Abstract:
PROBLEM TO BE SOLVED: To provide an apparatus and method for generating a triangular wave with low audio band noise content for class D amplifier circuits.SOLUTION: A triangular wave generator 24 comprises an active integrator 27 and a feedback circuit network 26. The active integrator 27 receives a square wave clock input and generates a triangular wave output. The active integrator 27 is connected with the feedback circuit network 26. Audio band noise content is reduced without significantly sacrificing linearity of the triangular wave output.
Abstract:
PROBLEM TO BE SOLVED: To automatically compensate for signal losses that occur for video signals transmitted over appreciable distances via conductors including twisted-pair cables. SOLUTION: A reference signal having a known form and strength (e.g., a pulse signal) is provided to each pair of conductors carrying a component of a video signal from a transmitter to a receiver. The receiver includes adjustable gain amplifiers for each conductor pair over which a component of the video signal is transmitted. The gains of the amplifiers are initially set at an initial level (e.g., their maximum gain) to enable detection of the reference signal. Once the reference signal is detected in a conductor pair, the amplifier gains are adjusted such that the level of the reference signal is restored approximately to its original form and strength. The apparatus for the automatic compensation is particularly applicable to the transmission of video over long lengths of CAT-5 or similar twisted-pair cables. COPYRIGHT: (C)2008,JPO&INPIT
Abstract in simplified Chinese:本案中一种用于自动补偿于导在线被传输之视频信号中的插入损失之方法与设备被提出。本发明特别可应用于在长距离之CAT-5或类似双绞线电缆上的视频传输。具有习知形式与强度之基准信号(如脉冲信号)被提供至承载由一发射器至一接收器的一视频信号的成份之一对导线。该接收器包括针对其上该视频信号之成份被传输的每一对导线之可调整的增益放大器。该等放大器之增益初始地在一初始位准(如其最大增益)被设置以允许该基准信号的检测。一旦该基准信号在一对导线被侦测,该等放大器增益被调整,使得该基准信号之位准被恢复至近似其原始形式与强度。
Abstract:
An audio amplifier that implements current mode control without the use of an explicit or separate current mode sensor is disclosed. The audio amplifier may include a pair of feedback loops that provide current from a node located before an inductor of an output filter and current from a node located after the inductor of the output filter to an integrator circuit. The integrator circuit may be formed from existing circuitry of the audio amplifier controller. Thus, current mode control can be implemented without a separate current mode sensor.
Abstract:
Methods of data encoding using trees formed with logic gates are described which lead to spatial compression of image data. Data encoding is achieved using a five-level wavelet transform, such as the Haar or the 2/10 transform. A dual transform engine is used, the first and engine being used for the first part of the first-level transform, the second part of the first-level transform and the subsequent-level transforms being performed by the second transform engine within a time interval which is less than or equal to the time taken by the first transform engine to effect the part-transform. Each bit plane of the resulting coefficients is then encoded by forming a tree structure from the bits and OR logical combinations thereof. Redundant data are removed from the resulting tree structure, and further data can be removed by using a predetermined compression profile. The resulting blocks of compressed data are of variable length and are packaged with sync words and index words for transmission so that the location and identity of the transformed data blocks can be determined from the received signal.