Abstract:
A method and apparatus for dynamically allocating the available bandwidth of a common transmission channel of a multiplexed system among multiple encoders in such a manner as to maximize and equalize the quality of the encoded data output by all of the encoders, while also preventing underflow or overflow of encoder or decoder buffers at each end of the common transmission channel, and moreover, while also ensuring compliance with (i.e., without violating) the data encoding and transmission protocol utilized by the system. Further, the bandwidth of the common transmission channel is preferably allocated using an algorithm that does not impose any constraints on the size of the encoder or decoder buffers, other than any constraints specified by the data transmission protocol employed in transmitting the encoded data over the common transmission channel. In a presently preferred embodiment, in which video signals from multiple sources are encoded, both the output channel rate ("bit rate") of each of the encoders and the target number of bits for each picture that is encoded by each encoder are controlled by a controller in accordance with a control algorithm which ensures that the quality of the encoded pictures output by all of the encoders is equalized and maximized, that no underflow or overflow of the encoder or decoder buffers occurs, and that the data encoding and transmission protocol utilized by the system is not violated. Further, the control algorithm employed by the controller preferably does not impose any constraints on the sizes or relative sizes of the encoder or decoder buffers. Moreover, the control algorithm employed by the controller preferably maintains all of the encoder buffers as empty as possible in order to provide increased flexibility to the rate allocation procedure.
Abstract:
The illumination device has a capped electric lamp (1), a reflector (10) and retention means (20) for keeping the lamp (1) fixed to the reflector (10), an electric element (4) of the lamp (1) being aligned with respect to the reflector (10). The cap (5) of the lamp (1) has sphere discs and/or V-shaped grooves as reference means (7) around an axis (3) of its lamp vessel (2), with respect to which the electric element (4) is aligned. The reflector (10) has about an opening (12) for inserting the lamp (1) V-shaped grooves and/or spherical discs as the alignment means (13), cooperating with the reference means of the lamp cap (5). The reference means (7) and the alignment means (13) allow for an easy, fast and reliable mounting of the lamp (1) in the reflector (10), the electric element (4) occupying a predetermined position therein.
Abstract:
The present invention relates to a thin-film resistor of a novel resistance material and to a sputtering target of this material. Said novel resistance material comprises a metal alloy having an intrinsically low TCR, and is characterized in accordance with the invention in that the resistance material also comprises a high-ohmic component. Said high-ohmic component preferably comprises a metal oxide and forms part of the resistance material in a quantity of 15-60 vol.%. The best results are achieved with a resistance material which comprises an alloy of CuNi as the metal alloy and SiO2 as the high-ohmic component. The resistors in accordance with the invention exhibit a relatively high resistance value as well as a relatively low TCR value.
Abstract:
The invention relates to a method of forming one or more through-holes in a metal workpiece, such as shaving foils or shaving combs, by means of an electrochemical machining apparatus (ECM apparatus). To this end, the method is characterized in that, during machining, the workpiece is provided on a substrate of an electroconductive, electrochemically inert material, such as a noble metal (alloy), in particular a noble metal (alloy) which is predominantly composed of Pt. Preferably, the workpiece is clamped onto the substrate. By virtue of said measures, rounding of the edges between the holes formed and the surface of the workpiece, which is clamped down on the substrate during machining, is reduced substantially. This has a favourable effect on the formation of sharp cutting faces.
Abstract:
The invention relates to a circuit arrangement for igniting and operating a discharge lamp (1) comprising inductive means, comprising a primary winding (PRIM) which passes a high-frequency current during ignition and during lamp operation, and a secondary winding (SEC) which is magnetically coupled to the primary winding and electrically coupled to an impedance M (C1, C3) for limiting the current passed by the secondary winding. The current through the secondary winding generates a DC voltage via rectifying means, by which current part of the circuit arrangement is supplied. According to the invention, the circuit arrangement is also provided with means X (R, S1) for increasing the impedance value of impedance M after ignition of the discharge lamp. It is achieved thereby that the amplitude of the DC voltage is at a desired level both before and after ignition of the discharge lamp, while no major power dissipation takes place during stationary lamp operation.
Abstract:
Known is a telecommunications system comprising a supply circuit for a telecommunications line comprising electronic impedances for emulating lump element coils. Such coils are used for preventing AC signals to enter the DC power supply leads. The supply circuit supplies DC current to the telecommunications line for feeding a telecommunications subscriber device at the other end of the line. The known circuit is not suitable for relatively large DC line currents that are needed when feeding multifunctional subscriber devices. A supply circuit is proposed being suitable for feeding a telecommunications subscriber device via a telecommunications line having a variable length that requires a considerable supply power. The supply circuit comprises an electronic impedance that comprises a transistor of which a main current path is coupled in a series arrangement with a main current path of a transistor of an impedance multiplying circuit. Preferably, the voltage between the main electrodes of a transistor of the electronic impedance circuit is controlled by means of closed loop control.
Abstract:
A battery charger whose charging current is shut off on the basis of the temperature difference between the ambient temperature, measured by means of a first sensor (RA), and the battery temperature, measured by means of a second sensor (RB). The error in the measurement of the temperature difference, which is caused by the imput voltage dependent heat generation by the power supply (PS) in the battery charger, is compensated by a third signal (k*Vi) which is representative of the anticipated additional heat generation as a result of a varying input voltage (Vi).
Abstract:
A description is given of a method and a device in which information is written on a medium and is read out, and there is established whether the information read is sufficiently reliable, and in which so-called erasure information is used to establish the influence of media defects and other imperfections on the occurrence of errors in a transmission system. The medium is, for example, a hard disk containing one or more bad spots whose location can be accurately detected. The implementation of the method makes accurate and fast computation of the bit error rate possible.
Abstract:
A disc-shaped information carrier (1) and a device for reading and/or writing information blocks in a track (9) are disclosed. For indicating the track (9), the information carrier (1) has a servo pattern (4) which includes position-information and synchronization elements (35, 36). The synchronization elements such as, for example, a brief pulse in a wobble, are distinguishable in adjacent windings (30, 31) of the track (9) in a predeterminable manner, for example as a result of alternating polarity or shifted positions. The device comprises a read/write head and a system control which during writing detects the synchronization elements and monitors whether a deviation occurs that indicates that the read/write head has wandered off to an adjacent winding. Writing is then interrupted. This is advantageous in that the least possible information in adjacent windings is overwritten in the case of disturbances resulting from shocks or defects of the information carrier. Furthermore, a reading device is described which interrupts the reading in dependence on the synchronization elements.
Abstract:
The invention provides a diode modulator circuit which is adapted to supply an acceptable S-correction of the S-linearity error of the line scanning of a picture tube (CRT) at substantially different line scan widths. A known diode modulator comprises two loops. The first loop comprises a series arrangement of a line deflection coil (LD) and an S-capacitor (CS), which series arrangement is arranged in parallel with a first flyback capacitor (CF1) and a first diode (D1). The second loop comprises a modulator coil (LB) arranged in parallel with a second flyback capacitor (CF2) and a second diode (D2). The two loops are arranged in series. An inner-pincushion capacitor (CSM) is arranged in a common path in which the line deflection current (Id) and a modulator current (Ib) flowing through the modulator coil (LB) flow in opposite directions. The amount of S-correction depends on the values of the S-correction capacitor (SC) and the inner-pincushion capacitor (CSM). The S-capacitor (CS) has been omitted in the diode modulator according to the invention. In this way, the amount of S-correction at minimal scan width will be zero because the common current (Im) flowing in the common path is zero if the diode modulator is in equilibrium. The diode modulator according to the invention can thus cope with picture tubes (CRT) which require a very low amount of S-correction at a small scan width without the need for an additional capacitor (CS2) and a thyristor switching circuit (T) to activate the additional capacitor (CS2) to lower the amount of S-correction at the small scan width. The invention is particularly useful if a continuous zoom between a 16/9 and a 4/3 scan width on a display tube with a 16/9 aspect ratio has to be performed in a simple way.