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US 11,777,410 B2Granted
Power supply apparatus for stabilizing power supply capability of auxiliary winding provided in transformer
AssigneeCanon Kabushiki Kaisha
InventorTakumi Moriyama
Life of this patent
Estimating the term…
Abstract
A protection circuit protects a rectifier circuit from an inrush current inputted to a smoothing circuit. A short-circuiting circuit does not short the protection circuit while an inrush current may occur, and shorts it while an inrush current does not occur. A transformer has a primary winding, a secondary winding and an auxiliary winding. A delay circuit delays a timing at which an operation of a load connected to the auxiliary winding is started with respect to a timing at which an operation of the short-circuiting circuit is started. A rectifying and smoothing circuit generates an output voltage by rectifying and smoothing the secondary side voltage. The short-circuiting circuit is driven by the output voltage.
Claims17
A power supply apparatus comprising:
- a rectifier circuit configured to rectify alternating current inputted from an alternating power supply;
- a smoothing circuit configured to smooth output of the rectifier circuit:
- a protection circuit configured to protect the rectifier circuit from an inrush current inputted to the smoothing circuit;
- a short-circuiting circuit configured to not short circuit the protection circuit in a period in which an inrush current may occur, and configured to short circuit the protection circuit in a period in which an inrush current does not occur;
- a transformer having a primary winding to which a primary side voltage generated by the smoothing circuit is applied, a secondary winding for generating a secondary side voltage corresponding to a predetermined winding ratio, and an auxiliary winding magnetically coupled to the primary winding;
- a delay circuit configured to delay a timing at which an operation of a load connected to the auxiliary winding is started with respect to an operation of a timing at which the short-circuiting circuit is started;
- a switching element configured to switch a current that flows through the primary winding so that the secondary side voltage becomes a target voltage;
- and
- a rectifying and smoothing circuit configured to generate an output voltage by rectifying and smoothing the secondary side voltage,
- wherein the short-circuiting circuit is driven by the output voltage.
7 more elements
An image forming apparatus comprising:
- a power supply apparatus;
- and
- an image forming unit configured to operate by being supplied with an output voltage from the power supply apparatus, and form an image on a recording medium,
- wherein the power supply apparatus comprises:
- a rectifier circuit configured to rectify alternating current inputted from an alternating power supply;
- a smoothing circuit configured to smooth output of the rectifier circuit:
- a protection circuit configured to protect the rectifier circuit from an inrush current inputted to the smoothing circuit;
- a short-circuiting circuit configured to not short circuit the protection circuit in a period in which an inrush current may occur, and configured to short circuit the protection circuit in a period in which an inrush current does not occur;
- a transformer having a primary winding to which a primary side voltage generated by a smoothing circuit is applied, a secondary winding for generating a secondary side voltage corresponding to a predetermined winding ratio, and an auxiliary winding magnetically coupled to the primary winding;
- a delay circuit configured to delay a timing at which an operation of a load connected to the auxiliary winding is started with respect to an operation of a timing at which the short-circuiting circuit is started;
- a switching element configured to switch a current that flows through the primary winding so that the secondary side voltage becomes a target voltage;
- and
- a rectifying and smoothing circuit configured to generate an output voltage by rectifying and smoothing the secondary side voltage,
- wherein the short-circuiting circuit is driven by the output voltage.
11 more elements
A power supply apparatus comprising:
- a rectifier circuit configured to rectify alternating current inputted from an alternating power supply;
- a smoothing circuit configured to smooth output of the rectifier circuit:
- a transformer having a primary winding to which a primary side voltage generated by the smoothing circuit is applied, a secondary winding for generating a secondary side voltage corresponding to a predetermined winding ratio, and an auxiliary winding magnetically coupled to the primary winding;
- a switching element configured to switch a current that flows through the primary winding so that the secondary side voltage becomes a target voltage;
- a rectifying and smoothing circuit configured to generate an output voltage by rectifying and smoothing the secondary side voltage;
- and
- a relay, provided on a primary side of the transformer and configured to be driven by the output voltage, and which becomes a part of a load of a secondary side of the transformer,
- wherein in a case where the relay becomes on by the output voltage being used as a voltage for turning the relay on, the load of the secondary side of the transformer increases, and a power supply capability of the auxiliary winding increases thereby.
5 more elements
Dependencies are inferred from the claim text.