Switching device

Abstract

To provide a switch device which can prevent welding of a contact on an electromagnetic relay.SOLUTION: A switch device 1 comprises: a first terminal T1 and a second terminal T2 which are provided on a power supply path SL connecting an AC power supply AC to a load L; a first semiconductor switch 10 provided between the first terminal T1 and the second terminal T2; an electromagnetic relay 40 which is connected in series to the first semiconductor switch 10; a second semiconductor switch 20 which is connected in parallel to the first semiconductor switch 10 and to the electromagnetic relay 40; and a control part 50 which controls the first semiconductor switch 10, the second semiconductor switch 20, and the electromagnetic relay 40. When a contact of the electromagnetic relay 40 is open, the control part 50 outputs an ON command to the second semiconductor switch 20, thereby bringing the second semiconductor switch 20 into a conduction state. The control part then closes the contact of the electromagnetic relay 40 after a predetermined period ts has passed from the point it has outputted the ON command to the second semiconductor switch 20.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a switching device for controlling a load. [Background technology]

[0002] Conventionally, devices for controlling a load have been known. As an example of this type of device, Patent Document 1 discloses a device including an electromagnetic relay provided in a power supply path connecting a power source and a load, and a semiconductor switch provided in the power supply path between the electromagnetic relay and the load. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-77447 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, in a switch device, when starting a load, both the electromagnetic relay and the semiconductor switch are turned on to supply power to the load. However, when the electromagnetic relay is turned on, an inrush current flows toward the load, and this inrush current can cause the contacts of the electromagnetic relay to weld together.

[0005] An object of the present invention is to prevent welding of the contacts of an electromagnetic relay in a switch device that closes the contacts of an electromagnetic relay to supply power from a power source to a load. [Means for solving the problem]

[0006] One aspect of the switch device of the present invention includes a first terminal and a second terminal provided in a power supply path connecting an AC power source and a load, a first semiconductor switch provided in the power supply path between the first terminal and the second terminal, an electromagnetic relay provided in the power supply path between the first terminal and the second terminal and connected in series to the first semiconductor switch, a second semiconductor switch connected in parallel to the first semiconductor switch and the electromagnetic relay, and a control unit that switches between conducting and non-conducting states of the first semiconductor switch, switches between outputting an ON command and releasing an ON command to the second semiconductor switch, and switches between opening and closing contacts of the electromagnetic relay, wherein the control unit brings the second semiconductor switch into a conducting state by outputting an ON command to the second semiconductor switch when the contacts of the electromagnetic relay are open, Furthermore, after the second semiconductor switch is brought into a conductive state, the first semiconductor switch is brought into a conductive state, and after the first semiconductor switch is brought into a conductive state, The contacts of the electromagnetic relay are closed. a first semiconductor switch provided in the power supply path between the first terminal and the second terminal; an electromagnetic relay provided in the power supply path between the first terminal and the second terminal and connected in series to the first semiconductor switch; a second semiconductor switch connected in parallel to the first semiconductor switch and the electromagnetic relay; and a control unit that switches the first semiconductor switch between conductive and non-conductive states, switches the output of an ON command to the second semiconductor switch and a release of the ON command, and switches the opening and closing of contacts of the electromagnetic relay, wherein the control unit outputs an ON command to the second semiconductor switch when the contacts of the electromagnetic relay are open, thereby bringing the second semiconductor switch into a conductive state, and closes the contacts of the electromagnetic relay after a predetermined period has elapsed since the output of the ON command to the second semiconductor switch, and the predetermined period is a period of at least several cycles of the AC current output from the AC power supply. a first semiconductor switch provided in the power supply path between the first terminal and the second terminal; an electromagnetic relay provided in the power supply path between the first terminal and the second terminal and connected in series to the first semiconductor switch; a second semiconductor switch connected in parallel to the first semiconductor switch and the electromagnetic relay; and a control unit that switches the first semiconductor switch between conductive and non-conductive states, switches the output of an ON command to the second semiconductor switch and a release of the ON command, and switches the opening and closing of contacts of the electromagnetic relay, wherein the control unit outputs an ON command to the second semiconductor switch while the contacts of the electromagnetic relay are open, thereby bringing the second semiconductor switch into a conductive state, and closes the contacts of the electromagnetic relay after a predetermined period has elapsed since the output of the ON command to the second semiconductor switch, and the predetermined period is a period of at least two but not more than six cycles of the AC current output from the AC power supply after the output of the ON command to the second semiconductor switch. One aspect of the switch device of the present invention includes a first terminal and a second terminal provided in a power supply path connecting an AC power source and a load, a first semiconductor switch provided in the power supply path between the first terminal and the second terminal, an electromagnetic relay provided in the power supply path between the first terminal and the second terminal and connected in series to the first semiconductor switch, a second semiconductor switch connected in parallel to the first semiconductor switch and the electromagnetic relay, and a control unit that switches the first semiconductor switch between conductive and non-conductive states, switches the output of an ON command to the second semiconductor switch and the release of the ON command, and switches the opening and closing of contacts of the electromagnetic relay, wherein the control unit brings the second semiconductor switch into a conductive state by outputting an ON command to the second semiconductor switch when the contacts of the electromagnetic relay are open, and closes the contacts of the electromagnetic relay when a predetermined period has elapsed since the output of the ON command to the second semiconductor switch and when a current flowing through the second semiconductor switch is smaller than a predetermined current value. One aspect of the switch device of the present invention includes a first terminal and a second terminal provided in a power supply path connecting an AC power source and a load, a first semiconductor switch provided in the power supply path between the first terminal and the second terminal, an electromagnetic relay provided in the power supply path between the first terminal and the second terminal and connected in series to the first semiconductor switch, a second semiconductor switch connected in parallel to the first semiconductor switch and the electromagnetic relay, and a control unit that switches the first semiconductor switch between conductive and non-conductive states, switches the output of an ON command to the second semiconductor switch and the release of an ON command, and switches the opening and closing of contacts of the electromagnetic relay, wherein the control unit brings the second semiconductor switch into a conductive state by outputting an ON command to the second semiconductor switch when the contacts of the electromagnetic relay are open, and closes the contacts of the electromagnetic relay when a predetermined period has elapsed since the output of the ON command to the second semiconductor switch and when the current flowing through the second semiconductor switch is smaller than the rated current of the electromagnetic relay. [Effects of the Invention]

[0007] According to the present invention, in a switch device that supplies power from a power source to a load by closing the contacts of an electromagnetic relay, welding of the contacts of the electromagnetic relay can be suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 10 is a circuit diagram of a switch device and a load control system according to a comparative example. [Figure 2] 10A and 10B are diagrams illustrating the operation of a switch device of a comparative example when starting a load. [Figure 3] 1 is a circuit diagram of a switch device and a load control system according to an embodiment; [Figure 4] 10A and 10B are diagrams illustrating the operation of the switch device according to the embodiment when starting up a load. [Figure 5] 10A and 10B are diagrams illustrating another example of the operation of the switch device according to the embodiment. [Figure 6] 10A and 10B are diagrams illustrating still another example of the operation of the switch device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] (Background to the invention) The process leading to the present invention will be described with reference to comparative examples.

[0010] FIG. 1 is a circuit diagram of a switch device 101 and a load control system 102 of a comparative example.

[0011] 1, a load control system 102 of the comparative example includes an alternating current power supply AC, a load L, and a switch device 101. The switch device 101 is provided in a power supply path SL that connects the alternating current power supply AC and the load L.

[0012] The load L is, for example, a lighting fixture such as a ceiling light or a downlight. The switch device 101 is composed of a semiconductor switch 110 provided in a power supply path SL, an electromagnetic relay 140 connected in series to the semiconductor switch 110 in the power supply path SL, and a control unit 150 that controls the on / off of the semiconductor switch 110 and the electromagnetic relay 140.

[0013] FIG. 2 is a diagram schematically illustrating the operation of the switch device 101 of the comparative example when starting up the load L. In FIG.

[0014] 2 shows the AC voltage output from the AC power supply AC and the control signal output to the electromagnetic relay 140 when starting up the load L. The figure also shows the switch voltage when starting up the load L, the load voltage applied to the load L, and the load current flowing through the load L. The switch voltage is the voltage across the semiconductor switch 110 and the electromagnetic relay 140.

[0015] In the switch device 101 of the comparative example, the load L is started by closing the contacts of the electromagnetic relay 140 while the semiconductor switch 110 is turned on. Starting the load L means performing an operation to switch the load L from a non-driving state to a drive control state, and for example, if the load L is a lighting fixture, it means performing an operation to switch the lighting fixture from an off state to a light control state.

[0016] When the contacts of the electromagnetic relay 140 are closed to start the load L, an inrush current flows through the load L. The inrush current is a large current that temporarily flows through the load L when power is applied to the load L. FIG. 2 shows an example in which the inrush current generated when starting the load L exceeds the rated current of the electromagnetic relay 140. In this example, the peak value of the inrush current exceeds the positive rated current of the electromagnetic relay 140 in the first half cycle of one cycle of the AC waveform of the AC voltage, and the peak value of the inrush current exceeds the negative rated current of the electromagnetic relay 140 in the next half cycle.

[0017] For example, in a capacitive load L such as a lighting fixture, a large inrush current flows through the load L when the contacts of the electromagnetic relay 140 are closed. This inrush current increases as the number of loads L connected in parallel to the switch device 101 increases. When the inrush current flowing through the load L increases, the current flowing through the electromagnetic relay 140 also increases, making the contacts of the electromagnetic relay 140 more likely to weld. Thus, the switch device 101 of the comparative example has a problem in that the contacts of the electromagnetic relay 140 weld when the contacts of the electromagnetic relay 140 are closed to supply power from the source to the load L.

[0018] The present invention has the following configuration in a switch device that closes the contacts of an electromagnetic relay to supply power from a power source to a load, in order to prevent the contacts of the electromagnetic relay from welding together.

[0019] Hereinafter, embodiments will be described with reference to the drawings. Note that each of the embodiments described below represents a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, components, component placement positions, and connection forms shown in the following embodiments are merely examples and are not intended to limit the present invention. Therefore, among the components in the following embodiments, components that are not described in the independent claims that represent the highest concept of the present invention will be described as optional components.

[0020] It should be noted that the drawings are schematic diagrams and are not necessarily strict illustrations. In addition, in the drawings, substantially the same components are denoted by the same reference numerals, and redundant explanations are omitted or simplified.

[0021] (Embodiment) The switch device according to the embodiment will be described with reference to FIGS.

[0022] FIG. 3 is a circuit diagram of the switch device 1 and the load control system 2 according to the embodiment.

[0023] As shown in FIG. 3, the load control system 2 includes an AC power supply AC, a load L, and a switch device 1.

[0024] The AC power source AC is, for example, a commercial power source of 100V AC or 200V AC. The AC power source AC outputs a sinusoidal AC voltage (or AC current) having a constant period. FIG. 3 shows a single-phase two-wire power supply path SL connecting the AC power source AC and a load L. The AC power source AC may be any commercial power source that outputs a predetermined AC voltage in the range of 100V or more and 242V or less.

[0025] The load L is, for example, a lighting fixture or an air conditioning device, and is installed on the ceiling, which is an example of a building construction material. Although one load L is shown in the figure, the load L is not limited to this and may be composed of multiple loads connected in parallel. The operation of the load L is controlled by the AC waveform of the AC power source AC and the switch device 1.

[0026] The switch device 1 switches between supplying and not supplying power output from an AC power source AC, thereby controlling the operation of the load L. The switch device 1 is installed, for example, on a wall, which is an example of a construction material of a building.

[0027] The switch device 1 has an information acquisition unit 70 that acquires operation information for operating the load L. For example, when the load L is a lighting fixture, the information acquisition unit 70 acquires operation information related to dimming of the lighting fixture, etc.

[0028] The information acquisition unit 70 may be, for example, a touch panel and button switches that accept user operation input, or an environmental sensor that detects the temperature and humidity inside the building. The information acquisition unit 70 may be a human sensor or a non-contact sensor that detects people, or a communication module that acquires operation information via wireless and infrared communication.

[0029] The switch device 1 controls the operation of the load L based on the operation information acquired by the information acquisition unit 70.

[0030] As shown in FIG. 3, the switch device 1 includes a first terminal T1, a second terminal T2, a first semiconductor switch 10, a power supply circuit unit 30, an electromagnetic relay 40, a second semiconductor switch 20, and a control unit 50.

[0031] The control unit 50 starts the load L by receiving an external operation input from a touch panel, a button switch, or the like. For example, by receiving an external operation input, the control unit 50 controls the conduction and non-conduction of the first semiconductor switch 10, the ON command and the release of the ON command for the second semiconductor switch 20, and the opening and closing of the contacts of the electromagnetic relay 40, thereby starting the load L. A specific example of the operation of the switch device 1 when starting the load L will be described later.

[0032] 3 are provided on a power supply path SL that connects an AC power source AC and a load L. In this example, the first terminal T1 is located closer to the AC power source AC than the second terminal T2, and the second terminal T2 is located closer to the load L than the first terminal T1.

[0033] The first semiconductor switch 10 is provided between a first terminal T1 and a second terminal T2 in the power supply path SL. The first semiconductor switch 10 is composed of two field effect transistors 11 and 12 connected in series to each other. The field effect transistors are, for example, N-type MOSFETs (Metal Oxide Semiconductor Field Effect Transistors).

[0034] Of the two field effect transistors, one field effect transistor 11 has a gate connected to the control unit 50, a drain connected to the electromagnetic relay 40, and a source connected to the source of the other field effect transistor 12. The other field effect transistor 12 has a gate connected to the control unit 50, a drain connected to the second terminal T2, and a source connected to the source of the one field effect transistor 11.

[0035] The first semiconductor switch 10 switches between a conductive state and a non-conductive state in response to a first gate signal s1 output from the control unit 50. For example, the field-effect transistors 11 and 12 of the first semiconductor switch 10 are instantly turned on by an ON command from the first gate signal s1, and are instantly turned off by an OFF command from the first gate signal s1. After the first semiconductor switch 10 is turned off, it maintains the non-conductive state until the next ON command is received.

[0036] The electromagnetic relay 40 is, for example, a normally open contact relay. The electromagnetic relay 40 is provided between the first terminal T1 and the second terminal T2 in the power supply path SL, and is connected in series to the first semiconductor switch 10. In the drawing, the electromagnetic relay 40 is disposed between the first terminal T1 and the first semiconductor switch 10, but is not limited to this, and the electromagnetic relay 40 may be disposed between the first semiconductor switch 10 and the second terminal T2.

[0037] The second semiconductor switch 20 is connected in parallel to the first semiconductor switch 10 and the electromagnetic relay 40. Specifically, one end of the second semiconductor switch 20 is connected to a node n1 between the first terminal T1 and the electromagnetic relay 40, and the other end of the second semiconductor switch 20 is connected to a node n2 between the first semiconductor switch 10 and the second terminal T2. In this example, the first terminal T1 and the node n1 are at the same potential, and the second terminal T2 and the node n2 are at the same potential.

[0038] The second semiconductor switch 20 is a semiconductor element that has a higher withstand voltage and is capable of passing a larger current than the first semiconductor switch 10. For example, the second semiconductor switch 20 is a silicon controlled rectifier (SCR) such as a thyristor or a bidirectional thyristor (e.g., a triac).

[0039] The second semiconductor switch 20 switches between a conductive state and a non-conductive state based on the second gate signal s2 output from the control unit 50 and the current flowing through the second semiconductor switch 20 itself. For example, the second semiconductor switch 20 becomes conductive when it receives an ON command from the second gate signal s2. On the other hand, when the second semiconductor switch 20 receives cancellation of the ON command from the second gate signal s2, it does not immediately become non-conductive but maintains the conductive state while current flows through it, and becomes non-conductive when the current flowing through it becomes zero. After becoming non-conductive, the second semiconductor switch 20 maintains the non-conductive state until it receives the next ON command.

[0040] The power supply circuit unit 30 is a circuit that generates a drive voltage (operating voltage) for driving the control unit 50 and the information acquisition unit 70. The power supply circuit unit 30 is electrically connected to a first terminal T1 via a first diode (not shown) and electrically connected to a second terminal T2 via a second diode (not shown). The power supply circuit unit 30 acquires power from the first terminal T1 or the second terminal T2 using an AC power source AC as a power source. The power supply circuit unit 30 converts the power acquired from the first terminal T1 or the second terminal T2 into a predetermined DC voltage and outputs it to the control unit 50 and the information acquisition unit 70 as a drive voltage.

[0041] The control unit 50 is configured by an MCU (Micro Controller Unit) and a plurality of gate circuits.

[0042] The control unit 50 is connected to the gate of the first semiconductor switch 10. Specifically, the control unit 50 is connected to the gate of one field effect transistor 11 and the gate of the other field effect transistor 12. The control unit 50 outputs a first gate signal s1 to the gates of the two field effect transistors 11 and 12, thereby switching the first semiconductor switch 10 between conductive and non-conductive states.

[0043] The control unit 50 is also connected to the gate of the second semiconductor switch 20. The control unit 50 outputs a second gate signal s2 to the gate of the second semiconductor switch 20 to give the second semiconductor switch 20 an ON command and a release of the ON command.

[0044] The control unit 50 is also connected to the electromagnetic relay 40. The control unit 50 outputs a contact open / close switching signal s3 to the electromagnetic relay 40, thereby switching the contact of the electromagnetic relay 40 between open and closed states.

[0045] FIG. 4 is a diagram schematically illustrating the operation of the switch device 1 according to the embodiment when the load L is started.

[0046] 4 shows the AC voltage output from the AC power supply AC, and control signals output from the control unit 50 to the second semiconductor switch 20, the first semiconductor switch 10, and the electromagnetic relay 40 when starting up the load L. The figure also shows the switch voltage when starting up the load L, the load voltage applied to the load L, the current flowing through the second semiconductor switch 20, and the current flowing through the electromagnetic relay 40. The switch voltage is the voltage across the second semiconductor switch 20 or the voltage across the first semiconductor switch 10 and the electromagnetic relay 40.

[0047] Starting the load L means performing an operation to switch the load L from a non-driving state to a drive control state. The control unit 50 receives an operation input to start the load L, and outputs various control signals to switch the load L from a non-driving state to a drive control state.

[0048] Before receiving an operation input to start the load L, the first semiconductor switch 10, the electromagnetic relay 40, and the second semiconductor switch 20 are all in a non-conductive state, and the voltage across the switches has the same waveform as the voltage waveform of the AC power source. The power supply circuit unit 30 generates a drive voltage based on this voltage across the switches and supplies it to the control unit 50. Therefore, the control unit 50 can output various control signals even when starting the load L.

[0049] As described above, if the load L is capacitive, a large inrush current flows through the load L when the contacts of the electromagnetic relay 40 are closed. For example, a lighting fixture, which is an example of the load L, has a diode bridge and a capacitor in its power input circuit, and when the lighting fixture is powered on, i.e., when the lighting fixture is started, charge is accumulated in the capacitor via the diode bridge. Therefore, when the lighting fixture is started, an inrush current flows toward the lighting fixture to accumulate charge in the capacitor.

[0050] In this embodiment, the control unit 50 bypasses the inrush current to the path in which the second semiconductor switch 20 is provided by turning on the second semiconductor switch 20 before the electromagnetic relay 40 so that the inrush current does not flow to the electromagnetic relay 40.

[0051] Specifically, when the control unit 50 receives an operation input to start the load L, it outputs an ON command to the second semiconductor switch 20 while the contacts of the electromagnetic relay 40 are open, thereby bringing the second semiconductor switch 20 into a conductive state. Then, the control unit 50 closes the contacts of the electromagnetic relay 40 after a predetermined period ts has elapsed since the control unit 50 output the ON command to the second semiconductor switch 20.

[0052] The predetermined period ts is a period of at least a plurality of cycles of the AC current output from the AC power supply AC. For example, the predetermined period ts is a period of at least two cycles and at most six cycles after an ON command is output to the second semiconductor switch 20. The predetermined period ts is set in advance by a timer or the like.

[0053] FIG. 4 shows how the current flowing through the second semiconductor switch 20, ie, the inrush current, decreases with each half cycle since an ON command is output to the second semiconductor switch 20.

[0054] The time it takes for the current flowing through the second semiconductor switch 20 to become smaller than the predetermined current value varies depending on the capacity of the load L and the number of loads L connected to the switch device 1. Therefore, the predetermined period ts, which is set by a timer or the like, is set with a margin, anticipating the range in which the capacity of the load L and the number of loads L connected to the switch device 1 will change.

[0055] The control unit 50 closes the contacts of the electromagnetic relay 40 after a predetermined period of time ts has elapsed since outputting an ON command to the second semiconductor switch 20, in other words, when the current flowing through the second semiconductor switch 20 is smaller than a predetermined current value. More specifically, the control unit 50 closes the contacts of the electromagnetic relay 40 when the current flowing through the second semiconductor switch 20 is smaller than the rated current of the electromagnetic relay 40. Note that when the current flowing through the second semiconductor switch 20 is smaller than the rated current of the electromagnetic relay 40, this refers to the case where the current values ​​are compared in absolute values. When comparing the current values ​​including positive and negative values ​​rather than absolute values, this refers to the case where the current flowing through the second semiconductor switch 20 is smaller than the positive rated current of the electromagnetic relay 40 and larger than the negative rated current.

[0056] In this way, by closing the contacts of the electromagnetic relay 40 after outputting an ON command to the second semiconductor switch 20, the inrush current flowing toward the load L can be bypassed to the path provided with the second semiconductor switch 20. This makes it possible to prevent the inrush current from flowing to the electromagnetic relay 40, and to prevent the contacts of the electromagnetic relay 40 from welding.

[0057] In addition, in this embodiment, in order to prevent a high voltage from being applied to the first semiconductor switch 10 when starting the load L, the control unit 50 turns on the first semiconductor switch 10 before the electromagnetic relay 40, and closes the contacts of the electromagnetic relay 40 after the first semiconductor switch 10 is turned on.

[0058] For example, if the first semiconductor switch 10 is turned on after the contacts of the electromagnetic relay 40 are closed, the voltage of the AC power source is directly applied to the first semiconductor switch 10, which may cause a malfunction in the first semiconductor switch 10. Therefore, by closing the contacts of the electromagnetic relay 40 after turning on the first semiconductor switch 10, the application of a high voltage to the first semiconductor switch 10 is prevented. This makes it possible to prevent a malfunction in the first semiconductor switch 10. Furthermore, since the application of a high voltage to the first semiconductor switch 10 can be prevented, there is no need to use a semiconductor element with high voltage resistance for the first semiconductor switch 10, and the cost of the switch device 1 can be reduced.

[0059] In the above embodiment, an example is shown in which the contacts of the electromagnetic relay 40 are closed at the same time as the release of the ON command for the second semiconductor switch 20 is output, but this is not limiting. As shown in other examples below, the timing at which the ON command for the second semiconductor switch 20 is released may be after the contacts of the electromagnetic relay 40 are closed, or may be before the contacts of the electromagnetic relay 40 are closed.

[0060] FIG. 5 is a diagram illustrating another example of the operation of the switch device 1. In FIG.

[0061] 5 shows the AC voltage output from the AC power supply AC, and control signals output from the control unit 50 to the second semiconductor switch 20, the electromagnetic relay 40, and the first semiconductor switch 10 when starting the load L. The figure also shows the operation of the first semiconductor switch 10 and other switches for driving and controlling the load L after the load L has been started.

[0062] As shown in Fig. 5, the control unit 50 outputs a release of the ON command to the second semiconductor switch 20 after the first semiconductor switch 10 is brought into conduction and the contacts of the electromagnetic relay 40 are closed. With this configuration, when the contacts of the electromagnetic relay 40 are closed, the conductive state of the second semiconductor switch 20 is maintained. Therefore, when the contacts of the electromagnetic relay 40 are closed and current begins to flow through the electromagnetic relay 40, the current value starts at approximately 0 A (amperes), preventing a sudden large current from flowing through the contacts of the electromagnetic relay 40. This prevents the contacts of the electromagnetic relay 40 from welding.

[0063] FIG. 6 is a diagram illustrating yet another example of the operation of the switch device 1. In FIG.

[0064] 6 shows the AC voltage output from the AC power supply AC, and control signals output from the control unit 50 to the second semiconductor switch 20, the electromagnetic relay 40, and the first semiconductor switch 10 when starting the load L. The figure also shows the operation of the first semiconductor switch 10 and other switches for driving and controlling the load L after the load L has been started.

[0065] 6, the control unit 50 outputs a release of the ON command to the second semiconductor switch 20 after the first semiconductor switch 10 is made conductive and before the contacts of the electromagnetic relay 40 are closed. This configuration can shorten the conductive period of the second semiconductor switch 20. As a result, the drive current for maintaining the conductive state of the second semiconductor switch 20 can be reduced, enabling the size of the power supply circuit to be reduced.

[0066] (summary) The configuration of the switch device according to this embodiment is exemplified below.

[0067] [Example 1] A switch device 1 according to this embodiment includes a first terminal T1 and a second terminal T2 provided in a power supply path SL connecting an alternating current power source AC and a load L, a first semiconductor switch 10 provided between the first terminal T1 and the second terminal T2 in the power supply path SL, an electromagnetic relay 40 provided between the first terminal T1 and the second terminal T2 in the power supply path SL and connected in series to the first semiconductor switch 10, a second semiconductor switch 20 connected in parallel to the first semiconductor switch 10 and the electromagnetic relay 40, and a control unit 50 that switches the first semiconductor switch 10 between conductive and non-conductive states, switches the output of an on command and release of the on command to the second semiconductor switch 20, and switches the opening and closing of the contacts of the electromagnetic relay 40. The control unit 50 outputs an ON command to the second semiconductor switch 20 while the contacts of the electromagnetic relay 40 are open, thereby putting the second semiconductor switch 20 into a conductive state, and closes the contacts of the electromagnetic relay 40 after a predetermined period of time ts has elapsed since the ON command was output to the second semiconductor switch 20.

[0068] In this way, by closing the contacts of the electromagnetic relay 40 after outputting an ON command to the second semiconductor switch 20, the inrush current flowing toward the load L can be bypassed to the path provided with the second semiconductor switch 20. This makes it possible to prevent the inrush current from flowing to the electromagnetic relay 40, and to prevent the contacts of the electromagnetic relay 40 from welding.

[0069] [Example 2] The control unit 50 outputs an ON command to the second semiconductor switch 20, then turns on the first semiconductor switch 10, and then closes the contacts of the electromagnetic relay 40 after turning on the first semiconductor switch 10.

[0070] In this way, by closing the contacts of the electromagnetic relay 40 after the first semiconductor switch 10 is turned on, it is possible to prevent a high voltage from being applied to the first semiconductor switch 10 and prevent malfunctions in the first semiconductor switch 10. Furthermore, since it is possible to prevent a high voltage from being applied to the first semiconductor switch 10, it is not necessary to use a semiconductor element with high voltage resistance for the first semiconductor switch 10, thereby reducing the cost of the switch device 1. The configuration of Example 2 is applicable to Example 1.

[0071] [Example 3] The control unit 50 outputs a release of the ON command to the second semiconductor switch 20 after the first semiconductor switch 10 is turned on and the contact of the electromagnetic relay 40 is closed.

[0072] In this way, by outputting a release of the ON command to the second semiconductor switch 20 after closing the contacts of the electromagnetic relay 40, the conductive state of the second semiconductor switch 20 is maintained when the contacts of the electromagnetic relay 40 are closed. Therefore, the current value when current starts to flow to the electromagnetic relay 40 starts from approximately 0 A (amperes), and it is possible to prevent a sudden large current from flowing through the contacts of the electromagnetic relay 40. This makes it possible to prevent the contacts of the electromagnetic relay 40 from welding. The configuration of Example 3 can be applied to Example 1 or Example 2.

[0073] [Example 4] The control unit 50 outputs a release of the ON command to the second semiconductor switch 20 after the first semiconductor switch 10 is turned on and before the contact of the electromagnetic relay 40 is closed.

[0074] In this way, by outputting a release of the ON command to the second semiconductor switch 20 before closing the contacts of the electromagnetic relay 40, the conduction period of the second semiconductor switch 20 can be shortened. Therefore, the drive current for maintaining the conduction of the second semiconductor switch 20 can be reduced. This makes it possible to reduce the size of the power supply circuit for driving the control unit 50. The configuration of Example 4 can be applied to Example 1 or Example 2.

[0075] [Example 5] When starting the load L, the control unit 50 outputs an ON command to the second semiconductor switch 20, and closes the contacts of the electromagnetic relay 40 after a predetermined period of time ts has elapsed since the ON command was output to the second semiconductor switch 20.

[0076] According to this configuration, when the load L is started, the inrush current flowing toward the load L can be bypassed to the path provided with the second semiconductor switch 20. This makes it possible to prevent the inrush current from flowing to the electromagnetic relay 40, and to prevent the contacts of the electromagnetic relay 40 from welding. The configuration of Example 5 can be applied to any of Examples 1 to 4.

[0077] [Example 6] The predetermined period ts is a period of at least several cycles of the alternating current output from the alternating current power supply AC.

[0078] By setting the predetermined period ts to a period of at least several cycles of the AC current in this way, it is possible to allow current to flow to the electromagnetic relay 40 when the inrush current flowing through the load L becomes sufficiently small. This makes it possible to prevent a large inrush current from flowing through the electromagnetic relay 40, and to prevent the contacts of the electromagnetic relay 40 from welding. The configuration of Example 6 can be applied to any of Examples 1 to 5.

[0079] [Example 7] The predetermined period ts is a period of time from when an ON command to the second semiconductor switch 20 is output to 2 to 6 cycles of the AC current output from the AC power supply AC.

[0080] By setting the predetermined period ts to be between 2 and 6 cycles of the AC current in this manner, it is possible to allow current to flow to the electromagnetic relay 40 when the inrush current flowing through the load L becomes sufficiently small. This makes it possible to prevent a large inrush current from flowing through the electromagnetic relay 40, and to prevent the contacts of the electromagnetic relay 40 from welding. The configuration of Example 7 can be applied to any of Examples 1 to 5.

[0081] [Example 8] The second semiconductor switch 20 is a semiconductor element that has a higher breakdown voltage than the first semiconductor switch 10 and is capable of passing a larger current.

[0082] According to this configuration, the inrush current flowing toward the load L can be bypassed to the path provided with the second semiconductor switch 20. This makes it possible to prevent the inrush current from flowing to the electromagnetic relay 40, and to prevent the contacts of the electromagnetic relay 40 from welding. The configuration of Example 8 can be applied to any of Examples 1 to 7.

[0083] [Example 9] The first semiconductor switch 10 is a switch including a field effect transistor, and the second semiconductor switch 20 is a thyristor or a bidirectional thyristor.

[0084] In this way, by using a switch including a field effect transistor as the first semiconductor switch 10, instantaneous switching between conductive and non-conductive states becomes possible.

[0085] Furthermore, by using a thyristor or a bidirectional thyristor as the second semiconductor switch 20, the second semiconductor switch 20 becomes a semiconductor element that has a higher withstand voltage and is capable of passing a large current than the first semiconductor switch 10. Therefore, an inrush current flowing toward the load L can be bypassed to a path in which the second semiconductor switch 20 is provided. This makes it possible to suppress the inrush current from flowing to the electromagnetic relay 40, and to suppress welding of the contacts of the electromagnetic relay 40. The configuration of Example 9 can be applied to any of Examples 1 to 8.

[0086] [Example 10] The control unit 50 closes the contacts of the electromagnetic relay 40 when the current flowing through the second semiconductor switch 20 is smaller than a predetermined current value.

[0087] In this way, when the current flowing through the second semiconductor switch 20 is smaller than a predetermined current value, the contacts of the electromagnetic relay 40 are closed, thereby preventing a large inrush current from flowing through the electromagnetic relay 40. This prevents the contacts of the electromagnetic relay 40 from welding together. The configuration of Example 10 can be applied to any of Examples 1 to 9.

[0088] [Example 11] The control unit 50 closes the contacts of the electromagnetic relay 40 when the current flowing through the second semiconductor switch 20 is smaller than the rated current of the electromagnetic relay 40 .

[0089] In this way, when the current flowing through the second semiconductor switch 20 is smaller than the rated current of the electromagnetic relay 40, the contacts of the electromagnetic relay 40 are closed, thereby preventing a large inrush current from flowing through the electromagnetic relay 40. This prevents the contacts of the electromagnetic relay 40 from welding together. The configuration of Example 11 can be applied to any of Examples 1 to 9.

[0090] (Other forms) Although the switch device has been described above based on the embodiments, the present invention is not limited to the above embodiments. For example, the present invention also includes forms obtained by applying various modifications to the above embodiments that would occur to those skilled in the art, and forms realized by arbitrarily combining the components and functions of the embodiments within the scope of the spirit of the present invention.

[0091] In the above, an example has been shown in which a thyristor or a bidirectional thyristor is used as the second semiconductor switch 20, but the present invention is not limited to this. The second semiconductor switch 20 may be any semiconductor element that has a higher breakdown voltage and is capable of passing a large current than the first semiconductor switch 10. For example, the second semiconductor switch 20 may be a MOSFET or an IGBT (Insulated Gate Bipolar Transistor) that has a high breakdown voltage and is capable of passing a large current.

[0092] Although the above example illustrates the case where the predetermined period ts is set by a timer, this is not limiting. For example, if the switch device 1 includes a current detection circuit (or a voltage detection circuit), the control unit 50 may use the current detection circuit to detect the value of the current flowing through the second semiconductor switch 20, and control the electromagnetic relay 40 to close the contacts when the detected current value is smaller than a predetermined current value. In this case, the voltage detection circuit is electrically connected to each of the first terminal T1 and the second terminal T2, and is configured to detect the current flowing through the second semiconductor switch 20 (or the voltage applied to the second semiconductor switch 20). In other words, the predetermined period ts in this embodiment may be a period determined by the current detection circuit until the current flowing through the second semiconductor switch 20 becomes smaller than a predetermined current value. [Explanation of symbols]

[0093] 1 Switching device 10 First semiconductor switch 20 Second semiconductor switch 40 Electromagnetic Relay 50 control section AC alternating current power supply L load SL power supply route T1 Terminal 1 T2 Terminal 2

Claims

1. a first terminal and a second terminal provided on a power supply path connecting an AC power source and a load; a first semiconductor switch provided in the power supply path between the first terminal and the second terminal; an electromagnetic relay provided in the power supply path between the first terminal and the second terminal and connected in series to the first semiconductor switch; a second semiconductor switch connected in parallel to the first semiconductor switch and the electromagnetic relay; a control unit that switches the first semiconductor switch between conductive and non-conductive states, switches the output of an ON command and a release of an ON command to the second semiconductor switch, and switches the opening and closing of the contacts of the electromagnetic relay; Equipped with The control unit outputs an ON command to the second semiconductor switch while the contact of the electromagnetic relay is open, thereby bringing the second semiconductor switch into a conductive state, and further brings the first semiconductor switch into a conductive state after bringing the second semiconductor switch into a conductive state, and closes the contact of the electromagnetic relay after bringing the first semiconductor switch into a conductive state. Switch device.

2. The control unit outputs a release of the ON command to the second semiconductor switch after the first semiconductor switch is turned on and after the contact of the electromagnetic relay is closed. The switch device according to claim 1 .

3. The control unit outputs a release of the ON command to the second semiconductor switch after the first semiconductor switch is turned on and before the contact of the electromagnetic relay is closed. The switch device according to claim 1 .

4. The control unit outputs an ON command to the second semiconductor switch when starting the load, and closes the contacts of the electromagnetic relay after a predetermined period has elapsed since the ON command was output to the second semiconductor switch and after the first semiconductor switch is made conductive. The switch device according to claim 1 .

5. a first terminal and a second terminal provided on a power supply path connecting an AC power source and a load; a first semiconductor switch provided in the power supply path between the first terminal and the second terminal; an electromagnetic relay provided in the power supply path between the first terminal and the second terminal and connected in series to the first semiconductor switch; a second semiconductor switch connected in parallel to the first semiconductor switch and the electromagnetic relay; a control unit that switches the first semiconductor switch between conductive and non-conductive states, switches the output of an ON command and a release of an ON command to the second semiconductor switch, and switches the opening and closing of the contacts of the electromagnetic relay; Equipped with the control unit outputs an ON command to the second semiconductor switch while the contact of the electromagnetic relay is open, thereby bringing the second semiconductor switch into a conductive state, and closes the contact of the electromagnetic relay after a predetermined period has elapsed since the ON command was output to the second semiconductor switch; The predetermined period is a period of at least a plurality of periods of the AC current output from the AC power supply. Switch device.

6. a first terminal and a second terminal provided on a power supply path connecting an AC power source and a load; a first semiconductor switch provided in the power supply path between the first terminal and the second terminal; an electromagnetic relay provided in the power supply path between the first terminal and the second terminal and connected in series to the first semiconductor switch; a second semiconductor switch connected in parallel to the first semiconductor switch and the electromagnetic relay; a control unit that switches the first semiconductor switch between conductive and non-conductive states, switches the output of an ON command and a release of an ON command to the second semiconductor switch, and switches the opening and closing of the contacts of the electromagnetic relay; Equipped with the control unit outputs an ON command to the second semiconductor switch while the contact of the electromagnetic relay is open, thereby bringing the second semiconductor switch into a conductive state, and closes the contact of the electromagnetic relay after a predetermined period has elapsed since the ON command was output to the second semiconductor switch; The predetermined period is a period of time from when an ON command is output to the second semiconductor switch to when the AC power supply outputs two or more cycles and six or less cycles of the AC current. Switch device.

7. a first terminal and a second terminal provided on a power supply path connecting an AC power source and a load; a first semiconductor switch provided in the power supply path between the first terminal and the second terminal; an electromagnetic relay provided in the power supply path between the first terminal and the second terminal and connected in series to the first semiconductor switch; a second semiconductor switch connected in parallel to the first semiconductor switch and the electromagnetic relay; a control unit that switches the first semiconductor switch between conductive and non-conductive states, switches the output of an ON command and a release of an ON command to the second semiconductor switch, and switches the opening and closing of the contacts of the electromagnetic relay; Equipped with The control unit outputs an ON command to the second semiconductor switch while the contact of the electromagnetic relay is open, thereby bringing the second semiconductor switch into a conductive state, and closes the contact of the electromagnetic relay when a predetermined period of time has elapsed since the ON command was output to the second semiconductor switch and the current flowing through the second semiconductor switch is smaller than a predetermined current value. Switch device.

8. a first terminal and a second terminal provided on a power supply path connecting an AC power source and a load; a first semiconductor switch provided in the power supply path between the first terminal and the second terminal; an electromagnetic relay provided in the power supply path between the first terminal and the second terminal and connected in series to the first semiconductor switch; a second semiconductor switch connected in parallel to the first semiconductor switch and the electromagnetic relay; a control unit that switches the first semiconductor switch between conductive and non-conductive states, switches the output of an ON command and a release of an ON command to the second semiconductor switch, and switches the opening and closing of the contacts of the electromagnetic relay; Equipped with The control unit outputs an ON command to the second semiconductor switch while the contacts of the electromagnetic relay are open, thereby bringing the second semiconductor switch into a conductive state, and closes the contacts of the electromagnetic relay when a predetermined period has elapsed since the ON command was output to the second semiconductor switch and the current flowing through the second semiconductor switch is smaller than the rated current of the electromagnetic relay. Switch device.

9. The second semiconductor switch is a semiconductor element that has a higher breakdown voltage and is capable of passing a larger current than the first semiconductor switch. The switch device according to any one of claims 1 to 8.

10. the first semiconductor switch is a switch including a field effect transistor, The second semiconductor switch is a thyristor or a bidirectional thyristor. The switch device according to any one of claims 1 to 8.

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