POWER SUPPLY SYSTEM AND IMAGE FORMING APPARATUS HAVING POWER SUPPLY SYSTEM
First Claim
1. A power supply system comprising:
- a switching power supply configured to rectify and smooth an alternating current voltage of an alternating current power supply and generate a predetermined direct current voltage;
a first capacitor including a first electrode and a second electrode, the first electrode being connected to one end of the alternating current power supply;
a second capacitor including a third electrode and a fourth electrode, the third electrode being connected to the other end of the alternating current power supply;
a rectification circuit configured to rectify an alternating current voltage applied to the first and second capacitors, the rectification circuit including an output line connected with an output line of the switching power supply;
a backflow regulation element that is provided on the output line of the rectification circuit and is configured to regulate backflow of current from the switching power supply towards the rectification circuit;
a signal generation circuit connected to the output line of the rectification circuit, the signal generation circuit configured to generate a detection signal corresponding to a zero cross point of the alternating current power supply based on an output of the rectification circuit;
a power supply line positioned at a more downstream side than the backflow regulation element and connected to the output line of the switching power supply and the output line of the rectification circuit;
an electricity storage unit connected to the power supply line;
a voltage limit element configured to limit a voltage of the output line of the rectification circuit to be lower than a voltage of the power supply line, anda control unit that is positioned at a more downstream side than the electricity storage unit, power being fed to the control unit through the power supply line,wherein the control unit is configured to detect a zero cross point based on the detection signal.
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Accused Products
Abstract
A power supply system includes: a switching power supply generating a voltage from an alternating current power supply; capacitors connected to the alternating current power supply; a rectification circuit configured to rectify an alternating current voltage applied to the capacitors; a backflow regulation regulating backflow of current from the switching power supply; a signal generation circuit generating a detection signal corresponding to a zero cross point of the alternating current power supply; a power supply line connected to the switching power supply and the rectification circuit; an electricity storage unit connected to the power supply line; a voltage limit element configured to limit a voltage of the output line of the rectification circuit, and a control unit, power being fed to the control unit through the power supply line. The control unit is configured to detect a zero cross point based on the detection signal.
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Citations
10 Claims
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1. A power supply system comprising:
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a switching power supply configured to rectify and smooth an alternating current voltage of an alternating current power supply and generate a predetermined direct current voltage; a first capacitor including a first electrode and a second electrode, the first electrode being connected to one end of the alternating current power supply; a second capacitor including a third electrode and a fourth electrode, the third electrode being connected to the other end of the alternating current power supply; a rectification circuit configured to rectify an alternating current voltage applied to the first and second capacitors, the rectification circuit including an output line connected with an output line of the switching power supply; a backflow regulation element that is provided on the output line of the rectification circuit and is configured to regulate backflow of current from the switching power supply towards the rectification circuit; a signal generation circuit connected to the output line of the rectification circuit, the signal generation circuit configured to generate a detection signal corresponding to a zero cross point of the alternating current power supply based on an output of the rectification circuit; a power supply line positioned at a more downstream side than the backflow regulation element and connected to the output line of the switching power supply and the output line of the rectification circuit; an electricity storage unit connected to the power supply line; a voltage limit element configured to limit a voltage of the output line of the rectification circuit to be lower than a voltage of the power supply line, and a control unit that is positioned at a more downstream side than the electricity storage unit, power being fed to the control unit through the power supply line, wherein the control unit is configured to detect a zero cross point based on the detection signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An image forming apparatus comprising:
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a power supply system comprising; a switching power supply configured to rectify and smooth an alternating current voltage of an alternating current power supply and generate a predetermined direct current voltage; a first capacitor including a first electrode and a second electrode, the first electrode being connected to one end of the alternating current power supply; a second capacitor including a third electrode and a fourth electrode, the third electrode being connected to the other end of the alternating current power supply; a rectification circuit configured to rectify an alternating current voltage applied to the first and second capacitors, the rectification circuit including an output line connected with an output line of the switching power supply; a backflow regulation element that is provided on the output line of the rectification circuit and is configured to regulate backflow of current from the switching power supply towards the rectification circuit; a signal generation circuit connected to the output line of the rectification circuit, the signal generation circuit configured to generate a detection signal corresponding to a zero cross point of the alternating current power supply based on an output of the rectification circuit; a power supply line positioned at a more downstream side than the backflow regulation element and connected to the output line of the switching power supply and the output line of the rectification circuit; an electricity storage unit connected to the power supply line; a voltage limit element configured to limit a voltage of the output line of the rectification circuit to be lower than a voltage of the power supply line, and a control unit that is positioned at a more downstream side than the electricity storage unit, power being fed to the control unit through the power supply line; and an image forming unit that forms an image, wherein the control unit is configured to detect a zero cross point based on the detection signal, and control the image forming unit by using the detection of the zero cross point. - View Dependent Claims (10)
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Specification