is described which comprises a reading device (6) and an optical record carrier (5) having at least two information planes (1, 2, 3). The radiation from the record carrier is converted in a detection system (15) into a detection signal (16) which is applied to a detection circuit (17). In order that this circuit can derive the read information from the detection signal in a reliable manner, the interference signals generated by the information planes which are not to be read should comply with a requirement, referred to as the interference requirement, which is characteristic of the detection circuit. Values for the parameters of the record carrier, such as the thickness of the layers between the information planes and the reflection and transmission coefficients of the information planes then follow from this interference requirement.

Abstract: A lighting system having at least one light source for supplying artificial light and a control unit for controlling the light source. The light source is of the type having an adjustable color temperature. The control unit is provided with a control signal form a signal from a signal generator. The signal generator is dependent on the mean daylight level. The control unit is arranged to adjust the color temperature of the light source in dependence on a predetermined relationship between the mean daylight level and the color temperature of the artificial light. The lighting system will provide artificial light which will when the daylight level, as measured on an office desk, increases from approximately 400 lux to approximately 800 lux, increase the color temperature from approximately 3300 K to approximately 4300 K.

Abstract: A drive circuit for supplying drive signals to a plurality of windings of a multi-phase d.c. motor. The drive circuit comprises a multi-phase inverter which supplies the drive signals to the motor windings; a phase detector which samples the back-emf signal of a winding in order to obtain a phase-error signal; a low-pass filter which generates a control signal dependent upon the phase-error signal; and a controllable oscillator which generates a frequency signal whose phase and frequency depend on the control signal. The timing with which the multi-phase inverter supplies the drive signals to the windings is dependent on the frequency signal. The drive circuit further comprises a masking circuit for temporarily inhibiting the further processing of the phase-error signal by the low-pass filter, at least during the presence of a flyback signal in the phase-error signal, as a result of which the processing of the flyback pulses present in the phase-error signal is inhibited.

Abstract: A dimming ballast lamp includes a lamp, a ballast circuit for converting AC input power to AC output power, a dimming interface circuit for generating a dimming control signal having a voltage level indicative of a selected dimming level of the lamp and a dimming circuit responsive to the dimming control signal for controlling operation of the ballast circuit. A feedback control circuit detects the lamp voltage and produces a feedback control signal in response to the lamp voltage exceeding a perscribed threshold voltage level. The dimming circuit, responsive to the feedback control signal, controls operation of the ballast circuit so as to increase lamp current thereby increasing the dimming level of the lamp, ensuring low temperature ignition of the lamp and protecting against lamp shutdown.

Abstract: A circuit arrangement for operating a high pressure discharge lamp having a full bridge commutator network. A capacitor across each of four commutator switches forms a tuned circuit together with a ballast coil for soft switching. To counteract the core material of the ballast coil from vibrating audibly during lamp operation about no more than 15% of the commutation cycle elapses between turning off the first of the four commutator swithes and turning on the last of the four commutator switches.

Abstract: The disclosed system includes a disc-shaped information carrier and an apparatus for reading and writing information blocks in a continuous track. For indicating the track, the information carrier has a servotrack in which a winding number is encoded per track winding. A winding number and an angular position can be determined from the address of an information block. The angular position is given relative to a reference angular position. This reference angular position is determined by one or more reference marks which are written on the information carrier prior to the first information block. The actual angular position is determined by counting the time relative to a known rotation time from the reading of a reference mark onwards. One or more pulses, for example tachopulses, are generated per revolution in the apparatus.

Abstract: The invention relates to a circuit arrangement for operating a high-pressure discharge lamp. A buffer capacitor is shunted by a branch which comprises a series circuit of a second capactor and a unidirectional element for blocking a current with which the second capacitor charges the buffer capacitor Re-ignition after a zero crossing of the low-frequency alternating current has a comparatively high amplitude so that the lamp re-ignites in a reliable manner.

Abstract: A circuit arrangement for operating a discharge lamp (LA), provided with input terminals (K1, K2) for connection to a supply voltage source. A rectifier (D1-D4) is coupled to the input terminals for rectifying a supply voltage delivered by the supply voltage source. A capacitor (C2) is coupled to the rectifier and a DC-AC converter (III) is coupled to the capacitor and is provided with terminals for accommodating a discharge lamp. The circuit arrangement is also provided with a circuit I (R1-R6. T1, T2, C1, V, VI, VII) for detecting periodic current pulses having an amplitude greater than a given value W1 and with a circuit II (IIa, S1) coupled to the circuit I for changing the operational state of the circuit arrangement. As a result, damage to the circuit arrangement is prevented when the circuit arrangement is used in combination with a dimmer unsuitable for the circuit arrangement.

Abstract: In an ignition circuit for a high-pressure discharge lamp having a pulse generating circuit in which ignition pulses are generated by a voltage-dependent breakdown element and a pulse transformer, a bandpass circuit has been inserted between the secondary winding of the pulse transformer and the discharge lamp. The bandpass filter is tuned to the fundamental frequency or a harmonic of the pulses generated by the pulse generation circuit.

Abstract: A low-pressure mercury discharge lamp is provided with a tubular discharge vessel (10) with end portions (11, 11') having an ionizable filling comprising mercury and rare gas. An electrode (20, 20') is arranged in the discharge vessel at each end portion and is fastened to current supply conductors (30A, 30B; 30A', 30B') which are passed through the end portion to the outside of the discharge vessel. At least one current supply conductor is covered with an amalgam in a zone (35A, 35B) which is at a distance from the end portion (11) via a path along the current supply conductor (30A, 30B). The amalgam can be comparatively easily applied in the lamp.

Abstract: A circuit arrangement for operating a discharge lamp comprising input terminals for connection to a supply voltage source. A load branch B has terminals for holding the discharge lamp and includes an inductive ballast. A device I is coupled to ends of the load branch and to the input terminals to generate a high-frequency voltage from the supply voltage furnished by the supply voltage source. A device II is coupled to the device I to adjust the power consumed by the discharge lamp, the frequency of the high-frequency voltage being dependent upon the adjusted value of the power consumption. A transformer having a primary winding and secondary windings with each secondary winding shunted by an electrode branch during lamp operation, which electrode branch includes an electrode of the discharge lamp. The primary winding forms part of a branch C which also includes a frequency-dependent impedance and which shunts the load branch.

Abstract: A lithotripsy combination, includes a therapy unit and a separate X-ray locating unit which has a first carriage and which can be coupled to the therapy unit via a coupling unit. The X-ray locating unit includes an X-ray source and an X-ray image converter for locating in at least two defined locating positions. Simple alignment of the X-ray locating unit and the therapy unit is achieved in that the therapy unit consists of a second carriage and a shockwave generator which is mounted thereon and which has a stationary focus relative to the carriage, that the two carriages (or parts rigidly connected thereto) can be coupled to one another, via the coupling unit, in such a manner that the coupled carriages can be displaced together and that the focus of the shockwave generator is situated, at least in the locating positions, on the central line which interconnects the X-ray source and the X-ray image converter.