Power source apparatus and electric device

Patent metadata

Field	Value
Publication number	US-2016294273-A1
Application number	US-201415036913-A
Country	US
Kind code	A1
Filing date	Apr 10, 2014
Priority date	Nov 26, 2013
Publication date	Oct 6, 2016
Grant date	—

Abstract

Provided are a power supply device capable of supplying required power even during standby and an electrical apparatus. A power supply device includes a current resonant circuit configured to drive a transformer and a resonant circuit using a switching element, the resonant circuit being connected to a primary side of the transformer, the switching element being periodically repeatedly turned on and off, and a controller configured to control the switching element so that the switching element performs a continuous operation in which the switching element is turned on and off continuously repeatedly or an intermittent operation in which the switching element is turned on and off intermittently repeatedly, in accordance with an external signal indicating the continuous operation or the intermittent operation.

First claim

1 - 8 . (canceled)

9 . A power supply device comprising:
a current resonant circuit configured to drive a transformer and a resonant circuit using a switching element, the resonant circuit being connected to a primary side of the transformer, the switching element being periodically repeatedly turned on and off, and a controller configured to control the switching element so that the switching element performs a continuous operation in which the switching element is turned on and off continuously repeatedly or an intermittent operation in which the switching element is turned on and off intermittently repeatedly, in accordance with an external signal from MPU, indicating the continuous operation or the intermittent operation, the power supply device further comprising a voltage detector configured to detect a voltage on a secondary side of the transformer; and a switching unit configured to, when the controller is controlling the switching element so that it performs the intermittent operation, in accordance with an external signal indicating the intermittent operation and when a voltage detected by the voltage detector has fallen below a predetermined first threshold voltage, cause the controller to control the switching element so that it forcibly switches to perform the continuous operation.

10 . The power supply device of claim 9 , wherein when the switching unit has caused the controller to control the switching element so that it forcibly switches to perform the continuous operation and when the voltage detected by the voltage detector has risen above a second threshold voltage which is higher than the first threshold voltage, the switching unit causes the controller to control the switching element so that it switches to perform the intermittent operation.

11 . The power supply device of claim 9 , wherein when the controller is being given an external signal indicating the continuous operation, the switching unit invalidates detection of the voltage by the voltage detector.

12 . The power supply device of claim 11 , wherein the voltage detector comprises a plurality of resistors connected to the secondary side of the transformer in series,
the switching unit comprises a photodiode configured to be turned on or off in accordance with a voltage divided by the resistors and a phototransistor disposed on a primary side of the transformer and configured to be turned on or off in response to the photodiode being turned on or off, and the controller comprises a transistor configured to determine the continuous operation or the intermittent operation in accordance with an on state or an off state of itself and is configured to turn on or off the transistor in response to the phototransistor being turned on or off.

13 . The power supply device of claim 12 , wherein the switching unit further comprises a diode connected to a cathode of the photodiode and is configured to, when the switching unit is being given an external signal indicating the continuous operation, turn on the diode.

14 . A power supply device that comprising:
a current resonant circuit configured to drive a transformer and a resonant circuit using a switching element, the resonant circuit being connected to a primary side of the transformer, the switching element being periodically repeatedly turned on and off, and a controller configured to control the switching element so that the switching element performs a continuous operation in which the switching element is turned on and off continuously repeatedly or an intermittent operation in which the switching element is turned on and off intermittently repeatedly, in accordance with an external signal from MPU, indicating the continuous operation or the intermittent operation, the power supply device further comprising a load detector configured to detect magnitude of a load on a secondary side of the transformer; and a switching unit configured to, when the controller is controlling the switching element so that it performs the intermittent operation, in accordance with an external signal indicating the intermittent operation and when a load detected by the load detector has become larger than a predetermined first threshold, cause the controller to control the switching element so that it forcibly switches to perform the continuous operation.

15 . A power supply device comprising:
a current resonant circuit configured to drive a transformer and a resonant circuit using a switching element, the resonant circuit being connected to a primary side of the transformer, the switching element being periodically repeatedly turned on and off, and a controller configured to control the switching element so that the switching element performs a continuous operation in which the switching element is turned on and off continuously repeatedly or an intermittent operation in which the switching element is turned on and off intermittently repeatedly, in accordance with an external signal from MPU, indicating the continuous operation or the intermittent operation, the power supply device further comprising a connection determination unit configured to determine whether an external device has been connected to a secondary side of the transformer; and a switching unit configured to, when the controller is controlling the switching element so that it performs the intermittent operation, in accordance with an external signal indicating the intermittent operation and when the connection determination unit determines that an external device has been connected, cause the controller to control the switching element so that it forcibly switches to perform the continuous operation.

16 . An electrical apparatus comprising:
the power supply device of claim 9 ; and a connector disposed on a secondary side of the transformer, wherein when the power supply device is given an external signal indicating the intermittent operation, the power supply device can supply power to an external device connected to the connector.

Assignees

• Eizo Corp

Inventors

• Kawamura Kunio
• Sakai Daisuke

Classifications

• H02M1/00 Primary

  Details of apparatus for conversion · CPC title

• H02M3/33523 Primary

  with galvanic isolation between input and output of both the power stage and the feedback loop · CPC title

• H02M2001/0032

  Electricity · mapped topic

• H02M3/33569

  having several active switching elements (H02M3/3353 takes precedence) · CPC title

• H02M3/33507

  with automatic control of the output voltage or current, e.g. flyback converters (H02M3/33561, H02M3/33569 take precedence) · CPC title