Abstract: An image forming apparatus includes a heat roller comprising a heater and configured to generate heat to fix a toner image on a print medium, a system controller configured to transmit, when printing is performed on a print medium, a control signal that indicates when power is to be supplied to the heater, and a heater control circuit configured to control amount of power supplied to the heater according to the control signal, a target temperature of the heater, and a current temperature of the heater. When printing is to be continuously performed on a plurality of print media, the system controller transmits the control signal to the heater control circuit a first predetermined time before start of printing.

Abstract: An image forming apparatus includes a heat roller comprising a heater and configured to generate heat to fix a toner image on a print medium, a system controller configured to transmit, when printing is performed on a print medium, a control signal that indicates when power is to be supplied to the heater, and a heater control circuit configured to control amount of power supplied to the heater according to the control signal, a target temperature of the heater, and a current temperature of the heater. When printing is to be continuously performed on a plurality of print media, the system controller transmits the control signal to the heater control circuit a first predetermined time before start of printing.

Abstract: A power converter includes a first circuit including an inductor and configured to convert an input voltage into a first voltage, a second circuit including a transformer and configured to convert the first voltage input to the insulating transformer to a second voltage, a control circuit configured to control the first circuit, a first power supply circuit including a first winding magnetically coupled to the inductor and configured to output a third voltage generated by the first winding to the first control circuit, and a second power supply circuit including a second winding magnetically coupled to the transformer and configured to output a fourth voltage generated by the second winding to the first control circuit. When the second voltage is not output the third voltage is output to the control circuit, and when the second voltage is output the fourth voltage is output to the control circuit.

Abstract: A power conversion device includes first and second current detectors. A coil is connected a first power terminal through the first and second current detectors. A first switch has a source terminal connected to the coil and a second semiconductor switch has a drain terminal connected to the coil. A first diode is connected between a drain terminal of the first semiconductor switch and a second power supply terminal. A second diode is connected between a source terminal of the second semiconductor switch and the second power terminal. A capacitor is connected in parallel with the first and second diodes. A control circuit is configured to turn the first and second semiconductor switches on or off based on current detections of the first and second current detectors.

Abstract: A power supply circuit includes a thermoelectric conversion element configured to generate electric power when it is differentially heated, an adjustable current circuit configured to draw a current from the thermoelectric conversion element and resultantly output a constant current over a period of time, a voltage conversion circuit configured to output a voltage based on the current output by the adjustable current circuit, and a control circuit configured to control the adjustable current circuit to change a target value of the constant current output by the adjustable current circuit.

Abstract: According to one embodiment, a power converting device includes a rectifier bridge configured to pulsate an AC voltage to generate a pulsating voltage, a first smoothing capacitor configured to smooth the pulsating voltage to generate a DC voltage, a primary winding connected to the first smoothing capacitor, a switch circuit configured to switch the DC voltage supplied from the first smoothing capacitor to the primary winding, and a first discharge circuit. The first discharge circuit includes a first discharge resistor configured to discharge electric charges remaining on the first smoothing capacitor and a first switch element configured to release the first discharge resistor from the first smoothing capacitor if the AC voltage is supplied and to connect the first discharge resistor to the first smoothing capacitor if the AC voltage is not supplied and the electric charges remain on the first smoothing capacitor.

Abstract: A power supply circuit includes a thermoelectric conversion element configured to generate electric power when it is differentially heated, an adjustable current circuit configured to draw a current from the thermoelectric conversion element and resultantly output a constant current over a period of time, a voltage conversion circuit configured to output a voltage based on the current output by the adjustable current circuit, and a control circuit configured to control the adjustable current circuit to change a target value of the constant current output by the adjustable current circuit.

Abstract: A power supply circuit includes a thermoelectric conversion element configured to generate electric power when it is differentially heated, an adjustable current circuit configured to draw a current from the thermoelectric conversion element and resultantly output a constant current over a period of time, a voltage conversion circuit configured to output a voltage based on the current output by the adjustable current circuit, and a control circuit configured to control the adjustable current circuit to change a target value of the constant current output by the adjustable current circuit.

Abstract: According to one embodiment, a power converting device includes a rectifier bridge configured to pulsate an AC voltage to generate a pulsating voltage, a first smoothing capacitor configured to smooth the pulsating voltage to generate a DC voltage, a primary winding connected to the first smoothing capacitor, a switch circuit configured to switch the DC voltage supplied from the first smoothing capacitor to the primary winding, and a first discharge circuit. The first discharge circuit includes a first discharge resistor configured to discharge electric charges remaining on the first smoothing capacitor and a first switch element configured to release the first discharge resistor from the first smoothing capacitor if the AC voltage is supplied and to connect the first discharge resistor to the first smoothing capacitor if the AC voltage is not supplied and the electric charges remain on the first smoothing capacitor.

Abstract: A power conversion circuit encompasses a rectifying circuit, a first switching element, a second switching element, a third switching element, a fourth switching element, a series connection of a capacitor and an induction coil, a voltage detection section and a control circuit. The series connection of the capacitor and the induction coil is connected between a first connection point and a second connection point. The control circuit switches a mode between a first operation mode in which pulse signals are input to the first switching element to the fourth switching element and a second operation mode in which the pulse signals are input to the first switching element and the second switching element, the third switching element is turned off and the fourth switching element is turned on.

Abstract: A power conversion device includes a low-pass filter, a second inductor, a first switch, a third switch, a second capacitor, and a controller. The low-pass filter is configured for direct coupling to an alternating current power source. The first switch is connected in series with a second switch, a first connection point. The third switch is connected in series with a fourth switch, a second connection point. The second capacitor is coupled to the first switch, the second switch, the third switch, and the fourth switch. The controller turns on and off the first, the second, the third, and the fourth switches based on a voltage of the alternating current power source directly coupled to the low-pass filter, a circuit current through the second inductor, a voltage across the second capacitor, and an average output voltage of the load circuit.

Abstract: A power supply circuit includes a thermoelectric conversion element configured to generate electric power when it is differentially heated, an adjustable current circuit configured to draw a current from the thermoelectric conversion element and resultantly output a constant current over a period of time, a voltage conversion circuit configured to output a voltage based on the current output by the adjustable current circuit, and a control circuit configured to control the adjustable current circuit to change a target value of the constant current output by the adjustable current circuit.

Abstract: A power supply circuit includes a thermoelectric conversion element configured to generate electric power when it is differentially heated, an adjustable current circuit configured to draw a current from the thermoelectric conversion element and resultantly output a constant current over a period of time, a voltage conversion circuit configured to output a voltage based on the current output by the adjustable current circuit, and a control circuit configured to control the adjustable current circuit to change a target value of the constant current output by the adjustable current circuit.

Abstract: According to one embodiment, a controller determines the polarity of the input voltage detected by an input voltage detector. Then, when the polarity of the input voltage is positive, the first switch is subject to pulse driving, and when the polarity of the input voltage is negative, the second switch is subject to pulse driving, where the pulse driving is carried out at an on/off timing determined on the basis of the respective detection outputs of an input voltage detector, an input current detector, an output voltage detector, and an output current detector.

Abstract: A power conversion circuit comprises a heating member, a series connection that connects a capacitor and an induction coil, and a control circuit. The heating member heats a toner image formed on a print medium. The series connection connecting a capacitor and an induction coil that generates a magnetic field to the heating member is connected between a first connection point and a second connection point. The control circuit switches, based on the voltage detected by the voltage detection section, between a first operation mode and a second operation mode, wherein in first operation mode, pulse signals are input to the first to fourth switching elements, and in second operation mode, pulse signals are input to first switching element and the second switching element, third switching element is turned off, and fourth switching element is turned on.

Abstract: There is provided a non-contact power transmission apparatus which can supply stable power from a power transmitting side to a power receiving side even if a load is changed. The power transmission apparatus transmits power from a power transmitting device to a power receiving device in a non-contact manner. The power transmitting device includes a series circuit which is connected to a direct-current power source, and includes a parallel resonance circuit including a first capacitor and a first inductor, and a switch element, a drive source to drive on or off the switch element, and a first series resonance circuit connected to a connection point between the parallel resonance circuit and the switch element and including a second inductor, a second capacitor and a power transmission coil.

Abstract: A power conversion circuit encompasses a rectifying circuit, a first switching element, a second switching element, a third switching element, a fourth switching element, a series connection of a capacitor and an induction coil, a voltage detection section and a control circuit. The series connection of the capacitor and the induction coil is connected between a first connection point and a second connection point. The control circuit switches a mode between a first operation mode in which pulse signals are input to the first switching element to the fourth switching element and a second operation mode in which the pulse signals are input to the first switching element and the second switching element, the third switching element is turned off and the fourth switching element is turned on.

Abstract: According to one embodiment, a power conversion device includes a first switch serially connected to a second switch, a first diode serially connected to a second diode, the first switch and the first diode connected to the second switch and the second diode, an AC power supply and an inductor serially connected to a connection point between the first switch and the second switch and a connection point between the first diode and the second diode, a capacitor serially connected to ends of the first diode and the second diode connected, and a potential difference between the ends of the capacitor is used as an output voltage. The control unit supplies a pulse signal to the first switch and the second switch to provide a sinusoidal current through the AC power supply, based on a detected power supply voltage, a detected circuit current, and a detected capacitor voltage.

Abstract: A power conversion circuit encompasses a rectifying circuit, a first switching element, a second switching element, a third switching element, a fourth switching element, a series connection of a capacitor and an induction coil, a voltage detection section and a control circuit. The series connection of the capacitor and the induction coil is connected between a first connection point and a second connection point. The control circuit switches a mode between a first operation mode in which pulse signals are input to the first switching element to the fourth switching element and a second operation mode in which the pulse signals are input to the first switching element and the second switching element, the third switching element is turned off and the fourth switching element is turned on.

Abstract: A power conversion circuit comprises a rectifying circuit, a first switching element, a second switching element, a third switching element, a fourth switching element, a series connection of a capacitor and an induction coil, a fifth switching element, a voltage detection section and a control circuit. The rectifying circuit rectifies an AC power supply. One side of the series connection of the capacitor and the induction coil is connected to a first connection point between the first switching element and the second switching element. The fifth switching element switches a state between a first connection state and a second connection state. The control circuit switches the fifth switching element between the first connection state and the second connection state based on the detection voltage by the voltage detection section and inputs a pulse signal to the first to the fourth switching elements.