Abstract: A bidirectional DC-DC converter includes a series circuit of a first winding of a first reactor, a second reactor, and a first switch connected to both ends of a first DC power source, a series circuit of a second switch and a second DC power source connected to both ends of the first switch, a series circuit of a second winding of the first reactor, a third reactor, a first selector switch, and a first diode connected to both ends of a series circuit of the second reactor and the first switch, a series circuit of a second selector switch, a second diode, and the second DC power source connected to both ends of a series circuit of the first selector switch and first diode, and a controller turning on/off the switches and the selector switches.

Abstract: A gate driving circuit is provided which is capable of alleviating the effect of a switching noise generated when an IGBT is turned on/off or a common mode noise on a gate driving signal. The gate driving circuit, a primary side and a secondary side thereof being insulated from each other by a pulse transformer; the primary side of the pulse transformer being grounded to a first ground potential point; the secondary side of the pulse transformer being grounded to a second ground potential point insulated from the first ground potential point; and a gate driving signal generated in a secondary winding of the pulse transformer being outputted through a receiver having impedance matching resistors on the input side, includes an electrostatic shield plate between a primary winding of the pulse transformer and the secondary winding, the electrostatic shield plate being grounded to the second ground potential point.

Abstract: A DC-DC converter includes a coupling transformer that has windings 11 and 12, switches (Tr1, Tr2) that are connected through the windings to both ends of a DC power source Vi, a series circuit that is connected to both ends of each of the switches and includes a diode and a smoothing capacitor, and a controller 100 that alternately turns on the switches Tr1 and Tr2 and simultaneously turns on the switches Tr1 and Tr2 for a predetermined overlapping period on every half cycle. The coupling transformer 1 includes an I-shaped core 4, two E-shaped cores 2 and 3 holding the I-shaped core 4 between them, and a gap 5 formed between each of center legs 2a and 3a of the E-shaped cores 2 and 3 and the I-shaped core 4. The windings 11 and 12 are wound around the I-shaped core 4.

Abstract: A bidirectional DC-DC converter includes a series circuit of a first winding of a first reactor, a second reactor, and a first switch connected to both ends of a first DC power source, a series circuit of a second switch and a second DC power source connected to both ends of the first switch, a series circuit of a second winding of the first reactor, a third reactor, a first selector switch, and a first diode connected to both ends of a series circuit of the second reactor and the first switch, a series circuit of a second selector switch, a second diode, and the second DC power source connected to both ends of a series circuit of the first selector switch and first diode, and a controller turning on/off the switches and the selector switches.

Abstract: A gate driving circuit is provided which is capable of alleviating the effect of a switching noise generated when an IGBT is turned on/off or a common mode noise on a gate driving signal. The gate driving circuit, a primary side and a secondary side thereof being insulated from each other by a pulse transformer; the primary side of the pulse transformer being grounded to a first ground potential point; the secondary side of the pulse transformer being grounded to a second ground potential point insulated from the first ground potential point; and a gate driving signal generated in a secondary winding of the pulse transformer being outputted through a receiver having impedance matching resistors on the input side, includes an electrostatic shield plate between a primary winding of the pulse transformer and the secondary winding, the electrostatic shield plate being grounded to the second ground potential point.

Abstract: The present invention includes: a main switch Tr1 connected to two ends of a DC power supply Vi via a first primary winding 1a and a second primary winding 1b, connected to the first primary winding in series, of a transformer T1; a series circuit connected to the two ends of the main switch, and including a reactor L1, a diode D1, a smoothing capacitor Co and a hoist winding 1c connected to the second primary winding in series; a series circuit connected to the two ends of the main switch, and including a diode D2, a diode D3 and the smoothing capacitor; a control circuit 10 to turn on and off the main switch; a soft-switching circuit Da1, Tra1, La1, Ca1 to cause the main switch to perform a soft-switching operation each time the main switch turns on; and a switching control circuit 20 to switch the soft-switching circuit between operating and non-operating modes in accordance with the state of a load.

Abstract: In order to achieve an object to reduce a surge voltage and suppress noise generation, the present invention provides a DC-DC converter with a snubber circuit, which boosts a voltage Vi of a DC power supply. The snubber circuit includes: a series circuit connected to both ends of a smoothing capacitor Co and including a snubber capacitor Cs and a snubber resistor Rs; a snubber diode Ds1 connected to a node at which the snubber capacitor Cs and the snubber resistor Rs are connected, and to a node at which a reactor Lr1 and an additional winding 1b of a transformer T1 are connected; and a snubber diode Ds2 connected to the node at which the snubber capacitor Cs and the snubber resistor Rs are connected, and to a node at which a reactor Lr2 and an additional winding 2b of a transformer T2 are connected.

Abstract: A resonant power conversion apparatus includes a transformer T1 having a primary winding n1, a secondary winding n2, a tertiary winding n3, and a reset winding nR, a series circuit of switches S1 and S2, a capacitor Cr1 and diode D1 to the switch S1, a capacitor Cr2 and diode D2 to the switch S2, a series circuit of the winding n1 and a diode Dn1, a series circuit of the winding nR and a diode DR, a reactor Lr connected between a connection point of the switches S1 and S2 and a connection point of the windings n2 and n3, a switch S10 connected between the DC power source and the winding n2, a switch S20 connected between the DC power source and the winding n3, and a controller 10 configured to perform a zero-voltage switching operation of the switches S1 and S2.

Abstract: A diesel engine start-up assisting device includes a plurality of first-and-second switching elements 11a to 11d between a common direct-current power source 1 and a plurality of electrical load 3a to 3d, a plurality of start-up assisting main parts 10a to 10d and an input-and-output unit 7. The diesel engine start-up assisting device is constructed so as to enable start-up of a diesel engine when power distribution is applied to at least one of the electrical loads 3a to 3d. In arrangement, the first-and-second switching elements 11a to 11d, the start-up assisting main parts 10a to 10d and the input-and-output unit 7 are integrated into one package having a lead frame. Defining the first-and-second switching element as a pair of switching elements, the first-and-second switching elements 11a to 11d are arranged in parallel with each other on the lead frame, and the lead frame has a notch part formed between two pairs of switching elements adjoined to each other.

Abstract: A semiconductor device (10) includes: an base substance (15) having a ferromagnetic material; a first semiconductor chip (11) and a second semiconductor chip (12) installed on the base substance (15); a first coil (131) installed on the base substance (15) and electrically connected to the first semiconductor chip (11); a second coil (132) installed on the first coil (131), electromagnetically connected to the first coil (131) and electrically connected to the second semiconductor chip (12); a transformer assembly (18) made of a ferromagnetic material and installed on the base substance (15), and a sealing body. The transformer assembly (18) includes a first core section (181), a first side shield section (182), and a first upper shield section (183).

Abstract: The present invention provides a DC-DC converter including a first series circuit connected to both ends of a first switch and formed of a winding of a first transformer, a first reactor, a first diode, and a smoothing capacitor, a second diode connected to a connection point of a primary winding of the first transformer, the winding of the first transformer and the first switch, and to one end of the smoothing capacitor, a second series circuit connected to both ends of a second switch and formed of a winding of a second transformer, a second reactor, a third diode, and the smoothing capacitor, a fourth diode connected to a connection point of a primary winding of the second transformer, the winding of the second transformer and the second switch, and to the one end of the smoothing capacitor, a third reactor connected to both ends of a series circuit of a secondary winding of the first transformer and a secondary winding of the second transformer, and a control circuit which alternately turns on the first s

Abstract: The present invention includes: a main switch Tr1 connected to two ends of a DC power supply Vi via a first primary winding 1a and a second primary winding 1b, connected to the first primary winding in series, of a transformer T1; a series circuit connected to the two ends of the main switch, and including a reactor L1, a diode D1, a smoothing capacitor Co and a hoist winding 1c connected to the second primary winding in series; a series circuit connected to the two ends of the main switch, and including a diode D2, a diode D3 and the smoothing capacitor; a control circuit 10 to turn on and off the main switch; a soft-switching circuit Da1, Tra1, La1, Ca1 to cause the main switch to perform a soft-switching operation each time the main switch turns on; and a switching control circuit 20 to switch the soft-switching circuit between operating and non-operating modes in accordance with the state of a load.

Abstract: A semiconductor device (10) includes: an base substance (15) having a ferromagnetic material; a first semiconductor chip (11) and a second semiconductor chip (12) installed on the base substance (15); a first coil (131) installed on the base substance (15) and electrically connected to the first semiconductor chip (11); a second coil (132) installed on the first coil (131), electromagnetically connected to the first coil (131) and electrically connected to the second semiconductor chip (12); a transformer assembly (18) made of a ferromagnetic material and installed on the base substance (15), and a sealing body. The transformer assembly (18) includes a first core section (181), a first side shield section (182), and a first upper shield section (183).

Abstract: In order to achieve an object to reduce a surge voltage and suppress noise generation, the present invention provides a DC-DC converter with a snubber circuit, which boosts a voltage Vi of a DC power supply. The snubber circuit includes: a series circuit connected to both ends of a smoothing capacitor Co and including a snubber capacitor Cs and a snubber resistor Rs; a snubber diode Ds1 connected to a node at which the snubber capacitor Cs and the snubber resistor Rs are connected, and to a node at which a reactor Lr1 and an additional winding 1b of a transformer T1 are connected; and a snubber diode Ds2 connected to the node at which the snubber capacitor Cs and the snubber resistor Rs are connected, and to a node at which a reactor Lr2 and an additional winding 2b of a transformer T2 are connected.

Abstract: A current-mode controlled DC-DC converter includes a comparator comparing a first or second current detection signal with a first or second reference current that is based on an error voltage of a voltage detection signal, a pulse generator generating a first pulse signal whose ON time is longer than an interval between when the second current detection signal reaches a minimum value and when the second current detection signal reaches the second reference current, a pulse generator generating a second pulse signal whose ON time is longer than an interval between when the first current detection signal reaches a minimum value and when the first current detection signal reaches the first reference current, the second pulse signal being behind the first pulse signal by a half period, and a PWM circuit generating a first or second PWM signal according to the pulse signal and an output signal from the comparator, thereby turning on/off a switch.

Abstract: A resonant power conversion apparatus includes a transformer T1 having a primary winding n1, a secondary winding n2, a tertiary winding n3, and a reset winding nR, a series circuit of switches S1 and S2, a capacitor Cr1 and diode D1 to the switch S1, a capacitor Cr2 and diode D2 to the switch S2, a series circuit of the winding n1 and a diode Dn1, a series circuit of the winding nR and a diode DR, a reactor Lr connected between a connection point of the switches S1 and S2 and a connection point of the windings n2 and n3, a switch S10 connected between the DC power source and the winding n2, a switch S20 connected between the DC power source and the winding n3, and a controller 10 configured to perform a zero-voltage switching operation of the switches S1 and S2.

Abstract: A diesel engine start-up assisting device includes a plurality of first-and-second switching elements 11a to 11d between a common direct-current power source 1 and a plurality of electrical load 3a to 3d, a plurality of start-up assisting main parts 10a to 10d and an input-and-output unit 7. The diesel engine start-up assisting device is constructed so as to enable start-up of a diesel engine when power distribution is applied to at least one of the electrical loads 3a to 3d. In arrangement, the first-and-second switching elements 11a to 11d, the start-up assisting main parts 10a to 10d and the input-and-output unit 7 are integrated into one package having a lead frame. Defining the first-and-second switching element as a pair of switching elements, the first-and-second switching elements 11a to 11d are arranged in parallel with each other on the lead frame, and the lead frame has a notch part formed between two pairs of switching elements adjoined to each other.

Abstract: The present invention provides a DC-DC converter including a first series circuit connected to both ends of a first switch and formed of a winding of a first transformer, a first reactor, a first diode, and a smoothing capacitor, a second diode connected to a connection point of a primary winding of the first transformer, the winding of the first transformer and the first switch, and to one end of the smoothing capacitor, a second series circuit connected to both ends of a second switch and formed of a winding of a second transformer, a second reactor, a third diode, and the smoothing capacitor, a fourth diode connected to a connection point of a primary winding of the second transformer, the winding of the second transformer and the second switch, and to the one end of the smoothing capacitor, a third reactor connected to both ends of a series circuit of a secondary winding of the first transformer and a secondary winding of the second transformer, and a control circuit which alternately turns on the first s

Abstract: A bi-directional DC-DC converter includes a first series circuit connected to ends of a first DC power source and including a first winding of a first reactor and a first switch; a second series circuit connected to ends of the first switch and including a second winding of the first reactor, a second reactor, a second switch, a third switch, and a second DC power source; a third series circuit connected to the ends of the first switch and including a fourth switch and the second DC power source; and a control circuit configured to turn on/off the switches and thereby carry out step-up and step-down operations between the first and second DC power sources.

Abstract: A current-mode controlled DC-DC converter includes a comparator comparing a first or second current detection signal with a first or second reference current that is based on an error voltage of a voltage detection signal, a pulse generator generating a first pulse signal whose ON time is longer than an interval between when the second current detection signal reaches a minimum value and when the second current detection signal reaches the second reference current, a pulse generator generating a second pulse signal whose ON time is longer than an interval between when the first current detection signal reaches a minimum value and when the first current detection signal reaches the first reference current, the second pulse signal being behind the first pulse signal by a half period, and a PWM circuit generating a first or second PWM signal according to the pulse signal and an output signal from the comparator, thereby turning on/off a switch.