Circuit board

Abstract

This circuit board (10) is equipped with a plurality of connection parts to which components can be connected. The plurality of connection parts includes a first connection part (14), a second connection part (15), and a third connection part (16), and forms a circuit pattern in which the first connection part (14), a power supply circuit (107), and the third connection part (16) are connected in series, and the second connection part (15), the power supply circuit (107), and the third connection part (16) are connected in series. The third connection part (16) is configured to be able to short-circuit two terminals constituting the third connection part (16) when no component requiring power is connected.

Description

circuit board

[0001] The present disclosure relates to a circuit board having a connection to another circuit board.

[0002] As an example of a device that uses a conventional circuit board having a connection part with another circuit board, Patent Document 1 discloses an air conditioner having a connector for connecting an outdoor unit to an external device. The air conditioner described in Patent Document 1 is configured so that even if a power supply part provided in the outdoor unit fails, power is supplied to the outdoor unit from an external device connected to the connector, and data stored in a memory part provided in the outdoor unit can be read by the external device.

[0003] Japanese Patent Application Laid-Open No. 2021-18030

[0004] Generally, electrical equipment from the same manufacturer and for the same purpose will have multiple models with different circuit configurations. For example, in the case of equipment that heats water by circulating it, such as floor heating, hot water heaters, and radiators, there are many lineups that vary in heater capacity, connection method, tank capacity, number and position of pumps, and connections to other actuators. Here, if circuit boards to control the heaters, pumps, and other actuators are individually prepared for each lineup, the large number of circuit boards that need to be designed will increase the development burden and cause costs to rise. For this reason, it is desirable to realize a common circuit board across lineups.

[0005] The present disclosure has been made in view of the above, and aims to realize a circuit board that can be applied to a plurality of different types of devices.

[0006] In order to solve the above-mentioned problems and achieve the object, the circuit board according to the present disclosure has a plurality of connection parts to which components can be connected, the plurality of connection parts including a first connection part, a second connection part, and a third connection part, a circuit pattern is formed that connects the first connection part and the first power source with the third connection part in series, and also connects the second connection part and the first power source with the third connection part in series, and the third connection part is configured so that the two terminals that make up the third connection part can be short-circuited when a component requiring power is not connected.

[0007] The circuit board according to the present disclosure has the advantage of being applicable to a plurality of different types of devices.

[0008] FIG. 1 is a diagram showing an example of a circuit board and components used in combination with the circuit board according to the first embodiment; FIG. 2 is a diagram showing another example of a circuit board and components used in combination with the circuit board according to the first embodiment; FIG. 3 is a diagram showing an example of a circuit board and components used in combination with the circuit board according to the second embodiment; FIG. 4 is a diagram showing another example of a connection method for a circuit board and components used in combination with the circuit board according to the second embodiment;

[0009] Hereinafter, a circuit board according to an embodiment of the present disclosure will be described in detail with reference to the drawings.

[0010] 1 is a diagram illustrating an example of a circuit board according to a first embodiment and a component used in combination with the circuit board. Fig. 1 illustrates an example in which the circuit board 10 according to the first embodiment is applied to a device having a heater.

[0011] Devices with heaters have protection circuits that prevent the heater from continuing to be energized when an abnormality occurs. Protection circuits are composed of a combination of multiple stages of contactors and thermostats depending on the heater's performance, etc. There are various connection methods for the components that make up the protection circuit, but by making multiple connection methods compatible, it is possible to share circuit boards between devices that use various heaters.

[0012] The circuit board 10 shown in FIG. 1 is connected to a power supply circuit 107, which is a first power supply. The circuit board 10 includes a noise filter 11 that removes noise components contained in the power supplied from the power supply circuit 107, and a first connection portion 14, a second connection portion 15, and a third connection portion 16 that are configured to allow components to be connected. The second connection portion 15 is configured to connect two components in parallel. Relays 12 and 13 are provided between the noise filter 11 and the second connection portion 15. The first connection portion 14, the second connection portion 15, and the third connection portion 16 are configured, for example, by connectors mounted on the circuit board 10.

[0013] The noise filter 11 is composed of a common mode choke coil, a Y capacitor, an X capacitor, a surge protection element, etc. Noise resistance and noise emission characteristics are improved by passing through this noise filter 11. By providing the noise filter 11 on the circuit board 10, it is no longer necessary to provide individual noise filters for each circuit that can be combined with the circuit board 10, which has the advantage of preventing extra costs and space requirements.

[0014] Furthermore, a heater circuit 100 is connected to the circuit board 10 via a first connection portion 14 , a second connection portion 15 and a third connection portion 16 .

[0015] The heater circuit 100 includes contactors 102, 103, and 104, and a heater 105. The heater 105 is equipped with a thermostat 106. When the heater 105 generates abnormal heat, the thermostat 106 detects this and opens both terminals of the thermostat 106.

[0016] A power supply circuit 101, which is a second power supply, is connected to the heater circuit 100. The power supply circuit 101 supplies power to a heating element of a heater 105 via a plurality of contactors connected in multiple stages, specifically via a first-stage contactor 102 and second-stage contactors 103 and 104. The contactors 102, 103, and 104 form a power supply path from the power supply circuit 101 to the heater 105.

[0017] In heater circuit 100, contactor 102 is a protective contactor for heater 105 and forms a protective circuit together with thermostat 106. Contactors 103 and 104 are control contactors for heater 105. Heater circuit 100 is configured such that a protective contactor and a control contactor are connected in series. Note that, because the control contactor switches on and off frequently, it is common to arrange multiple control contactors in parallel to extend their switching life.

[0018] The coil of contactor 102 has both ends connected to first connection portion 14 of circuit board 10 and receives power from power supply circuit 107. The coils of contactors 103 and 104 have both ends connected to second connection portion 15 of circuit board 10 and receive power from power supply circuit 107. The power supply to the coils of contactors 103 and 104 is controlled by a control circuit (not shown) mounted on circuit board 10 that opens and closes relays 12 and 13. The thermostat 106 has both ends connected to third connection portion 16 of circuit board 10 and receives power from power supply circuit 107.

[0019] When power is supplied from power supply circuit 107 to circuit board 10, and heater 105 of heater circuit 100 is not abnormally overheating, both ends of thermostat 106 are shorted, causing contactor 102 to turn on. Furthermore, relays 12 and 13 are controlled by a microcomputer or the like to energize the coils of contactors 103 and 104, thereby energizing heater 105. Circuit patterns are formed on circuit board 10 so that the coil of contactor 102 connected to first connection portion 14 and thermostat 106 connected to third connection portion 16 are in a series relationship, and so that relays 12 and 13 for controlling contactors 103 and 104 connected to second connection portion 15 are in a series relationship with thermostat 106 connected to third connection portion 16. Therefore, when the thermostat 106 detects abnormal heat generation in the heater 105, that is, when the temperature detected by the thermostat 106 reaches or exceeds a predetermined threshold, the thermostat 106 turns off and both ends become open, and as a result, the contactors 102, 103, and 104 also turn off, thereby stopping the supply of power to the heater 105.

[0020] Fig. 2 is a diagram showing another example of the circuit board and components used in combination with the circuit board according to embodiment 1. Fig. 2 shows an example in which the circuit board 10 is applied to a device having a heater, similar to Fig. 1, but the configuration of the components used in combination is different.

[0021] 2, a heater circuit 200 is connected to the circuit board 10 via a first connection portion 14, a second connection portion 15, and a third connection portion 16. In the heater circuit 200, the same reference numerals as those in the heater circuit 100 shown in FIG.

[0022] The heater circuit 200 includes contactors 103 and 104, a capillary-type thermostat 202, and a heater 201. The heater 201 is provided with a temperature detection unit 203 of the thermostat 202. In the heater circuit 200, the thermostat 202 is provided between the power supply circuit 101 and the contactors 103 and 104. When the thermostat 202 detects abnormal heat generation in the heater 201, the power supply from the power supply circuit 101 to the contactors 103 and 104 is stopped. This causes the first connection 14 of the circuit board 10 to be in an open state. Typically, a component such as a connector is used to create the open state of the first connection 14. Furthermore, because the thermostat 202 is not connected to the circuit board 10, a jumper connector 206, whose poles are connected by lead wires, is connected to the third connection 16, shorting the two terminals of the third connection 16. It should be noted that the two terminals of the third connection portion 16 may be short-circuited by other methods, such as by using a jumper wire instead of the jumper connector 206 .

[0023] 2, when relays 12 and 13 on circuit board 10 are closed, current flows through the coils of contactors 103 and 104, turning on contactors 103 and 104. At this time, if thermostat 202 has not detected abnormal heat generation in heater 201, power is supplied from power supply circuit 101 to heater 201.

[0024] As described above, the circuit board 10 according to this embodiment includes the first connection portion 14, the second connection portion 15, and the third connection portion 16 that are connected to an external circuit, and is configured to be able to output power supplied from the power supply circuit 107 to the circuits connected to the first connection portion 14, the second connection portion 15, and the third connection portion 16. The circuit board 10 also has a circuit pattern that connects the third connection portion 16 in series with the first connection portion 14 and the second connection portion 15. The circuit board 10 can be used in combination with multiple types of heater circuits having protection circuits with different configurations.

[0025] 3 is a diagram showing an example of a circuit board and components used in combination with the circuit board according to embodiment 2. In embodiment 1, circuit board 10 was described that can be used in combination with a plurality of heater circuits having different configurations, but in this embodiment, a circuit board that can be used in combination with a device that does not have a heater, i.e., a device that does not include a heater circuit such as heater circuits 100 and 200 described in embodiment 1, will be described.

[0026] The circuit board 10a according to the second embodiment is configured such that, compared to the circuit board 10 according to the first embodiment, a converter 17 that converts AC power into DC power to generate control power, a microcontroller 18 that serves as a control circuit, and a differential pressure regulating valve control terminal 19 are added. The converter 17 is realized by combining a rectifier circuit and an isolated DC-DC converter, for example. The differential pressure regulating valve control terminal 19 may be configured by a connector or the like, similar to the first connection portion 14 and the like.

[0027] A power supply circuit 301, a transformer 302 serving as a step-down transformer, and a differential pressure regulating valve (PICV: Pressure Independent Control Valve) 303 are connected to the circuit board 10a. Specifically, the primary side of the transformer 302 is connected to the third connection portion 16 of the circuit board 10a, and a control signal input terminal of the differential pressure regulating valve 303 is connected to the differential pressure regulating valve control terminal 19 of the circuit board 10a. A jumper connector 311 is connected to the first connection portion 14 of the circuit board 10a, shorting the two terminals of the first connection portion 14. Power is supplied to the transformer 302 from the power supply circuit 301 connected to the circuit board 10a via the noise filter 11 and the third connection portion 16. The secondary side of the transformer 302 is connected to the power supply terminal of the differential pressure regulating valve 303 via a relay connector 304, and power converted to a voltage by the transformer 302 is supplied to the differential pressure regulating valve 303 as drive power. The operation of the differential pressure regulating valve 303 is controlled by the microcomputer 18 .

[0028] The transformer 302 is a step-down transformer that outputs approximately 24V AC when 200V AC is input from a commercial power supply. Connecting the transformer 302 in the position shown in Figure 3 also establishes a series connection to the noise filter 11, improving resistance to burst noise and lightning surge noise, which are subject to immunity testing, compared to when the transformer 302 is directly connected to the commercial power supply. Furthermore, there is no need for terminal blocks or wiring required for connection, and power can be taken directly from the circuit board 10a via the third connection part 16.

[0029] The circuit board 10a according to the second embodiment can be used in equipment that does not use a heater, in addition to the heater circuits 100 and 200 of the configuration examples shown in Figures 1 and 2 described in the first embodiment. Furthermore, when used as shown in Figure 3, that is, when the circuit board 10a is used in equipment that does not use a heater, cost reduction can be achieved by not mounting the relays 12 and 13 between the noise filter 11 and the second connection part 15. When the circuit board 10a is used in combination with the heater circuit 100 or 200 described in the first embodiment, the microcomputer 18 can control the relays 12 and 13.

[0030] The transformer 302 typically transforms the 200V AC supplied from a commercial power source to approximately 24V AC, a voltage that does not pose a risk of electric shock to humans. It also serves to insulate the primary and secondary voltages according to safety standards. The transformer 302 is typically designed with an insulation class (basic insulation or reinforced insulation) that meets the safety standard. The circuit board 10a also includes drive circuits for the connected heaters (heater 105 shown in FIG. 1 and heater 201 shown in FIG. 2 ), as well as control components such as a converter 17 that converts AC voltage to DC voltage and a microcomputer 18. The microcomputer 18 sends a control signal to the differential pressure regulating valve 303 via a differential pressure regulating valve control terminal 19. The transformer 302 provides insulation (basic insulation or reinforced insulation) between the primary and secondary sides. However, when the differential pressure regulating valve 303 is connected to the secondary side, the secondary side of the transformer 302 and the secondary side of the converter 17 are treated as the same in terms of insulation. By using a converter having a configuration including an isolated DC-DC converter as converter 17, it is possible to realize a configuration that satisfies the immunity and emission requirements of the product while achieving the insulation design of the same device. Furthermore, by using jumper connector 311 so that the connection configuration of Figure 3 is also realized in addition to the connection configurations of Figures 1 and 2 described in embodiment 1, it is possible to use the same circuit board 10a even if the number of connection configurations of the product is increased, which is advantageous in terms of development efficiency and development costs.

[0031] Although Fig. 3 shows an example in which the primary side of the transformer 302 is connected to the third connection portion 16 of the circuit board 10a, the connection shown in Fig. 4 may also be used. Fig. 4 is a diagram showing another example of a method of connecting the circuit board according to the second embodiment and components used in combination with the circuit board.

[0032] In the example shown in Fig. 4, a transformer 302 and a differential pressure regulating valve 303 are connected to the circuit board 10a, similar to the example shown in Fig. 3, but the connection position of the transformer 302 is different. Specifically, in the connection method shown in Fig. 4, the transformer 302, which was connected to the third connection part 16 in the connection method shown in Fig. 3, is connected to the second connection part 15. In addition, a jumper connector 312 is connected to the third connection part 16 to short-circuit the two terminals of the third connection part 16.

[0033] In the connection method shown in Figure 3, the differential pressure adjustment valve 303 is always energized, resulting in a standby current flowing. However, the differential pressure adjustment valve 303 does not need to be operated all the time; it only needs to be operated when it is necessary to adjust the differential pressure generated at the input port where water enters. Therefore, the connection method shown in Figure 4 makes it possible to supply power to the differential pressure adjustment valve 303 only when it is necessary to operate it. In other words, by controlling the relay 12 between the differential pressure adjustment valve 303 and the noise filter 11 to close when it is necessary to operate the differential pressure adjustment valve 303, and opening the relay 12 when it is no longer necessary to operate the differential pressure adjustment valve 303, it is possible to prevent more current than necessary from flowing through the circuit and achieve energy savings.

[0034] The circuit board 10 a according to this embodiment has the advantage that it can be used in combination with a plurality of types of heater circuits, and can also be used in combination with the differential pressure adjustment valve 303 .

[0035] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention.

[0036] 10, 10a Circuit board, 11 Noise filter, 12, 13 Relay, 14 First connection portion, 15 Second connection portion, 16 Third connection portion, 17 Converter, 18 Microcomputer, 19 Differential pressure regulating valve control terminal, 100, 200 Heater circuit, 101, 107, 301 Power supply circuit, 102, 103, 104 Contactor, 105, 201 Heater, 106, 202 Thermostat, 203 Temperature detection unit, 206, 311, 312 Jumper connector, 302 Transformer, 303 Differential pressure regulating valve, 304 Relay connector.

Claims

1. A circuit board comprising a plurality of connection parts to which components can be connected, the plurality of connection parts including a first connection part, a second connection part, and a third connection part, a circuit pattern is formed that connects the first connection part and a first power source with the third connection part in series, and also connects the second connection part and the first power source with the third connection part in series, and the third connection part is configured so that two terminals constituting the third connection part can be short-circuited when no component requiring power is connected.

2. The circuit board according to claim 1, wherein a noise filter is mounted between the first power supply and the first connecting portion, the second connecting portion, and the third connecting portion.

3. The circuit board according to claim 1 or 2, wherein a relay is mounted between the first power supply and the second connection part, a protective contactor provided on a path for supplying power from the second power supply to the heater is connected to the first connection part, a control contactor for the heater provided on the path is connected to the second connection part, and a thermostat that opens a circuit when it detects that the temperature near the heater is equal to or higher than a predetermined threshold is connected to the third connection part.

4. The circuit board according to claim 1 or 2, wherein a relay is mounted between the first power supply and the second connection part, a control contactor for the heater provided on a path for supplying power from the second power supply to the heater is connected to the second connection part, and a jumper connector for short-circuiting two terminals constituting the third connection part is connected to the third connection part.

5. A circuit board as claimed in claim 1 or 2, comprising: a converter that converts power supplied from the first power source into control power; a control circuit that operates by receiving the control power; and a differential pressure control valve control terminal that outputs a control signal for the differential pressure control valve generated by the control circuit, wherein a transformer that generates power for driving the differential pressure control valve is connected to the third connection part, a jumper connector that shorts between two terminals that make up the first connection part is connected to the first connection part, and an input terminal of the control signal for the differential pressure control valve is connected to the differential pressure control valve control terminal.

6. A circuit board as claimed in claim 1 or 2, wherein a relay is mounted between the first power supply and the second connection part, and the circuit board has a converter that converts power supplied from the first power supply into control power, a control circuit that operates by receiving the control power, and a differential pressure control valve control terminal that outputs a control signal for the differential pressure control valve generated by the control circuit, wherein a transformer that generates power for driving the differential pressure control valve is connected to the second connection part, a jumper connector that shorts between two terminals that constitute the third connection part is connected to the third connection part, and an input terminal of a control signal for the differential pressure control valve is connected to the differential pressure control valve control terminal.

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