Abstract: A wireless power transmission device that enables wireless power receiving device to identify wireless communication circuit without using communication of the wireless communication circuit of wireless power transmission device. A wireless power transmission device for wirelessly transmitting power to a wireless power receiving device includes a power transmission coil, a power transmission circuit configured to supply alternating current (AC) power to the power transmission coil, and a power transmission side communication circuit configured to communicate with the wireless power receiving device. The power transmission circuit is configured to supply a first AC power to the power transmission coil. The first AC power is an AC power having an intermittent supply period in an intermittent pattern representing identification information of the power transmission side communication circuit.

Abstract: Provided is a wireless power transmission device that can enable a wireless power receiving device to identify a wireless communication circuit without using communication of the wireless communication circuit of a wireless power transmission device. A wireless power transmission device for wirelessly transmitting power to a wireless power receiving device includes a power transmission coil, a power transmission circuit configured to supply alternating current (AC) power to the power transmission coil, and a power transmission side communication circuit configured to communicate with the wireless power receiving device. The power transmission circuit is configured to supply a first AC power to the power transmission coil. The first AC power is an AC power having an intermittent supply period in an intermittent pattern representing identification information of the power transmission side communication circuit.

Abstract: Provided is a switching power-supply device capable of balancing a plurality of converter blocks operated in parallel. The switching power-supply device includes a first series circuit of first and second switching elements, a second series circuit of third and fourth switching elements, which circuits are connected in parallel with a power supply, and a control circuit that turns on-and-off the first and second switching elements, alternately, with an arbitrary frequency and turns on-and-off the third and fourth switching elements, alternately, with the same frequency as the arbitrary frequency. The control circuit controls a phase difference of switching signals of the first and second series circuits.

Abstract: Provided is a highly-efficient switching power-supply device having a wide input voltage range. The switching power-supply device includes: a first series circuit including first and second switching elements and a second series circuit including third and fourth switching elements, which are connected in parallel with a power supply; a series resonance circuit including a primary coil and a capacitor connected in parallel with the second switching element; a reactor connected between a connection point of the third and fourth switching elements and the capacitor; a transformer having the primary coil and a secondary coil; and a control circuit that turns on-and-off the first and second switching elements, alternately, and turns on-and-off the third and fourth switching elements, alternately. The control circuit switches the first and second series circuits when an input voltage is low and switches only the first series circuit when the input voltage is high.

Abstract: A switching power-supply device includes: a first series circuit including a first switching element; and a second switching element, a second series circuit including a third switching element and a fourth switching element; and a control unit that, while making frequencies of switching signals of the first series circuit and the second series circuit be the same, performs control of turning on-and-off the first switching element and the second switching element, alternately, with dead time at which the first switching element and the second switching element become off and turning on-and-off the third switching element and the fourth switching element, alternately, with dead time at which the third switching element and the fourth switching element become off, wherein the control unit controls a phase difference between the switching signal of the first series circuit and the switching signal of the second series circuit.

Abstract: Provided is a switching power-supply device capable of balancing a plurality of converter blocks operated in parallel. The switching power-supply device includes a first series circuit of first and second switching elements, a second series circuit of third and fourth switching elements, which circuits are connected in parallel with a power supply, and a control circuit that turns on-and-off the first and second switching elements, alternately, with an arbitrary frequency and turns on-and-off the third and fourth switching elements, alternately, with the same frequency as the arbitrary frequency. The control circuit controls a phase difference of switching signals of the first and second series circuits.

Abstract: Provided is a highly-efficient switching power-supply device having a wide input voltage range. The switching power-supply device includes: a first series circuit including first and second switching elements and a second series circuit including third and fourth switching elements, which are connected in parallel with a power supply; a series resonance circuit including a primary coil and a capacitor connected in parallel with the second switching element; a reactor connected between a connection point of the third and fourth switching elements and the capacitor; a transformer having the primary coil and a secondary coil; and a control circuit that turns on-and-off the first and second switching elements, alternately, and turns on-and-off the third and fourth switching elements, alternately. The control circuit switches the first and second series circuits when an input voltage is low and switches only the first series circuit when the input voltage is high.

Abstract: A switching power-supply device includes: a first series circuit including a first switching element; and a second switching element, a second series circuit including a third switching element and a fourth switching element; and a control unit that, while making frequencies of switching signals of the first series circuit and the second series circuit be the same, performs control of turning on-and-off the first switching element and the second switching element, alternately, with dead time at which the first switching element and the second switching element become off and turning on-and-off the third switching element and the fourth switching element, alternately, with dead time at which the third switching element and the fourth switching element become off, wherein the control unit controls a phase difference between the switching signal of the first series circuit and the switching signal of the second series circuit.

Abstract: A switching power source apparatus has a pulse generator of a first pulse. A first resonant series circuit receives the first pulse signal and passes a current having a 90-degree phase delay with respect to the first pulse signal. The current of the first resonant series circuit turns on/off a switching element Q21. A second resonant series circuit receives the second pulse signal and passes a current having a 90-degree phase delay with respect to the second pulse signal. The current of the second resonant series circuit turns on/off a switching element Q22. The pulse generator has a third transformer T3 that has secondary windings to output the first and second pulse signals according to a voltage that is applied to the third transformer and is synchronized with drive signals for the switching elements Q11 and Q12.

Abstract: In conventional multi-output switching power supply device, power is supplied from a relatively high voltage side output to a relatively low voltage side output through a dropper circuit which generates relatively large power loss so as to improve the voltage accuracy of a non-stabilized output, so that power supply efficiency is low and heat generated from the dropper circuit is high. One DC power supply of a plurality of DC power supplies on the secondary side is a stabilized output (24 V output terminal TM3) having a voltage stabilizing means for stabilizing the output voltage by feeding back the output voltage to a primary side control circuit 4, and the rest of the DC power supplies are non-stabilized outputs (12 V output terminals TM4) not having a voltage stabilizing means for feeding back the output voltage to the primary side.

Abstract: A switching power-supply apparatus includes a first converter 3, a second converter 4, an output smoothing capacitor Co1, a series resonance circuit 1 and a control circuit 11. The first converter 3, in which switching elements Q11 and Q12 are connected to both ends of a direct-current power-supply Vin in series, and a capacitor Ci1 and a primary winding Np1 of a transformer T1 including an auxiliary winding Na1 are connected to both ends of the switching element Q12 in series, includes diodes D11 and D12 that rectify voltages generated in secondary windings Ns11 and Ns12 of the transformer T1. The second converter 4, in which switching elements Q21 and Q22 are connected to the both ends of the direct-current power-supply Vin in series, and a capacitor Ci12 and a primary winding Np2 of a transformer T2 are connected to both ends of the switching element Q22 in series, includes diodes D21 and D22 that rectify voltages generated in secondary windings Ns21 and Ns22 of the transformer T2.

Abstract: A gate driver of a switching element Q1 includes transistors Q2 and Q3 that are totem-pole-connected to both ends of a DC power source Vcc1, transistors Q4 and Q5 that are totem-pole-connected to both ends of a DC power source Vcc2 and have emitters connected to the gate of the switching element Q1, and a transformer T1 having a primary winding and a secondary winding. The primary winding is connected to a collector of one of the transistors Q1 and Q2, and through a capacitor, emitters of the transistors Q1 and Q2. The second winding is connected to bases of the transistors Q4 and Q5 and the emitters of the transistors Q4 and Q5. A maximum duty cycle of a pulse signal is determined according to a primary winding voltage of the transformer and a forward base-emitter voltage of the transistors Q4 and Q5.

Abstract: A multiple-output switching power supply unit includes: a voltage generating circuit Q1, Q2, T1a, 10a configured to generate a pulse voltage by intermittently interrupting a direct current power supply 1; a series resonance circuit including a current resonance capacitor Cri2, a primary winding P2 of a transformer T2, and a switching element Q3, the pulse voltage generated in the voltage generating circuit being applied to the series resonance circuit; a rectifying/smoothing circuit D2, C2 configured to rectify and smooth a voltage which is generated in a secondary winding S2 of the transformer, and thus to output a direct current output voltage; and a control circuit 11 configured to turn on and off the switching element based on the direct current output voltage.

Abstract: A multiple-output switching power source apparatus has a series resonant circuit connected in parallel with a switch Q2 and including a primary winding and a current resonant capacitor, a first rectifying-smoothing circuit rectifying and smoothing a voltage of a secondary winding in an ON period of the switch to provide a voltage Vo1, a series resonant circuit connected in parallel with the switch and including a primary winding and a current resonant circuit, a second rectifying-smoothing circuit rectifying and smoothing a voltage of a secondary winding in the ON period of the switch Q2 to provide a voltage Vo2, and a control circuit controlling an ON period of a switch Q1 according to the output voltage Vo1 and the ON period of the switch Q2 according to the voltage Vo2 and limit the ON period of the switch Q1 if the voltage Vo2 exceeds a predetermined voltage.

Abstract: A gate driver of a switching element Q1 includes transistors Q2 and Q3 that are totem-pole-connected to both ends of a DC power source Vcc1, transistors Q4 and Q5 that are totem-pole-connected to both ends of a DC power source Vcc2 and have emitters connected to the gate of the switching element Q1, and a transformer T1 having a primary winding and a secondary winding. The primary winding is connected to a collector of one of the transistors Q1 and Q2, and through a capacitor, emitters of the transistors Q1 and Q2. The second winding is connected to bases of the transistors Q4 and Q5 and the emitters of the transistors Q4 and Q5. A maximum duty cycle of a pulse signal is determined according to a primary winding voltage of the transformer and a forward base-emitter voltage of the transistors Q4 and Q5.

Abstract: A switching power source apparatus has a pulse generator of a first pulse. A first resonant series circuit receives the first pulse signal and passes a current having a 90-degree phase delay with respect to the first pulse signal. The current of the first resonant series circuit turns on/off a switching element Q21. A second resonant series circuit receives the second pulse signal and passes a current having a 90-degree phase delay with respect to the second pulse signal. The current of the second resonant series circuit turns on/off a switching element Q22. The pulse generator has a third transformer T3 that has secondary windings to output the first and second pulse signals according to a voltage that is applied to the third transformer and is synchronized with drive signals for the switching elements Q11 and Q12.

Abstract: A multiple-output switching power source apparatus includes a control circuit to adjust a time for applying a DC voltage to a primary winding of a transformer by turning on/off a switching element Q1, a first rectifying-smoothing circuit for a first secondary winding of the transformer, a second rectifying-smoothing circuit for a switching element Q2 to provide a second output voltage connected to an output terminal of the first rectifying-smoothing circuit through the switching element Q2, a third rectifying-smoothing circuit for a second secondary winding of the transformer and provide a third output voltage, a first end of the second secondary winding of the transformer being connected to the switching element Q2, and a control circuit 13 to adjust an ON/OFF time of the switching element Q2 according to the voltage of the first secondary winding of the transformer, the second output voltage, and the third output voltage.

Abstract: A multiple output switching power source apparatus includes first and second transformers each having a primary winding, a first secondary winding, and a second secondary winding; a first control circuit adjusting a time for applying a DC voltage to the primary winding of the first transformer; a first rectifying-smoothing circuit rectifying and smoothing a voltage generated at the first secondary winding of the first transformer and providing a first output voltage; a second control circuit adjusting a time for applying the DC voltage to the primary winding of the second transformer; a second rectifying-smoothing circuit rectifying and smoothing a voltage generated at the first secondary winding of the second transformer and providing a second output voltage; and a third rectifying-smoothing circuit rectifying and smoothing a voltage across a series winding having the second secondary windings of the first and second transformers and providing a third output voltage.

Abstract: In conventional multi-output switching power supply device, power is supplied from a relatively high voltage side output to a relatively low voltage side output through a dropper circuit which generates relatively large power loss so as to improve the voltage accuracy of a non-stabilized output, so that power supply efficiency is low and heat generated from the dropper circuit is high. One DC power supply of a plurality of DC power supplies on the secondary side is a stabilized output (24 V output terminal TM3) having a voltage stabilizing means for stabilizing the output voltage by feeding back the output voltage to a primary side control circuit 4, and the rest of the DC power supplies are non-stabilized outputs (12 V output terminals TM4) not having a voltage stabilizing means for feeding back the output voltage to the primary side.

Abstract: In a power supplying system that includes a plurality of power supply devices, each of which has a backflow prevention circuit at an output side thereof, and supplies power to a load device, a backflow prevention circuit is configured by using a hetero-junction FET (HEMT). A normally-on type GaNFET is used for the hetero-junction FET (HEMT), so that the backflow prevention circuit is further simplified.