Power conversion circuit
AssigneesKabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
InventorYutaka Usami
Life of this patent
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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.
Claims15
A power conversion circuit, comprising:
- a rectifying circuit configured to rectify an AC power supply;
- a first switching element connected to a positive terminal of an output terminal of the rectifying circuit;
- a second switching element connected between the first switching element and a negative terminal of the output terminal of the rectifying circuit;
- a third switching element connected to the positive terminal of the output terminal of the rectifying circuit;
- a fourth switching element connected between the third switching element and the negative terminal of the output terminal of the rectifying circuit;
- a series connection of a capacitor and an induction coil connected between a first connection point between the first switching element and the second switching element and a second connection point between the third switching element and the fourth switching element;
- a voltage detection section configured to detect a voltage of the AC power supply;
- and
- a control circuit configured to switch 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, and wherein switching between the first operation mode and the second operation mode is according to a relationship between the detected voltage and a preset upper limit value and a preset lower limit value.
An image forming apparatus, comprising:
- a power conversion circuit, comprising:
- a rectifying circuit configured to rectify an AC power supply;
- a first switching element connected to a positive terminal of an output terminal of the rectifying circuit;
- a second switching element connected between the first switching element and a negative terminal of the output terminal of the rectifying circuit;
- a third switching element connected to the positive terminal of the output terminal of the rectifying circuit;
- a fourth switching element connected between the third switching element and the negative terminal of the output terminal of the rectifying circuit;
- a series connection of a capacitor and an induction coil connected between a first connection point between the first switching element and the second switching element and a second connection point between the third switching element and the fourth switching element;
- a voltage detection section configured to detect a voltage of the AC power supply;
- and
- a control circuit configured to switch 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, and wherein switching between the first operation mode and the second operation mode is according to a relationship between the detected voltage and a preset upper limit value and a preset lower limit value.
A power conversion method in a circuit comprising a first switching element connected to a positive terminal of an output terminal of a rectifying circuit, a second switching element connected between the first switching element and a negative terminal of the output terminal of the rectifying circuit, a third switching element connected to the positive terminal of the output terminal of the rectifying circuit, a fourth switching element connected between the third switching element and the negative terminal of the output terminal of the rectifying circuit, and a series connection of a capacitor and an induction coil connected between a first connection point between the first switching element and the second switching element and a second connection point between the third switching element and the fourth switching element, comprising:
- rectifying an AC power supply;
- detecting a voltage of the AC power supply;
- and
- switching 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, and wherein switching between the first operation mode and the second operation mode is according to a relationship between the detected voltage and a preset upper limit value and a preset lower limit value.
Dependencies are inferred from the claim text.