CN112533327B

CN112533327B - Load control device

Info

Publication number: CN112533327B
Application number: CN202010980523.2A
Authority: CN
Inventors: 宫本贤吾; 后藤周作
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2019-09-17
Filing date: 2020-09-17
Publication date: 2023-05-30
Anticipated expiration: 2040-09-17
Also published as: TW202114470A; JP2021048020A; CN112533327A; JP7308409B2

Abstract

The present disclosure provides a load control device that makes power supply to a load easily stable. The load control device (1) is provided with a switching unit (2), a first power supply circuit (41), a second power supply circuit (42), an internal circuit (3), and a precharge circuit (43). The switch unit (2) is interposed between the power source (11) and the load (12). The first power supply circuit (41) generates electric power based on the voltages applied to both ends of the switching section (2). The second power supply circuit (42) generates electric power based on the voltages applied to both ends of the switching section (2). The internal circuit (3) is supplied with electric power by the first power supply circuit (41) or the second power supply circuit (42). A precharge circuit (43) charges a capacitor element (C3) included in one of the first power supply circuit (41) and the second power supply circuit (42) with power from the other of the first power supply circuit (41) and the second power supply circuit (42).

Description

Load control device

Technical Field

The present disclosure relates generally to a load control device, and more particularly, to a load control device provided with a switching unit interposed between a power source and a load.

Background

In document 1 (japanese laid-open patent publication No. 2012-14953), a load control device (2-wire dimmer) for dimming a load (LED lighting fixture) is described. The load control device described in document 1 includes a switching unit (triac), a control unit (control circuit), and a power generation circuit (power generation circuit) interposed between an ac power source and a load. The control unit performs on control of the switching unit based on a detection signal of a detection circuit for detecting a zero-crossing point of the ac power supply. The power generation circuit is connected between both ends of the switching unit, and generates power (power supply) for operating the control unit during the off period of the switching unit.

Disclosure of Invention

Problems to be solved by the invention

In such a load control device, there are the following problems: when the power consumption of the control unit or the other parts is increased, the power applied by the control unit is insufficient, and the power supply to the load is liable to become unstable.

The purpose of the present disclosure is to provide a load control device that facilitates stable power supply to a load.

Solution for solving the problem

A load control device according to one aspect of the present disclosure includes a switching unit, a first power supply circuit, a second power supply circuit, an internal circuit, and a precharge circuit. The switch portion is interposed between the power source and the load. The first power supply circuit generates electric power based on a voltage applied to both ends of the switching section. The second power supply circuit generates electric power based on a voltage applied to both ends of the switching section. The internal circuit is supplied with power by the first power supply circuit or the second power supply circuit. The precharge circuit charges a capacitive element included in one of the first power supply circuit and the second power supply circuit with power from the other of the first power supply circuit and the second power supply circuit.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present disclosure, there is an advantage in that the power supply to the load is easily stabilized.

Drawings

Fig. 1 is a block diagram showing an outline configuration of a load control device according to embodiment 1.

Fig. 2 is a circuit diagram showing a specific example of the load control device.

Fig. 3 is a circuit diagram showing a specific example of the load control device, and particularly, a circuit diagram showing a relationship with the control unit.

Fig. 4 is an explanatory diagram of the operation of the load control device in the charging mode.

Fig. 5 is an explanatory diagram of the operation of the load control device in the off mode.

Fig. 6 is an explanatory diagram of the operation of the load control device in the on mode.

Fig. 7A is a graph showing the voltage across the capacitor of the output stage of the first power supply circuit in the load control device described above.

Fig. 7B is a graph showing the voltage across the capacitor of the output stage of the second power supply circuit in the load control device.

Fig. 8 is a block diagram showing a schematic configuration of a load control device according to a first modification of embodiment 1.

Fig. 9 is a block diagram showing an outline configuration of the load control device according to embodiment 2.

Description of the reference numerals

1. 1A, 1B: a load control device; 2: a switch section; 3: an internal circuit; 11: a power supply; 12: a load; 41: a first power supply circuit; 42: a second power supply circuit; 43: a precharge circuit; 411: a first current limiting circuit (first charging path); 412: a quick charge path (second charge path); c1, C0: a capacitive element; c2: a capacitive element (first capacitive element, capacitor); and C3: capacitive element (second capacitive element, capacitor).

Detailed Description

(embodiment 1)

(1) Summary of the inventionsummary

Next, an outline of the load control device 1 according to embodiment 1 will be described with reference to fig. 1.

As shown in fig. 1, a load control device 1 according to the present embodiment includes a switching unit 2 interposed between a power source 11 and a load 12. The term "inserted" as used in the present disclosure means electrically connected and interposed between the power source 11 and the load 12, so that the switching section 2 is electrically connected between the power source 11 and the load 12 in the circuit constituted by the power source 11 and the load 12. In other words, the load 12 and the power supply 11 are electrically connected via the switching section 2.

The switching unit 2 is implemented by a semiconductor switch such as a transistor or a triac, for example. In the present embodiment, the load control device 1 is a so-called electronic switch that electronically switches conduction/non-conduction between the power source 11 and the load 12 by electronically controlling the switching unit 2. The load control device 1 includes a pair of terminals 101 and 102 (see fig. 2), and the switch unit 2 is electrically connected between the pair of

terminals

101 and 102. In other words, inside the load control device 1, the terminal 101 and the terminal 102 are electrically connected via the switch section 2. The switch section 2 is interposed between the power source 11 and the load 12 by connecting one terminal 101 (first terminal) to the power source 11 and connecting the other terminal 102 (second terminal) to the load 12.

According to this configuration, the load control device 1 can control the state of energization (the state of supply of electric power) in which electric power is supplied from the power source 11 to the load 12 by the switching unit 2. Basically, if the operation state of the switch section 2 is in the conductive state, the terminal 101 and the terminal 102 are conductive via the switch section 2, and if the operation state of the switch section 2 is in the cut-off state, the terminal 101 and the terminal 102 are non-conductive. That is, if the switching unit 2 is in the on state, the power supply from the power supply 11 to the load 12 is performed via the load control device 1, and if the switching unit 2 is in the off state, the power supply from the power supply 11 to the load 12 is cut off by the load control device 1.

The load control device 1 according to the present embodiment further includes an internal circuit 3 and a power generation circuit 4. The internal circuit 3 includes a control section 31 and the like for controlling the switch section 2. The power generation circuit 4 is configured to generate power for the operation of the internal circuit 3.

The power generation circuit 4 generates power for the operation of the internal circuit 3 based on the voltage applied to both ends of the switching section 2. The power generation circuit 4 includes a first power supply circuit 41 and a second power supply circuit 42, and supplies power for operation to the internal circuit 3 from either one of the first power supply circuit 41 and the second power supply circuit 42. In other words, the first power supply circuit 41 and the second power supply circuit 42 included in the power generation circuit 4 each generate electric power for the operation of the internal circuit 3 by taking as input a voltage applied between the pair of

terminals

101 and 102 by the power supply 11. As described above, the load control device 1 can secure the electric power for the operation of the internal circuit 3 from the pair of

terminals

101 and 102 for inserting the switch unit 2 between the power supply 11 and the load 12.

That is, the load control device 1 is a so-called 2-wire load control device capable of securing electric power by which the internal circuit 3 operates by 2 wires connected to the pair of

terminals

101 and 102. In such a 2-wire load control device 1, it is not necessary to provide a power supply terminal for supplying electric power for operating the internal circuit 3 in addition to the pair of

terminals

101 and 102, and wiring work in the case of providing the load control device 1 is simplified.

Here, the load control device 1 according to the present embodiment includes a switching unit 2, a first power supply circuit 41, a second power supply circuit 42, an internal circuit 3, and a precharge circuit 43. The switch section 2 is interposed between the power source 11 and the load 12. The first power supply circuit 41 generates electric power based on the voltage applied to both ends of the switching section 2. The second power supply circuit 42 generates electric power based on the voltage applied to both ends of the switching section 2. The internal circuit 3 is supplied with electric power by the first power supply circuit 41 or the second power supply circuit 42. The precharge circuit 43 charges the capacitor element C3 included in one of the first power supply circuit 41 and the second power supply circuit 42 with power from the other of the first power supply circuit 41 and the second power supply circuit 42.

That is, the load control device 1 according to the present embodiment includes the switching unit 2, the first power supply circuit 41, the second power supply circuit 42, and the internal circuit 3, and further includes the precharge circuit 43. By connecting the power from one of the first power supply circuit 41 and the second power supply circuit 42 (japanese: connecting) to the capacitor element C3 of the other of the first power supply circuit 41 and the second power supply circuit 42 through the precharge circuit 43, it is possible to reduce, for example, the time taken to charge the capacitor element C3 when starting the supply of the power from the other circuit to the internal circuit 3. Therefore, according to the load control device 1, at least when the supply source for supplying power to the internal circuit 3 is switched from one of the first power supply circuit 41 and the second power supply circuit 42 to the other of the first power supply circuit 41 and the second power supply circuit 42, the switching is easily and smoothly achieved. As a result, there are the following advantages: it is easy to suppress fluctuation of the power supplied from the power supply 11 to the load 12 when switching between the first power supply circuit 41 and the second power supply circuit 42, and it is easy to stabilize the power supply to the load 12.

(2) Details of the

(2.1) precondition

In the present embodiment, the load control device 1 is fixed to an object to be mounted on a building. The term "mounting object" as used in the present disclosure is an object for fixing the load control device 1, and includes, for example, a building such as a wall, a ceiling, or a floor of a building, a daily appliance such as a table, a shelf, or a counter (including a door/window partition), or the like. The building in which the load control device 1 is installed is, for example, a residential facility such as a single house or a group house, or a non-residential facility such as a business, store, school, factory, hospital, or care facility.

In the present embodiment, as an example, it is assumed that the load control device 1 is a buried wiring device that is mounted on an object to be mounted, which is constituted by a wall of a house. It is assumed that the power source 11 is, for example, a commercial ac power source (system power source) of 100 [ V ] and 60 [ Hz ] single phase. Further, it is assumed that the load 12 is a lighting device (lighting fixture) including a light source including an LED (Light Emitting Diode: light emitting diode) and a lighting circuit for lighting the light source. In this load 12, the light source is turned on when power is supplied from the power supply 11.

The load control device 1 includes

terminals

101 and 102 for connecting wires, and the load control device 1 is electrically connected to the power source 11 and the load 12 via the wires by connecting the

terminals

101 and 102 with wires led around a wall (object to be mounted), for example. The electric wire may be directly connected to the power source 11 (system power source or the like), or may be indirectly connected to the power source 11 (system power source or the like) via a switchboard or the like.

The "terminals" such as the

terminals

101 and 102 described in the present disclosure may not be members for connecting wires or the like, and may be, for example, leads of electronic components, a part of conductors included in a circuit board, or the like.

In addition, in the present disclosure, in comparison of 2 values, "more" includes both a case where 2 values are equal and a case where one of the 2 values exceeds the other. However, the term "above" as used herein may be defined as "greater than" and "greater than" includes only the case where one of the 2 values exceeds the other. That is, since whether or not 2 values are equal is included can be arbitrarily changed depending on the setting of the reference value or the like, there is no technical difference in terms of "above" or "greater than". Likewise, "less than" may also have the same meaning as "below".

(2.2) integral Structure of load control device

Next, the overall configuration of the load control device 1 according to the present embodiment will be described with reference to fig. 1 to 3.

As shown in fig. 1, the load control device 1 includes a switching unit 2, a power generation circuit 4, and an internal circuit 3. The power generation circuit 4 includes a first power supply circuit 41, a second power supply circuit 42, and a precharge circuit 43. That is, the load control device 1 includes the switching unit 2, the internal circuit 3, the first power supply circuit 41, the second power supply circuit 42, and the precharge circuit 43. In the present embodiment, as shown in fig. 2, the load control device 1 further includes a pair of

terminals

101 and 102, zero-crossing (ZC)

detection units

51 and 52,

voltage detection units

53 and 54, a charge detection unit 55, and a level shift circuit 56. These components (the switch unit 2 and the

terminals

101 and 102, etc.) of the load control device 1 are housed in 1 case.

The pair of

terminals

101, 102 are members for electrically and mechanically connecting electric wires, respectively. As an example, the pair of

terminals

101 and 102 are so-called quick connection terminals in which electric wires are inserted from terminal holes to connect the electric wires.

The switching unit 2 is interposed between the power source 11 and the load 12, and is configured to switch on/off between the power source 11 and the load 12. In the present embodiment, the switching unit 2 includes 2 MOSFETs (Metal-Oxide-Semiconductor Field Effect Transistor: metal Oxide semiconductor field effect transistors) 21 and 22 electrically connected in series between a pair of

terminals

101 and 102, as an example. The 2

MOSFETs

21, 22 are respectively enhancement n-channel MOSFETs. The source terminals of the 2

MOSFETs

21, 22 are connected to each other, that is, the 2

MOSFETs

21, 22 are connected in a so-called reverse series, whereby on/off is switched for bidirectional current.

The gate terminals of the

MOSFETs

21 and 22 are electrically connected to a level shift circuit 56. The level shift circuit 56 receives a control signal Si10 (see fig. 3) from a control unit 31 described later, and thereby drives the

MOSFETs

21 and 22.

As described above, the switch unit 2 includes the off state and the on state as the operation states. The on state includes not only a state in which the switching section 2 is continuously turned on but also a state in which the switching section 2 is intermittently turned on. That is, in the present disclosure, the off state of the switching unit 2 refers to a state in which the supply of electric power from the power source 11 to the load 12 is cut off, and the on state of the switching unit 2 refers to a state in which the supply of electric power from the power source 11 to the load 12 is performed.

Here, it is assumed that an ac voltage is applied from the power supply 11 to the switching unit 2 in a state where the switching unit 2 is non-conductive. That is, if the switching section 2 is in non-conduction, a voltage applied across the switching section 2 (hereinafter, also referred to as "inter-switching voltage") is substantially equal to an alternating voltage from the power supply 11. Hereinafter, the polarity of the high potential of the terminal 101 of the inter-switch voltage is referred to as "positive polarity", and the polarity of the high potential of the terminal 102 of the inter-switch voltage is referred to as "negative polarity".

The zero-crossing

detection units

51 and 52 are configured to detect zero-crossing points of the inter-switch voltage by detecting the magnitude of the inter-switch voltage. The zero-crossing detection section 51 is electrically connected to the terminal 101.

The zero-crossing detection unit 51 compares the absolute value of the voltage between the terminal 101 and ground (reference potential point) with a reference value (for example, 10 [ V ]) to detect a zero-crossing point when the voltage between the switches is switched from negative to positive. That is, the zero-crossing detection unit 51 determines the zero-crossing point when detecting that the switching voltage of the positive polarity is shifted from the state smaller than the reference value to the state equal to or higher than the reference value. The zero-crossing detector 52 is electrically connected to the terminal 102. The zero-crossing detection section 52 detects a zero-crossing point when the inter-switch voltage is switched from the positive polarity to the negative polarity by comparing the absolute value of the inter-terminal 102-ground (reference potential point) voltage with a reference value (for example, 10 [ V ]). That is, the zero-crossing detection unit 52 determines the zero-crossing point when detecting that the negative inter-switch voltage is shifted from a state smaller than the reference value to a state equal to or higher than the reference value.

Therefore, the time of the detection timing of the zero-crossing point detected by the zero-crossing

detection units

51, 52 is slightly delayed from the time of the zero-crossing point (0 [ V ]) in the strict sense.

As described above, the power generation circuit 4 includes the first power supply circuit 41, the second power supply circuit 42, and the precharge circuit 43. In the present embodiment, as shown in fig. 2 and 3, the power generation circuit 4 includes primary side diodes D1 and D2, secondary side diodes D3 and D4, and a DC/DC converter 44 in addition to the first power supply circuit 41, the second power supply circuit 42, and the precharge circuit 43. In the figure, the DC/DC converter 44 is denoted as "DC/DC" only.

The power generation circuit 4 generates power for the operation of the internal circuit 3 based on the voltage applied to both ends of the switching section 2. That is, the power generation circuit 4 receives as input the inter-switch voltage, and supplies the internal circuit 3 with the power for operation. In the present embodiment, the power generation circuit 4 outputs the output voltage Vout from its output terminal. The output voltage Vout is applied to the internal circuit 3, whereby electric power is supplied from the electric power generation circuit 4 to the internal circuit 3.

Here, the input end of the first power supply circuit 41 is electrically connected to the pair of

terminals

101 and 102 via the primary side diodes D1 and D2, respectively. Similarly, the second power supply circuit 42 has its input terminals electrically connected to the pair of

terminals

101 and 102 via the primary side diodes D1 and D2, respectively. The output terminal of the first power supply circuit 41 is electrically connected to the DC/DC converter 44 via the secondary side diode D3. The output terminal of the second power supply circuit 42 is electrically connected to the DC/DC converter 44 via the secondary side diode D4. The DC/DC converter 44 converts a direct-current voltage input from the first power supply circuit 41 or the second power supply circuit 42 into an output voltage Vout formed of a direct-current voltage of a predetermined magnitude. Thereby, the power generation circuit 4 supplies power from any one of the 2 circuits, that is, the first power supply circuit 41 and the second power supply circuit 42, to the internal circuit 3.

In the present embodiment, the power supply source of the internal circuit 3 is switched according to the operation state of the switch unit 2. That is, as described above, the operation state of the switching unit 2 includes the off state in which the power supply from the power supply 11 to the load 12 is interrupted and the on state in which the power supply from the power supply 11 to the load 12 is performed. Here, in the off state, electric power is supplied from the first power supply circuit 41 to the internal circuit 3, and in the on state, electric power is supplied from the second power supply circuit 42 to the internal circuit 3. The precharge circuit 43 charges the capacitor element C3 included in the second power supply circuit 42 with the electric power from the first power supply circuit 41. In other words, the first power supply circuit 41 is a power supply circuit for power supply at the time of disconnection for supplying power to the internal circuit 3 in the disconnected state. The second power supply circuit 42 is a power supply circuit for on-time for supplying power to the internal circuit 3 in an on-state.

As described above, in the present embodiment, the power supply source of the internal circuit 3 is switched between the first power supply circuit 41 and the second power supply circuit 42 according to whether the operation state of the switching unit 2 is the off state or the on state. In short, the power generation circuit 4 includes 2 power supply circuits, i.e., the first power supply circuit 41 and the second power supply circuit 42, and the 2 power supply circuits are used separately in the off state and the on state of the switch section 2.

Further, the first power supply circuit 41 for the off-state and the second power supply circuit 42 for the on-state are different in required characteristics. That is, in the first power supply circuit 41 for the time of disconnection, the switch section 2 is in the disconnected state, and therefore, in order to reduce the leakage current flowing between the pair of

terminals

101 and 102 after passing through the power generation circuit 4, it is required to have a relatively high impedance. On the other hand, in the second power supply circuit 42 for on-time, the switch section 2 is in an on state, and therefore, in order to efficiently generate electric power in the electric power generation circuit 4, it is required to have a relatively low impedance. Therefore, the first power supply circuit 41 charges the capacitive element C2 of the output stage at a relatively high voltage, and the second power supply circuit 42 charges the capacitive element C3 of the output stage at a relatively low voltage. Therefore, the voltage Vc2 across the capacitor element C2 of the first power supply circuit 41 is different from the voltage Vc3 across the capacitor element C3 of the second power supply circuit 42, and the voltage Vc2 across the capacitor element C2 is higher than the voltage Vc3 across the capacitor element C3.

The DC/DC converter 44 converts the voltage Vc2 across the capacitor element C2 of the first power supply circuit 41 or the voltage Vc3 across the capacitor element C3 of the second power supply circuit 42 into the output voltage Vout formed of a DC voltage having a predetermined magnitude. This stably applies the output voltage Vout of a predetermined magnitude from the power generation circuit 4 to the internal circuit 3.

In the present embodiment, the precharge circuit 43 charges the capacitive element C3 included in the second power supply circuit 42 with the electric power from the first power supply circuit 41. That is, when the switch section 2 is in the off state, the precharge circuit 43 charges the capacitor element C3 of the second power supply circuit 42 for on by the electric power from the first power supply circuit 41 for off. This makes it possible to smoothly switch from the first power supply circuit 41 for off to the second power supply circuit 42 for on at least when the switch is turned from the off state to the on state. In other words, even when switching from the first power supply circuit 41 to the second power supply circuit 42, the internal circuit 3 is smoothly supplied with electric power.

The power generation circuit 4 will be described in detail in the column "(2.3) of the configuration of the power generation circuit", and therefore only the general configuration of the power generation circuit 4 will be described here. As shown in fig. 2 and 3, in the present embodiment, the first power supply circuit 41 has a step-down (Dropper) power supply circuit 410, a first current limiting circuit 411, a quick charge path 412, a capacitive element C0, and a capacitive element C2. The second power supply circuit 42 includes a low impedance circuit 420, a second current limiting circuit 421, a constant current maintaining circuit 422, diodes D5 to D7, a capacitor element C1, and a capacitor element C3.

The voltage detection unit 53 is configured to detect the voltage Vc2 across the capacitor element C2 of the first power supply circuit 41. That is, as the capacitor element C2 is charged, the voltage (the two-terminal voltage Vc 2) detected by the voltage detecting unit 53 increases. The voltage detection unit 54 is configured to detect the voltage Vc3 across the capacitor element C3 of the second power supply circuit 42. That is, as the capacitor element C3 is charged, the voltage (the two-terminal voltage Vc 3) detected by the voltage detecting unit 54 increases.

The charge detection unit 55 detects the charge state of the capacitive element C1 of the second power supply circuit 42. Specifically, the charge detection unit 55 is electrically connected to a series circuit of a zener diode ZD1 and a resistor R1 connected to the output terminal of the low impedance circuit 420. The charge detection unit 55 is connected to a connection point between the zener diode ZD1 and the resistor R1, and the charge detection unit 55 detects that the charging of the capacitor element C1 is completed, based on the voltage Vc1 across the capacitor element C1 becoming equal to or greater than the threshold value.

As shown in fig. 1, the internal circuit 3 includes a control unit 31, a wireless communication unit 32, and a touch panel 33. The power generated by the operation of the internal circuit 3 including the control unit 31, the wireless communication unit 32, and the touch panel 33 is generated by the power generation circuit 4. In other words, the control unit 31, the wireless communication unit 32, and the touch panel 33 included in the internal circuit 3 each receive power from the power generation circuit 4 and operate.

The control unit 31 includes, for example, a microcontroller having 1 or more processors and 1 or more memories as a main configuration. The microcontroller executes programs recorded in 1 or more memories by 1 or more processors to realize the functions as the control unit 31. The program may be recorded in advance in a memory, or may be provided by being recorded in a non-transitory recording medium such as a memory card, or may be provided through an electric communication line. In other words, the program is a program for causing 1 or more processors to function as the control unit 31.

The control unit 31 performs on/off control of at least the switching unit 2. The control unit 31 may control the switching unit 2 (hereinafter also referred to as "load control") by phase control (including inverse phase control) or PWM (Pulse Width Modulation: pulse width modulation) control to adjust the amount of electric power supplied from the power source 11 to the load 12 per unit time. The control unit 31 also controls each part of the power generation circuit 4.

Specifically, as shown in fig. 3, the control unit 31 acquires detection signals Si1 and Si2 indicating the detection results from the zero-crossing

detection units

51 and 52, respectively. Similarly, the control unit 31 acquires the detection signals Si5 and Si6 indicating the detection results from the

voltage detection units

53 and 54, respectively, and acquires the detection signal Si8 indicating the detection result from the charge detection unit 55. As shown in fig. 3, the control unit 31 outputs a control signal Si10 for controlling the switching unit 2 to the level shift circuit 56. The control section 31 outputs control signals Si3 and Si4 for controlling the step-down power supply circuit 410 and the quick charge path 412. The control unit 31 outputs control signals Si9 and Si7 for controlling the low impedance circuit 420 and the constant current holding circuit 422.

In this way, the control unit 31 appropriately acquires the detection signals Si1, si2, si5, si6, and Si8 and outputs the control signals Si3, si4, si7, si9, and Si10, thereby controlling the switching unit 2 and the power generation circuit 4.

The wireless communication unit 32 directly performs wireless communication with another communication device via radio waves, or indirectly performs wireless communication via radio waves via a repeater or the like. The communication between the wireless communication unit 32 and the communication device is, for example, wireless communication according to a communication standard such as a specific low power radio station (a radio station not requiring permission) in the 920MHz band, wi-Fi (registered trademark), bluetooth (registered trademark), or the like. As another example of the communication device, there are a sensor terminal such as a human sensor, a remote controller that receives a human operation, and the like. The wireless communication unit 32 performs two-way communication with these communication devices, whereby the control unit 31 can control the switching unit 2 based on the wireless signal from the communication device.

The touch panel 33 is a touch panel display having a display function and a touch sensor function. The touch panel 33 functions as a user interface, and for example, displays information such as the operation status of the load control device 1 to give a person or receives a touch operation by a person to output a signal. By having such a touch panel 33, the control section 31 can control the switch section 2 based on the operation of the touch panel 33 by a person.

(2.3) Structure of Power Generation Circuit

Next, a more detailed configuration of the power generation circuit 4 in the load control device 1 will be described with reference to fig. 1 to 3.

As described above, the power generation circuit 4 has the first power supply circuit 41, the second power supply circuit 42, the precharge circuit 43, the primary side diodes D1, D2, the secondary side diodes D3, D4, and the DC/DC converter 44. In fig. 1 (the same applies to fig. 8 and 9 described later), the DC/DC converter 44 included in the power generation circuit 4 is omitted.

As described above, the respective input terminals of the input terminal of the first power supply circuit 41 and the input terminal of the second power supply circuit 42 are electrically connected to the pair of

terminals

101, 102 via the primary side diodes D1, D2, respectively. The output terminal of the first power supply circuit 41 and the output terminal of the second power supply circuit 42 are electrically connected to the DC/DC converter 44 via the secondary side diodes D3 and D4, respectively. Therefore, the voltage applied to both ends of the switching section 2 is rectified by the primary side diodes D1, D2 and then input to the first power supply circuit 41 or the second power supply circuit 42, and the output of the first power supply circuit 41 or the second power supply circuit 42 is input to the DC/DC converter 44.

As shown in fig. 2 and 3, the first power supply circuit 41 has a step-down power supply circuit 410, a first current limiting circuit 411, a quick charge path 412, a capacitive element C0 (capacitor) on the primary side, and a capacitive element C2 (capacitor) on the secondary side.

The step-down power supply circuit 410 reduces the voltage obtained by rectifying the voltage applied to both ends of the switching section 2. The capacitor element C0 is connected to the output terminal of the step-down power supply circuit 410, and is charged by the output of the step-down power supply circuit 410. The capacitive element C0 on the primary side is a capacitor charged with a high voltage and having a small capacity compared to the capacitive element C2 on the secondary side. That is, the voltage Vc0 across the capacitor element C0 is higher than the voltage Vc2 across the capacitor element C2.

As described above, the first power supply circuit 41 has a capacitor (capacitive element C2) at its output stage. The capacitor (capacitor element C2) of the output stage functions as a buffer for absorbing the fluctuation of the power consumption in the internal circuit 3. The voltage Vc2 across the capacitor element C2 is applied as an output of the first power supply circuit 41 to the DC/DC converter 44 via the secondary side diode D3.

The first current limiting circuit 411 is interposed between the capacitive element C0 on the primary side and the capacitive element C2 on the secondary side. The first current limiting circuit 411 forms a charging path for flowing a current flowing to the capacitive element C2, that is, a charging current of the capacitive element C2. The first current limiting circuit 411 is a constant current circuit, and limits the magnitude of the current flowing in the first current limiting circuit 411, that is, the charging path of the capacitive element C2, to a first current value (for example, 0.5 mA) or less.

The quick charge path 412 is interposed between the capacitive element C0 on the primary side and the capacitive element C2 on the secondary side. That is, the first current limiting circuit 411 is electrically connected in parallel with the quick charge path 412 between the capacitive element C0 on the primary side and the capacitive element C2 on the secondary side. The quick charge path 412 forms a charge path for flowing a current flowing to the capacitive element C2, that is, a charge current of the capacitive element C2. The fast charge path 412 constitutes a low impedance charge path compared to the first current limiting circuit 411.

The conduction/non-conduction of the quick charge path 412 is controlled by a control signal Si4 from the control section 31. When the supply of electric power from the first power supply circuit 41 to the internal circuit 3 is started, the control unit 31 turns on the quick charge path 412 by the control signal Si 4. The term "supply start time" when the power supply from the first power supply circuit 41 to the internal circuit 3 is started includes both when the load control device 1 is started and when the switch section 2 is switched from the on state to the off state.

In summary, in the present embodiment, the first power supply circuit 41 has the first capacitive element C2, the first charging path for charging the first capacitive element C2, and the second charging path has a lower impedance than the first charging path. The first capacitance element C2 is a capacitance element different from the capacitance element C3 (second capacitance element C3) charged by the precharge circuit 43. When the supply of electric power from the first power supply circuit 41 to the internal circuit 3 is started, the first power supply circuit 41 charges the first capacitive element C2 through the second charging path. That is, the first current limiting circuit 411 corresponds to a "first charging path", and the quick charging path 412 corresponds to a "second charging path". As described above, the first power supply circuit 41 has 2 charging paths as the charging paths of the capacitor element C2, and when the supply of electric power to the internal circuit 3 is started, the capacitor element C2 is quickly charged through the quick charging path 412 (second charging path).

As shown in fig. 2 and 3, the second power supply circuit 42 includes a low impedance circuit 420, a second current limiting circuit 421, a constant current holding circuit 422, diodes D5 to D7, a primary-side capacitance element C1 (capacitor), and a secondary-side capacitance element C3 (capacitor).

The low impedance circuit 420 is interposed between the output terminals (cathodes) of the primary side diodes D1, D2 and the primary side capacitive element C1. The low impedance circuit 420 forms a charging path for allowing a current flowing to the capacitive element C1, that is, a charging current of the capacitive element C1 to flow. The low impedance circuit 420 constitutes a low impedance charging path compared to the first current limiting circuit 411.

The capacitor element C1 is connected to the output terminal of the low impedance circuit 420 via the diode D5, and is charged by the output of the low impedance circuit 420. The primary-side capacitive element C1 is a capacitor charged with a high voltage and having a small capacity as compared with the secondary-side capacitive element C3. That is, the voltage Vc1 across the capacitor element C1 is higher than the voltage Vc3 across the capacitor element C3. In the second power supply circuit 42, the capacitor of the output stage is charged with a lower voltage than the first power supply circuit 41. Therefore, the secondary side capacitor element C3 in the second power supply circuit 42 has a lower withstand voltage and a larger capacity than the secondary side capacitor element C2 in the first power supply circuit 41.

In this way, the second power supply circuit 42 has a capacitor (capacitive element C3) at its output stage. The capacitor (capacitor element C3) of the output stage functions as a buffer for absorbing the fluctuation of the power consumption in the internal circuit 3. The voltage Vc3 across the capacitor element C3 is applied as an output of the second power supply circuit 42 to the DC/DC converter 44 via the secondary side diode D4.

The second current limiting circuit 421 is interposed between the primary-side capacitive element C1 and the secondary-side capacitive element C3. The second current limiting circuit 421 forms a charging path for allowing a current flowing to the capacitive element C3, that is, a charging current of the capacitive element C3 to flow. The second current limiting circuit 421 is a constant current circuit, and limits the magnitude of the current flowing in the second current limiting circuit 421, that is, the charging path of the capacitive element C3, to a second current value (for example, 3 mA) or less.

The constant current maintenance circuit 422 forms a current path when the secondary-side capacitive element C3 is fully charged. Specifically, the constant current maintenance circuit 422 includes a series circuit of a zener diode ZD2 and a MOSFET 423. The constant current maintenance circuit 422 is electrically connected to a connection point of the capacitor element C3 and the secondary side diode D4. The conduction/non-conduction of the constant current maintenance circuit 422 is controlled by a control signal Si7 from the control section 31. When the capacitor element C3 is fully charged, the control unit 31 turns on the constant current holding circuit 422 by the control signal Si 7.

Diodes D6 and D7 are electrically connected to the output terminal of precharge circuit 43. The diode D6 is interposed between the precharge circuit 43 and the primary-side capacitive element C1.

The input terminal of the precharge circuit 43 is electrically connected to a connection point of the primary-side capacitive element C0 in the first power supply circuit 41 and the first current limiting circuit 411 (or the quick charge path 412). That is, the precharge circuit 43 is interposed between the capacitive element C0 on the primary side of the first power supply circuit 41 and the second power supply circuit 42. Here, the precharge circuit 43 constitutes a low-impedance charging path as compared with the quick charging path 412.

Thereby, the precharge circuit 43 can charge the primary-side capacitive element C1 via the diode D6 by using the electric power from the first power supply circuit 41. The diode D7 is interposed between the precharge circuit 43 and the secondary-side capacitive element C3. Thereby, the precharge circuit 43 can charge the secondary-side capacitive element C3 via the diode D7 by using the electric power from the first power supply circuit 41.

As described above, in the present embodiment, the first power supply circuit 41 and the second power supply circuit 42 have capacitors (the capacitive element C2 and the capacitive element C3) at the respective output stages. The capacitive element C3 charged by the precharge circuit 43 is a capacitor (of the output stage) of any one of the first power supply circuit 41 and the second power supply circuit 42. In the present embodiment, as described above, the precharge circuit 43 charges the capacitive element C3 included in the second power supply circuit 42 with the electric power from the first power supply circuit 41. That is, the capacitance element C3 charged by the precharge circuit 43 is a capacitor (capacitance element C3) of the output stage of the second power supply circuit 42.

(2.4) operation of load control device

Next, the operation of the load control device 1 according to the present embodiment will be described with reference to fig. 4 to 7B. Fig. 4 shows the operation of the load control device 1 in the charging mode, which is the charging of the capacitive elements C0, C1, C2, and C3. Fig. 5 shows the operation of the load control device 1 in the off state, that is, the off mode of the switching unit 2, and fig. 6 shows the operation of the load control device 1 in the on state, that is, the on mode of the switching unit 2.

First, the load control device 1 operates in the charging mode shown in fig. 4 immediately after the start-up, that is, immediately after the start of the power supply. Immediately after the start-up, the capacitive elements C0, C2 of the first power supply circuit 41 and the capacitive elements C1, C3 of the second power supply circuit 42 are both in an uncharged state. At this time, in the load control device 1, the switching section 2 is in an off state, and the quick charge path 412 is in an on state by the control signal Si4 from the control section 31. Accordingly, in the charging mode of fig. 4, the first power supply circuit 41 charges the capacitive elements C0 and C2 with the current I1 via the step-down power supply circuit 410 by using the voltages applied to both ends of the switching section 2. In particular, the capacitive element C2 is charged rapidly with the current I1 via the rapid charging path 412, that is, without being limited by the current of the first current limiting circuit 411.

In the charging mode of fig. 4, the second power supply circuit 42 charges the capacitor elements C1 and C3 with the current I1 via the precharge circuit 43 by using the voltages applied to both ends of the switch section 2. That is, since the precharge circuit 43 is of lower low impedance than the quick charge path 412, the power from the first power supply circuit 41 is fused to the second power supply circuit 42 via the precharge circuit 43. Therefore, in the charging mode, the precharge circuit 43 charges the capacitive elements C1, C3 of the second power supply circuit 42 with the electric power from the first power supply circuit 41. As a result, in the charging mode shown in fig. 4, the capacitive elements C0 to C3 of both the first power supply circuit 41 and the second power supply circuit 42 are charged at the same time with the current I1.

When the capacitor element C2 on the secondary side of the first power supply circuit 41 is charged and the voltage Vc2 across the capacitor element C2 becomes equal to or greater than the threshold value, the detection signal Si5 from the voltage detection unit 53 is received, and the operation mode of the load control device 1 is switched to the off mode. That is, the load control device 1 shifts from the charging mode shown in fig. 4 to the off mode shown in fig. 5. At this time, in the load control device 1, the switching section 2 is in the off state, and the quick charge path 412 becomes non-conductive by the control signal Si4 from the control section 31. Thus, the lighting device as the load 12 is turned off.

In the off mode of fig. 5, the DC/DC converter 44 is supplied with electric power by the first power supply circuit 41 at the current I2 by the voltage applied to both ends of the switching section 2. At this time, a current I2 limited to a first current value (for example, 0.5 mA) or less via the first current limiting circuit 411 flows to the first power supply circuit 41. In this way, in the off mode shown in fig. 5, the power generation circuit 4 is set to a high impedance, and thus, the leakage current flowing between the pair of

terminals

101 and 102 after passing through the power generation circuit 4 can be reduced. Thus, it becomes easy to prevent the lighting device as the load 12 from being erroneously turned on in the off mode, for example.

On the other hand, when the switching unit 2 is switched from the off state to the on state, the operation mode of the load control device 1 is switched to the on mode. That is, the load control device 1 shifts from the off mode shown in fig. 5 to the on mode shown in fig. 6. At this time, in the load control device 1, the switching unit 2 is in an on state. Thus, the lighting device as the load 12 is turned on.

In the on mode of fig. 6, the DC/DC converter 44 is supplied with electric power by the second power supply circuit 42 at a current I3 by a voltage applied to both ends of the switching section 2. At this time, a current I3 limited to a second current value (for example, 3 mA) or less via the second current limiting circuit 421 flows to the second power supply circuit 42. Then, if the capacitor element C3 is fully charged, the control unit 31 turns on the constant current holding circuit 422 by the control signal Si 7. In this way, in the on mode shown in fig. 6, the current flowing to the power generation circuit 4 is limited, and the impedance of the power generation circuit 4 can be stabilized. Thus, in the on mode, for example, the lighting state of the lighting device as the load 12 is easily stabilized.

When the switching unit 2 is switched from the on state to the off state, the operation mode of the load control device 1 is switched to the charging mode. That is, the load control device 1 shifts from the conduction mode shown in fig. 6 to the charging mode shown in fig. 4. Thereafter, the load control device 1 repeats the operations of fig. 4 to 6 described above, that is, the operations of the charging mode, the off mode, and the on mode in a cycle.

As described above, in the load control device 1 according to the present embodiment, the precharge circuit 43 charges the capacitor element C3 when the supply of electric power from the first power supply circuit 41 to the internal circuit 3 is started. The term "supply start time" when the power supply from the first power supply circuit 41 to the internal circuit 3 is started includes both when the load control device 1 is started and when the switch section 2 is switched from the on state to the off state. That is, the load control device 1 operates in the charging mode at the initial start-up time and at the time of switching the switching unit 2 from the on state to the off state. In the charging mode, the precharge circuit 43 charges the capacitive elements C1 and C3 of the second power supply circuit 42 with the electric power from the first power supply circuit 41.

As a result, when switching from the off mode to the on mode, the capacitor elements C1 and C3 of the second power supply circuit 42 are in a charged state, and therefore, the power supply source of the internal circuit 3 is easily and smoothly switched from the first power supply circuit 41 to the second power supply circuit 42. That is, in the charging mode, the capacitor elements C1 and C3 of the second power supply circuit 42 are charged by the precharge circuit 43 using the electric power from the first power supply circuit 41, and therefore, when switching from the off mode to the on mode, it is not necessary to separately charge the capacitor elements C1 and C3. Thus, when switching from the first power supply circuit 41 to the second power supply circuit 42, electric power is smoothly supplied to the internal circuit 3 (seamless). As a result, the fluctuation of the voltage applied from the power generation circuit 4 to the internal circuit 3 is suppressed, and the operation of the control unit 31 and the like is stabilized.

The internal circuit 3 is a circuit in which power consumption varies. The capacitor element C3 (charged by the precharge circuit 43) is for alleviating the influence of variations in power consumption on the inputs of the first power supply circuit 41 and the second power supply circuit 42. That is, in the present embodiment, the internal circuit 3 includes a circuit in which power consumption varies as in the wireless communication unit 32 and the touch panel 33. On the other hand, the capacitor element C3 charged by the precharge circuit 43 is a capacitor serving as a buffer, and absorbs the fluctuation of the power consumption of the internal circuit 3 to thereby alleviate the influence of the fluctuation of the power consumption on the inputs of the first power supply circuit 41 and the second power supply circuit 42. In other words, the capacitor element C3 is used to mitigate the influence on the inputs of the first power supply circuit 41 and the second power supply circuit 42 caused by the fluctuation of the power consumption.

As an example, fig. 7A and 7B show a case where variations in power consumption are absorbed by the capacitive elements C2 and C3. Fig. 7A shows the voltage Vc2 across the capacitor (capacitive element C2) of the output stage of the first power supply circuit 41 with the horizontal axis as the time axis. Fig. 7B shows the voltage Vc3 across the capacitor (capacitive element C3) of the output stage of the second power supply circuit 42 with the horizontal axis as the time axis. The voltage value V1 in fig. 7A is the voltage Vc2 across the capacitor C2 when fully charged, and the voltage value V2 in fig. 7B is the voltage Vc3 across the capacitor C3 when fully charged (V1 > V2).

In fig. 7A and 7B, a period T1 indicates a period during which the radio communication unit 32 of the internal circuit 3 receives radio waves, a period T2 indicates a period during which the radio communication unit 32 transmits radio waves, and a period T3 indicates a period during which the radio communication unit 32 continues to receive radio waves. That is, the wireless communication unit 32 of the internal circuit 3 increases its power consumption by performing the reception or transmission operation. At this time, since the electric energy stored in the capacitor elements C2 and C3 is consumed, the voltages Vc2 and Vc3 at both ends of the capacitor elements C2 and C3 are reduced. As described above, when the power consumption of the internal circuit 3 fluctuates, the fluctuation is absorbed by the capacitor elements C2 and C3, and therefore the influence of the fluctuation in power consumption is less likely to occur on the primary side of the first power supply circuit 41 and the second power supply circuit 42.

In other words, the load control device 1 includes the capacitors (the capacitive elements C2 and C3) for buffering, and can compensate for a shortage of the current flowing to the internal circuit 3 by the discharge current of the capacitors (the capacitive elements C2 and C3). Therefore, the load control device 1 can supply the electric power required by the internal circuit 3, although the electric current flowing through the electric power generation circuit 4 is limited by the first current limiting circuit 411 or the second current limiting circuit 421.

In particular, when the power consumption of the internal circuit 3 is relatively large and the power consumption of the internal circuit 3 varies relatively large as in the present embodiment, the meaning of the precharge circuit 43 described above becomes large.

That is, when the internal circuit 3 includes a circuit that consumes a relatively large amount of power, such as the wireless communication unit 32 and the touch panel 33, a capacitor (capacitive elements C2 and C3) having a relatively large capacity is used as a buffer of the power generation circuit 4. In the off state, since the first power supply circuit 41 is set to have a high impedance, the withstand voltage of the capacitor element C2 becomes a relatively high voltage. On the other hand, in the on state, the capacity of the capacitor element C3 becomes particularly large because the capacitor element C3 is charged with a low voltage. In this way, when the secondary side capacitor element C2 of the first power supply circuit 41 and the secondary side capacitor element C3 of the second power supply circuit 42 are used together, a large capacitor having a relatively high withstand voltage and a relatively large capacity is required.

Further, when the capacity of the capacitor element C2 increases, the charging of the capacitor element C2 takes time, so that when switching from the on state to the off state, a leakage current easily flows between the pair of

terminals

101 and 102 after passing through the power generation circuit 4. As a result, for example, the lighting device as the load 12 easily blinks.

In the present embodiment, the first power supply circuit 41 and the second power supply circuit 42 are used separately in the off state and the on state of the switch section 2, and thus the capacitance elements C2 and C3 can be made relatively small. Then, the precharge circuit 43 fuses the power from the first power supply circuit 41 to the capacitive elements C1 and C3 of the second power supply circuit 42, thereby smoothing the switching from the first power supply circuit 41 to the second power supply circuit 42. Thus, although 2 power supply circuits, that is, the first power supply circuit 41 and the second power supply circuit 42, are used as the power generation circuit 4, power is smoothly supplied to the internal circuit 3, and fluctuation of the voltage applied from the power generation circuit 4 to the internal circuit 3 is suppressed.

(3) Modification examples

Embodiment 1 is but one of the various embodiments of the present disclosure. As long as the object of the present disclosure can be achieved, various modifications can be made to embodiment 1 according to the design or the like. For example, the specific circuit shown in fig. 2 is only one example of the load control device 1 of the present disclosure, and various modifications can be made according to the design or the like. The drawings described in the present disclosure are schematic drawings, and the ratio of the sizes and the ratio of the thicknesses of the constituent elements in the drawings do not necessarily reflect the actual dimensional ratio. The functions equivalent to the control unit 31 of the load control device 1 according to embodiment 1 can be realized by a control method, a (computer) program, a non-transitory recording medium in which the program is recorded, or the like.

Next, a modification of embodiment 1 is described. The modifications described below can be applied in appropriate combination.

(3.1) first modification example

As shown in fig. 8, a load control device 1A according to a first modification of embodiment 1 is different from the load control device 1 according to embodiment 1 in the following points: the precharge circuit 43 causes a current for precharge to flow bi-directionally between the first power supply circuit 41 and the second power supply circuit 42. Hereinafter, the same components as those of embodiment 1 will be denoted by common reference numerals, and description thereof will be omitted as appropriate.

That is, in the present modification, the first power supply circuit 41 has a first capacitance element C2 different from the second capacitance element C3 (charged by the precharge circuit 43), that is, the capacitance element C3. The precharge circuit 43 charges the second capacitive element C3 with the power from the first power supply circuit 41, and charges the first capacitive element C2 with the power from the second power supply circuit 42.

In embodiment 1, the precharge circuit 43 unilaterally supplies power from the first power supply circuit 41 to the capacitor element C3 of the second power supply circuit 42, but in this modification, power from the second power supply circuit 42 may be supplied to the capacitor element C2 of the first power supply circuit 41. The second power supply circuit 42 is a relatively low-voltage circuit as compared with the first power supply circuit 41, and therefore, in the case where power is fused from the second power supply circuit 42 to the capacitance element C2 of the first power supply circuit 41, the precharge circuit 43 is realized by including a voltage boosting circuit. That is, the precharge circuit 43 can charge the capacitor element C2 by, for example, boosting the voltage Vc1 across the capacitor element C1 on the primary side of the second power supply circuit 42 and applying the boosted voltage to the capacitor element C2 of the first power supply circuit 41.

(3.2) other modifications

The load control device 1 in the present disclosure includes a computer system in the control section 31 and the like. The computer system has a main structure of a processor and a memory as hardware. The function as the load control device 1 in the present disclosure is realized by executing a program recorded in a memory of a computer system by a processor. The program may be recorded in advance in a memory of the computer system, may be provided via an electric communication line, or may be recorded in a non-transitory recording medium such as a memory card, an optical disk, or a hard disk drive readable by the computer system. The processor of a computer system is composed of one or more electronic circuits including a semiconductor Integrated Circuit (IC) or a large scale integrated circuit (LSI). The integrated circuits such as an IC or an LSI described herein include integrated circuits called a system LSI, a VLSI (Very Large Scale Integration: very large scale integration), or a ULSI (Ultra Large Scale Integration: very large scale integration), and the names thereof are different depending on the degree of integration. Further, an FPGA (Field-Programmable Gate Array: field programmable gate array) programmed after the manufacture of an LSI, or a logic device capable of reconstructing a bonding relationship inside the LSI or reconstructing a circuit division inside the LSI can be used as a processor. The plurality of electronic circuits may be integrated in 1 chip, or may be provided in a plurality of chips in a distributed manner. The plurality of chips may be integrated in 1 device or may be provided in a plurality of devices in a distributed manner. The computer system described herein includes a microcontroller having 1 or more processors and 1 or more memories. Thus, the microcontroller is also composed of one or more electronic circuits including a semiconductor integrated circuit or a large scale integrated circuit.

At least a part of the functions of the load control device 1 are integrated in 1 case and are not necessarily required for the load control device 1, and the constituent elements of the load control device 1 may be provided in a plurality of cases in a distributed manner. For example, the touch panel 33 may be provided in a different housing from the control unit 31. At least a part of the functions of the control unit 31 and the like may be realized by a server, cloud (cloud computing), or the like.

In embodiment 1, the precharge circuit 43 unilaterally supplies power from the first power supply circuit 41 to the capacitor element C3 of the second power supply circuit 42, but the precharge circuit 43 may unilaterally supply power from the second power supply circuit 42 to the capacitor element C2 of the first power supply circuit 41. That is, the precharge circuit 43 may charge the capacitor element included in one of the first power supply circuit 41 and the second power supply circuit 42 with power from the other of the first power supply circuit 41 and the second power supply circuit 42, and may charge the capacitor element C2 included in the first power supply circuit 41 with power from the second power supply circuit 42.

In addition, the circuit design can be changed appropriately, for example, a switching power supply circuit is used instead of the step-down power supply circuit 410 or the like.

In embodiment 1, the power source 11 is a commercial power source having a single phase of 100 [ V ] or 60 [ Hz ], but may be a commercial power source having a single phase of 100 [ V ] or 50 [ Hz ]. The voltage value of the power supply 11 is not limited to 100 [ V ].

In embodiment 1, the load control device 1 is a single-pole switch, but may be of another configuration. For example, the load control device 1 may be a so-called three-way switch capable of connecting 3 wires. The load control device 1 may be a so-called four-way switch capable of connecting 4 wires. In the case where the load control device 1 constitutes a three-way switch, by combining 2 load control devices 1, for example, the energization state of the load 12 can be switched at 2 positions, that is, an upstairs portion and a downstairs portion of a stairway in a building.

In embodiment 1, the zero-crossing detection unit 51 is configured to detect zero crossing when the inter-switch voltage is switched from the negative polarity to the positive polarity, based on the terminal 101-ground voltage becoming equal to or higher than the reference value, but the opposite may be adopted. That is, the zero-crossing detection unit 51 may be configured to detect a zero crossing when the inter-switch voltage is switched from the positive polarity to the negative polarity, based on the fact that the inter-switch voltage is smaller than the reference value. Similarly, the zero-crossing detection unit 52 is configured to detect zero crossing when the inter-switch voltage is switched from the positive polarity to the negative polarity based on the inter-switch voltage becoming equal to or higher than the reference value, but the opposite may be adopted. That is, the zero-crossing detection unit 52 may be configured to detect a zero crossing when the inter-switch voltage is switched from the negative polarity to the positive polarity, based on the terminal 102-ground voltage becoming smaller than the reference value.

The load 12 is not limited to a lighting device including a light source including an LED, and may be a lighting device including a light source other than an LED. The load 12 is not limited to the illumination device, and may be, for example, a ventilator, a display device, an electric shutter, an air conditioner, a crime prevention device, or the like (including a device, a system, and a device). The load 12 is not limited to 1 apparatus, and may be a plurality of apparatuses electrically connected in series or parallel.

The load control device 1 may further include an operation terminal for connecting the slave device. The slave unit includes a contact portion such as a push button switch, and the load control device 1 detects on/off of the contact portion. In this case, the load control device 1 controls the switching unit 2 according to the operation (on/off of the contact unit) of the slave unit to switch the operation state of the switching unit 2. That is, in the slave unit, for example, each time the push-button switch is pushed to turn on the contact unit, the load control device 1 operates to switch the off state and the on state of the switch unit 2. In short, in the load control device 1, the control of the switch unit 2 may be performed not only based on the outputs of the wireless communication unit 32 and the touch panel 33, but also based on the operation of the slave unit. Thus, by providing the load control device 1 and the sub-machine separately at 2 positions, for example, an upstairs portion and an downstairs portion of a stairway in a building, it is possible to switch the energization state in which the load 12 is energized at the 2 positions.

The internal circuit 3 may also include a sensor circuit, a timer circuit, or the like, in addition to or instead of the wireless communication unit 32 and the touch panel 33. As an example, the sensor circuit includes a human sensor and/or a brightness sensor for detecting the presence or absence of a human. The load control device 1 can control the switching unit 2 based on the outputs of the sensor circuits, the timer circuits, and the like.

In the above embodiment, the switching unit 2 has 2

MOSFETs

21 and 22, but the switching unit is not limited to the MOSFETs, and may be other semiconductor switches. For example, the switching unit 2 may be realized by a 3-terminal triac (triac), or a semiconductor element of a double gate (dual gate) structure using a wide band gap semiconductor material such as GaN (gallium nitride).

(embodiment 2)

The load control device 1B according to the present embodiment is different from the load control device 1 according to embodiment 1 in the following points: as shown in fig. 9, 1 capacitor C4 is provided instead of the secondary-side capacitive elements of the first power supply circuit 41 and the second power supply circuit 42. Hereinafter, the same components as those of embodiment 1 will be denoted by common reference numerals, and description thereof will be omitted as appropriate.

In the present embodiment, 1 capacitor C4 is provided instead of the secondary-side capacitive elements C2 and C3 of the first power supply circuit 41 and the second power supply circuit 42 (see fig. 2). The precharge circuit 43 charges the capacitive element C1 on the primary side of the second power supply circuit 42. That is, in the present embodiment, only the primary-side capacitive elements C0 and C1 (see fig. 2) may be provided independently in the first power supply circuit 41 and the second power supply circuit 42, and the precharge circuit 43 may be configured to fuse electric power between these primary-side capacitive elements C0 and C1.

In this case, the precharge circuit 43 may charge the capacitor element included in one of the first power supply circuit 41 and the second power supply circuit 42 with power from the other of the first power supply circuit 41 and the second power supply circuit 42. That is, the precharge circuit 43 may charge not only the capacitive element C1 included in the second power supply circuit 42 with the power from the first power supply circuit 41, but also the capacitive element C0 included in the first power supply circuit 41 with the power from the second power supply circuit 42.

The precharge circuit 43 may cause a precharge current to flow in both directions between the first power supply circuit 41 and the second power supply circuit 42.

The configuration described in embodiment 2 (including the modification) can be appropriately combined with the various configurations described in embodiment 1 (including the modification).

(summary)

As described above, the load control devices (1, 1A, 1B) according to the first aspect include the switch unit (2), the first power supply circuit (41), the second power supply circuit (42), the internal circuit (3), and the precharge circuit (43). The switch unit (2) is interposed between the power source (11) and the load (12). The first power supply circuit (41) generates electric power based on the voltage applied to both ends of the switching section (2). The second power supply circuit (42) generates electric power based on the voltages applied to both ends of the switching section (2). The internal circuit (3) is supplied with electric power by the first power supply circuit (41) or the second power supply circuit (42). A precharge circuit (43) charges capacitive elements (C0-C3) included in one of the first power supply circuit (41) and the second power supply circuit (42) with power from the other of the first power supply circuit (41) and the second power supply circuit (42).

According to this aspect, the precharge circuit (43) can supply power from one of the first power supply circuit (41) and the second power supply circuit (42) to the other of the first power supply circuit (41) and the second power supply circuit (42), and thereby can shorten the time taken to charge the capacitive elements (C0 to C3) when starting the supply of power to the internal circuit (3). Therefore, at least when the supply source for supplying power to the internal circuit (3) is switched from one of the first power supply circuit (41) and the second power supply circuit (42) to the other of the first power supply circuit (41) and the second power supply circuit (42), the switching is easily and smoothly achieved. As a result, there are the following advantages: it is easy to suppress fluctuation of power supplied from the power supply 11 to the load 12 when switching between the first power supply circuit 41 and the second power supply circuit 42, and it is easy to stabilize power supply to the load 12.

In the load control devices (1, 1A, 1B) according to the second aspect, in the first aspect, the operation state of the switching unit (2) includes a cut-off state in which power supply from the power supply (11) to the load (12) is cut off, and a conduction state in which power supply from the power supply (11) to the load (12) is performed. In the off state, power is supplied from the first power supply circuit (41) to the internal circuit (3). In the on state, power is supplied from the second power supply circuit (42) to the internal circuit (3). The precharge circuit (43) charges the capacitive elements (C1, C3) included in the second power supply circuit (42) with power from the first power supply circuit (41).

According to this aspect, when switching from the off state to the on state, the capacitive elements (C1, C3) of the second power supply circuit (42) used in the on state can be charged in advance, and switching from the first power supply circuit (41) to the second power supply circuit (42) can be easily and smoothly achieved.

In the load control devices (1, 1A, 1B) according to the third aspect, in the second aspect, the precharge circuit (43) charges the capacitor elements (C1, C3) when starting the supply of power from the first power supply circuit (41) to the internal circuit (3).

In the load control device (1, 1A, 1B) according to the fourth aspect, in the second or third aspect, the first power supply circuit (41) has a first capacitance element (C2) different from a second capacitance element (C3) that is the capacitance element (C3); a first charging path; and a second charging path. The first charging path is a path for charging the first capacitive element (C2). The second charging path is a path for charging the first capacitive element (C2), and is low-impedance compared to the first charging path. When the supply of power from the first power supply circuit (41) to the internal circuit (3) is started, the first capacitor element (C2) is charged through the second charging path.

According to this aspect, when the supply of electric power from the first power supply circuit (41) to the internal circuit (3) is started, the first capacitor element (C2) can be quickly charged through the second charging path, and the output of the first power supply circuit (41) can be quickly stabilized.

In the load control device (1, 1A, 1B) according to the fifth aspect, in any one of the second to fourth aspects, the first power supply circuit (41) has a first capacitance element (C2) different from a second capacitance element (C3) that is a capacitance element. The precharge circuit (43) charges the second capacitive element (C3) with power from the first power supply circuit (41), and charges the first capacitive element (C2) with power from the second power supply circuit (42).

According to this aspect, the precharge circuit (43) can bidirectionally fuse electric power between the first power supply circuit (41) and the second power supply circuit (42).

In the load control device (1, 1A, 1B) according to the sixth aspect, in any one of the first to fifth aspects, the first power supply circuit (41) and the second power supply circuit (42) have capacitors (C2, C3) at respective output stages. The capacitive elements (C2, C3) are capacitors (C2, C3) of either the first power supply circuit (41) or the second power supply circuit (42).

According to this aspect, the first power supply circuit (41) and the second power supply circuit (42) have the capacitors (C2, C3) independently at the respective output stages, and thus it is easy to avoid enlargement of these capacitors (C2, C3).

In the load control device (1, 1A, 1B) according to the seventh aspect, in any one of the first to sixth aspects, the internal circuit (3) is a circuit in which power consumption varies. The capacitive elements (C0-C3) are used for alleviating the influence of the fluctuation of the consumed power on the input of the first power supply circuit (41) and the second power supply circuit (42).

According to this mode, there are the following advantages: the fluctuation of the power consumption of the internal circuit (3) is less likely to cause the fluctuation of the power supplied from the power supply (11) to the load (12), and the power supply to the load (12) is more likely to be stable.

The structures according to the second to seventh aspects are not necessary for the load control devices (1, 1A, 1B), and can be omitted appropriately.

Claims

1. A load control device is provided with:

a switch unit interposed between the power supply and the load;

a first power supply circuit that generates electric power based on a voltage applied to both ends of the switching section;

a second power supply circuit that generates electric power based on a voltage applied to both ends of the switching section;

an internal circuit to which power is supplied by the first power supply circuit or the second power supply circuit; and

a precharge circuit that charges the capacitive element,

The operation state of the switch unit includes a cut-off state in which the power supply from the power supply to the load is cut off, and a conduction state in which the power supply from the power supply to the load is performed,

wherein, in the cut-off state, power is supplied from the first power supply circuit to the internal circuit,

in the on state, power is supplied from the second power supply circuit to the internal circuit,

the capacitive element includes a first capacitive element that the first power supply circuit has at the output stage and a second capacitive element that the second power supply circuit has at the output stage,

in the off state, the precharge circuit charges the second capacitive element with power from the first power supply circuit, and in the on state, the precharge circuit charges the first capacitive element with power from the second power supply circuit.

2. The load control device of claim 1 wherein the load control device comprises,

the precharge circuit charges the second capacitive element when supply of electric power from the first power supply circuit to the internal circuit is started.

3. The load control device according to claim 1 or 2, characterized in that,

The first power supply circuit has:

a first charging path for charging the first capacitive element; and

a second charging path for charging the first capacitive element, the second charging path being of low impedance compared to the first charging path,

in the off state, the first capacitor element is charged through the second charging path when the supply of electric power from the first power supply circuit to the internal circuit is started.

4. The load control device according to claim 1 or 2, characterized in that,

the internal circuit is a circuit in which power consumption varies,

the capacitor element mitigates an influence of the fluctuation of the power consumption on inputs of the first power supply circuit and the second power supply circuit.