CN112533327A

CN112533327A - Load control device

Info

Publication number: CN112533327A
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: 2021-03-19
Anticipated expiration: 2040-09-17
Also published as: CN112533327B; JP7308409B2; TW202114470A; JP2021048020A

Abstract

The present disclosure provides a load control device that facilitates stable power supply to a load. A load control device (1) is provided with a switch 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 inserted between the power source (11) and the load (12). The first power supply circuit (41) generates power based on a voltage applied to both ends of the switch unit (2). The second power supply circuit (42) generates power based on a voltage applied to both ends of the switch unit (2). The internal circuit (3) is supplied with power from the first power supply circuit (41) or the second power supply circuit (42). A precharge circuit (43) charges a capacitance 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 including a switch unit interposed between a power supply and a load.

Background

A load control device (2-wire dimmer) for dimming a load (LED lighting fixture) is described in document 1 (japanese laid-open patent publication No. 2012-14953). The load control device described in document 1 includes a switch unit (triac) interposed between an ac power supply and a load, a control unit (control circuit), and a power generation circuit (power supply generation circuit). The control unit controls the switching unit to be turned on based on a detection signal of a detection circuit for detecting a zero cross point of the alternating-current power supply. The power generation circuit is connected between both ends of the switch unit, and generates power (power supply) for operation of the control unit during the off period of the switch 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 power consumption other than the control unit increases, the power for operation of the control unit becomes insufficient, and the power supply to the load tends to become unstable.

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

Means for solving the problems

A load control device according to one aspect of the present disclosure includes a switch 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 power based on a voltage applied to both ends of the switch section. The second power supply circuit generates power based on a voltage applied to both ends of the switch 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 capacitor 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 power supply to a load is easily stabilized.

Drawings

Fig. 1 is a block diagram showing a schematic 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 shows a relationship with the control unit.

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

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

Fig. 6 is an explanatory diagram of an 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 described above.

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 a schematic 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 source; 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 fast charging path (second charging path); c1, C0: a capacitive element; c2: a capacitive element (first capacitive element, capacitor); c3: a capacitive element (second capacitive element, capacitor).

Detailed Description

(embodiment mode 1)

(1) Summary of the invention

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 is a device including a switch unit 2 interposed between a power supply 11 and a load 12. The term "interposed" in the present disclosure means to be interposed between the power source 11 and the load 12 in electrical connection so that the switch 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 switch section 2.

The switch 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 controls the switch unit 2 to electronically switch conduction/non-conduction between the power source 11 and the load 12. 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, in the load control device 1, the terminal 101 and the terminal 102 are electrically connected via the switch unit 2. The switch unit 2 is inserted between the power source 11 and the load 12 by connecting one terminal 101 (first terminal) to the power source 11 and the other terminal 102 (second terminal) to the load 12.

With this configuration, the load control device 1 can control the energization state (power supply state) in which the load 12 is energized from the power source 11 by the switch unit 2. Basically, if the operating state of the switch unit 2 is on, the

terminals

101 and 102 are on via the switch unit 2, and if the operating state of the switch unit 2 is off, the

terminals

101 and 102 are off. That is, if the switch unit 2 is in the on state, the power supply from the power source 11 to the load 12 is performed via the load control device 1, and if the switch unit 2 is in the off state, the power supply from the power source 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 unit 31 for controlling the switch unit 2, and the like. The power generation circuit 4 generates power for operation of the internal circuit 3.

The power generation circuit 4 generates power for operation of the internal circuit 3 based on the voltage applied to both ends of the switch unit 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 generate power for operating the internal circuit 3, using, as input, the voltage applied between the pair of

terminals

101 and 102 by the power supply 11. In this manner, the load control device 1 can secure electric power for operating the internal circuit 3 from the pair of

terminals

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

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

terminals

101 and 102. In the 2-wire load control device 1, it is not necessary to provide a power supply terminal for supplying power for operation of the internal circuit 3 separately from the pair of

terminals

101 and 102, and wiring work when the load control device 1 is provided is also simplified.

Here, the load control device 1 according to the present embodiment includes 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 power based on the voltage applied to both ends of the switch section 2. The second power supply circuit 42 generates power based on the voltage applied to both ends of the switch section 2. The internal circuit 3 is supplied with power from the first power supply circuit 41 or the second power supply circuit 42. The precharge circuit 43 charges the capacitive 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 precharge circuit 43 in addition to the switch unit 2, the first power supply circuit 41, the second power supply circuit 42, and the internal circuit 3. By fusing (japanese) power from one of the first power supply circuit 41 and the second power supply circuit 42 to the capacitive element C3 of the other of the first power supply circuit 41 and the second power supply circuit 42 by the precharge circuit 43, it is possible to shorten, for example, the time taken to charge the capacitive element C3 when the supply of power from the other circuit to the internal circuit 3 is started. Therefore, according to the load control device 1, at least when the supply source that supplies 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 performed. As a result, the following advantages are obtained: it is easy to suppress variation in the power supplied from the power source 11 to the load 12 when switching between the first power supply circuit 41 and the second power supply circuit 42, and to stabilize the power supply to the load 12.

(2) Details of

(2.1) precondition

In the present embodiment, the load control device 1 is fixed to an object to be installed in a building. The "mounting object" referred to in the present disclosure is an object for fixing the load control device 1, and includes, for example, a building such as a wall, ceiling, or floor of a building, or a daily appliance (including a door/window partition) such as a table, shelf, or counter. The building in which the load control device 1 is installed is, for example, a residential facility such as a single residence or a collective residence, or a non-residential facility such as an office, a shop, a school, a factory, a hospital, or a nursing facility.

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

The load control device 1 includes

terminals

101 and 102 for connecting electric wires, and the load control device 1 is electrically connected to the power source 11 and the load 12 via the electric wires by connecting the electric wires routed through a wall (an object to be mounted) to the

terminals

101 and 102, for example. The electric wire may be directly connected to the power supply 11 (system power supply, etc.), or may be indirectly connected to the power supply 11 (system power supply, etc.) via a distribution board, etc.

The "terminals" such as the

terminals

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

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

(2.2) overall 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 switch 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 switch 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 (shown as "ZC" in the figure)

detectors

51 and 52,

voltage detectors

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

terminals

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

The pair of

terminals

101 and 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 to connect the electric wires by inserting the electric wires through terminal holes.

The switch unit 2 is interposed between the power source 11 and the load 12, and switches on/off between the power source 11 and the load 12. In the present embodiment, the switch section 2 includes, as an example, 2 MOSFETs (Metal-Oxide-Semiconductor Field Effect transistors) 21 and 22 electrically connected in series between the pair of

terminals

101 and 102. These 2

MOSFETs

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

MOSFETs

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

MOSFETs

21, 22 are connected in so-called reverse series, thereby switching on/off for a bidirectional current.

The gate terminals of the

MOSFETs

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

MOSFETs

21 and 22.

As described above, the switch unit 2 includes the off state and the on state as its operating state. The on state includes not only a state in which the switch section 2 is continuously on but also a state in which the switch section 2 is intermittently on. That is, in the present disclosure, the off state of the switch unit 2 means a state in which the power supply from the power source 11 to the load 12 is cut off, and the on state of the switch unit 2 means a state in which the power supply 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 non-conductive state of the switching unit 2. That is, if the switch unit 2 is in the non-conductive state, the voltage applied across the switch unit 2 (hereinafter also referred to as "inter-switch voltage") is substantially equal to the ac voltage from the power supply 11. Hereinafter, the polarity of the inter-switch voltage at the terminal 101 at the high potential is referred to as "positive polarity", and the polarity of the inter-switch voltage at the terminal 102 at the high potential is referred to as "negative polarity".

The zero-

cross detectors

51 and 52 are configured to detect a zero-cross point of the inter-switch voltage by detecting a magnitude of the inter-switch voltage. The zero cross detector 51 is electrically connected to the terminal 101.

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

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

cross detectors

51 and 52 is slightly delayed from the zero-cross point (0 [ V ]) in a 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 diodes D1 and D2, secondary 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 represented as "DC/DC" only.

The power generation circuit 4 generates power for operation of the internal circuit 3 based on the voltage applied to both ends of the switch unit 2. That is, the power generation circuit 4 receives the inter-switch voltage as an input and supplies power for operation to the internal circuit 3. 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, and thereby power is supplied from the power generation circuit 4 to the internal circuit 3.

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

terminals

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

terminals

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

In the present embodiment, the power supply source of the internal circuit 3 is switched according to the operating state of the switch unit 2. That is, as described above, the operating state of the switch unit 2 includes the off state in which the power supply from the power source 11 to the load 12 is cut off and the on state in which the power supply from the power source 11 to the load 12 is performed. Here, in the off state, power is supplied from the first power supply circuit 41 to the internal circuit 3, and 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 element C3 included in the second power supply circuit 42 with the power from the first power supply circuit 41. In other words, the first power supply circuit 41 is a power supply circuit for use at the time of disconnection for supplying power to the internal circuit 3 in a disconnected state. The second power supply circuit 42 is a power supply circuit for use in the on state for supplying power to the internal circuit 3 in the 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 depending on whether the operating state of the switch 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 in a manner differentiated between the off state and the on state of the switch unit 2.

In addition, the first power supply circuit 41 for the off time and the second power supply circuit 42 for the on time have a difference in required characteristics. That is, since the switch unit 2 is in the off state in the first power supply circuit 41 for use in the off state, it is required to have a relatively high impedance in order to reduce a leakage current flowing between the pair of

terminals

101 and 102 after passing through the power generation circuit 4. On the other hand, since the switch unit 2 is in the on state in the second power supply circuit 42 for the on state, a relatively low impedance is required in order to efficiently generate power in the power generation circuit 4. 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 end-to-end voltage Vc2 of the capacitive element C2 of the first power supply circuit 41 is different from the end-to-end voltage Vc3 of the capacitive element C3 of the second power supply circuit 42, and the end-to-end voltage Vc2 is higher than the end-to-end voltage Vc 3.

The DC/DC converter 44 converts the end-to-end voltage Vc2 of the capacitive element C2 of the first power supply circuit 41 or the end-to-end voltage Vc3 of the capacitive element C3 of the second power supply circuit 42 into an output voltage Vout formed of a DC voltage of a predetermined magnitude. Thereby, the output voltage Vout of a predetermined magnitude is stably applied 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 power from the first power supply circuit 41. That is, when the switch unit 2 is in the off state, the precharge circuit 43 charges the capacitive element C3 of the second power supply circuit 42 for the on state with the electric power from the first power supply circuit 41 for the off state. As a result, at least when the power supply device is switched from the off state to the on state, the switching from the first power supply circuit 41 for off to the second power supply circuit 42 for on is smooth. In other words, even when switching from the first power supply circuit 41 to the second power supply circuit 42, power is smoothly supplied to the internal circuit 3.

The power generation circuit 4 will be described in detail in the column "(2.3) configuration of 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 includes a step-down (Dropper) power supply circuit 410, a first current limiting circuit 411, a fast charge path 412, a capacitor element C0, and a capacitor 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 detector 53 detects a voltage Vc2 between both ends of the capacitive element C2 of the first power supply circuit 41. That is, as the capacitor element C2 is charged, the voltage detected by the voltage detector 53 (the end-to-end voltage Vc2) increases. The voltage detector 54 detects a voltage Vc3 between both ends of the capacitive element C3 of the second power supply circuit 42. That is, as the capacitor element C3 is charged, the voltage detected by the voltage detector 54 (the end-to-end voltage Vc3) increases.

The charge detector 55 detects the charged state of the capacitive element C1 of the second power supply circuit 42. Specifically, the charge detector 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 detector 55 is connected to a connection point between the zener diode ZD1 and the resistor R1, and the charge detector 55 detects that the charging of the capacitor C1 is completed based on the voltage Vc1 between both ends of the capacitor C1 being equal to or higher 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 for 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 operate by receiving power supply from the power generation circuit 4.

The control unit 31 has, as a main structure, a microcontroller having 1 or more processors and 1 or more memories, for example. The microcontroller realizes the function as the control unit 31 by executing the program recorded in the 1 or more memories by the 1 or more processors. The program may be recorded in advance in the memory, may be provided by recording 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 controls at least the switching unit 2 to be turned on/off. The control unit 31 may control the switching unit 2 by phase control (including inverse phase control) or PWM (Pulse Width Modulation) control (hereinafter also referred to as "load 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 controller 31 acquires detection signals Si1 and Si2 indicating detection results from the zero-

cross detectors

51 and 52, respectively. Similarly, controller 31 obtains detection signals Si5 and Si6 indicating the detection results from

voltage detectors

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

In this manner, the controller 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 switch unit 2 and the power generation circuit 4.

The wireless communication unit 32 directly performs wireless communication with another communication device using radio waves as a medium, or indirectly performs wireless communication using radio waves as a medium 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 (radio station not requiring permission) in a 920MHz band, Wi-Fi (registered trademark), or Bluetooth (registered trademark). As examples of other communication devices, there are sensor terminals such as a human sensor, and remote controllers that receive human operations. The wireless communication unit 32 performs bidirectional communication with these communication devices, and the control unit 31 can control the switch unit 2 based on a wireless signal from the communication device.

The touch panel 33 is a touch panel display, and has a display function and a touch sensor function. The touch panel 33 functions as a user interface, and can present information such as the operating state of the load control device 1 to a person by display or output a signal by receiving a touch operation by a person. By having such a touch panel 33, the control section 31 can control the switch section 2 based on an 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 not shown.

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 and 102 via the primary-side diodes D1 and D2, respectively. Further, 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 secondary-side diodes D3, D4, respectively. Therefore, the voltage applied to both ends of the switch section 2 is rectified by the primary side diodes D1 and 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 steps down a voltage obtained by rectifying a voltage applied to both ends of the switch unit 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 primary side capacitive element C0 is a capacitor charged with a high voltage and having a small capacity, compared to the secondary side capacitive element C2. That is, the end-to-end voltage Vc0 of the capacitive element C0 is higher than the end-to-end voltage Vc2 of the capacitive element C2.

In this manner, the first power supply circuit 41 includes a capacitor (capacitive element C2) at its output stage. The capacitor (capacitive element C2) of the output stage functions as a buffer for absorbing variations in power consumption in the internal circuit 3. The both-end voltage Vc2 of the capacitive element C2 is applied to the DC/DC converter 44 via the secondary-side diode D3 as an output of the first power supply circuit 41.

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

The fast charging path 412 is inserted 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 between the capacitive element C0 on the primary side and the capacitive element C2 on the secondary side in parallel with the quick charge path 412. 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 charge path of low impedance compared to the first current limiting circuit 411.

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 first power supply circuit 41 to internal circuit 3 is started, control unit 31 turns on fast charge path 412 by control signal Si 4. The "supply start time" for starting the supply of power from the first power supply circuit 41 to the internal circuit 3 includes both the time when the load control device 1 is started and the time when the switch unit 2 is switched from the on state to the off state.

In short, in the present embodiment, the first power supply circuit 41 includes the first capacitive element C2, a first charging path for charging the first capacitive element C2, and a second charging path for charging the first capacitive element C2, and the second charging path has a low impedance compared to the first charging path. The first capacitive element C2 is a capacitive element different from the capacitive element C3 (second capacitive 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 fast charging path 412 corresponds to a "second charging path". In this manner, the first power supply circuit 41 has 2 charging paths as the charging paths of the capacitive element C2, and when the supply of electric power to the internal circuit 3 is started, the capacitive element C2 is rapidly charged through the rapid 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 maintaining circuit 422, diodes D5 to D7, a primary-side capacitive element C1 (capacitor), and a secondary-side capacitive element C3 (capacitor).

The low impedance circuit 420 is inserted 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 flowing a current flowing to the capacitive element C1, that is, a charging current of the capacitive element C1. 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 end-to-end voltage Vc1 of the capacitive element C1 is higher than the end-to-end voltage Vc3 of the capacitive element C3. In addition, in the second power supply circuit 42, the capacitor of the output stage is charged at a lower voltage than the first power supply circuit 41. Therefore, the secondary-side capacitive element C3 in the second power supply circuit 42 has a lower withstand voltage and a larger capacity than the secondary-side capacitive element C2 in the first power supply circuit 41.

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

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 flowing a current flowing to the capacitive element C3, that is, a charging current of the capacitive element C3. The second current limiting circuit 421 is a constant current circuit, and limits the magnitude of the current flowing through the second current limiting circuit 421, that is, the charging path of the capacitive element C3, to a second current value (for example, 3mA) or less.

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

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

The input terminal of the precharge circuit 43 is electrically connected to the connection point of the capacitive element C0 on the primary side 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 inserted 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 charging path of low impedance compared to the fast charging path 412.

Thus, the precharge circuit 43 can charge the primary-side capacitive element C1 with the power from the first power supply circuit 41 via the diode D6. The diode D7 is inserted between the precharge circuit 43 and the secondary side capacitive element C3. Thus, the precharge circuit 43 can charge the secondary-side capacitive element C3 with the power from the first power supply circuit 41 via the diode D7.

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) in their respective output stages. The capacitive element C3 charged by the precharge circuit 43 is a capacitor (of the output stage) of either 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 power from the first power supply circuit 41. That is, the capacitive element C3 charged by the precharge circuit 43 is a capacitor (capacitive element C3) of the output stage of the second power supply circuit 42.

(2.4) operation of the 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 when the capacitor elements C0, C1, C2, and C3 are charged. Fig. 5 shows the operation of the load control device 1 in the off mode, which is the off state of the switch unit 2, and fig. 6 shows the operation of the load control device 1 in the on mode, which is the on state of the switch unit 2.

First, the load control device 1 operates in the charging mode shown in fig. 4 immediately after the start, that is, immediately after the start of 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 all in the uncharged state. At this time, in load control device 1, switch unit 2 is in the off state, and fast charge path 412 is in the on state by control signal Si4 from control unit 31. Therefore, in the charging mode of fig. 4, in the first power supply circuit 41, the capacitance elements C0 and C2 are charged with the current I1 via the step-down power supply circuit 410 by the voltage applied to both ends of the switch section 2. Particularly, for the capacitive element C2, it is charged quickly with the current I1 via the quick 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 through the precharge circuit 43 by the voltage applied to both ends of the switch unit 2. That is, since the precharge circuit 43 is a lower low impedance than the fast 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 power from the first power supply circuit 41. As a result, in the charging mode shown in fig. 4, the capacitor 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 end-to-end voltage Vc2 of the capacitor element C2 becomes equal to or higher than the threshold value, the operation mode of the load control device 1 is switched to the off mode in response to the detection signal Si5 from the voltage detector 53. That is, the load control device 1 shifts from the charging mode shown in fig. 4 to the disconnection mode shown in fig. 5. At this time, in the load control device 1, the switch unit 2 is in the off state, and the quick charge path 412 is rendered non-conductive by the control signal Si4 from the control unit 31. Therefore, the lighting device as the load 12 is turned off.

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

terminals

101 and 102 after passing through the power generation circuit 4 can be reduced. Therefore, it becomes easy to prevent the lighting device, for example, the load 12 from lighting up by mistake in the shutdown mode.

On the other hand, when the switch 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 switch unit 2 is in the on state. Therefore, 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 power by the second power supply circuit 42 at a current I3 by the voltage applied to both ends of the switch section 2. At this time, the current I3 limited to the second current value (for example, 3mA) 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 controller 31 turns on the constant current holding circuit 422 by the control signal Si 7. Thus, in the on mode shown in fig. 6, the current flowing through the power generation circuit 4 is limited, and the impedance of the power generation circuit 4 can be stabilized. Therefore, in the on mode, for example, the lighting state of the lighting device as the load 12 is easily stabilized.

When the switch 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 on mode shown in fig. 6 to the charging mode shown in fig. 4. Thereafter, the load control device 1 cyclically repeats the operations of fig. 4 to 6, that is, the operations of the charging mode, the cutoff mode, and the on mode.

As described above, in the load control device 1 according to the present embodiment, the precharge circuit 43 charges the capacitive element C3 when the supply of power from the first power supply circuit 41 to the internal circuit 3 is started. The "supply start time" for starting the supply of power from the first power supply circuit 41 to the internal circuit 3 includes both the time when the load control device 1 is started and the time when the switch unit 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 and at the time when the switch unit 2 is switched 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 power from the first power supply circuit 41.

As a result, when the off mode is switched 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 precharge circuit 43 charges the capacitance elements C1 and C3 of the second power supply circuit 42 with the 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 capacitance elements C1 and C3. Therefore, when switching from the first power supply circuit 41 to the second power supply circuit 42, electric power is smoothly (seamless) supplied to the internal circuit 3. 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 whose power consumption varies. The capacitor element C3 (charged by the precharge circuit 43) is used to mitigate the influence of variations in power consumption on the input 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 whose power consumption varies, such as the wireless communication unit 32 and the touch panel 33. On the other hand, the capacitive element C3 charged by the precharge circuit 43 is a capacitor as a buffer, and absorbs the variation in power consumption of the internal circuit 3, thereby alleviating the influence of the variation in power consumption on the input 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 of the variation in power consumption on the input to the first power supply circuit 41 and the second power supply circuit 42.

As an example, fig. 7A and 7B show a case where fluctuations in power consumption are absorbed by the capacitive elements C2 and C3. Fig. 7A shows the end-to-end voltage Vc2 of the capacitor (capacitive element C2) of the output stage of the first power supply circuit 41 with the horizontal axis as a time axis. Fig. 7B shows the end-to-end voltage Vc3 of the capacitor (capacitive element C3) of the output stage of the second power supply circuit 42 with the horizontal axis as a time axis. The voltage value V1 in fig. 7A is the end-to-end voltage Vc2 when the capacitive element C2 is fully charged, and the voltage value V2 in fig. 7B is the end-to-end voltage Vc3 when the capacitive element C3 is 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 a radio wave, a period T2 indicates a period during which the radio communication unit 32 transmits a radio wave, and a period T3 indicates a period during which the radio communication unit 32 continues to receive a radio wave. That is, the wireless communication unit 32 of the internal circuit 3 consumes more power for receiving or transmitting. At this time, since the electric energy stored in the capacitive elements C2 and C3 is consumed, the voltages Vc2 and Vc3 across the capacitive elements C2 and C3 drop. As described above, when the power consumption of the internal circuit 3 fluctuates, the fluctuation is absorbed by the capacitance elements C2 and C3, and therefore, the influence of the fluctuation in the power consumption is less likely to occur on the primary sides 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 thus can compensate for the shortage of the current flowing in 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 necessary for 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, as in the present embodiment, when the power consumption of the internal circuit 3 is relatively large and the variation in the power consumption of the internal circuit 3 is also relatively large, the meaning of the precharge circuit 43 as described above becomes large.

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

Further, when the capacitance of the capacitor element C2 increases, it takes time to charge the capacitor element C2, and therefore, 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 is likely to flicker.

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 unit 2, whereby the capacitance elements C2 and C3 can be made relatively small. Further, the precharge circuit 43 supplies 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, i.e., 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 variations in voltage applied from the power generation circuit 4 to the internal circuit 3 are suppressed.

(3) Modification example

Embodiment 1 is only one of various embodiments of the present disclosure. Embodiment 1 can be variously modified according to design and the like as long as the object of the present disclosure can be achieved. For example, the specific circuit shown in fig. 2 is merely an example of the load control device 1 of the present disclosure, and various modifications thereof can be made in accordance with design and the like. The drawings described in the present disclosure are schematic drawings, and the ratio of the size and the ratio of the thickness of each component in each drawing do not necessarily reflect the actual dimensional ratio. Further, the functions equivalent to those of the control unit 31 of the load control device 1 according to embodiment 1 can be embodied by a control method, a (computer) program, a non-transitory recording medium in which a program is recorded, or the like.

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

(3.1) first modification

As shown in fig. 8, a load control device 1A according to a first modification of embodiment 1 differs from the load control device 1 according to embodiment 1 in the following respects: the precharge circuit 43 bidirectionally flows a precharge current between the first power supply circuit 41 and the second power supply circuit 42. Hereinafter, the same configurations as those in embodiment 1 are denoted by the same reference numerals and description thereof is omitted as appropriate.

That is, in the present modification, the first power supply circuit 41 includes the first capacitive element C2 different from the second capacitive element C3 that is the capacitive element C3 (charged by the precharge circuit 43). The precharge circuit 43 charges the second capacitance element C3 with power from the first power supply circuit 41, and charges the first capacitance element C2 with 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 capacitive element C3 of the second power supply circuit 42, but in the present modification, power can be supplied from the second power supply circuit 42 to the capacitive element C2 of the first power supply circuit 41. Since the second power supply circuit 42 is a relatively low-voltage circuit compared to the first power supply circuit 41, the precharge circuit 43 is implemented by including a booster circuit when power is supplied from the second power supply circuit 42 to the capacitive element C2 of the first power supply circuit 41. That is, the precharge circuit 43 can charge the capacitive element C2 by boosting the end-to-end voltage Vc1 of the capacitive element C1 on the primary side of the second power supply circuit 42 and applying the boosted voltage to the capacitive element C2 of the first power supply circuit 41, for example.

(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 is mainly structured by a processor and a memory as hardware. The functions as the load control device 1 in the present disclosure are 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 disc, or a hard disk drive that is readable by the computer system. A processor of a computer system is constituted by one or more electronic circuits including a semiconductor Integrated Circuit (IC) or a large scale integrated circuit (LSI). The integrated circuits such as IC and LSI include those called system LSI, VLSI (Very Large Scale Integration), or ULSI (Ultra Large Scale Integration), and their names are different depending on the degree of Integration. Furthermore, an FPGA (Field-Programmable Gate Array) programmed after the manufacture of the LSI or a logic device capable of reconstructing a connection relationship inside the LSI or reconstructing circuit division inside the LSI can be used as a processor. The plurality of electronic circuits may be collected in 1 chip, or may be disposed in a plurality of chips in a distributed manner. The plurality of chips may be collected 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 more than 1 processor and more than 1 memory. Thus, the microcontroller is also constituted by one or more electronic circuits including a semiconductor integrated circuit or a large-scale integrated circuit.

It is not essential for the load control device 1 to collect at least a part of the functions of the load control device 1 in 1 housing, and the components of the load control device 1 may be provided in a plurality of housings in a distributed manner. For example, the touch panel 33 may be provided in a housing different from the control section 31. At least a part of the functions of the control unit 31 and the like may be realized by a server, a cloud (cloud computing), or the like, for example.

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

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

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

In embodiment 1, the load control device 1 is a single-pole switch (japanese: chip スイッチ), but may have 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. When the load control device 1 constitutes a three-way switch, the energization state of the load 12 can be switched at 2 positions, for example, the upstairs and downstairs of the stairs in the building by combining 2 load control devices 1.

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

The load 12 is not limited to the lighting device including the light source constituted by the LED, and may be a lighting device including a light source other than the LED. The load 12 is not limited to a lighting device, and may be a device (including a device, a system, and a device) such as a ventilation fan, a display device, an electric blind, an air conditioner, or a crime prevention device. Further, the load 12 is not limited to 1 device, and may be a plurality of devices electrically connected in series or in parallel.

The load control device 1 may further include an operation terminal for connecting the slave unit. The slave unit includes a contact unit such as a push switch, and the load control device 1 detects on/off of the contact unit. In this case, the load control device 1 controls the switching unit 2 to switch the operating state of the switching unit 2 according to the operation of the slave unit (on/off of the contact unit). That is, in the slave unit, for example, each time the button switch is pressed to turn on the contact portion, the load control device 1 operates to switch the off state and the on state of the switch portion 2. In short, in the load control device 1, the switch unit 2 may be controlled not only by the outputs of the wireless communication unit 32 and the touch panel 33 but also by the operation of the slave unit. Therefore, by separately providing the load control device 1 and the slave units at 2 positions, for example, the upstairs portion and the downstairs portion of the stairs in the building, the energization state for energizing the load 12 can be switched at 2 positions.

The internal circuit 3 may be provided with 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. For example, the sensor circuit includes a human detection sensor and/or a brightness sensor for detecting the presence of a human. The load control device 1 can control the switch unit 2 based on the outputs of the sensor circuit, the timer circuit, and the like.

In the above embodiment, the switch unit 2 has 2

MOSFETs

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

(embodiment mode 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 capacitance elements of the first power supply circuit 41 and the second power supply circuit 42. Hereinafter, the same configurations as those in embodiment 1 are denoted by the same reference numerals and description thereof is omitted as appropriate.

In this 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 capacitor 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 fuse power between the primary capacitor elements C0 and C1.

In this case, the precharge circuit 43 may be configured to charge a 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 charges 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 bidirectionally between the first power supply circuit 41 and the second power supply circuit 42.

The configuration (including the modification) described in embodiment 2 can be adopted in appropriate combination with the various configurations (including the modification) described in embodiment 1.

(conclusion)

As described above, the load control device (1, 1A, 1B) according to the first aspect includes 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 inserted between the power source (11) and the load (12). The first power supply circuit (41) generates power based on a voltage applied to both ends of the switch unit (2). The second power supply circuit (42) generates power based on a voltage applied to both ends of the switch unit (2). The internal circuit (3) is supplied with power from the first power supply circuit (41) or the second power supply circuit (42). A precharge circuit (43) charges capacitance elements (C0-C3) included in one of a first power supply circuit (41) and a 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) fuses 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), thereby making it possible to reduce the time taken to charge the capacitance elements (C0 to C3) at the start of supply of power to the internal circuit (3). Therefore, when at least 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 can be easily and smoothly performed. As a result, the following advantages are obtained: the variation of power supplied from a power source (11) to a load (12) when switching between a first power supply circuit (41) and a second power supply circuit (42) is easily suppressed, and the power supply to the load (12) is easily stabilized.

In the load control devices (1, 1A, 1B) according to the second aspect, in the first aspect, the operating state of the switch unit (2) includes a cut-off state in which the power supply from the power source (11) to the load (12) is cut off, and an on state in which the power supply from the power source (11) to the load (12) is performed. In the disconnected 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). A precharge circuit (43) charges a capacitance element (C1, C3) included in a second power supply circuit (42) with power from a 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 capacitance elements (C1, C3) at the start of 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) includes a first capacitive element (C2) different from a second capacitive element (C3) which is a capacitive 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 power from the first power supply circuit (41) to the internal circuit (3) is started, the first capacitive element (C2) can be charged quickly through the second charging path, and the output of the first power supply circuit (41) can be stabilized as quickly as possible.

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

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

In the load control devices (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 their respective output stages. The capacitance elements (C2, C3) are capacitors (C2, C3) of either one of the first power supply circuit (41) and the second power supply circuit (42).

According to this embodiment, the first power supply circuit (41) and the second power supply circuit (42) have capacitors (C2, C3) independently in their respective output stages, and therefore it is easy to avoid an increase in the size of these capacitors (C2, C3).

In the load control devices (1, 1A, 1B) according to the seventh aspect, the internal circuit (3) is a circuit in which power consumption varies in any one of the first to sixth aspects. The capacitance elements (C0-C3) are used for alleviating the influence of the variation of the power consumption 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 variation in power consumption of the internal circuit (3) is less likely to cause variation in power supplied from the power source (11) to the load (12), and the power supply to the load (12) is easily stabilized.

The configurations according to the second to seventh aspects are not essential to the load control devices (1, 1A, 1B), and can be omitted as appropriate.

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 power based on a voltage applied to both ends of the switch section;

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

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

and a precharge circuit configured to charge a capacitor 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.

2. The load control device according to claim 1,

the operating state of the switching unit includes a cut-off state in which the supply of power from the power supply to the load is cut off, and an on state in which the supply of power from the power supply to the load is performed,

wherein in the 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 precharge circuit charges the capacitance element included in the second power supply circuit with power from the first power supply circuit.

3. The load control device according to claim 2,

the precharge circuit charges the capacitive element at the start of supply of power from the first power supply circuit to the internal circuit.

4. The load control device according to claim 2 or 3,

the first power supply circuit has:

a first capacitive element different from a second capacitive element which is the capacitive element;

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,

wherein the first capacitive element is charged through the second charging path at the start of supply of power from the first power supply circuit to the internal circuit.

5. The load control device according to any one of claims 2 to 4,

the first power supply circuit has a first capacitive element different from a second capacitive element as the capacitive element,

the precharge circuit charges the second capacitive element with power from the first power supply circuit, and charges the first capacitive element with power from the second power supply circuit.

6. The load control device according to any one of claims 1 to 5,

the first power supply circuit and the second power supply circuit have capacitors at respective output stages,

the capacitance element is a capacitor of any one of the first power supply circuit and the second power supply circuit.

7. The load control device according to any one of claims 1 to 6,

the internal circuit is a circuit whose power consumption varies,

the capacitor element mitigates an influence of a variation in the power consumption on the input of the first power supply circuit and the second power supply circuit.