Power supply circuit and image forming apparatus
First Claim
1. A power supply circuit comprising:
- a bridge circuit having a first switching element connected to a first direct-current power supply and a second switching element connected in series with the first switching element, and configured to output a voltage, in accordance with switching of the first switching element and of the second switching element, to a load;
first and second drive circuits configured to drive the first and second switching elements, respectively, so that the first and second switching elements alternatingly enter an on state in accordance with an input pulse signal;
a capacitor connected between the first drive circuit and an output terminal of the bridge circuit, and configured to generate a charge voltage used for driving of the first switching element by the first drive circuit, in accordance with charging by being supplied with a charging current from a second direct-current power supply while the first switching element is in an off state;
an inductance component for noise suppression provided in a path in which the charging current flows; and
a voltage limit element connected in parallel with the inductance component, and configured to limit a voltage that occurs at the inductance component.
1 Assignment
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Accused Products
Abstract
A half bridge circuit of a class-D amplifier outputs a voltage in accordance with switching of a first switching element and of a second switching element, to a load. A high side gate drive circuit and a low side gate drive circuit respectively drive the first and second switching elements. A bootstrap capacitor connected between the high side gate drive circuit and an output terminal of the half bridge circuit is charged by a charging current from a second direct-current power supply while the first switching element is off. An inductance component for noise suppression, and a voltage limit element that is connected in parallel with the inductance component and is for limiting a voltage that occurs at the inductance component, are provided on a path in which the charging current flows.
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Citations
12 Claims
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1. A power supply circuit comprising:
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a bridge circuit having a first switching element connected to a first direct-current power supply and a second switching element connected in series with the first switching element, and configured to output a voltage, in accordance with switching of the first switching element and of the second switching element, to a load; first and second drive circuits configured to drive the first and second switching elements, respectively, so that the first and second switching elements alternatingly enter an on state in accordance with an input pulse signal; a capacitor connected between the first drive circuit and an output terminal of the bridge circuit, and configured to generate a charge voltage used for driving of the first switching element by the first drive circuit, in accordance with charging by being supplied with a charging current from a second direct-current power supply while the first switching element is in an off state; an inductance component for noise suppression provided in a path in which the charging current flows; and a voltage limit element connected in parallel with the inductance component, and configured to limit a voltage that occurs at the inductance component. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An image forming apparatus comprising:
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(A) an image formation unit configured to form an image on a recording material; and (B) a power supply circuit configured to supply a voltage to the image formation unit, wherein the power supply circuit comprises; (a) a bridge circuit having a first switching element connected to a first direct-current power supply and a second switching element connected in series with the first switching element, and configured to output a voltage, in accordance with switching of the first switching element and of the second switching element, to a load; (b) first and second drive circuits configured to drive the first and second switching elements, respectively, so that the first and second switching elements alternatingly enter an on state in accordance with an input pulse signal; (c) a capacitor connected between the first drive circuit and an output terminal of the bridge circuit, and configured to generate a charge voltage used for driving of the first switching element by the first drive circuit in accordance with charging by being supplied with a charging current from a second direct-current power supply while the first switching element is in an off state; an inductance component for noise suppression provided in a path in which the charging current flows; and a voltage limit element connected in parallel with the inductance component, and configured to limit a voltage that occurs at the inductance component. - View Dependent Claims (12)
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Specification