Electrical device, display device, and power supply device

Abstract

The purpose of the present invention is to improve the efficiency of a power supply device by suppressing power loss when load power becomes small. There is provided: an insulated first power conversion unit (103) inputting a DC input voltage to obtain a first power output having a DC voltage of a first value; an insulated second power conversion unit (104) inputting the DC input voltage to obtain a second power supply output having a DC voltage of a second value different from the first value; and a non-insulating third power conversion unit (105) inputting the DC voltage having the second value obtained by the second power conversion unit to obtain a third power supply output having the DC voltage having the first value. When the first load section (13) is in a second mode (light load mode) in which the load power of the first load section (13) is equal to or less than a threshold value, the third power supply output is output from the switching unit (106) and supplied to the first load section (13), whereby it is possible to suppress power loss and improve the efficiency of the power supply device when the load power is reduced.

Description

Technical Field

[0001] The present technology relates to an electric equipment device, a display device, and a power supply device, and more particularly, to an electric equipment device and the like capable of suppressing power loss generated in a power supply device. Background Art

[0002] For example, Patent Document 1 describes a power supply device in which two insulating power supply circuits having different rated powers are provided in parallel and when the load becomes smaller, power loss can be suppressed by switching to the insulating power supply circuit having the smaller rated power.

[0003] Reference List

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2007-104409. Summary of the invention

[0006] Problems to be solved by the present invention

[0007] An object of the present technology is to improve the efficiency of a power supply device by suppressing power loss when load power decreases.

[0008] Solution to the problem

[0009] The concept of the present technology is an electrical equipment device, comprising:

[0010] a first load unit;

[0011] a second load cell; and

[0012] A power supply device, wherein

[0013] The power supply device comprises:

[0014] An input voltage generating unit configured to input a commercial AC power source to generate a DC input voltage;

[0015] a first power conversion unit, which is of an insulating type and is configured to input a DC input voltage to obtain a first power output having a DC voltage of a first value;

[0016] a second power conversion unit of an insulating type and configured to input a DC input voltage to obtain a second power output of a DC voltage having a second value different from the first value;

[0017] a third power conversion unit, which is of a non-insulated type and is configured to input a DC voltage having a second value to obtain a third power output having a DC voltage having a first value;

[0018] a switching unit configured to selectively output a first power output or a third power output;

[0019] a power output providing unit configured to provide the power output output from the switching unit to the first load unit and to provide the second power output to the second load unit; and

[0020] The control unit is configured to enable the switching unit to output a first power output in a first mode in which the load power of the first load unit is greater than a threshold, and to enable the switching unit to output a third power output in a second mode in which the load power of the first load unit is equal to or less than the threshold.

[0021] The electrical equipment device according to the present technology includes a first load unit, a second load unit and a power supply device. Here, the required voltage value between the first load unit and the second load unit is different. The power supply device includes an input voltage generating unit, a first power conversion unit, a second power conversion unit, a third power conversion unit, a switching unit, a power output providing unit and a control unit.

[0022] In the input voltage generating unit, a commercial AC power source is input, and a DC input voltage is generated. The first power conversion unit is an insulation type, and the first power conversion unit inputs the DC input voltage generated by the input voltage generating unit to obtain a first power output having a DC voltage of a first value. The second power conversion unit is an insulation type, and the second power conversion unit inputs the DC input voltage generated by the input voltage generating unit to obtain a second power output having a DC voltage of a second value different from the first value. The third power conversion unit is a non-insulation system, and the third power conversion unit inputs the DC voltage having a second value obtained by the second power conversion unit to obtain a third power output having a DC voltage of the first value.

[0023] The switching unit selectively outputs the first power output obtained by the first power conversion unit or the third power output obtained by the third power conversion unit. The power output providing unit provides the power output output from the switching unit to the first load unit, and provides the second power output obtained by the second power conversion unit to the second load unit. The control unit is configured to make the switching unit output the first power output in a first mode (heavy load mode) in which the load power of the first load unit is greater than a threshold value, and to make the switching unit output the third power output in a second mode (light load mode) in which the load power of the first load unit is equal to or less than the threshold value.

[0024] For example, the control unit may be configured to stop the third power conversion unit in the first mode, and to stop the first power conversion unit in the second mode. In this case, for example, the switching unit may have a configuration in which a switching element, a diode, an AC relay, a photo MOSFET, etc. are provided on each of a path between the output side and the first power conversion unit and a path between the output side and the third power conversion unit.

[0025] In addition, for example, the control unit may be configured to stop the first power conversion unit in the second mode. In this case, for example, the switching unit may have a configuration in which two MOSFETs are arranged in series so that the directions of the parasitic diodes are opposite to each other on the path between the output side and the third power conversion unit, or a configuration in which an AC relay, a photo MOSFET, etc. are arranged.

[0026] In addition, for example, the input voltage generating unit may include: a rectifying unit that rectifies the commercial AC power supply; and a fourth power conversion unit that is a boost type and a non-insulated type and is input with the output voltage of the rectifying unit to obtain a DC input voltage. In this case, for example, the control unit may be configured to stop the boost operation of the fourth power conversion unit in the second mode. In addition, in this case, for example, the fourth power conversion unit may include a PFC circuit.

[0027] In addition, for example, the input voltage generating unit may include a fourth power conversion unit that is a boost type and a non-insulated type and is input to a commercial AC power source to obtain a DC input voltage. In this case, for example, the fourth power conversion unit may include a totem pole PFC circuit. In addition, in this case, for example, a dual boost PFC circuit may be used.

[0028] In addition, for example, the first power conversion unit may include an LLC current resonant DC-DC converter or a flyback converter, the second power conversion unit may include an LLC current resonant DC-DC converter or a flyback converter, and the third power conversion unit may include a boost DC-DC converter, a buck DC-DC converter, or a boost / buck DC-DC converter.

[0029] In addition, for example, a user operation unit that allows a user to perform an operation for changing the load power of the first load unit may be further included.

[0030] As described above, in the present technology, a power supply device includes: a first power conversion unit, which is an insulating type and is configured to input a DC input voltage to obtain a first power supply output having a DC voltage of a first value; a second power conversion unit, which is an insulating type and is configured to input a DC input voltage to obtain a second power supply output having a DC voltage of a second value different from the first value; and a third power conversion unit, which is a non-insulating type and is configured to input a DC voltage having a second value obtained by the second power conversion unit to obtain a third power supply output having a DC voltage of the first value. In a second mode (light load mode) in which the load power of the first load unit is equal to or less than a threshold value, the third power supply output is output from the switching unit and provided to the first load unit, and when the load power is reduced, the efficiency of the power supply device can be improved by suppressing power loss.

[0031] Another concept of the present technology is a display device, comprising:

[0032] Display unit;

[0033] Load cells, as distinct from display cells; and

[0034] A power supply device, wherein

[0035] The power supply device comprises:

[0036] An input voltage generating unit configured to input a commercial AC power source to generate a DC input voltage;

[0037] a first power conversion unit, which is of an insulating type and is configured to input a DC input voltage to obtain a first power output having a DC voltage of a first value;

[0038] a second power conversion unit of an insulating type and configured to input a DC input voltage to obtain a second power output of a DC voltage having a second value different from the first value;

[0039] a third power conversion unit, which is of a non-insulated type and is configured to input a DC voltage having a second value to obtain a third power output having a DC voltage having a first value;

[0040] a switching unit configured to selectively output a first power output or a third power output;

[0041] a power output providing unit configured to provide the power output output from the switching unit to the display unit and to provide the second power output to the load unit; and

[0042] The control unit is configured to enable the switching unit to output a first power output in a first mode in which the load power of the display unit is greater than a threshold, and to enable the switching unit to output a third power output in a second mode in which the load power of the display unit is equal to or less than the threshold.

[0043] The display device of the present technology includes a display unit, a load unit different from the display unit, and a power supply device. Here, the voltage value required between the display unit and the load unit is different. The power supply device includes an input voltage generating unit, a first power conversion unit, a second power conversion unit, a third power conversion unit, a switching unit, a power output providing unit, and a control unit.

[0044] In the input voltage generating unit, a commercial AC power source is input, and a DC input voltage is generated. The first power conversion unit is an insulation type, and the first power conversion unit inputs the DC input voltage generated by the input voltage generating unit to obtain a first power output having a DC voltage of a first value. The second power conversion unit is an insulation type, and the second power conversion unit inputs the DC input voltage generated by the input voltage generating unit to obtain a second power output having a DC voltage of a second value different from the first value. The third power conversion unit is a non-insulation system, and the third power conversion unit inputs the DC voltage having a second value obtained by the second power conversion unit to obtain a third power output having a DC voltage of the first value.

[0045] The switching unit selectively outputs a first power output obtained by the first power conversion unit or a third power output obtained by the third power conversion unit. The power output providing unit provides the power output output from the switching unit to the display unit, and provides the second power output obtained by the second power conversion unit to a load unit different from the display unit. The control unit is configured to cause the switching unit to output the first power output in a first mode (heavy load mode) in which the load power of the display unit is greater than a threshold value, and to cause the switching unit to output the third power output in a second mode (light load mode) in which the load power of the display unit is equal to or less than the threshold value.

[0046] For example, the display unit may be a liquid crystal panel or an organic EL panel with a backlight. In addition, for example, a user operation unit may be further included that allows the user to perform an operation for changing the display brightness of the display unit, and the load power of the display unit may vary according to the change in the display brightness.

[0047] As described above, in the present technology, a power supply device includes: a first power conversion unit, which is an insulating type and is configured to input a DC input voltage to obtain a first power supply output having a DC voltage of a first value; a second power conversion unit, which is an insulating type and is configured to input a DC input voltage to obtain a second power supply output having a DC voltage of a second value different from the first value; and a third power conversion unit, which is a non-insulating type and is configured to input a DC voltage having a second value obtained by the second power conversion unit to obtain a third power supply output having a DC voltage of the first value. In a second mode (light load mode) in which the load power of the display unit is equal to or less than a threshold value, the third power supply output is output from the switching unit and provided to the display unit, and when the load power is reduced, the efficiency of the power supply device can be improved by suppressing power loss.

[0048] In addition, another concept of the present technology is a power supply device, comprising:

[0049] An input voltage generating unit configured to input a commercial AC power source to generate a DC input voltage;

[0050] a first power conversion unit, which is of an insulating type and is configured to input a DC input voltage to obtain a first power output having a DC voltage of a first value;

[0051] a second power conversion unit of an insulating type and configured to input a DC input voltage to obtain a second power output of a DC voltage having a second value different from the first value;

[0052] a third power conversion unit, which is of a non-insulated type and is configured to input a DC voltage having a second value to obtain a third power output having a DC voltage having a first value;

[0053] a switching unit configured to selectively output a first power output or a third power output;

[0054] a power output providing unit configured to provide the power output output from the switching unit to the first load unit and to provide the second power output to the second load unit; and

[0055] The control unit is configured to enable the switching unit to output a first power output in a first mode in which the load power of the first load unit is greater than a threshold, and to enable the switching unit to output a third power output in a second mode in which the load power of the first load unit is equal to or less than the threshold.

[0056] The power supply device of the present technology includes an input voltage generating unit, a first power converting unit, a second power converting unit, a third power converting unit, a switching unit, a power output providing unit, and a control unit.

[0057] In the input voltage generating unit, a commercial AC power source is input, and a DC input voltage is generated. The first power conversion unit is an insulation type, and the first power conversion unit inputs the DC input voltage generated by the input voltage generating unit to obtain a first power output having a DC voltage of a first value. The second power conversion unit is an insulation type, and the second power conversion unit inputs the DC input voltage generated by the input voltage generating unit to obtain a second power output having a DC voltage of a second value different from the first value. The third power conversion unit is a non-insulation system, and the third power conversion unit inputs the DC voltage having a second value obtained by the second power conversion unit to obtain a third power output having a DC voltage of the first value.

[0058] The switching unit selectively outputs the first power output obtained by the first power conversion unit or the third power output obtained by the third power conversion unit. The power output providing unit provides the power output output from the switching unit to the first load unit, and provides the second power output obtained by the second power conversion unit to the second load unit. The control unit is configured to make the switching unit output the first power output in a first mode (heavy load mode) in which the load power of the first load unit is greater than a threshold value, and to make the switching unit output the third power output in a second mode (light load mode) in which the load power of the first load unit is equal to or less than the threshold value.

[0059] As described above, in the present technology, there are provided: a first power conversion unit, which is an insulating type and is configured to input a DC input voltage to obtain a first power supply output having a DC voltage of a first value; a second power conversion unit, which is an insulating type and is configured to input a DC input voltage to obtain a second power supply output having a DC voltage of a second value different from the first value; and a third power conversion unit, which is a non-insulating type and is configured to input a DC voltage having a second value obtained by the second power conversion unit to obtain a third power supply output having a DC voltage of the first value. In a second mode (light load mode) in which the load power of the first load unit is equal to or less than a threshold value, the third power supply output is output from the switching unit and provided to the first load unit, and when the load power is reduced, the efficiency of the power supply device can be improved by suppressing power loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 is a block diagram showing a configuration example of a power supply device.

[0061] Figure 2 It is shown Figure 1 A diagram showing the role and function of each power circuit in a power supply device.

[0062] Figure 3 is a block diagram showing another configuration example of the power supply device.

[0063] Figure 4 It is shown Figure 3 A diagram showing the role and function of each power circuit in a power supply device.

[0064] Figure 5 is a block diagram showing a configuration example of a TV monitor.

[0065] Figure 6 is a block diagram showing a configuration example of a power supply device included in a TV monitor.

[0066] Figure 7 It is shown Figure 6 A diagram showing the role and function of each power circuit in a power supply device.

[0067] Figure 8 : is a diagram showing a configuration example of a PFC circuit (step-up DC-DC converter).

[0068] Fig. 9 is a diagram showing a configuration example of an LLC current resonance DC-DC converter.

[0069] Fig.10 is a diagram showing a configuration example of a flyback converter.

[0070] Fig.11 It is schematically shown Figure 6 A diagram showing the operation of a rectifier circuit, a power supply circuit, etc. in a power supply device.

[0071] Fig.12 is a diagram showing a configuration example of a step-up DC-DC converter.

[0072] Fig.13 is a diagram showing a configuration example of a step-down DC-DC converter.

[0073] Fig.14 is a diagram showing a configuration example of a step-up / step-down DC-DC converter.

[0074] Fig.15 It is shown Figure 6 A diagram showing an example of a configuration of a switching circuit in a power supply device and an outline of control performed by a control signal CS.

[0075] Fig.16 It is shown Fig.15 Flowchart of an example of operation control performed by the CPU on a portion related to power output A of the power supply device in the configuration example.

[0076] Fig.17 It is shown Figure 6FIG. 2 is a diagram showing another example of the configuration of a switching circuit in a power supply device and an overview of control performed by a control signal CS.

[0077] Fig.18 It is shown Fig.17 Flowchart of an example of operation control performed by the CPU on a portion related to power output A of the power supply device in the configuration example.

[0078] Fig.19 It is shown Figure 6 A diagram showing still another example of the configuration of a switching circuit in a power supply device and an overview of control performed by a control signal CS.

[0079] Fig. 20 It is shown Fig.19 Flowchart of an example of operation control performed by the CPU on a portion related to power output A of the power supply device in the configuration example.

[0080] Fig.21 is a block diagram showing another configuration example of a power supply device included in a TV monitor.

[0081] Fig. 22 is a diagram schematically showing the operation when the PFC circuit (step-up DC-DC converter) operates.

[0082] Fig.23 is a diagram schematically showing the operation when the PFC circuit (step-up DC-DC converter) is stopped.

[0083] Fig.24 It is schematically shown Fig.21 A diagram showing the operation of a rectifier circuit, a power supply circuit, etc. in a power supply device.

[0084] Fig.25 It is schematically shown by a bar graph Figure 1 , Figure 3 , Figure 6 and Fig.21 Graph showing the individual power supply circuits and the overall power loss in each power supply device under light load.

[0085] Fig.26 It is used for comparison and explanation Figure 1 and Figure 6 A diagram showing the efficiency of a power supply unit at light load.

[0086] Fig. 27 is a block diagram showing still another configuration example of a power supply device included in a TV monitor.

[0087] Fig.28 is a diagram showing a configuration example of a totem pole PFC circuit.

[0088] Fig.29 is a diagram showing a configuration example of a dual boost PFC circuit.

[0089] Fig.30 : is a block diagram showing a configuration example of a general electric equipment device including the power supply device of the present technology. DETAILED DESCRIPTION

[0090] Hereinafter, a mode for carrying out the present invention (hereinafter, referred to as “embodiment”) will be described. Note that the description will be made in the following order.

[0091] 1. Implementation Method

[0092] 2. Modification

[0093] <1. Implementation Method>

[0094] [Configuration example of power supply unit]

[0095] Figure 1 2 shows a configuration example of a power supply device 300. The power supply device 300 includes a rectifier circuit 301, a power supply circuit 302, a power supply circuit 303, and a power supply circuit 304.

[0096] The rectifier circuit 301 rectifies the input commercial AC power. As shown in the figure, the rectifier circuit 301 is composed of a bridge rectifier circuit having four rectifier diodes. The power supply circuit 302 constitutes a non-insulated power conversion unit, and outputs a DC input voltage using the output of the rectifier circuit 301 as input. Figure 2 As shown, the power supply circuit 302 has the function of boosting voltage and improving power factor and harmonics, and includes, for example, a power factor correction (PFC) circuit as a boost DC-DC converter.

[0097] The power supply circuit 303 constitutes an insulating type power conversion unit, and obtains a power supply output A having a DC voltage of a first value by taking the output of the power supply circuit 302 as an input. Figure 2 As shown, the power supply circuit 303 has the functions of insulation and voltage reduction, and includes, for example, an LLC current resonant converter, a flyback converter, etc. The power supply output A obtained by the power supply circuit 303 is provided to the first load unit.

[0098] The power supply circuit 304 constitutes an insulating type power conversion unit, and obtains a power supply output B having a DC voltage of a second value different from the first value by taking the output of the power supply circuit 302 as an input. Figure 2 As shown, the power supply circuit 303 has the functions of insulation and voltage reduction, and includes, for example, an LLC current resonant converter, a flyback converter, etc. The power supply output A obtained by the power supply circuit 303 is provided to the first load unit.

[0099] The reason for dividing the power circuit into power circuit 303 and power circuit 304 in this way is that the voltage values ​​required by the first load unit and the second load unit are different, that is, the voltage value required by the first load unit is a first value, and the voltage value required by the second load unit is a second value.

[0100] exist Figure 1 In the case of the power supply device 300 shown, even at a light load with reduced load power, the power output A is supplied to the first load unit from the power supply circuit 303. Therefore, there is a problem that the power efficiency is reduced due to the power loss of the power supply circuit 303.

[0101] Figure 3 4 shows a configuration example of a power supply device 400. The power supply device 400 corresponds to the power supply device described in the above-mentioned reference 1. The power supply device 400 includes a rectifying circuit 401, a power supply circuit 402, a power supply circuit 403, a power supply circuit 404, a power supply circuit 405, and a switching circuit 406.

[0102] The rectifier circuit 401 rectifies the input commercial AC power. As shown in the figure, the rectifier circuit 401 is composed of a bridge rectifier circuit having four rectifier diodes. The power supply circuit 402 constitutes a non-insulated power conversion unit, and outputs a DC input voltage using the output of the rectifier circuit 401 as input. Figure 4 As shown, the power supply circuit 402 has the function of boosting voltage and improving power factor and harmonics, and includes, for example, a power factor correction (PFC) circuit as a boost DC-DC converter.

[0103] The power supply circuit 403 constitutes an insulating type power conversion unit, and obtains a power supply output having a DC voltage of a first value by taking the output of the power supply circuit 402 as an input. Figure 4 As shown, the power supply circuit 403 has the functions of insulation and voltage reduction, and includes, for example, an LLC current resonant converter, a flyback converter, and the like.

[0104] The power supply circuit 404 constitutes an insulating type power conversion unit, and obtains a power supply output B having a DC voltage of a second value different from the first value by taking the output of the power supply circuit 402 as an input. Figure 4 As shown, the power circuit 404 has the functions of insulation and voltage reduction, and includes, for example, an LLC current resonant converter, a flyback converter, etc. The power output B obtained by the power circuit 404 is provided to the second load unit.

[0105] The power supply circuit 405 constitutes an insulating power conversion unit, and similar to the above-mentioned power supply circuit 403, takes the output of the power supply circuit 402 as input to obtain a power supply output having a DC voltage of a first value. Figure 4 As shown, the power supply circuit 405 has the functions of insulation and voltage reduction, and includes, for example, an LLC current resonant converter, a flyback converter, etc. The rated power of the power supply circuit 405 is lower than the rated power of the power supply circuit 403 .

[0106] The switching circuit 406 selectively outputs the power output of the power circuit 403 or the power output of the power circuit 405 as the power output A. The power output A is provided to the first load unit.

[0107] In the case where the load power of the first load unit is a large heavy load, the power supply circuit 403 is set to the operating state (the power supply circuit 405 is in the stopped state), and in the switching circuit 406, the power output obtained by the power supply circuit 403 is output as the power output A. However, in the case where the load power of the first load unit is a small light load, the power supply circuit 405 is set to the operating state (the power supply circuit 403 is in the stopped state), and in the switching circuit 406, the power output obtained by the power supply circuit 405 is output as the power output A.

[0108] exist Figure 3 In the case of the power supply device 400 shown in FIG. 1 , switching is performed so that when the load power of the first load unit is lightly loaded and the load power of the first load unit is reduced, the power output A is provided from the power supply circuit 405 having a small rated power to the first load unit provided with the power output A, so that Figure 1 Compared with the power supply device 300 shown in FIG. 1 , power loss can be reduced and power supply efficiency can be improved. However, since the insulating power supply circuit 405 is used, there is a problem that power loss corresponding to the insulating transformer occurs and the power supply efficiency is reduced accordingly.

[0109] "TV monitor configuration example"

[0110] Figure 5 A configuration example of a TV monitor 10 as an embodiment is shown. The TV monitor 10 includes a central processing unit (CPU) 11 , a user operation unit 12 , an LED load unit 13 , a system load unit 14 , and a power supply device 100 .

[0111] The CPU 11 constitutes a control unit that controls the television monitor 10 as a whole. The user operation unit 12 receives various operations of the user and sends an operation signal to the CPU 11. The LED load unit 13 refers to a display unit including, for example, a liquid crystal panel or an organic electroluminescent (EL) panel having a backlight with a light emitting diode (LED). The system load unit 14 includes a video or audio signal processing circuit, a speaker drive circuit, a liquid crystal drive circuit, and the like. Note that in the example shown, only two of the LED load unit 13 and the system load unit 14 are shown, and illustration of the other load units is omitted for simplicity of description.

[0112] The load power of the LED load unit 13 is, for example, several tens of W to several hundreds of W. In this case, for example, when the user performs an operation of changing the display brightness by the image quality setting from the user operation unit 12, the display brightness in the LED load unit 13 is changed under the control of the CPU 11, and the load power of the LED load unit 13 is changed accordingly. For example, the load power of the LED load unit 13 increases in the case where the display brightness is high, and decreases in the case where the display brightness is low. In addition, the load power of the system load unit 14 is, for example, several W to several hundreds of W.

[0113] The power supply device 100 outputs a power output to be provided to each load unit. For example, the power supply device 100 outputs a power output A as a power output to be provided to the LED load unit 13, and outputs a power output B as a power output to be provided to the system load unit 14. The power output A is a power output of a DC voltage having a first value, for example, a voltage value of 20 V to 40 V. The power output B is a power output of a DC voltage having a second value, for example, a voltage value of 12.7 V.

[0114] Figure 6 1 shows a configuration example of a power supply device 100. In this configuration example, parts related to the output of power output A and power output B are shown, and other parts related to the power output are omitted. The power supply device 100 includes a rectifier circuit 101, a power supply circuit 102, a power supply circuit 103, a power supply circuit 104, a power supply circuit 105, a switching circuit 106, and a switching control unit 107.

[0115] The rectifier circuit 101 rectifies the input commercial AC power. As shown in the figure, the rectifier circuit 101 is composed of, for example, a bridge rectifier circuit having four rectifier diodes. Note that the configuration of the rectifier circuit 101 is not limited to the bridge rectifier circuit, and may be another configuration.

[0116] The power supply circuit 102 constitutes a fourth power conversion unit. The power supply circuit 102 constitutes a non-insulated power conversion unit and outputs a DC input voltage using the output of the rectifier circuit 101 as input. Figure 7 As shown, the power supply circuit 102 has the function of boosting voltage and improving power factor and harmonics, and includes, for example, a power factor correction (PFC) circuit as a boost DC-DC converter.

[0117] Figure 8 1 shows a configuration example of a PFC circuit (boost DC-DC converter). The PFC circuit includes an inductor L1, a switching element Q1, a diode D1, and a smoothing capacitor Cout, because the PFC circuit is conventionally known and will not be described in detail. The switching element Q1 is composed of a MOSFET and is switched by a drive control circuit (not shown).

[0118] return Figure 6 The power supply circuit 103 constitutes a first power conversion unit. The power supply circuit 103 constitutes an insulating power conversion unit, and uses the output of the power supply circuit 102 as an input to obtain a power output having a DC voltage of a first value. The first value is the voltage value required by the above-mentioned LED load unit 13, for example, 20V to 40V. Figure 7 As shown, the power supply circuit 103 has the functions of insulation and voltage reduction, and includes, for example, an LLC current resonance DC-DC converter, a flyback converter, and the like.

[0119] Fig. 9 An example of a configuration of an LLC current resonant DC-DC converter is shown. The LLC current resonant DC-DC converter includes switching elements Q1 and Q2, a resonant inductor Lr1, a resonant capacitor Cr1, a transformer Tr, diodes D1 and D2, and a smoothing capacitor Cout, because the LLC current resonant DC-DC converter is conventionally known and will not be described in detail. The switching elements Q1 and Q2 are composed of MOSFETs and are switched by a drive control circuit (not shown).

[0120] Fig.10 An example of a configuration of a flyback converter is shown. The flyback converter includes a switching element Q1, a transformer Tr, a diode D1, and a smoothing capacitor Cout, because the flyback converter is conventionally known and will not be described in detail. The switching element Q1 is composed of a MOSFET and is switched by a drive control circuit (not shown).

[0121] return Figure 6 , the power supply circuit 104 constitutes a second power conversion unit. The power supply circuit 104 constitutes an insulating power conversion unit, and uses the output of the power supply circuit 102 as an input to obtain a power output B of a DC voltage having a second value different from the first value. The second value is the voltage value required by the above-mentioned system load unit 14, for example, 12.7V. Similar to the above-mentioned power supply circuit 103, as Figure 7 As shown, the power circuit 104 has the functions of insulation and voltage reduction, and includes, for example, an LLC current resonant converter, a flyback converter, etc. The power output B obtained by the power circuit 104 is provided to the system load unit 14 .

[0122] Fig.11 The operation of the rectifier circuit 101, the power circuit 102, and the like in the power supply device 100 is schematically shown. Here, the solid line waveform indicates the case where the voltage of the commercial AC power supply is 240 V, and the dotted line waveform indicates the case where the voltage of the commercial AC power supply is 100 V. In either case, the voltage is stepped up in the power supply circuit 102, and a DC input voltage of, for example, 400 V is output.

[0123] Then, in the power supply circuit 103, insulation and voltage reduction from the commercial AC power supply are performed, and a power supply output having a DC voltage of a first value (20 V to 40 V) is obtained. In the power supply circuit 104, insulation and voltage reduction from the commercial AC power supply are performed, and a power supply output (power supply output B) having a DC voltage of a second value (12.7 V) is obtained.

[0124] return Figure 6 The power supply circuit 105 constitutes a third power conversion unit. The power supply circuit 105 constitutes a non-insulated power conversion unit, and similar to the above-mentioned power supply circuit 103, uses the output of the power supply circuit 104 as input to obtain a power output of the first value. Figure 7 As shown, the power supply circuit 105 has a voltage step-up function and includes, for example, a voltage step-up DC-DC converter, etc. The rated power of the power supply circuit 105 is made lower than the rated power of the power supply circuit 103 .

[0125] Fig.12 An example of a configuration of a boost DC-DC converter is shown. The boost DC-DC converter includes an inductor L1, a switching element Q1, a diode D1, and a smoothing capacitor Cout, because the boost DC-DC converter is conventionally known and will not be described in detail. The switching element Q1 is composed of a MOSFET and is switched by a drive control circuit (not shown).

[0126] Note that a description has been given above in which the LED load unit 13 (see Figure 5 ) The required voltage value (first value) is, for example, 20V to 40V, and the system load unit 14 (see Figure 5 ), that is, the output voltage value of the power supply circuit 104 is, for example, 12.7 V. Therefore, the power supply circuit 105 has a voltage boosting function.

[0127] However, according to the specification of the LED load unit 13, when the first value is smaller than the second value, the power supply circuit 105 having a step-down function is used and is constituted by, for example, a step-down DC-DC converter or the like.

[0128] Fig.13 An example of a configuration of a step-down DC-DC converter is shown. The step-down DC-DC converter includes switching elements Q1 and Q2, an inductor L1, and a smoothing capacitor Cout, because the step-down DC-DC converter is conventionally known and will not be described in detail. The switching elements Q1 and Q2 are composed of MOSFETs and are switched by a drive control circuit (not shown).

[0129] In addition, according to the specifications of the LED load unit 13, when the first value adopts two values ​​greater than the second value and less than the second value, a power supply circuit 105 with a boost / buck function is used, and the power supply circuit 105 is composed of, for example, a boost / buck DC-DC converter (SEPIC converter) or the like.

[0130] Fig.14 An example of a configuration of a step-up / step-down DC-DC converter is shown. The step-up / step-down DC-DC converter includes an inductor L1, a switching element Q1, a capacitor C1, an inductor L2, a diode D1, and a smoothing capacitor Cout, because the step-up / step-down DC-DC converter is conventionally known and will not be described in detail. The switching element Q1 is composed of a MOSFET and is switched by a drive control circuit (not shown).

[0131] return Figure 6 , the switching circuit 106 selectively outputs the power output of the power circuit 103 or the power output of the power circuit 105 as the power output A. The power output A output from the switching circuit 106 is provided to the LED load unit 13 .

[0132] The switching control unit 107 is based on the slave CPU 11 (see Figure 5 ) controls the power output A output from the switching circuit 106.

[0133] As described above, for example, when the user performs an operation of changing the display brightness by the image quality setting from the user operation unit 12, the display brightness in the LED load unit 13 is changed under the control of the CPU 11, and the load power of the LED load unit 13 is changed accordingly. The CPU 11 calculates and obtains the load power of the LED load unit 13 based on the voltage value and the current value or with reference to the table information indicating the correspondence relationship between the display brightness and the load power. The process of the CPU 11 obtaining the load power of the LED load unit 13 is performed when, for example, the TV monitor 10 is powered on, and thereafter, is performed every time the display brightness is changed.

[0134] The CPU 11 compares the load power of the LED load unit 13 with a threshold value (e.g., the value of the rated power of the power supply circuit 105), and sets the level of the control signal CS to "1 (high)" or "0 (low)". For example, the level of the control signal CS is set to "0 (low)" in the first mode in which the load power of the LED load unit 13 is greater than the threshold value and is a heavy load, and is set to "1 (high)" in the second mode in which the load power of the LED load unit 13 is equal to or less than the threshold value and is a light load.

[0135] The power output A output from the switching circuit 106 is the power output obtained by the power circuit 103 in the first mode when the level of the control signal CS is "0 (low)" and the load power of the LED load unit 13 is greater than the threshold and is a heavy load, and is the power output obtained by the power circuit 105 in the second mode when the level of the control signal CS is "1 (high)" and the load power of the LED load unit 13 is equal to or less than the threshold and is a light load.

[0136] Fig.15 An example of the configuration of the switching circuit 106 and an outline of control by the control signal CS are shown. The switching circuit 106 has switching elements Q1, Q2 constituted by MOSFETs. Note that the switching elements Q1 and Q2 are not limited to those constituted by MOSFETs.

[0137] The switching element Q1 is provided on a path between the output side of the switching circuit 106 and the power supply circuit 103 , and the switching element Q2 is provided on a path between the output side of the switching circuit 106 and the power supply circuit 105 .

[0138] The on / off of the switching elements Q1 and Q2 is controlled by the switching control unit 107 based on the control signal CS. In this case, when the control signal CS is "0 (low)", the switching element Q1 is turned on, and the switching element Q2 is turned off. In addition, when the control signal CS is "1 (high)", the switching element Q1 is turned off, and the switching element Q2 is turned on.

[0139] Furthermore, the operation of the power supply circuit 103 and the power supply circuit 105 is controlled based on the control signal CS by the switching control unit 107. In this case, when the control signal CS is "0 (low)", the power supply circuit 103 is set to the operating state, and the power supply circuit 105 is set to the stop state. Furthermore, when the control signal CS is "1 (high)", the power supply circuit 103 is set to the stop state, and the power supply circuit 105 is set to the operating state. Note that although Fig.15 Although not shown, the power supply circuit 102 and the power supply circuit 104 are always in operation.

[0140] As a result, when the load power of the LED load unit 13 is greater than the threshold value and is a heavy load, the power output obtained by the power supply circuit 103 is output from the switching circuit 106 as the power output A. However, when the load power of the LED load unit 13 is equal to or less than the threshold value and is a light load, the power output obtained by the power supply circuit 105 is output from the switching circuit 106 as the power output A.

[0141] Fig.16 The flowchart shows Fig.15 An example of operation control performed by the CPU 11 on a portion related to the power output A of the power supply device 100 in the configuration example of FIG.

[0142] First, in step ST1, the CPU 11 starts operating. Next, in step ST2, the CPU 11 sets the power circuit 102 to an operating state, sets the power circuit 103 to an operating state, sets the power circuit 104 to an operating state, and sets the power circuit 105 to a stopped state.

[0143] Next, in step ST3, the CPU 11 determines whether the LED load unit 13 is heavy load or light load. In this case, the CPU 11 obtains the load power of the LED load unit 13, compares the load power with a threshold value, and determines whether the LED load unit 13 is heavy load or light load.

[0144] When it is determined that the LED load unit 13 is a heavy load, in step ST4, the CPU 11 sets the control signal CS to be sent to the power supply device 100 to "0 (low)". Next, in step ST5, the CPU 11 sets the power supply circuit 102 to the operating state, sets the power supply circuit 103 to the operating state, sets the power supply circuit 104 to the operating state, and sets the power supply circuit 105 to the stopped state.

[0145] Next, in step ST6, the CPU 11 turns on the switching element Q1 in the switching circuit 106, turns off the switching element Q2 in the switching circuit 106, and sets the power output obtained by the power supply circuit 103 to be output as the power output A. After the processing of step ST6, the CPU 11 returns to the processing of step ST3.

[0146] Furthermore, in the case where it is determined in step ST3 that the LED load unit 13 is a light load, in step ST7, the CPU 11 sets the control signal CS to be sent to the power supply device 100 to "1 (High)". Next, in step ST8, the CPU 11 sets the power supply circuit 102 to the operating state, sets the power supply circuit 103 to the stopped state, sets the power supply circuit 104 to the operating state, and sets the power supply circuit 105 to the operating state.

[0147] Next, in step ST9, the CPU 11 turns off the switching element Q1 in the switching circuit 106, turns on the switching element Q2 in the switching circuit 106, and sets the power output obtained by the power supply circuit 105 to be output as the power output A. After the processing of step ST9, the CPU 11 returns to the processing of step ST3.

[0148] Fig.17 1 shows an example of another configuration of the switching circuit 106 and an outline of the control performed by the control signal CS. The switching circuit 106 includes diodes D1 and D2. The diode D1 is provided on the path between the output side of the switching circuit 106 and the power supply circuit 103, and the diode D2 is provided on the path between the output side of the switching circuit 106 and the power supply circuit 105.

[0149] The operation of the power supply circuit 103 and the power supply circuit 105 is controlled based on the control signal CS by the switching control unit 107. In this case, when the control signal CS is "0 (low)", the power supply circuit 103 is set to the operating state, and the power supply circuit 105 is set to the stop state. In addition, when the control signal CS is "1 (high)", the power supply circuit 103 is set to the stop state, and the power supply circuit 105 is set to the operating state. Note that although Fig.17 Although not shown, the power supply circuit 102 and the power supply circuit 104 are always in operation.

[0150] Therefore, with Fig.15Similar to the configuration example of , when the load power of the LED load unit 13 is greater than the threshold value and is a heavy load, the power output obtained by the power supply circuit 103 is output from the switching circuit 106 as the power output A. However, when the load power of the LED load unit 13 is equal to or less than the threshold value and is a light load, the power output obtained by the power supply circuit 105 is output from the switching circuit 106 as the power output A.

[0151] Note that Fig.17 In the case of the configuration example of , there is a forward voltage drop in the diodes D1 and D2, and conduction loss occurs. Fig.15 In the case of the configuration example, this conduction loss can be suppressed.

[0152] Fig.18 The flowchart shows Fig.17 An example of operation control performed by the CPU 11 on a portion related to the power output A of the power supply device 100 in the configuration example of FIG.

[0153] First, in step ST11, the CPU 11 starts operation. Next, in step ST12, the CPU 11 sets the power supply circuit 102 to an operating state, sets the power supply circuit 103 to an operating state, sets the power supply circuit 104 to an operating state, and sets the power supply circuit 105 to a stopped state.

[0154] Next, in step ST13, the CPU 11 determines whether the LED load unit 13 is heavy load or light load. In this case, the CPU 11 obtains the load power of the LED load unit 13, compares the load power with a threshold value, and determines whether the LED load unit 13 is heavy load or light load.

[0155] When it is determined that the LED load unit 13 is a heavy load, in step ST14, the CPU 11 sets the control signal CS to be sent to the power supply device 100 to "0 (low)". Next, in step ST15, the CPU 11 sets the power supply circuit 102 to the operating state, sets the power supply circuit 103 to the operating state, sets the power supply circuit 104 to the operating state, sets the power supply circuit 105 to the stop state, and sets the power output obtained by the power supply circuit 103 as the power output A output state. After the processing of step ST5, the CPU 11 returns to the processing of step ST13.

[0156] Furthermore, when it is determined in step ST13 that the LED load unit 13 is a light load, in step ST16, the CPU 11 sets the control signal CS to be transmitted to the power supply device 100 to "1 (High)". Next, in step ST17, the CPU 11 sets the power supply circuit 102 to the operating state, sets the power supply circuit 103 to the stopped state, sets the power supply circuit 104 to the operating state, sets the power supply circuit 105 to the operating state, and sets the power output obtained by the power supply circuit 105 as the power output A output state. After the processing of step ST17, the CPU 11 returns to the processing of step ST3.

[0157] Fig.19 An example of another configuration of the switching circuit 106 and an outline of the control performed by the control signal CS are shown. This example is an example in which the power supply circuit 105 is always set in an operating state. In the switching circuit 106, two MOSFETs are arranged in series on a path between the output side of the switching circuit 106 and the power supply circuit 105 so that the directions of the parasitic diodes are opposite to each other. In this case, the two MOSFETs constitute the switching elements Q1 and Q2.

[0158] The on / off of the switching elements Q1 and Q2 is controlled by the switching control unit 107 based on the control signal CS. In this case, when the control signal CS is "0 (low)", the switching elements Q1 and Q2 are turned off. In addition, when the control signal CS is "1 (high)", the switching elements Q1 and Q2 are turned on.

[0159] Furthermore, the operation of the power supply circuit 103 is controlled based on the control signal CS by the switching control unit 107. In this case, when the control signal CS is "0 (low)", the power supply circuit 103 is set to the operating state. Furthermore, when the control signal CS is "1 (high)", the power supply circuit 103 is in the stopped state. Note that, as described above, the power supply circuit 105 is always in the operating state, and the power supply circuit 102 and the power supply circuit 104 are always in the operating state, although Fig.19 Not shown in .

[0160] As a result, when the load power of the LED load unit 13 is greater than the threshold value and is a heavy load, the power output obtained by the power circuit 103 is output as the power output A from the switching circuit 106. In this case, the power circuit 105 is in operation. However, the two switching elements Q1 and Q2 connected in series are turned off and connected in series in such a way that the directions of their parasitic diodes are opposite to each other, so that the path from the power circuit 105 to the output side of the switching circuit 106 is completely cut off, and therefore, the power output obtained by the power circuit 105 is not output as the power output A. However, when the load power of the LED load unit 13 is equal to or less than the threshold value and is a light load, the power output obtained by the power circuit 105 is output as the power output A from the switching circuit 106.

[0161] Fig. 20 The flowchart shows Fig.19 An example of operation control performed by the CPU 11 on a portion related to the power output A of the power supply device 100 in the configuration example of FIG.

[0162] First, in step ST21, the CPU 11 starts operating. Next, in step ST22, the CPU 11 sets the power supply circuit 102 to an operating state, sets the power supply circuit 103 to an operating state, sets the power supply circuit 104 to an operating state, and sets the power supply circuit 105 to an operating state.

[0163] Next, in step ST23, the CPU 11 determines whether the LED load unit 13 is heavy load or light load. In this case, the CPU 11 obtains the load power of the LED load unit 13, compares the load power with a threshold value, and determines whether the LED load unit 13 is heavy load or light load.

[0164] When it is determined that the LED load unit 13 is a heavy load, in step ST24, the CPU 11 sets the control signal CS to be sent to the power supply device 100 to "0 (low)". Next, in step ST25, the CPU 11 sets the power supply circuit 102 to the operating state, sets the power supply circuit 103 to the operating state, sets the power supply circuit 104 to the operating state, and sets the power supply circuit 105 to the operating state.

[0165] Next, in step ST26, the CPU 11 turns off both the switch elements Q1 and Q2 of the switching circuit 106, and sets the power output obtained by the power circuit 103 to be output as the power output A. After the process of step ST26, the CPU 11 returns to the process of step ST23.

[0166] Furthermore, when it is determined in step ST23 that the LED load unit 13 is a light load, in step ST27, the CPU 11 sets the control signal CS to be transmitted to the power supply device 100 to "1 (High)". Next, in step ST28, the CPU 11 sets the power supply circuit 102 to the operating state, sets the power supply circuit 103 to the stopped state, sets the power supply circuit 104 to the operating state, and sets the power supply circuit 105 to the operating state.

[0167] Next, in step ST29, the CPU 11 turns on both the switch elements Q1 and Q2 of the switching circuit 106, and sets the power output obtained by the power circuit 105 to be output as the power output A. After the processing of step ST29, the CPU 11 returns to the processing of step ST23.

[0168] Note that although detailed description is omitted, except for the above Fig.15 , Fig.17 as well as Fig.19 In addition to the illustrated example, a configuration in which an AC relay, a photo MOSFET, or the like is provided is also conceivable as the configuration of the switching circuit 106 .

[0169] As mentioned above, in Figure 5 In the TV monitor 10 shown in FIG. 1 , in the second mode in which the load power of the LED load unit 13 is equal to or less than the threshold value and is a light load, the power supply device 100 (see FIG. 1 ) Figure 6 ) The power output obtained by the power circuit 105 with a smaller rated power, rather than the power output obtained by the power circuit 103 with a larger rated power, is output from the switching circuit 106 via the power circuit 104 as the power output A, and the power output A is provided to the LED load unit 13. Therefore, the power loss when the load power is reduced can be suppressed, and the efficiency can be improved.

[0170] Note that Figure 6 In the power supply device 100 shown, in the second mode in which the load power of the LED load unit 13 is equal to or less than the threshold value and is a light load, the power output obtained by the power supply circuit 105 is output from the output switching circuit 106 as the power output A. In addition, the power supply circuits 102, 104, and 105 are set in the operating state, and the power supply circuit 103 is set in the stopped state.

[0171] However, at this time, it is conceivable to set the power supply circuit 104 and the power supply circuit 105 to the operating state and the power supply circuit 102 and the power supply circuit 103 to the stopped state to further reduce the loss power and improve the power supply efficiency.

[0172] Fig.21In this case, a configuration example of the power supply device 100A is shown. Fig.21 In, with Figure 6 The corresponding parts in the figure are given the same reference numerals, and their detailed description will be appropriately omitted.

[0173] In the power supply device 100A, when the power output obtained by the power supply circuit 105 is output as the power output A from the output switching circuit 106 , the power supply circuit 102 is set to the stopped state together with the power supply circuit 103 .

[0174] In this case, since the power supply circuit 102 is in a stopped state, the power factor and harmonics are not improved. However, in the second mode where the load power of the LED load unit 13 is equal to or less than the threshold value and is a light load, countermeasures against harmonics become unnecessary and therefore there is no problem. The threshold value at this time is determined, for example, so that the input power of the power supply device 100A is 75W or less.

[0175] In addition, in this case, since the power supply circuit 102 is in a stopped state, the voltage boost is not performed. Therefore, the output voltage of the power supply circuit 102 is obtained by smoothing the rectification part of the commercial AC power supply by the smoothing capacitor provided at the output stage. For example, when the voltage of the commercial AC power supply is 100V, the output voltage of the power supply circuit 102 is about 141V, and when the voltage of the commercial AC power supply is 240V, the output voltage of the power supply circuit 102 is about 338V.

[0176] Fig. 22 The operation is schematically shown when the PFC circuit (step-up DC-DC converter) constituting the power supply circuit 102 operates. In this case, the output voltage of the input rectification circuit 301 is stepped up by the on / off operation of the switching element Q1, and then smoothed by the smoothing capacitor Cout to become a DC input voltage. Fig.23 The operation is schematically shown when the PFC circuit (step-up DC-DC converter) constituting the power supply circuit 102 is stopped. In this case, the output voltage of the rectification circuit 101 is input, and is smoothed by the smoothing capacitor Cout to become a DC input voltage.

[0177] As described above, when the power supply circuit 102 is in the stopped state, the output voltage of the power supply circuit 102 fluctuates according to the voltage of the commercial AC power supply and adopts a wide voltage range. However, in this case, by configuring the power supply circuit 104 with a power supply circuit having high line regulation performance (e.g., a flyback converter), the voltage values ​​of the power supply output A and the power supply output B can be maintained at the same voltage as Figure 6 The value is similar to that of the case of the power supply device 100.

[0178] Fig.24 The operation of the rectifier circuit 101, the power supply circuit 102, etc. in the second mode in which the load power of the LED load unit 13 in the power supply circuit 100A is equal to or less than the threshold value and is a light load is schematically shown. Here, the solid line waveform indicates the case where the voltage of the commercial AC power supply is 240V, and the dotted line waveform indicates the case where the voltage of the commercial AC power supply is 100V. In either case, the power supply circuit 102 does not perform boosting, and outputs DC input voltages of approximately 141V and 338V, respectively. Then, in the power supply circuit 104, insulation and step-down from the commercial AC power supply are performed, and a power supply output (power supply output B) having a DC voltage of a second value (12.7V) is obtained.

[0179] Fig.25 The bar graph schematically shows that when the first load unit is lightly loaded, Figure 1 The power supply device 300 shown (herein, defined as "power supply device 1"), Figure 3 The power supply device 400 shown (herein, defined as "power supply device 2"), Figure 6 The power supply device 100 shown (herein, defined as "power supply device 3"), and Fig.21 The respective power circuits and the overall power loss of the power supply device 100A (here, defined as "power supply device 4") are shown. Note that in the power supply devices 100 and 100A, the LED load unit 13 corresponds to the first load unit.

[0180] Furthermore, in power supply device 300, power supply circuit 302 constitutes power supply circuit 1, power supply circuit 303 constitutes power supply circuit 2, and power supply circuit 304 constitutes power supply circuit 3. Furthermore, in power supply device 400, power supply circuit 402 constitutes power supply circuit 1, power supply circuit 403 constitutes power supply circuit 2, power supply circuit 404 constitutes power supply circuit 3, and power supply circuit 405 constitutes power supply circuit 4.

[0181] Furthermore, in the power supply devices 100 and 100A, the power supply circuit 102 constitutes the power supply circuit 1 , the power supply circuit 103 constitutes the power supply circuit 2 , the power supply circuit 104 constitutes the power supply circuit 3 , and the power supply circuit 105 constitutes the power supply circuit 4 .

[0182] With respect to the power supply circuit 1, since the power supply device 4 is in the stopped state, the loss is minimized. With respect to the power supply circuit 2, only the power supply device 1 is set to the running state, and the loss occurs. With respect to the power supply circuit 3, since the power supply device 3 is configured to further use the output of the power supply circuit 3 in the power supply circuit 4, the loss is slightly larger than that of the power supply devices 1 and 2. In addition, with respect to the power supply circuit 3, since the power supply device 4 uses a flyback converter having good line regulation characteristics, the loss is slightly larger than that in the case where the power supply device 3 uses, for example, an LLC current resonant converter. With respect to the power supply circuit 4, since the power supply circuit 4 is not used in the power supply device 1, the power supply device 1 has no loss, and since the power supply devices 2 and 3 are non-insulated types, the loss in the power supply devices 2 and 3 is smaller than that in the power supply device 2 of the insulation type.

[0183] Therefore, as the entire power supply device, the power loss of power supply device 3 is smaller than the power losses of power supply devices 1 and 2 , and the power loss of power supply device 4 is further smaller than the power loss of power supply device 3 .

[0184] exist Fig.26 In the graph of (a), the solid line "a" indicates Figure 6 The first situation (corresponding to the first situation in which the power supply circuit 103 is in the running state (on) and the power supply circuit 105 is in the stopping state (off) in the power supply device 300 shown in FIG. Figure 1 The corresponding relationship between the output power [W] and the efficiency [%] of the power supply device 100 shown in FIG. Fig.26 In the graph of (a), the dashed line “b” indicates Figure 6 The corresponding relationship between the output power [W] and the efficiency [%] in the second case where the power circuit 103 is in the stopped state (OFF) and the power circuit 105 is in the operating state (ON) in the power supply device 100 is shown.

[0185] Fig.26 (b) shows an example of input power Pin, output power Pout, power loss Ploss, and efficiency (Efficiency) at light load in the first and second cases described above. In the first case, when output A (power supply output A) is 22W, output B (power supply output B) is 5W, and Pout is 27W, Pin is 33W, Ploss is 6W, and the efficiency is 82%. However, in the second case described above, when output A (power supply output A) is 22W, output B (power supply output B) is 5W, and Pout is 27W, Pin is 31W, Ploss is 4W, and the efficiency is 87%.

[0186] From this result, it can be seen that Figure 6 In the power supply device 100 shown in FIG. Figure 1Compared with the power supply device 300 shown, the power loss at light load is reduced and the efficiency is improved.

[0187] <2. Modification>

[0188] Note that the above Figure 6 The power supply device 100 shown has a configuration in which a commercial AC power supply is rectified by a rectifier circuit 101 and then input into a power supply circuit 102 to generate an input DC voltage. However, it is also conceivable to use a power supply circuit capable of directly generating an input DC voltage from a commercial AC power supply without using a rectifier circuit that converts an AC voltage into a DC pulse voltage.

[0189] Fig. 27 An example of the configuration of the power supply device 100B in this case is shown. Fig. 27 In, with Figure 6 The parts corresponding to those in FIG. 1 are given the same reference numerals, and their detailed description will be omitted as appropriate. In the power supply device 100B, the commercial AC power is directly input to the power supply circuit 102B, and Figure 6 The power supply circuit 102 in the power supply device 100 shown generates the input DC voltage similarly. The other parts of the power supply device 100B are similar to those of FIG. Figure 6 The illustrated power supply apparatus 100 is similarly configured. The power supply circuit 102B includes, for example, a totem pole PFC circuit, a dual boost PFC circuit, or the like.

[0190] Fig.28 1 shows a configuration example of a totem pole PFC circuit. The totem pole PFC circuit includes an inductor L1, switching elements Q1 and Q2, diodes D1 and D2, and a smoothing capacitor Cout, which is conventionally known and will not be described in detail. The switching elements Q1 and Q2 are composed of MOSFETs and are switched by a drive control circuit (not shown).

[0191] Fig.29 An example of a configuration of a dual boost PFC circuit is shown. The dual boost PFC circuit includes inductors L1 and L2, switching elements Q1 and Q2, diodes D1 and D2, and a smoothing capacitor Cout, which is conventionally known and will not be described in detail. The switching elements Q1 and Q2 are composed of MOSFETs and are switched by a drive control circuit (not shown).

[0192] Furthermore, in the above-described embodiment, the TV monitor 10 has been described as an example of an electrical equipment device including the power supply device of the present technology (see Figure 5 ). However, the electrical equipment device including the power supply device of the present technology is not limited to the TV monitor 10.

[0193] Fig.30 The configuration example of a general electric equipment device 20 including the power supply device of the present technology is shown. The electric equipment device 20 includes a central processing unit (CPU) 21 , a user operation unit 22 , a first load unit 23 , a second load unit 24 , and a power supply device 120 .

[0194] The CPU 21 constitutes a control unit for controlling the entire electrical device 20. The user operation unit 22 receives various operations of the user and sends operation signals to the CPU 21. The first load unit 23 is connected to the above Figure 5 The second load unit 24 is a load unit corresponding to the LED load unit 13 in the TV monitor 10 shown in FIG. Figure 5 The load unit corresponds to the system load unit 14 in the illustrated TV monitor 10. Note that in the illustrated example, only two of the first load unit 23 and the second load unit 24 are shown, and illustration of the other load units is omitted for simplicity of description.

[0195] and Figure 5 Similar to the LED load unit 13 in the illustrated TV monitor 10 , the load power of the first load unit 23 changes to a heavy load or a light load according to the operation state of the first load unit 23 set by the user through the user operation unit 22 , for example.

[0196] The power supply device 120 and Figure 5 The power supply device 100 in the TV monitor 10 shown (see Figure 6 ) is configured similarly. Note that the power supply device 120 may be configured similarly to the power supply device 100A (see Fig.21 ) and power supply device 100B (see Fig. 27 ) is configured similarly. The control signal CS is provided from the CPU 21 to the power supply device 120. The level of the control signal CS is "0 (low)" in the first mode in which the load power of the first load unit 23 is greater than the threshold value and is a heavy load, and is "1 (high)" in the second mode in which the load power of the first load unit 23 is equal to or less than the threshold value and is a light load.

[0197] The power supply device 120 outputs a power output to be provided to each load unit. For example, the power supply device 120 is controlled by the control signal CS and outputs the power output corresponding to the load unit. Figure 6 The power supply device 100 shown in FIG. 1 outputs a power supply output A similar to the power supply output A to be supplied to the first load unit 23, and outputs the power supply output A similar to the power supply output A to be supplied to the first load unit 23. Figure 6 The power output of the power supply device 100 shown is similar to the power output B as the power to be supplied to the second load unit 24 .

[0198] Since the power output A outputted from the power supply device 120 is controlled by the control signal CS in this manner, Figure 6 Similar to the illustrated power supply device 100 , the power supply device 120 can suppress power loss when the load power is reduced to improve efficiency.

[0199] Furthermore, in the above-described embodiment, it has been described that the power supply circuits 103 and 104 as the first power conversion unit and the second power conversion unit include, for example, LLC current resonant converters (see Fig. 9 ) and flyback converters (see Fig.10 ), but the first power conversion unit and the second power conversion unit according to the present technology include general insulation converters having other similar functions. In addition, in the above-mentioned embodiment, it has been described that the power supply circuit 105 as the third power conversion unit includes, for example, a step-up DC-DC converter (see Fig.12 ), step-down DC-DC converter (see Fig.13 ), step-up / step-down DC-DC converter (SEPIC converter) (see Fig.14 ) etc., but the third power conversion unit according to the present technology includes a general non-insulated converter having other similar functions. In addition, in the above-mentioned embodiment, an example has been described in which a switching element, a diode, an AC relay, a photo MOSFET, etc. are provided as the switching circuit 106 as the switching unit (see Fig.15 , Fig.17 and Fig.19 ), but the switching circuit in the present technology includes a general switching circuit having other similar functions.

[0200] In addition, although the preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the technical scope of the present disclosure is not limited to such examples. It is obvious that a person skilled in the art of the present disclosure can implement various types of changed or modified examples within the scope of the technical ideas recorded in the claims, and will naturally understand that such examples also belong to the technical scope of the present disclosure.

[0201] In addition, the effects described in this specification are only exemplary or illustrative, not restrictive. That is, in combination with or instead of the above effects, the technology according to the present disclosure can produce other effects that are obvious to those skilled in the art from the description of this specification.

[0202] Meanwhile, the present technology may also have the following configurations.

[0203] (1) An electrical device comprising:

[0204] a first load unit;

[0205] a second load cell; and

[0206] A power supply device, wherein

[0207] The power supply device comprises:

[0208] an input voltage generating unit configured to input a commercial alternating current (AC) power source to generate a direct current (DC) input voltage;

[0209] a first power conversion unit, which is of an insulating type and is configured to input a DC input voltage to obtain a first power output having a DC voltage of a first value;

[0210] a second power conversion unit of an insulating type and configured to input a DC input voltage to obtain a second power output of a DC voltage having a second value different from the first value;

[0211] a third power conversion unit, which is of a non-insulated type and is configured to input a DC voltage having a second value to obtain a third power output having a DC voltage having a first value;

[0212] a switching unit configured to selectively output a first power output or a third power output;

[0213] a power output providing unit configured to provide the power output output from the switching unit to the first load unit and to provide the second power output to the second load unit; and

[0214] The control unit is configured to enable the switching unit to output the first power output in a first mode when the load power of the first load unit is greater than a threshold, and to enable the switching unit to output the third power output in a second mode when the load power of the first load unit is equal to or less than the threshold.

[0215] (2) The electrical equipment device according to (1) above, wherein:

[0216] The control unit stops the third power converting unit in the first mode, and stops the first power converting unit in the second mode.

[0217] (3) The electrical equipment device according to (2) above, wherein:

[0218] The switching unit has a configuration in which a switching element or a diode is provided on each of a path between the output side and the first power conversion unit and a path between the output side and the third power conversion unit.

[0219] (4) The electrical equipment device according to (1) above, wherein:

[0220] The control unit stops the first power conversion unit in the second mode.

[0221] (5) The electrical equipment device according to (4) above, wherein:

[0222] The switching unit has a configuration in which two metal oxide semiconductor field effect transistors (MOSFETs) are provided in series on a path between the output side and the third power conversion unit such that directions of parasitic diodes are opposite to each other.

[0223] (6) The electrical equipment device according to any one of (1) to (5) above, wherein:

[0224] The input voltage generating unit includes: a rectifying unit rectifying the commercial AC power; and a fourth power converting unit which is a step-up type and a non-insulated type and to which the output voltage of the rectifying unit is input to obtain a DC input voltage.

[0225] (7) The electrical equipment device according to (6) above, wherein:

[0226] The control unit stops the boost operation of the fourth power conversion unit in the second mode.

[0227] (8) The electrical equipment device according to (6) or (7) above, wherein:

[0228] The fourth power conversion unit includes a power factor correction (PFC) circuit.

[0229] (9) The electrical equipment device according to any one of (1) to (5) above, wherein:

[0230] The input voltage generating unit includes a fourth power converting unit which is a step-up type and a non-insulation type and is input with a commercial AC power source to obtain a DC input voltage.

[0231] (10) The electrical equipment device according to (9) above, wherein:

[0232] The fourth power conversion unit includes a totem pole PFC circuit.

[0233] (11) The electrical equipment device according to (9) above, wherein:

[0234] The fourth power conversion unit includes a dual-boost PFC circuit.

[0235] (12) The electrical equipment device according to any one of (1) to (11) above, wherein:

[0236] The first power conversion unit includes an LLC current resonant DC-DC converter or a flyback converter,

[0237] The second power conversion unit includes an LLC current resonant DC-DC converter or a flyback converter, and

[0238] The third power conversion unit includes a step-up DC-DC converter, a step-down DC-DC converter, or a step-up / step-down DC-DC converter.

[0239] (13) The electrical equipment device according to any one of (1) to (12) above, further comprising:

[0240] A user operation unit allows a user to perform an operation for changing a load power of the first load unit.

[0241] (14) A display device comprising:

[0242] Display unit;

[0243] Load cells, as distinct from display cells; and

[0244] A power supply device, wherein

[0245] The power supply device comprises:

[0246] An input voltage generating unit configured to input a commercial AC power source to generate a DC input voltage;

[0247] a first power conversion unit, which is of an insulating type and is configured to input a DC input voltage to obtain a first power output having a DC voltage of a first value;

[0248] a second power conversion unit of an insulating type and configured to input a DC input voltage to obtain a second power output of a DC voltage having a second value different from the first value;

[0249] a third power conversion unit, which is of a non-insulated type and is configured to input a DC voltage having a second value to obtain a third power output having a DC voltage having a first value;

[0250] a switching unit configured to selectively output a first power output or a third power output;

[0251] a power output providing unit configured to provide the power output output from the switching unit to the display unit and to provide the second power output to the load unit; and

[0252] The control unit is configured to enable the switching unit to output a first power output in a first mode in which the load power of the display unit is greater than a threshold, and to enable the switching unit to output a third power output in a second mode in which the load power of the display unit is equal to or less than the threshold.

[0253] (15) The display device according to (14), wherein:

[0254] The display unit is a liquid crystal panel or an organic electroluminescent (EL) panel with a backlight.

[0255] (16) The display device according to (14) or (15), further comprising:

[0256] A user operation unit allows a user to perform an operation for changing the display brightness of the display unit, wherein

[0257] The load power of the display unit varies according to the display brightness.

[0258] (17) A power supply device comprising:

[0259] An input voltage generating unit configured to input a commercial AC power source to generate a DC input voltage;

[0260] a first power conversion unit, which is of an insulating type and is configured to input a DC input voltage to obtain a first power output having a DC voltage of a first value;

[0261] a second power conversion unit of an insulating type and configured to input a DC input voltage to obtain a second power output of a DC voltage having a second value different from the first value;

[0262] a third power conversion unit, which is of a non-insulated type and is configured to input a DC voltage having a second value to obtain a third power output having a DC voltage having a first value;

[0263] a switching unit configured to selectively output a first power output or a third power output;

[0264] a power output providing unit configured to provide the power output output from the switching unit to the first load unit and to provide the second power output to the second load unit; and

[0265] The control unit is configured to enable the switching unit to output the first power output in a first mode when the load power of the first load unit is greater than a threshold, and to enable the switching unit to output the third power output in a second mode when the load power of the first load unit is equal to or less than the threshold.

[0266] (18) A power supply device according to (17) above, wherein:

[0267] The input voltage generating unit includes: a rectifying unit rectifying the commercial AC power; and a fourth power converting unit which is a step-up type and a non-insulated type and to which the output voltage of the rectifying unit is input to obtain a DC input voltage.

[0268] (19) A power supply device according to (17) above, wherein:

[0269] The input voltage generating unit includes a fourth power converting unit which is a step-up type and a non-insulation type and is input with a commercial AC power source to obtain a DC input voltage.

[0270] (20) A power supply device according to any one of (17) to (19) above, wherein:

[0271] The first power conversion unit includes an LLC current resonant DC-DC converter or a flyback converter,

[0272] The second power conversion unit includes an LLC current resonant DC-DC converter or a flyback converter, and

[0273] The third power conversion unit includes a step-up DC-DC converter, a step-down DC-DC converter, or a step-up / step-down DC-DC converter.

[0274] Reference Mark List

[0275] 10 TV monitor

[0276] 11 CPU

[0277] 12 User operation unit

[0278] 13 LED load units

[0279] 14 System Load Unit

[0280] 20 Electrical equipment

[0281] 21 CPU

[0282] 22 User operation unit

[0283] 23 First load unit

[0284] 24 Second load unit

[0285] 100, 100A, 100B, 120 Power Supply Unit

[0286] 101 Rectifier Circuit

[0287] 102, 102B, 103, 104, 105 Power supply circuit

[0288] 106 Switching Circuit

[0289] 107 Switching control unit.

Claims

1. An electrical equipment device, comprising: a first load unit; a second load unit; as well as A power supply device, wherein The power supply device comprises: An input voltage generating unit configured to input a commercial AC power source to generate a DC input voltage; A first power conversion unit, which is of an insulating type and is configured to input the DC input voltage to obtain a first power output having a DC voltage of a first value; a second power conversion unit, which is of an insulating type and is configured to input the DC input voltage to obtain a second power output of a DC voltage having a second value different from the first value; a third power conversion unit, which is of a non-insulated type and is configured to input a DC voltage having the second value to obtain a third power output having a DC voltage having the first value; a switching unit, configured to selectively output the first power output or the third power output; a power output providing unit configured to provide the power output output from the switching unit to the first load unit, and to provide the second power output to the second load unit; and A control unit is configured to enable the switching unit to output the first power output in a first mode in which the load power of the first load unit is greater than a threshold, and to enable the switching unit to output the third power output in a second mode in which the load power of the first load unit is equal to or less than the threshold.

2. The electrical equipment device according to claim 1, wherein: The control unit stops the third power converting unit in the first mode, and stops the first power converting unit in the second mode.

3. The electrical equipment device according to claim 2, wherein: The switching unit has a configuration in which a switching element or a diode is provided on each of a path between an output side and the first power conversion unit and a path between the output side and the third power conversion unit.

4. The electrical equipment device according to claim 1, wherein The control unit stops the first power conversion unit in the second mode.

5. The electrical equipment device according to claim 4, wherein: The switching unit has a configuration in which two MOSFETs are provided in series on a path between the output side and the third power conversion unit such that directions of parasitic diodes are opposite to each other.

6. The electrical equipment device according to claim 1, wherein: The input voltage generating unit includes: a rectifying unit that rectifies the commercial AC power supply; and a fourth power converting unit that is a boost type and a non-insulated type and to which the output voltage of the rectifying unit is input to obtain the DC input voltage.

7. The electrical equipment device according to claim 6, wherein: The control unit stops a boost operation of the fourth power conversion unit in the second mode.

8. The electrical equipment device according to claim 6, wherein: The fourth power conversion unit includes a PFC circuit.

9. The electrical equipment device according to claim 1, wherein: The input voltage generating unit includes a fourth power converting unit which is a step-up type and a non-insulated type and is input to the commercial AC power source to obtain the DC input voltage.

10. The electrical equipment device according to claim 9, wherein: The fourth power conversion unit includes a totem pole PFC circuit.

11. The electrical equipment device according to claim 9, wherein: The fourth power conversion unit includes a dual boost PFC circuit.

12. The electrical equipment device according to claim 1, wherein: The first power conversion unit includes an LLC current resonant DC-DC converter or a flyback converter, The second power conversion unit includes an LLC current resonant DC-DC converter or a flyback converter, and The third power conversion unit includes a step-up DC-DC converter, a step-down DC-DC converter, or a step-up / step-down DC-DC converter.

13. The electrical equipment device according to claim 1, further comprising: A user operation unit allows a user to perform an operation for changing the load power of the first load unit.

14. A display device, comprising: Display unit; a load unit, different from the display unit; as well as A power supply device, wherein The power supply device comprises: An input voltage generating unit configured to input a commercial AC power source to generate a DC input voltage; A first power conversion unit, which is of an insulating type and is configured to input the DC input voltage to obtain a first power output having a DC voltage of a first value; a second power conversion unit, which is of an insulating type and is configured to input the DC input voltage to obtain a second power output of a DC voltage having a second value different from the first value; a third power conversion unit, which is of a non-insulated type and is configured to input a DC voltage having the second value to obtain a third power output having a DC voltage having the first value; a switching unit, configured to selectively output the first power output or the third power output; a power output providing unit configured to provide the power output output from the switching unit to the display unit, and to provide the second power output to the load unit; and A control unit is configured to cause the switching unit to output the first power output in a first mode in which the load power of the display unit is greater than a threshold, and to cause the switching unit to output the third power output in a second mode in which the load power of the display unit is equal to or less than the threshold.

15. The display device according to claim 14, wherein: The display unit includes an organic EL panel or a liquid crystal panel with a backlight.

16. The display device according to claim 14, further comprising: A user operation unit allows a user to perform an operation for changing the display brightness of the display unit, wherein: The load power of the display unit varies according to the change of the display brightness.

17. A power supply device, comprising: An input voltage generating unit configured to input a commercial AC power source to generate a DC input voltage; A first power conversion unit, which is of an insulating type and is configured to input the DC input voltage to obtain a first power output having a DC voltage of a first value; a second power conversion unit, which is of an insulating type and is configured to input the DC input voltage to obtain a second power output of a DC voltage having a second value different from the first value; a third power conversion unit, which is of a non-insulated type and is configured to input a DC voltage having the second value to obtain a third power output having a DC voltage having the first value; a switching unit, configured to selectively output the first power output or the third power output; a power output providing unit configured to provide the power output output from the switching unit to a first load unit, and to provide the second power output to a second load unit; as well as A control unit is configured to enable the switching unit to output the first power output in a first mode in which the load power of the first load unit is greater than a threshold, and to enable the switching unit to output the third power output in a second mode in which the load power of the first load unit is equal to or less than the threshold.

18. The power supply device according to claim 17, wherein: The input voltage generating unit includes: a rectifying unit that rectifies the commercial AC power supply; and a fourth power converting unit that is a boost type and a non-insulated type and to which the output voltage of the rectifying unit is input to obtain the DC input voltage.

19. The power supply device according to claim 17, wherein: The input voltage generating unit includes a fourth power converting unit which is a step-up type and a non-insulated type and is input to the commercial AC power source to obtain the DC input voltage.

20. The power supply device according to claim 17, wherein: The first power conversion unit includes an LLC current resonant DC-DC converter or a flyback converter, The second power conversion unit includes an LLC current resonant DC-DC converter or a flyback converter, and The third power conversion unit includes a step-up DC-DC converter, a step-down DC-DC converter, or a step-up / step-down DC-DC converter.

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