Power supply switching circuit and air conditioner

Abstract

A power supply switching circuit (50) comprises: a control circuit (2) to which a voltage from a battery (3) is constantly applied and which has a control unit (7) for controlling the operation of an actuator (22); a voltage detection unit (1) that detects a voltage value of AC voltage output by an AC power supply (20); a cut-off unit (4) that is disposed between a connection point (12), at which the AC power supply (20) and the voltage detection unit (1) are connected, and the control circuit (2), and that cuts off power supply to the actuator (22) of the AC voltage applied to the actuator (22) via the control circuit (2); and a switching unit (5) that performs a closing operation, when the cut-off unit (4) performs an opening operation, so that the voltage output from the battery (3) is applied to the control circuit (2) .

Description

Technical Field

[0001] The present disclosure relates to a power supply switching circuit that switches power supply to an actuator mounted on a device between an external power supply and an internal power supply, and an air conditioner.

Background Art

[0002] Patent Document 1 below discloses an air conditioner that is charged by receiving power from a commercial power supply as an external power supply and is equipped with a battery as an internal power supply for supplying secondary power to an actuator of the air conditioner. In this Patent Document 1, when the supply state of power from the commercial power supply is detected and it is determined that the supply of the power has been interrupted, the secondary power of the battery is supplied to the controller by the power switching means so that the controller can continue the control operation.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional technology represented by Patent Document 1 above, when the power from the commercial power supply is interrupted, it is necessary to temporarily stop the air conditioning operation. For this reason, in the conventional technology, there is a problem that it is necessary to stop the operation of the device in order to switch the power supply to the internal power supply, that is, the battery.

[0005] The present disclosure has been made in view of the above, and an object thereof is to obtain a power supply switching circuit that can switch the power supply to the internal power supply without stopping the operation of the device.

Means for Solving the Problems

[0006] In order to solve the above-described problems and achieve the object, the power supply switching circuit according to the present disclosure is disposed between an external power supply, which is an AC power supply, and an actuator, and switches the power supply to the actuator between the external power supply and an internal power supply. The power supply switching circuit includes a control circuit having a control unit, a voltage detection unit, a first cutoff unit, and a switching unit. The control unit has a voltage constantly applied thereto by the internal power supply and controls the operation of the actuator. The voltage detection unit detects the voltage value of the AC voltage output by the external power supply. The first cutoff unit is disposed between the connection point where the external power supply and the voltage detection unit are connected and the control circuit, and cuts off the power supply to the actuator of the AC voltage applied to the actuator via the control circuit. The switching unit performs a closing operation so that the voltage output from the internal power supply is applied to the control circuit when the first cutoff unit performs an opening operation.

Effect of the Invention

[0007] According to the power supply switching circuit according to the present disclosure, there is an effect that it is possible to switch to power supply from the internal power supply without stopping the operation of the device.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0009] With reference to the accompanying drawings, the power supply switching circuit and the air conditioner according to the embodiments of the present disclosure will be described in detail. Note that the embodiments described below are examples, and the scope of the present disclosure is not limited by the following embodiments.

[0010] Embodiment 1. FIG. 1 is a diagram showing a configuration example of an air conditioner 100 according to Embodiment 1. The air conditioner 100 according to Embodiment 1 includes a battery 3, an actuator 22, and a power supply switching circuit 50. The power supply switching circuit 50 is disposed between an AC power supply 20 and the actuator 22. The AC power supply 20 is an external power supply, while the battery 3 is an internal power supply built in the air conditioner 100. The power supply switching circuit 50 has a function of switching the power supply to the actuator 22 between the AC power supply 20 and the battery 3.

[0011] The power supply switching circuit 50 includes a voltage detection unit 1, a control circuit 2, a cutoff unit 4, and a switching unit 5. The control circuit 2 includes a control unit 7. The actuator 22 is connected to the control circuit 2. An example of the actuator 22 is, although not shown, a blower fan of the indoor unit or the outdoor unit of the air conditioner 100, or a flap for adjusting the air direction of the indoor unit. The control unit 7 of the control circuit 2 controls the operation of the actuator 22 by controlling the drive current flowing through the fan motor that drives the blower fan or the stepping motor that operates the flap. The voltage detection unit 1 is connected to both ends of the AC power supply 20 and detects the voltage value of the AC voltage output by the AC power supply 20. Note that the air conditioner 100 is an example of a device, and the actuator 22 may be a device or a device provided in a device other than the air conditioner.

[0012] The cutoff unit 4 has make-and-break contacts (not shown). The opening and closing operation of the cutoff unit 4 is controlled by the control unit 7. The cutoff unit 4 is arranged on one of the electrical wirings 8 connecting the AC power supply 20 and the voltage detection unit 1. Specifically, the cutoff unit 4 is arranged between one connection point 12 where the AC power supply 20 and the voltage detection unit 1 are connected and the control circuit 2. Note that the cutoff unit 4 may be arranged on the other electrical wiring 9 connecting the AC power supply 20 and the voltage detection unit 1. In this case, the cutoff unit 4 is arranged between the other connection point 13 where the AC power supply 20 and the voltage detection unit 1 are connected and the control circuit 2. With any of these configurations, the AC voltage output from the AC power supply 20 is applied to the actuator 22 via the cutoff unit 4 and the control circuit 2. Further, the cutoff unit 4 receives control by the control unit 7 and cuts off the power supply to the actuator 22 of the AC voltage applied to the actuator 22. Note that in this document, the cutoff unit 4 may be described as the "first cutoff unit".

[0013] The switching unit 5 has make-and-break contacts (not shown). The opening and closing operation of the switching unit 5 is controlled by the control unit 7. The switching unit 5 is connected between the electrical wiring 8 and the battery 3. Here, when the contacts of the cutoff unit 4 are controlled to open, the contacts of the switching unit 5 are controlled to close. Therefore, when the cutoff unit 4 performs an opening operation, the switching unit 5 performs a closing operation so that the voltage output from the battery 3 is applied to the control circuit 2.

[0014] The control unit 7 is configured such that the voltage from the battery 3 is constantly applied. With this configuration, even when the power supply to the actuator 22 is switched from the AC power supply 20 to the battery 3, the control unit 7 can perform the power supply switching without stopping the air conditioning operation by the air conditioner 100. Further, with this configuration, the switching of the power supply from the AC power supply 20 to the battery 3 can be self-contained by the air conditioner 100 without relying on an external signal.

[0015] Further, the battery 3 is connected between the electric wiring 8 and the electric wiring 9. The connection point on the electric wiring 8 side exists between the cutoff part 4 and the control circuit 2. Therefore, when the cutoff part 4 and the control circuit 2 are electrically connected, the battery 3 is connected to the power supply switching circuit 50 so that power supply from the battery 3 to the actuator 22 and charging of the battery 3 by the AC power supply 20 can be simultaneously performed.

[0016] Next, the power supply switching operation by the control unit 7 will be described with reference to FIGS. 2 and 3. FIG. 2 is a flowchart for explaining the power supply switching operation in the first embodiment. FIG. 3 is a time chart for explaining the power supply switching operation in the first embodiment. In the explanations of FIGS. 2 and 3, the AC power supply 20 is referred to as an "external power supply". Further, in FIG. 3, "battery OFF" means that the battery 3 and the control circuit 2 are not electrically connected, and "battery ON" means that the battery 3 and the control circuit 2 are electrically connected.

[0017] The control unit 7 controls the opening and closing operations of the cutoff part 4 and the switching part 5 based on the detection result of the voltage detection unit 1. In a state where the power supply to the actuator 22 is from the external power supply (step S11), the control unit 7 detects whether the AC voltage is a different voltage based on the detection result of the voltage detection unit 1 (step S12). Here, "different voltage" means that the AC voltage is not a normal voltage, and is a concept including the case where the AC voltage is an abnormal voltage. In this document, the determination of whether the AC voltage is a different voltage is made based on the detection value of the voltage detection unit 1 being the first threshold value which is the higher potential side threshold value and the second threshold value which is the lower potential side threshold value, as shown in FIG. 3. Specifically, when the detection value of the AC voltage is within the range of the first threshold value and the second threshold value, the control unit 7 determines that the AC voltage is a normal voltage. When the detection value of the AC voltage is outside the range of the first threshold value and the second threshold value, the control unit 7 determines that the AC voltage is a different voltage.

[0018] Return to the description of the flowchart in FIG. 2. In step S12, when a normal voltage is detected, the process of step S12 is repeated. On the other hand, in step S12, when an abnormal voltage is detected, the control unit 7 switches to power supply from the battery 3 (step S13).

[0019] Furthermore, in the state of step S13 where power supply to the actuator 22 is being performed from the battery 3, the control unit 7 detects whether the AC voltage is an abnormal voltage based on the detection result of the voltage detection unit 1 (step S14). In step S14, when an abnormal voltage is detected, that is, when an abnormal voltage is continuously detected, the control unit 7 continues power supply from the battery 3 (step S15). Then, the process returns to step S14. On the other hand, in step S14, when a normal voltage is detected, the control unit 7 switches to power supply from the external power source (step S16). Then, the process returns to step S12, and the process from step S12 is repeated.

[0020] In FIG. 3, the period before time t1, the period from time t2 to time t3, and the period after time t4 indicate periods in which the detection value of the voltage detection unit 1 is a normal voltage. In these periods, the contact of the cutoff unit 4 is controlled to be closed and the contact of the switching unit 5 is controlled to be open so that the battery 3 is turned off. Also, the period from time t1 to time t2 and the period from time t3 to time t4 indicate periods in which the detection value of the voltage detection unit 1 is an abnormal voltage. In these periods, the contact of the cutoff unit 4 is controlled to be open and the contact of the switching unit 5 is controlled to be closed so that the battery 3 is turned on.

[0021] Next, the hardware configuration for realizing the functions of the control unit 7 in the first embodiment will be described with reference to the drawings in FIGS. 4 and 5. FIG. 4 is a block diagram showing an example of the hardware configuration for realizing the functions of the control unit 7 in the first embodiment. When realizing the functions of the control unit 7 in the first embodiment, as shown in FIG. 4, a configuration including a processor 200 that performs calculations, a memory 202 in which a program read by the processor 200 is stored, and an interface 204 that inputs and outputs signals can be adopted.

[0022] The processor 200 is an example of an arithmetic means. The processor 200 may be an arithmetic means referred to as a microprocessor, a microcomputer, a microcontroller, a CPU (Central Processing Unit), or a DSP (Digital Signal Processor). Also, the memory 202 may include non-volatile or volatile semiconductor memories such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable ROM), EEPROM (registered trademark) (Electrically EPROM), magnetic disks, flexible disks, optical disks, compact disks, mini disks, and DVDs (Digital Versatile Disc).

[0023] The memory 202 stores a program for executing the functions of the control unit 7 in Embodiment 1 and the two thresholds described above. The processor 200 can perform the above-described processing by receiving and transmitting necessary information via the interface 204, executing the program stored in the memory 202 by the processor 200, and referring to the two thresholds stored in the memory 202 by the processor 200. The calculation result by the processor 200 can be stored in the memory 202.

[0024] In addition, when implementing the functions of the control unit 7 in Embodiment 1, the configuration shown in FIG. 5 may also be used. FIG. 5 is a block diagram showing another example of the hardware configuration for implementing the functions of the control unit 7 in Embodiment 1. In FIG. 5, the processor 200 and the memory 202 shown in FIG. 4 are replaced by a processing circuit 203. The above-mentioned two thresholds are held in the processing circuit 203. The processing circuit 203 corresponds to a single circuit, a composite circuit, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof. Information input to the processing circuit 203 and information output from the processing circuit 203 can be obtained via the interface 204.

[0025] As described above, the power supply switching circuit according to Embodiment 1 is disposed between an external power supply, which is an AC power supply, and an actuator, and switches the power supply to the actuator between the external power supply and an internal power supply. The power supply switching circuit includes a control circuit having a control unit, a voltage detection unit, a first cutoff unit, and a switching unit. The control unit has a voltage constantly applied by the internal power supply and controls the operation of the actuator. The voltage detection unit detects the voltage value of the AC voltage output by the external power supply. The first cutoff unit is disposed between the connection point where the external power supply and the voltage detection unit are connected and the control circuit, and cuts off the power supply to the actuator of the AC voltage applied to the control circuit via the control circuit. The switching unit performs a closing operation so that the voltage output from the internal power supply is applied to the control circuit when the first cutoff unit performs an opening operation. Thereby, even when the power supply to the actuator is switched from the external power supply to the internal power supply, the power supply can be switched without stopping the air conditioning operation by the air conditioner. In addition, the switching of the power supply from the external power supply to the internal power supply can be self-contained by the air conditioner without relying on an external signal.

[0026] In the above configuration, when the voltage detection unit detects a different voltage, the first cutoff unit performs an open operation and the switching unit performs a close operation. The operations of the first cutoff unit and the switching unit are controlled by a control unit to which a voltage from an internal power source is constantly applied. Thereby, the switching from the external power source to the internal power source for the actuator can be smoothly and surely performed without stopping the air conditioning operation by the air conditioner.

[0027] Further, the air conditioner according to Embodiment 1 includes an actuator, an internal power source, and a power supply switching circuit that switches power supply to the actuator between an external power source, which is an AC power source, and the internal power source. The power supply switching circuit includes a control circuit having a control unit, a voltage detection unit, a first cutoff unit, and a switching unit. The control unit has a voltage constantly applied from the internal power source and controls the operation of the actuator. The voltage detection unit detects the voltage value of the AC voltage output from the external power source. The first cutoff unit is disposed between the connection point where the external power source and the voltage detection unit are connected and the control circuit, and cuts off the power supply to the actuator of the AC voltage applied to the actuator via the control circuit. The switching unit performs a close operation so that the voltage output from the internal power source is applied to the control circuit when the first cutoff unit performs an open operation. Thereby, even when the power supply to the actuator is switched from the external power source to the internal power source, the power supply can be switched without stopping the air conditioning operation by the air conditioner. Further, the switching of the power supply from the external power source to the internal power source can be self - contained by the air conditioner without relying on an external signal.

[0028] Further, in the air conditioner according to Embodiment 1, the internal power source is connected to the power supply switching circuit such that when the first cutoff unit and the control circuit are electrically connected, the power supply to the actuator by the external power source and the charging of the internal power source by the external power source are simultaneously performed. Thereby, the internal power source can be kept in an operable state without performing a special charging operation.

[0029] Embodiment 2. FIG. 6 is a diagram showing a configuration example of the air conditioner 100A according to Embodiment 2. In FIG. 6, in the air conditioner 100A according to Embodiment 2, in the configuration of the air conditioner 100 according to Embodiment 1 shown in FIG. 1, the power supply switching circuit 50 is replaced with a power supply switching circuit 50A. In the power supply switching circuit 50A, a cutoff unit 6 is further added to the configuration of FIG. 1. The cutoff unit 6 has an open / close contact (not shown). The opening / closing operation of the cutoff unit 6 is controlled by the control unit 7. The cutoff unit 6 is arranged in the other electrical wiring 9 connecting the AC power supply 20 and the voltage detection unit 1. Specifically, the cutoff unit 6 is arranged between the other connection point 13 to which the AC power supply 20 and the voltage detection unit 1 are connected and the control circuit 2. Regarding other configurations, they are the same as or equivalent to those in FIG. 1, and the same or equivalent components are denoted by the same reference numerals, and duplicate explanations are omitted. In this document, the cutoff unit 6 may be described as the "second cutoff unit".

[0030] The cutoff unit 6 is provided to ensure the operation of the power supply switching circuit 50A. For this reason, the cutoff unit 6 is controlled in the same manner as the cutoff unit 4. Therefore, when the cutoff unit 4 performs a closing operation, the cutoff unit 6 also performs a closing operation, and when the cutoff unit 4 performs an opening operation, the cutoff unit 6 also performs an opening operation.

[0031] According to the power supply switching circuit 50A configured as described above, even when one of the contacts of the cutoff units 4 and 6 has a short-circuit failure, the circuit part for supplying power from the AC power supply 20 is surely cut off by the other cutoff unit that has no short-circuit failure. Thereby, it is possible to prevent a spreading failure to circuit elements other than the cutoff units 4 and 6 and surely protect the power supply switching circuit 50A.

[0032] As described above, the power supply switching circuit according to Embodiment 2 is arranged in the other electrical wiring for electrically connecting the external power supply and the control circuit, and further includes a second cutoff unit that operates in the same manner as the first cutoff unit. Thereby, it is possible to prevent a spreading failure to circuit elements other than the first and second cutoff units and surely protect the power supply switching circuit.

[0033] The configurations shown in the above embodiments are merely examples, and it is possible to combine them with other known technologies, and it is also possible to omit or change a part of the configuration without departing from the gist.

Description of Reference Numerals

[0034] 1 Voltage detection unit, 2 Control circuit, 3 Battery, 4, 6 Cutoff unit, 5 Switching unit, 7 Control unit, 8, 9 Electrical wiring, 12, 13 Connection points, 20 AC power supply, 22 Actuator, 50, 50A Power supply switching circuit, 100, 100A Air conditioner, 200 Processor, 202 Memory, 203 Processing circuit, 204 Interface.

Claims

1. A power supply switching circuit disposed between an external power supply, which is an AC power supply, and an actuator, and switching the power supply to the actuator between the external power supply and an internal power supply, the power supply switching circuit comprising: The power supply switching circuit includes: A control circuit having a control unit to which a voltage from the internal power supply is constantly applied and which controls the operation of the actuator; A voltage detection unit that detects different voltages of the AC voltage output by the external power supply; A first cutoff unit disposed between a connection point where the external power supply and the voltage detection unit are connected and the control circuit, and cutting off the power supply of the AC voltage applied to the actuator via the control circuit to the actuator; A switching unit that closes so that the voltage output from the internal power supply is applied to the control circuit when the first cutoff unit performs an open operation; A power supply switching circuit comprising the above.

2. When the voltage detection unit detects a different voltage, the first cutoff unit performs an open operation and the switching unit performs a closed operation. The power supply switching circuit according to Claim 1. The power supply switching circuit according to claim 1.

3. The operations of the first cutoff unit and the switching unit are controlled by the control unit. The power supply switching circuit according to claim 1 or 2. The power supply switching circuit according to claim 1 or 2.

4. The power supply switching circuit is disposed in another electrical wiring for electrically connecting the external power supply and the control circuit, and further includes a second cutoff unit that performs the same operation as the first cutoff unit. The power supply switching circuit according to claim 1. The power supply switching circuit according to claim 1.

5. An air conditioner comprising an actuator, an internal power supply, and a power supply switching circuit that switches the power supply to the actuator between an external power supply, which is an AC power supply, and the internal power supply, The power supply switching circuit includes: A control circuit having a control unit to which a voltage from the internal power supply is constantly applied and which controls the operation of the actuator; A voltage detection unit that detects different voltages of the AC voltage output by the external power supply; A first cutoff unit disposed between a connection point where the external power supply and the voltage detection unit are connected and the control circuit, and cutting off the power supply of the AC voltage applied to the actuator via the control circuit to the actuator; A switching unit that closes so that the voltage output from the internal power supply is applied to the control circuit when the first cutoff unit performs an open operation; An air conditioner comprising the above.

6. When the internal power source and the control circuit are electrically connected, the internal power source is connected to the power supply switching circuit such that power supply to the actuator by the external power source and charging of the internal power source by the external power source are simultaneously performed. The air conditioner according to claim 5.

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