Abstract: An audio system is provided that comprises a headphone for reading music information or the like recorded in a memory card attached to an external interface to reproduce audio signal and for outputting sound conforming to the audio signal; and a remote control unit for transmitting control signal for controlling reproduction function or the like of the music information of the headphone to the headphone due to infrared rays. In the audio system, the control signal of infrared rays of less data amount compared with the audio signal or the like is transmitted. Accordingly, circuit configuration and component configuration can be made simpler, the remote control unit can be downsized, and the headphone and the remote control unit can be made wireless, resulting in an easier handling.

Abstract: To provide a digital amplifier and a switching power supply which are effective to realize a noise level required for a high grade and output digital amplifier and a switching power supply. In an embodiment, a noise component extraction circuit is coupled to the output stage of a D-class driver. The noise component extraction circuit extracts a noise component included in the output of the D-class driver and adjusts the phase and gain of the extracted noise component. After its phase and gain have been adjusted, the extracted noise component is added to the output of a low-pass filter. As a result, the noise component remaining in an audio signal that has passed through the low-pass filter is canceled.

Abstract: A switching power supply circuit comprises a switching element for controlling the on/off state of an input power supply according to a drive pulse generated on the basis of a clock pulse having a prescribed period. Breakdown of circuit elements due to current superposition is effectively prevented by detecting current flowing through the switching element and flywheel current, and comparing these detected results with a first and second reference value, respectively.

Abstract: Multiple output power source apparatus enables to optimize efficiency for each output and to perform simultaneous shutdown and synchronous oscillations between the outputs. Power source circuits of various types connected to a power source are provided, and those power source circuits have a function of outputting an abnormality signal to other power source circuits when an abnormality occurs in the own circuit and shutting down the operation of the own circuit by an abnormality signal from other power source circuits and a function of outputting a synchronous oscillation signal synchronized with a switching oscillation frequency used for controlling the own circuit to other power source circuits and conducting synchronous control of the switching frequency used for controlling other power source circuits.

Abstract: A switching power supply circuit comprises a switching element for controlling the on/off state of an input power supply according to a drive pulse generated on the basis of a clock pulse having a prescribed period. Breakdown of circuit elements due to current superposition is effectively prevented by detecting current flowing through the switching element and flywheel current, and comparing these detected results with a first and second reference value, respectively.

Abstract: In a card socket (21-1) having a socket body (21) in which a memory card (10-1) is set and socket electrodes (22) formed on a bottom surface of the socket body (21) to be electrically contacted to exposed electrodes (12) of the memory card (10-1) when set into the card socket (21-1), the memory card (10-1) is magnetically contacted and fixed to the bottom surface of the socket body (21). The card socket (21-1) further has a card removal button (24) for releasing the memory card (10-1) from the card socket (21-1).

Abstract: In a card socket (21-1) having a socket body (21) in which a memory card (10-1) is set and socket electrodes (22) formed on a bottom surface of the socket body (21) to be electrically contacted to exposed electrodes (12) of the memory card (10-1) when set into the card socket (21-1), the memory card (10-1) is magnetically contacted and fixed to the bottom surface of the socket body (21). The card socket (21-1) further has a card removal button (24) for releasing the memory card (10-1) from the card socket (21-1).

Abstract: The centrifuge of the present invention is a centrifuge wherein a rotor is engaged integrally with a drive shaft, in the direction of turning, so that it can be freely attached and detached, wherein the drive shaft is attached to the equipment frame through elastic members, a spherical surface is formed in the upper part of the drive shaft, a spherical concave surface corresponding to the spherical surface in the drive shaft is formed in the top surface of a bearing hole in the rotor, the spherical concave surface of the bearing hole is made to ride on the spherical surface of the drive shaft, and the rotor is engaged so that it can swing freely relative to the drive shaft.

Abstract: A detector including filters adapted so that a signal is inputted thereto to judge whether or not a noise signal is included, or to what extent such noise signal is included; and an operation unit for synthetically judging, on the basis of results that these filters have judged, whether or not a noise signal is included, or to what extent such noise signal is included, thus to automatically detect the quantity of noises included in the signal.A noise reduction device operative to control the noise reduction operation on the basis of an output of this detector to suppress adverse effects resulting from the fact that noise reduction is implemented to a signal having a high SN ratio.

Abstract: When a first videotape as a reference is reproduced by a rotary head, the periodic noise output by the signal-processing section is extracted by the extracting means and stored in the memory section according to the reproduction timing. Then, when a second videotape on which a desired video signal has been recorded is reproduced, an electric signal reproduced from the second videotape by the rotary head is processed by the signal processing section, from the output of which,the periodic noise stored in the memory-section is then subtracted. As a result of this, the periodic noise is removed from the video signal reproduced for the second videotape.

Abstract: An input video signal is supplied to an input terminal 10, and is input to one input terminal of a subtracter 11 and to a high-pass filter. The level of a high-frequency component from a high-pass filter 12 is adjusted by a first variable gain amplifier 13 whose gain can be externally adjusted, and the level-adjusted component is then input to a limiter 15. The limiter 15 extracts a component having a limiter level or less as a noise component. The level of the noise component extracted by the limiter 15 is adjusted by a variable gain amplifier 16 whose gain can be externally adjusted, and the level-adjusted noise component is then supplied to the other input terminal of the subtracter 11. Gain control of the first variable gain amplifier 13 is equivalent to matching the limiter level of the limiter to the level of the input noise component.

Abstract: A noise canceller circuit is connected in a stage succeeding a picture quality control circuit to which the video signal is input. A noise cancel amount for the video signal can be controlled so as to correspond to the gain in the frequency characteristic at the same time when the adjustment of the frequency characteristic of the video signal is performed in the picture quality control circuit. As a result, the noise cancel amount in the nosie canceller circuit can be controlled correspondingly to the level of the noise component even if a level of the noise component in the video signal is changed when the gain in a certain bandwidth of the video signal is adjusted in the picture quality control circuit. Therefore, the noise component can be cancelled effectively.

Abstract: A first circuit generates a first voltage which increases at a predetermined time constant in synchronism with the leading edge of a pulse contained in a sync signal. A second circuit compares the first voltage with a fixed second voltage. When the trailing edge of the pulse contained in the sync signal arrives at the first circuit before the increasing first voltage reaches the fixed second voltage, the first circuit stops generating the first voltage. A third circuit compares the first voltage with a fixed third voltage and a fixed fourth voltage which are higher than the fixed second voltage, and generates a train of burst gate pulses which become high in level after the first voltage exceeds the fixed third voltage, and low in level after the first voltage exceeds the fixed fourth voltage.