Abstract: An audio signal processing circuit for an audio reproduction apparatus at least having sound source located substantially at left and right sides to a listener, is provided. The audio signal processing circuit includes a phase difference control portion. The phase difference control portion receives a left channel signal for the left sound source and a right channel signal for the right sound source, controls a phase difference between the left and right channel signals so as to produce a relative phase difference in the range of 140 degrees to 160 degrees, and outputs the phase difference controlled left and right channel signals for the left and right sound source, respectively.

Abstract: A switching power supply circuit of the present invention includes: a transformer including a main winding and an auxiliary winding, which are magnetically coupled together on a primary winding side; a switching element for intermittently supplying a direct-current voltage to the main winding; and a controller for turning ON/OFF the switching element using a voltage induced across the auxiliary winding by the intermittent supply of the direct-current voltage. The switching power supply circuit includes a startup circuit, the startup circuit including: a startup switch connected to the main winding; and a driving pulse generator for outputting a driving pulse to the startup switch for turning ON the startup switch.

Abstract: An audio signal processing circuit for an audio reproduction apparatus at least having sound source located substantially at left and right sides to a listener, is provided. The audio signal processing circuit includes a phase difference control portion. The phase difference control portion receives a left channel signal for the left sound source and a right channel signal for the right sound source, controls a phase difference between the left and right channel signals so as to produce a relative phase difference in the range of 140 degrees to 160 degrees, and outputs the phase difference controlled left and right channel signals for the left and right sound source, respectively.

Abstract: A switching amplifier including a PWM circuit 14, a driver 15, a switching output circuit 16 and an LPF 17 is provided with a fluctuation detection circuit 12 for detecting fluctuations in the power supply voltage. The fluctuation detection circuit 12 includes detection resistors 122 and 123 connected in series between a positive power supply 19 and a negative power supply 20. A fluctuating signal RPL occurring at a fluctuation detection terminal 121 is supplied to the inverted input terminal of a differential amplifier 131 of a non-inverted amplifier circuit 13. The non-inverted amplifier circuit 13 inverts the fluctuating signal RPL, mixes the inverted fluctuating signal into the input signal eS, amplifies the mixed signal, and supplying the amplified signal to the PWM circuit 14.

Abstract: A switching power supply circuit of the present invention includes: a transformer including a main winding and an auxiliary winding, which are magnetically coupled together on a primary winding side; a switching element for intermittently supplying a direct-current voltage to the main winding; and a controller for turning ON/OFF the switching element using a voltage induced across the auxiliary winding by the intermittent supply of the direct-current voltage. The switching power supply circuit includes a startup circuit, the startup circuit including: a startup switch connected to the main winding; and a driving pulse generator for outputting a driving pulse to the startup switch for turning ON the startup switch.

Abstract: Surround-effect, providing no unnatural feeling to the listeners who sit next to each other under side-by-side basis through virtual sound sources, is realized. A surround left channel signal SL and a surround right channel signal SR are mixed with an adder 10 and are in monaural. A first monophonic signal and a second monophonic signal thus resulted are supplied to a virtual localization processor 12. A first virtual localization output of the processor 12 is supplied to a front left speaker SPL and a front right speaker SPR and a second virtual localization output thereof is supplied to a front center speaker SPC. In this way, virtual sound sources can be created at the right and the left to the listener 2. Similarly, virtual sound sources can also be created at the right and the left to the listener 3. Sound fields from the virtual surround sources are in reverse to the listener 2 and the listener 3.

Abstract: An audio signal processing circuit for an audio reproduction apparatus at least having sound source located substantially at left and right sides to a listener, is provided. The audio signal processing circuit includes a phase difference control portion. The phase difference control portion receives a left channel signal for the left sound source and a right channel signal for the right sound source, controls a phase difference between the left and right channel signals so as to produce a relative phase difference in the range of 140 degrees to 160 degrees, and outputs the phase difference controlled left and right channel signals for the left and right sound source, respectively.

Abstract: A switching amplifier including a PWM circuit 14, a driver 15, a switching output circuit 16 and an LPF 17 is provided with a fluctuation detection circuit 12 for detecting fluctuations in the power supply voltage. The fluctuation detection circuit 12 includes detection resistors 122 and 123 connected in series between a positive power supply 19 and a negative power supply 20. A fluctuating signal RPL occurring at a fluctuation detection terminal 121 is supplied to the inverted input terminal of a differential amplifier 131 of a non-inverted amplifier circuit 13. The non-inverted amplifier circuit 13 inverts the fluctuating signal RPL, mixes the inverted fluctuating signal into the input signal eS, amplifies the mixed signal, and supplying the amplified signal to the PWM circuit 14.

Abstract: In a switching power supply of the present invention, when a voltage output from start-up means is greater than a driving voltage produced by output means, the voltage from the start-up means is provided to control means, whereby the switching power supply can be started up reliably. Furthermore, when the voltage output from the start-up means is less than the driving voltage produced by the output means, the current path is blocked in the start-up means so that no voltage is provided to the control means from the start-up means, whereby it is possible to reduce the power consumption during the steady operation.

Abstract: In a switching power supply of the present invention, when a voltage output from start-up means is greater than a driving voltage produced by output means, the voltage from the start-up means is provided to control means, whereby the switching power supply can be started up reliably. Furthermore, when the voltage output from the start-up means is less than the driving voltage produced by the output means, the current path is blocked in the start-up means so that no voltage is provided to the control means from the start-up means, whereby it is possible to reduce the power consumption during the steady operation.

Abstract: The present invention includes producing a first processed signal which localizes sound image at a first localization position and a second processed signal which localizes sound image at a second localization position; multiplying one of the first and the second processed signals by a coefficient k which varies in the range of 0 to 1; multiplying the other signal by a coefficient 1−k; and adding the processed signal multiplied by the coefficient k and the processed signal multiplied by the coefficient 1−k.

Abstract: It is an object of the present invention to provide an apparatus for localizing a sound image capable of achieving so called "surround-effect" sufficiently with a simple structure while maintaining a sufficient width of a frontal sound field. Both surround left and surround right signals SL, SR are supplied to a sideward localizer 12 for localizing the sound image reproduced by the signals to positions of sideward of a listener. Also, front left and front right signals FL, FR are supplied to the sideward localizer 12. In this way, the sound image reproduced by the signals is localized at positions between speakers arranged in front side and sidewards of the listener, so that a sufficient width of frontal sound field can be maintained eventually.