JP2011125139A - Power supply for electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To bring power consumption of a main power supply down to zero in standby state by self-stopping the main power supply itself, when the main operation is turned off, in a power supply of a two-power supply system, including a standby power supply which supplies standby power in standby state, and the main power supply which supplies main power required for the main operation. <P>SOLUTION: A standby power supply circuit 1 normally outputs a predetermined voltage, and a main power supply circuit 2 includes a main switch element 12 for controlling supplying and interrupting a main power required for the main operation; a drive signal input element 16 to which a drive signal required for the main operation is input externally; an on switch element 13 which conducts, while the drive signal is input to the drive signal input element and conducts the main switch element, while conducting; an off switch element 14 which conducts, after the drive signal is no longer input to the drive signal input element and does not conduct the main switch element 12; and an oscillation circuit 15; which generates power for conducting the off-switch element 14, after the on switch element 13 no longer conducts. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power supply device for an electronic device in which a part of the function of a control circuit is activated in order to constantly receive a control signal from a remote control device such as a television receiver or a recording device.

  In an electronic device such as a television receiver or a recording device, how to reduce standby power in a so-called standby state in which an image is reproduced on a monitor screen and data is not recorded or read from a recording medium. is important.

  The electric device described in Patent Document 1 includes a first switching regulator device that supplies power for control during operation and a second switching regulator device that supplies power for operation, and standby power in a standby state In addition, driving power for driving the first switching regulator device is supplied from the second switching regulator device. Although the specific circuit configurations of the first switching regulator device and the second switching regulator device are not drawn, the primary side into which commercial power is drawn is generally insulated from the secondary side operated by the user Therefore, it is considered that the second switching regulator device is provided with an insulating transformer, and a current always flows through the transformer. Therefore, it is estimated that the power loss in the second switching regulator device for high output is not small. Further, such a configuration is substantially equivalent to having three power supply circuits, and the configuration of the power supply apparatus becomes complicated.

  In the digital device described in Patent Document 2, the power supply unit for supplying power to the main controller on which the OS is mounted and the main controller always operate independently, and an on / off signal for the digital device is externally provided. Is received, power management means for controlling the supply of power to the main controller according to the state of the OS of the main controller is provided. For example, when the digital device is a liquid crystal television receiver, a main power source for performing main operations such as driving of a liquid crystal panel and lighting of a backlight is provided separately, and is the same as the electric device of Patent Document 1 above. In addition, substantially three power supply circuits are provided. The state of the main power supply in the standby state is not particularly mentioned and is unknown.

  In a power supply device for an electronic device described in Patent Document 3, a storage battery is built in a power supply circuit, power is supplied from the storage battery in a standby state, and power consumption in the standby state is zero. According to such a configuration, a storage battery and its charging circuit are required, the circuit configuration is complicated, and the cost increases. Moreover, when it is not used for a long period of time, the storage battery is discharged, which causes a problem that a control signal cannot be received from the remote control device.

JP 2000-156968 A JP 2001-320650 A JP 2001-218280 A

  The present invention has been made to solve the above-described problems of the conventional example. The standby power supply for supplying the minimum standby power required in the standby state without using a storage battery, and the main power for performing the main operation. A power supply device for an electronic device that has only a main power supply that supplies power, and that self-stops itself when the main operation is turned off, thereby reducing power consumption of the main power supply in a standby state to zero. The purpose is to provide.

  In order to achieve the above object, the invention of claim 1 is a power supply device for an electronic device comprising a standby power supply circuit for supplying standby power in a standby state and a main power supply circuit for supplying main power for performing a main operation. The standby power supply circuit always outputs a predetermined voltage in the standby state and in the main operation, and the main power supply circuit controls supply and cutoff of the main power for the main operation. A main switch element, a drive signal input element to which a drive signal for performing the main operation from the outside is input, and conductive while the drive signal is input to the drive signal input element. An on-switch element that causes the main switch element to conduct; an off-switch element that conducts after the drive signal is no longer input to the drive signal input element; After the switch element is turned off, characterized by comprising an oscillation circuit for generating a power for conducting the off switch element.

  According to a second aspect of the present invention, in the power supply device for an electronic device according to the first aspect, the main switch element is a field effect transistor (FET), and the on-switch element is in the standby power supply circuit while conducting. Is input to the gate of the field effect transistor, and the off-switch element is turned on to ground the gate of the field effect transistor.

  According to a third aspect of the present invention, in the electronic apparatus power supply device according to the first or second aspect, the oscillation circuit includes a capacitor and a resistor, and is connected to the standby power supply circuit via the on-switch element. When the standby power supply circuit becomes non-conductive, a trigger signal for making the off-switch element conductive is output.

  According to a fourth aspect of the present invention, in the power supply device for an electronic device according to any one of the first to third aspects, the main switch element is a primary coil of an insulating transformer provided in the main power supply circuit. The current flowing through the primary coil of the insulated transformer is cut off by being connected in series to each other and being non-conductive.

  According to the first aspect of the present invention, the oscillation circuit is provided in the main power supply circuit, and the off-switch element is driven by using the oscillation circuit as a power source. Therefore, when an external drive signal is not input to the drive signal input element, The main power circuit is turned off. Therefore, a standby power supply that supplies the minimum standby power in a standby state without using a storage battery as in Patent Document 3 and without requiring three power supply circuits as in Patent Document 1 or Patent Document 2. When the main operation is turned off, the main power supply itself is self-stopped by the dual power supply system having only the main power supply for supplying the main power for performing the main operation, thereby reducing the power consumption of the main power supply in the standby state to zero. can do. Further, the main power supply circuit itself can be simplified.

  According to the second aspect of the present invention, even when a field effect transistor is used as the main switch element, the gate of the field effect transistor is grounded by the conduction of the off switch element. It is possible to quickly turn off the main operation.

  According to the invention of claim 3, since the trigger signal for conducting the off switch element is generated by discharging the electric charge stored in the capacitor provided in the oscillation circuit, the circuit configuration is simplified, In addition, power saving can be realized.

  According to the fourth aspect of the present invention, since the main switch element becomes non-conductive, no power pole flows through the power supply circuit, so that the power consumption of the main power supply circuit in the standby state can be reduced to zero. .

1 is a diagram showing a circuit configuration of a power supply device for an electronic apparatus according to an embodiment of the present invention.

  A power supply device for an electronic apparatus according to an embodiment of the present invention will be described with reference to FIG. The power supply device for the electronic device includes a standby power supply circuit 1 that supplies standby power in a standby state of an electronic device (the whole is not shown), and a main power supply circuit 2 that supplies main power for performing the main operation of the electronic device. And a rectifying unit 4 that rectifies an alternating current supplied from a commercial power source (AC) 3. Here, the standby power supply circuit 1 always outputs a predetermined voltage in both the standby state and the main operation state of the electronic device, and the specific circuit configuration is not particularly limited. In FIG. 1, the standby power supply circuit 1 is depicted as a black box.

  On the other hand, the main power supply circuit 2 is configured to reduce power consumption to zero in the standby state of the electronic device. The main power supply circuit 2 is connected in series to, for example, an insulating transformer 10 and a primary side coil 11 of the insulating transformer 10, and is connected to a primary coil for conducting (ON) or interrupting (OFF) a current of the primary side coil. The switch element 12, the on switch element 13 for making the main switch element 12 conductive, the off switch element 14 for making the main switch element 12 nonconductive, and electric power for making the off switch element 14 conductive For example, an oscillation circuit 15 for driving, and a drive signal input element 16 for receiving a drive signal for causing the electronic apparatus to perform a main operation from the outside.

  The alternating current supplied from the commercial power supply 3 is rectified by the rectifying unit 4 and then input to the standby power supply circuit 1 and when the main switch element 12 of the main power supply circuit 2 is conductive (ON), It flows to the primary coil 11 of the insulating transformer 10. And the main operation | movement of an electronic device is performed by the induced electromotive force generate | occur | produced in the secondary side coil (not shown) of the insulated transformer 10. FIG. In other words, the main operation of the electronic device is stopped by shutting off the current flowing through the primary coil 11 of the insulating transformer 10 by turning off the main switch element 12.

  The main switch element 12 is, for example, a field effect transistor (hereinafter referred to as FET), and its source is connected to one end of the primary side coil 11 of the insulating transformer 10 and its drain is grounded. By inputting a control signal having a predetermined voltage to the gate of the FET, the FET is turned on, and a current flows through the primary side coil 11 of the insulated transformer 10. The on-switch element 13 is, for example, a PNP bipolar transistor, and the emitter and base thereof are connected to the standby power supply circuit 1 and the collector is connected to the gate of the main switch element 12. The base of the on switch element 13 is connected to a drive signal input element 16 such as a photocoupler. The off switch element 14 is, for example, an NPN type bipolar transistor, and has a collector connected to the gate of the main switch element 12, a base connected to the output terminal of the oscillation circuit 15, and an emitter grounded. The oscillation circuit 15 is composed of, for example, a capacitor 15a, a resistor 15b, a coil 15c, and the like, and its input terminal is connected to the collector of the on-switch element 13. When the on-switch element 13 is conducting, a current flows through the oscillation circuit 15 and the capacitor 15a is charged.

  In the standby state of the electronic device, since the drive signal is not input to the drive signal input element 16, that is, the input terminal of the photocoupler, the output terminal of the photocoupler is non-conductive (off) and is turned on from the standby power supply circuit 1. No current flows through the circuit from the base of the switch element 13 to the output side of the drive signal input element 16. For this reason, a control signal having a predetermined voltage is not input to the base of the on switch element 13, and the on switch element 13 is non-conductive (off), thereby causing the main switch element 12 to be non-conductive (off). At this time, the off switch element 14 is also non-conductive (off).

  When a drive signal is input to the input terminal of the drive signal input element 16 (photocoupler) from the outside, for example, a remote control signal receiver of an electronic device, the output terminal of the photocoupler is turned on, and the standby power supply circuit 1 A control signal having a predetermined voltage is input to the base of the on switch element 13, and the on switch element 13 is turned on (turned on), whereby the main switch element 12 is also turned on (turned on). And an electric current flows into the primary side coil 11 of the insulated transformer 10, and the main operation | movement of an electronic device is performed by the induced electromotive force generate | occur | produced in the secondary side coil of the insulated transformer 10. FIG. At this time, although the capacitor 15a of the oscillation circuit 15 is charged, the off switch element 14 remains non-conductive (off).

  When the drive signal is no longer input to the input terminal of the drive signal input element 16, no current flows from the standby power supply circuit 1 through the base of the on switch element 13 to the output side of the drive signal input element 16, and the on switch The element 13 is turned off (off). By the way, the FET used as the main switch element 12 has a characteristic that the gate voltage is immediately reduced to zero due to the parasitic capacitance, and a certain time is required until the main switch element 12 becomes non-conductive (off) (turn-off delay). have. According to the configuration of the present embodiment, the gate of the FET used as the main switch element 12 is grounded via the off switch element 14, and the capacitor 15a discharges at the same time as the on switch element 13 becomes non-conductive (off). Then, a predetermined voltage is input to the base of the off switch element 14 via a resistor or the like, and the off switch element 14 is turned on. As a result, the charge charged at the gate of the FET is discharged and the voltage drops rapidly, so that the main switch element 12 becomes non-conductive (off). As a result, the current of the primary side coil 11 of the insulated transformer 10 is cut off, no induced electromotive force is generated in the secondary side coil of the insulated transformer 10, and the main operation of the electronic device is stopped.

  When the main switch element 12 is in a non-conduction (off) state, no current flows from the standby power supply circuit 1 to the main power supply circuit 2, so that the power consumption by the main power supply circuit 2 in the standby state can be made zero. . When an external drive signal is not input to the drive signal input element, the main switch element is automatically turned off and the main power supply circuit is turned off. Therefore, the battery and other power sources as in the prior art are not required, the configuration of the entire power supply device is simple, and the cost can be reduced.

  Although not specifically shown or described, it goes without saying that the standby power supply circuit 1 supplies standby power to the remote control signal receiving unit and the like in the standby state. Further, the electronic device is not limited to a television receiver or a recording device, and can be applied to all electronic devices operated by a remote controller by a user.

DESCRIPTION OF SYMBOLS 1 Standby power supply circuit 2 Main power supply circuit 3 Commercial power supply 4 Rectification part 10 Insulation type transformer 11 Primary side coil 12 Main switch element (FET)
13 ON switch element 14 OFF switch element 15 Oscillation circuit 16 Drive signal input element

Claims (4)

A standby power supply circuit for supplying standby power in a standby state, and a power supply device for an electronic device including a main power supply circuit for supplying main power for performing main operation,
The standby power supply circuit always outputs a predetermined voltage in the standby state and the main operation,
The main power circuit is
A main switch element for controlling supply and cut-off of main power for the main operation;
A drive signal input element to which a drive signal for performing the main operation is input from the outside;
An on-switch element that conducts while the drive signal is input to the drive signal input element and that conducts the main switch element while conducting;
An off switch element that is turned on after the drive signal is no longer input to the drive signal input element and that makes the main switch element non-conductive;
A power supply device for an electronic device, comprising: an oscillation circuit that generates electric power for making the off switch element conductive after the on switch element becomes nonconductive. The main switch element is a field effect transistor (FET),
While the on-switch element is conducting, the voltage output from the standby power supply circuit is input to the gate of the field effect transistor,
2. The power supply device for an electronic device according to claim 1, wherein the off-switch element is electrically connected to ground a gate of the field effect transistor.   The oscillation circuit includes a capacitor and a resistor, and is connected to the standby power supply circuit via the on-switch element. When the standby power supply circuit becomes non-conductive, a trigger signal for making the off-switch element conductive The power supply device for an electronic device according to claim 1, wherein   The main switch element is connected in series to a primary coil of an insulating transformer provided in the main power supply circuit, and cuts off a current flowing through the primary coil of the insulating transformer by being non-conductive. The power supply device for an electronic device according to any one of claims 1 to 3.

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