Abstract: To provide a switching power supply apparatus which can achieve the followings simultaneously in high levels: the voltage waveform capable of reducing switching noise to the least is in a sine-waveform; capable of providing an output of stable voltage without a control, and a simple response; and capable of corresponding to instantaneous peak current without having saturation of the core. It relates to an improvement of a resonance-type Royer converter with less switching noise as a base, which is directed to be used for audio equipment. A second inductor is inserted to the primary side inductor between a rectifier circuit and a smoothing means, which is coupled to the primary-side inductor in a same magnetic circuit in a direction of canceling a DC magnetic flux. Moreover, timing of the next cycle is determined by applying a center tap voltage of a transformer to a synchronous signal input terminal of a control IC. Thereby, a self-excited oscillating action is actually stabled.

Abstract: To provide a switching power supply apparatus which can achieve the followings simultaneously in high levels: the voltage waveform capable of reducing switching noise to the least is in a sine-waveform; capable of providing an output of stable voltage without a control, and a simple response; and capable of corresponding to instantaneous peak current without having saturation of the core. It relates to an improvement of a resonance-type Royer converter with less switching noise as a base, which is directed to be used for audio equipment. A second inductor is inserted to the primary side inductor between a rectifier circuit and a smoothing means, which is coupled to the primary-side inductor in a same magnetic circuit in a direction of canceling a DC magnetic flux. Moreover, timing of the next cycle is determined by applying a center tap voltage of a transformer to a synchronous signal input terminal of a control IC. Thereby, a self-excited oscillating action is actually stabled.

Abstract: The present invention relates to an isolated-type switching power supply apparatus, which includes a power supply, a transformer being connected to said power supply, a switching element for switching an electric current going through a primary coil of the transformer so that energy generated on the primary side of the transformer is sent to the secondary side in accordance with the operation of the switching element. The present invention has a modulating circuit for modulating an output on the secondary side of said transformer, a transmitting rout for transmitting an output of the modulating circuit to the primary side of the transformer, a demodulating circuit for demodulating the output transferred through the transferring rout; and the controlling circuit controls the switching element in accordance with an output of the demodulating circuit and the controlling circuit is disposed on the primary side of the transformer.

Abstract: A switching power supply apparatus which has an input power source; a transformer having a primary winding, a secondary winding, an input winding and a magnetic flux canceling winding being connected to the secondary winding in series; a main switch for switching an electric current going through the primary winding; a bypassing capacitor for bypassing the primary winding; a sub switch for clamping a surge voltage, which is generated in the primary winding; a clamping circuit constituted of the sub switch and a clamping capacitor; a first rectifying switch for rectifying an electric current going through the secondary winding and the magnetic flux canceling winding during when the main switch is being OFF; a second rectifying switch for rectifying an electric current going through the magnetic flux canceling winding during when the main switch is being ON; and a smoothing capacitor for smoothing an electric current going through the magnetic flux canceling winding; and the magnetic flux canceling winding is p

Abstract: The present invention relates to an isolated-type switching power supply apparatus, which includes a power supply, a transformer being connected to said power supply, a switching element for switching an electric current going through a primary coil of the transformer so that energy generated on the primary side of the transformer is sent to the secondary side in accordance with the operation of the switching element. The present invention has a modulating circuit for modulating an output on the secondary side of said transformer, a transmitting rout for transmitting an output of the modulating circuit to the primary side of the transformer, a demodulating circuit for demodulating the output transferred through the transferring rout; and the controlling circuit controls the switching element in accordance with an output of the demodulating circuit and the controlling circuit is disposed on the primary side of the transformer.

Abstract: A power supply apparatus having an AC power supply, a transformer, a switching element and a control circuit for controlling an operation of the switching element: where an electrical current is supplied to the primary side of the transformer intermittently when a main unit of an electrical appliance to which the power supply apparatus is applied is in a standby mode so that unnecessary power consumption is reduced. Further, a capacitance is provided between the AC power supply and the control circuit instead of the conventional initializing resistance and the control circuit is driven using an electrical current going through a reactance component of the capacitor, so that the energy loss is not caused any more by the initializing resistance.

Abstract: A switching power supply apparatus which has an input power source; a transformer having a primary winding, a secondary winding, an input winding and a magnetic flux canceling winding being connected to the secondary winding in series; a main switch for switching an electric current going through the primary winding; a bypassing capacitor for bypassing the primary winding; a sub switch for clamping a surge voltage, which is generated in the primary winding; a clamping circuit constituted of the sub switch and a clamping capacitor, a first rectifying switch for rectifying an electric current going through the secondary winding and the magnetic flux canceling winding during when the main switch is being OFF; a second rectifying switch for rectifying an electric current going through the magnetic flux canceling winding during when the main switch is being ON; and a smoothing capacitor for smoothing an electric current going through the magnetic flux canceling winding; and the magnetic flux canceling winding is p

Abstract: A power supply apparatus having an AC power supply, a transformer, a switching element and a control circuit for controlling an operation of the switching element: where an electrical current is supplied to the primary side of the transformer intermittently when a main unit of an electrical appliance to which the power supply apparatus is applied is in a standby mode so that unnecessary power consumption is reduced. Further, a capacitance is provided between the AC power supply and the control circuit instead of the conventional initializing resistance and the control circuit is driven using an electrical current going through a reactance component of the capacitor, so that the energy loss is not caused any more by the initializing resistance.

Abstract: The present invention relates to an isolated-type switching power supply apparatus, which includes a power supply, a transformer being connected to said power supply, a switching element for switching an electric current going through a primary coil of the transformer so that energy generated on the primary side of the transformer is sent to the secondary side in accordance with the operation of the switching element. The present invention has a modulating circuit for modulating an output on the secondary side of said transformer, a transmitting rout for transmitting an output of the modulating circuit to the primary side of the transformer, a demodulating circuit for demodulating the output transferred through the transferring rout; and the controlling circuit controls the switching element in accordance with an output of the demodulating circuit and the controlling circuit is disposed on the primary side of the transformer.

Abstract: A power supply apparatus having an AC power supply, a transformer, a switching element and a control circuit for controlling an operation of the switching element: where an electrical current is supplied to the primary side of the transformer intermittently when a main unit of an electrical appliance to which the power supply apparatus is applied is in a standby mode so that unnecessary power consumption is reduced. Further, a capacitance is provided between the AC power supply and the control circuit instead of the conventional initializing resistance and the control circuit is driven using an electrical current going through a reactance component of the capacitor, so that the energy loss is not caused any more by the initializing resistance.

Abstract: In the DC-DC converter according to the present invention, an intermediate tap is provided in the free-wheel inductor; the free-wheeling current goes out through the tap. The switch at the main switch side is driven by an N-channel FET (NPN transistor) and a pulse transformer, or the switch constitutes a P-channel FET (PNP transistor), so that the driving circuit at the rectifying side can be made simple. Further, the DC-DC converter includes loss-less snubber circuits or a soft switching circuit having a sub-switch in order to absorb and recover the surge energy from a leaked inductance, which is generated by the addition of the intermediate tap. Moreover, the driving circuit for the soft switching circuit is also simplified.

Abstract: A power supply apparatus having an AC power supply, a transformer, a switching element and a control circuit for controlling an operation of the switching element: where an electrical current is supplied to the primary side of the transformer intermittently when a main unit of an electrical appliance to which the power supply apparatus is applied is in a standby mode so that unnecessary power consumption is reduced. Further, a capacitance is provided between the AC power supply and the control circuit instead of the conventional initializing resistance and the control circuit is driven using an electrical current going through a reactance component of the capacitor, so that the energy loss is not caused any more by the initializing resistance.

Abstract: The single-phase AC-DC converter includes a PFC power supply section, where a rectified current obtained by rectifying an electric current from an AC supply is switched; a DC-DC power supply section, where a direct current obtained by rectifying and smoothing an electric current from an AC supply is switched; a first switching element for conducting a switching operation in the PFC power supply section; a second switching element for conducting a switching operation in the DC-DC power supply section; a drive pulse generating circuit for generating first drive pulses for driving said first switching element and second drive pulses for driving said second switching element; and a servo loop for controlling the drive pulse generating circuit. The servo loop is constituted of only one serve loop; and the duty ratio of the drive pulses for driving the first switching element is different from the duty ratio of the drive pulses for driving the second switching element from each other in a linked manner.

Abstract: The single-phase AC-DC converter includes a PFC power supply section, where a rectified current obtained by rectifying an electric current from an AC supply is switched; a DC-DC power supply section, where a direct current obtained by rectifying and smoothing an electric current from an AC supply is switched; a first switching element for conducting a switching operation in the PFC power supply section; a second switching element for conducting a switching operation in the DC-DC power supply section; a drive pulse generating circuit for generating first drive pulses for driving said first switching element and second drive pulses for driving said second switching element; and a servo loop for controlling the drive pulse generating circuit. The servo loop is constituted of only one serve loop; and the duty ratio of the drive pulses for driving the first switching element is different from the duty ratio of the drive pulses for driving the second switching element from each other in a linked manner.

Abstract: An output of a first converter for switching a rectified line current and an output of a second converter for switching a direct current are added together so that an efficiency, a power factor, a holding time, and a ripple characteristic can be improved. Further, the power supply apparatus can be made compact and the cost for manufacturing the apparatus can be reduced. A flyback converter type output circuit and a forward converter type output circuit are used in a parallel manner so that a transformer having a high efficiency can be used, and it becomes easier to control the apparatus.

Abstract: A power supply apparatus having an AC power supply, a transformer, a switching element and a control circuit for controlling an operation of the switching element: where an electrical current is supplied to the primary side of the transformer intermittently when a main unit of an electrical appliance to which the power supply apparatus is applied is in a standby mode so that unnecessary power consumption is reduced. Further, a capacitance is provided between the AC power supply and the control circuit instead of the conventional initializing resistance and the control circuit is driven using an electrical current going through a reactance component of the capacitor, so that the energy loss is not caused any more by the initializing resistance.

Abstract: A power supply apparatus includes a switching element for relaying electrical current to be supplied to a transformer and a controlling circuit for controlling an operation of said switching element. The controlling circuit has a first oscillator which works to continuously drive the switching element and a second oscillator which works to intermittently operate the switching element. An amount of electrical current to be supplied to the transformer is controlled by changing a duty cycle or an oscillating period of the second oscillator in accordance with a variation of the amount of load current. Further, an initiating resistance for initiating the controlling circuit and a "cut-off" circuit cutting the resistance off: it is arranged such that the resistance is "cut-off" from the controlling circuit after initiating the controlling circuit in order to avoid that a significant amount of current is consumed at the resistance after initiating the circuit.

Abstract: When reproducing an audio signal with a conventional audio signal reproducing system, an unnaturalness in the quality of the reproduced sound occurs. The unnaturalness is caused by the frequency spectrum of the reproduced sound which is decreased or cut off at an upper limit of a reproducible frequency range or at an upper limit of an audible frequency range. The present invention adds a random noise component and/or a higher harmonics component exceeding over the upper limit of the reproducible frequency range or the upper limit of the audible frequency range to the original audio signal. By so doing, the reproduced sound has an excellent audio quality which can be sensed by the listener.