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JP-7854616-B2 - Switching device

JP7854616B2JP 7854616 B2JP7854616 B2JP 7854616B2JP-7854616-B2

Inventors

  • 丸岡 晴喜
  • 宮本 賢吾
  • 後藤 周作

Assignees

  • パナソニックＩＰマネジメント株式会社

Dates

Publication Date
20260507
Application Date
20230327

Claims (11)

  1. A first terminal and a second terminal are provided in the power supply path connecting the AC power source and the load, A first semiconductor switch is provided between the first terminal and the second terminal in the power supply path, A second semiconductor switch connected in parallel to the first semiconductor switch, A control unit that, at each half-cycle or multiplier of the half-cycle appearing in the AC waveform of the AC power supply, switches the conduction and non-conduction of the first semiconductor switch, and switches the output of an ON command and an ON command release for the second semiconductor switch, Equipped with, The control unit outputs an ON command to the second semiconductor switch before switching the first semiconductor switch from conductive to non-conductive, thereby making the second semiconductor switch conductive, and after switching the first semiconductor switch to non-conductive, before the current flowing to the load by the AC power supply becomes zero, the control unit outputs a release of the ON command to the second semiconductor switch at the same timing during the half cycle or the half cycle multiplication.
  2. The first semiconductor switch is a switch that includes a field-effect transistor, The switch device according to claim 1, wherein the second semiconductor switch is a thyristor or a bidirectional thyristor.
  3. The switch device according to claim 1, wherein the second semiconductor switch maintains a conductive state even after receiving the cancellation of the ON command output from the control unit, and changes the conductive state to a non-conductive state when the current of the AC power supply becomes zero.
  4. Furthermore, it includes a power supply circuit that generates a drive voltage for driving the control unit, The power supply circuit is electrically connected to the first terminal via a first rectifier element and electrically connected to the second terminal via a second rectifier element, as described in claim 1.
  5. The switch device according to claim 1, wherein the control unit has a voltage detection unit that detects the voltage applied to the first semiconductor switch, and outputs an ON command to the second semiconductor switch when the voltage applied to the first semiconductor switch is higher than a predetermined voltage.
  6. The voltage detection unit is electrically connected to the first terminal and the second terminal, The switch device according to claim 5, wherein the control unit outputs an ON command to the second semiconductor switch when the potential at the first terminal or the second terminal is higher than a predetermined potential.
  7. Furthermore, the power supply path includes an electromagnetic relay provided between the first semiconductor switch and the second terminal, The switch device according to claim 1, wherein the electromagnetic relay is connected in series with the first semiconductor switch.
  8. The control unit has a voltage detection unit that detects the voltage applied to the first semiconductor switch, and when the voltage applied to the first semiconductor switch is higher than a predetermined voltage, the electromagnetic relay, which is in a conductive state, is turned into a non-conductive state, as described in claim 7.
  9. The second semiconductor switch is connected in parallel to the first semiconductor switch and the electromagnetic relay. The switch device according to claim 8, wherein the control unit outputs an ON command to the second semiconductor switch when the voltage applied to the first semiconductor switch is higher than a predetermined voltage.
  10. Furthermore, it includes an information acquisition unit that acquires operation information for operating the load, The switch device according to claim 1, wherein the control unit controls the conduction and non-conductivity of the first semiconductor switch, and the on command and release of the on command for the second semiconductor switch, based on the operation information.
  11. Furthermore, it includes an information acquisition unit that acquires operation information for operating the load, The switch device according to claim 7, wherein the control unit controls the conduction and non-conductivity of the first semiconductor switch, the on command and release of the on command for the second semiconductor switch, and the conduction and non-conductivity of the electromagnetic relay based on the operation information.

Description

This invention relates to a switch device for controlling load. Conventionally, devices for controlling loads such as lighting fixtures are known. As an example of this type of device, Patent Document 1 discloses a dimming device comprising a first switch element provided between an AC power source and a load, a second switch element connected in parallel to the first switch element, and a zero-cross detection circuit for detecting zero-crossings in the waveform output from the AC power source. In this dimming device, the conduction and non-conductivity of one of the two switch elements is controlled based on the zero-crossing timing detected by the zero-cross detection circuit. Patent No. 6389911 This is a circuit diagram of a comparative example switch device and load control system.This is a timing chart showing the operation of the switch device in the comparative example.This is a circuit diagram of a switch device and load control system according to Embodiment 1.This is a timing chart showing the operation of the switch device according to Embodiment 1.This is a circuit diagram of a switch device and load control system according to Embodiment 2.This is a circuit diagram of a switch device and load control system according to a modified example of Embodiment 2.This is a circuit diagram of a switch device and load control system according to Embodiment 3.This is a circuit diagram of a switch device and load control system according to a modified example of Embodiment 3. (Background leading to the present invention) The background leading to the present invention will be explained with reference to comparative examples. Figure 1 is a circuit diagram of a comparative example switch device 101 and load control system 102. As shown in Figure 1, the comparative example load control system 102 comprises an AC power supply, a load L, and a switch device 101. The switch device 101 is installed in the power supply path SL connecting the AC power supply and the load L. The load L is, for example, a lighting device such as a ceiling light or downlight. The switch device 101 is composed of semiconductor switches 110, such as field-effect transistors. Figure 2 is a timing chart showing the operation of the comparative example switch device 101. The figure shows the switching between conduction and non-conductivity of the semiconductor switch 110, the inter-switch voltage (the voltage across the semiconductor switch 110), and the load current supplied to the load L. In the load control system 102, the control unit 150 generates a load current of a predetermined waveform by switching the conduction and non-conductivity of the semiconductor switch 110 at half-cycle intervals in the AC waveform of the AC power supply, thereby controlling the operation of the load L. For example, if the load L is an inductive device such as a lighting fixture, a back electromotive force (EMF) is generated when the semiconductor switch 110 is turned off (t = t2). This back EMF, caused by the load L, can overvoltage the semiconductor switch 110, potentially damaging it. The switch device of the present invention has the following configuration to suppress the generation of back electromotive force due to the load L when the semiconductor switch is turned off. Furthermore, even if back electromotive force due to the load L is generated, the switch device of the present invention has the following configuration to suppress malfunctions in the semiconductor switch caused by the generated back electromotive force. The embodiments will be described below with reference to the drawings. The embodiments described below are all preferred specific examples of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement positions of components, and connection configurations shown in the following embodiments are examples and are not intended to limit the present invention. Accordingly, components in the following embodiments that are not described in the independent claims representing the highest-level concept of the present invention will be described as optional components. Please note that each figure is a schematic diagram and not necessarily a strictly accurate representation. Furthermore, the same reference numerals are used for substantially identical components in each figure, and redundant explanations are omitted or simplified. (Embodiment 1) The switch device according to Embodiment 1 will be described with reference to Figures 3 and 4. Figure 3 is a circuit diagram of the switch device 1 and load control system 2 according to Embodiment 1. As shown in Figure 3, the load control system 2 comprises an AC power supply, a load L, and a switch device 1. AC power supply refers to, for example, a commercial power supply of 100V or 200V AC. AC power supply outputs a sinusoidal alternating current (or AC voltage) with a constant period. Figure 3 shows a single-phase two-wire power supply path SL connecting