Electromagnetic valve driving circuit and water heater

Abstract

According to the electromagnetic valve driving circuit and the water heater, the electromagnetic valve driving circuit comprises a driving chip, and the driving chip comprises a plurality of proportional valve driving circuits and a plurality of section valve driving circuits; the proportional valve driving circuit comprises a voltage comparator and a first switching circuit; two input ends of the voltage comparator are connected with a proportional valve control signal input end and a feedback input end of the driving chip, an output end of the voltage comparator is connected with a control end of the first switching circuit, one end of a switching path of the first switching circuit is connected with a power supply end of the driving chip, and the other end of the switching path is connected with a proportional valve driving signal output end of the driving chip; the segmented valve driving circuit comprises a second switching circuit, the control end of the second switching circuit is connected with the segmented valve control signal input end of the driving chip, one end of a switching path of the second switching circuit is connected with the power end of the driving chip, and the other end of the switching path of the second switching circuit is connected with the segmented valve driving signal output end of the driving chip. The technical problem of circuit complexity in the prior art is solved.

Description

Technical Field

[0001] The present invention belongs to the field of circuit technology, and more specifically, relates to a solenoid valve drive circuit and a water heater. Background Art

[0002] In the design of the water heater control board, the proportional valve drive circuit and the segmented valve drive circuit are essential circuits. Moreover, a multi-channel segmented valve drive circuit is generally designed to drive multiple segmented valves.

[0003] The current control board design solutions all adopt a discrete device solution composed of multiple-stage triodes and peripheral circuits. With the limited space reserved for the control board in the water heater itself, the number of devices is numerous, which occupies a large amount of PCB space. At the same time, a large number of devices make the PCB layout and wiring difficult.

[0004] In addition, this part of the circuit is a high-frequency and high-current concentrated area in the entire PCBA. The device layout and wiring problems are extremely likely to cause EMC and overall machine reliability problems.

[0005] Therefore, the current discrete drive solution has a complex circuit, a large PCB area occupation, and many lines, resulting in difficult layout and wiring. The same circuit of different PCBA has different effects and poor consistency. Summary of the Invention

[0006] The present invention provides a solenoid valve drive circuit, which solves the technical problem of complex circuit in the prior art.

[0007] To achieve the above technical purpose, the present invention is realized by the following technical solutions:

[0008] The solenoid valve drive circuit includes:

[0009] A drive chip, which includes:

[0010] A plurality of proportional valve drive circuits, each of the proportional valve drive circuits includes a voltage comparator and a first switch circuit; a first input terminal of the voltage comparator is connected to a proportional valve control signal input terminal of the drive chip, a second input terminal of the voltage comparator is connected to a feedback input terminal of the drive chip, an output terminal of the voltage comparator is connected to a control terminal of the first switch circuit, and one end of a switch path of the first switch circuit is connected to a power supply terminal of the drive chip, and the other end is connected to a proportional valve drive signal output terminal of the drive chip;

[0011] A plurality of segmented valve drive circuits, each of the segmented valve drive circuits includes a second switch circuit; a control terminal of the second switch circuit is connected to a segmented valve control signal input terminal of the drive chip, and one end of a switch path of the second switch circuit is connected to a power supply terminal of the drive chip, and the other end is connected to a segmented valve drive signal output terminal of the drive chip.

[0012] In some embodiments of the present application, the first switching circuit includes a first switching transistor and a second switching transistor;

[0013] The control end of the first switching transistor is connected to the output end of the voltage comparator. One end of the switching path of the first switching transistor is connected to the power supply end of the driving chip through a first voltage dividing circuit, and the other end is grounded;

[0014] The control end of the second switching transistor is connected to the voltage dividing node of the first voltage dividing circuit. One end of the switching path of the second switching transistor is connected to the power supply end of the driving chip, and the other end is connected to the proportional valve driving signal output end of the driving chip.

[0015] In some embodiments of the present application, the second switching circuit includes a third switching transistor and a fourth switching transistor;

[0016] The control end of the third switching transistor is connected to the input end of the segmented valve control signal of the driving chip. One end of the switching path of the third switching transistor is connected to the power supply end of the driving chip through a second voltage dividing circuit, and the other end is grounded;

[0017] The control end of the fourth switching transistor is connected to the voltage dividing node of the second voltage dividing circuit. One end of the switching path of the fourth switching transistor is connected to the power supply end of the driving chip, and the other end is connected to the segmented valve driving signal output end of the driving chip.

[0018] In some embodiments of the present application, the driving chip further includes:

[0019] A power switch detection circuit, which includes a fifth switching transistor. The control end of the fifth switching transistor is connected to the power supply end of the driving chip. One end of the switching path of the fifth switching transistor is grounded, and the other end is connected to the power switch detection output end of the driving chip;

[0020] The power switch detection output end of the driving chip is connected to a DC power supply through a pull-up resistor.

[0021] In some embodiments of the present application, the driving chip further includes:

[0022] A segmented valve detection circuit, which includes a sixth switching transistor. The control end of the sixth switching transistor is grounded through a first voltage dividing resistor, and the control end of the sixth switching transistor is connected to the other end of the switching path of the fourth switching transistor through a second voltage dividing resistor. A third voltage dividing resistor is connected in parallel at both ends of the switching path of the fourth switching transistor; One end of the switching path of the sixth switching transistor is grounded, and the other end is connected to the segmented valve detection output end of the driving chip;

[0023] The segmented valve detection output end of the driving chip is connected to a DC power supply through a pull-up resistor.

[0024] In some embodiments of the present application, the driving chip further includes an undervoltage detection circuit and a fault output circuit;

[0025] The undervoltage detection circuit, its detection end is connected to the power supply terminal VCC of the driving chip, and its output end outputs an undervoltage signal;

[0026] The fault output circuit, its input end is connected to the output end of the undervoltage detection circuit, and its output end is connected to the fault alarm output end of the driving chip.

[0027] In some embodiments of the present application, the driving chip further includes at least one of an overtemperature protection circuit, an overcurrent protection circuit, a short-circuit protection circuit, and an open-circuit protection circuit.

[0028] In some embodiments of the present application, the power supply terminal of the driving chip is grounded through a decoupling capacitor.

[0029] In some embodiments of the present application, all ports of the driving chip are evenly divided into two columns for layout.

[0030] In some embodiments of the present application, the driving chip includes 16 ports; among them, ports 1 to 8 are arranged in one column, and ports 16 to 9 are arranged in another column; the two columns of ports are arranged opposite to each other;

[0031] Port 1 is the feedback input terminal FB, port 2 is the power supply terminal VCC, port 3 is the proportional valve drive signal output terminal OUT0, port 4 is the floating terminal NC, port 5 is the segmented valve drive signal output terminal OUT1, port 6 is the segmented valve drive signal output terminal OUT2, port 7 is the segmented valve drive signal output terminal OUT3, and port 8 is the ground terminal;

[0032] Port 9 is the ground terminal, port 10 is the fault alarm output terminal FAULT, port 11 is the segmented valve detection output terminal DET1, port 12 is the power switch detection output terminal DET2, port 13 is the segmented valve control signal input terminal IN3, port 14 is the segmented valve control signal input terminal IN2, port 15 is the segmented valve control signal input terminal IN1, and port 16 is the proportional valve control signal input terminal IN0.

[0033] Based on the design of the above solenoid valve driving circuit, the present invention proposes a water heater, including the solenoid valve driving circuit described above.

[0034] Compared with the prior art, the advantages and positive effects of the present invention are as follows: The solenoid valve drive circuit and water heater of the present invention, the solenoid valve drive circuit includes a drive chip, and the drive chip includes a plurality of proportional valve drive circuits and a plurality of segmented valve drive circuits; the proportional valve drive circuit is used to drive the proportional valve to operate, and the proportional valve drive circuit includes a voltage comparator and a first switch circuit; the first input terminal of the voltage comparator is connected to the proportional valve control signal input terminal of the drive chip, the second input terminal of the voltage comparator is connected to the feedback input terminal of the drive chip, the output terminal of the voltage comparator is connected to the control terminal of the first switch circuit, and one end of the switch path of the first switch circuit is connected to the power supply terminal of the drive chip, and the other end is connected to the proportional valve drive signal output terminal of the drive chip; the segmented valve drive circuit is used to drive the segmented valve to operate; the segmented valve drive circuit includes a second switch circuit, the control terminal of the second switch circuit is connected to the segmented valve control signal input terminal of the drive chip, one end of the switch path of the second switch circuit is connected to the power supply terminal of the drive chip, and the other end of the switch path of the second switch circuit is connected to the segmented valve drive signal output terminal of the drive chip. Therefore, in the solenoid valve drive circuit of the present invention, a plurality of proportional valve drive circuits and a plurality of segmented valve drive circuits are integrated in the drive chip, which simplifies the circuit design, reduces the circuit occupied space, reduces the difficulty of circuit layout and wiring, and solves the technical problem of complex circuits in the prior art.

[0035] After reading the detailed description of the embodiments of the present invention in conjunction with the drawings, other features and advantages of the present invention will become clearer. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0037] Figure 1 is a schematic circuit structure diagram of an embodiment of the solenoid valve drive circuit proposed by the present invention;

[0038] Figure 2 is the internal circuit schematic diagram of the drive chip;

[0039] Figure 3 is the pin assignment and port function description diagram of the drive chip. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following will further elaborate on the present invention in conjunction with the drawings and embodiments.

[0041] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0042] In addition, it should also be noted that in the description of the present invention, unless otherwise clearly specified and defined, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0043] Embodiment 1

[0044] The solenoid valve drive circuit of this embodiment includes a drive chip IC1 and a peripheral circuit, as shown in Figure 1 shown.

[0045] The drive chip includes several proportional valve drive circuits and several segmented valve drive circuits. The drive chip also has a power supply terminal VCC, several feedback input terminals FB, several proportional valve control signal input terminals IN0, several proportional valve drive signal output terminals OUT0, several segmented valve control signal input terminals, several segmented valve drive signal output terminals, etc.

[0046] In some embodiments of the present application, one proportional valve drive circuit is integrated in the drive chip. Therefore, correspondingly, the drive chip has one feedback input terminal FB, one proportional valve control signal input terminal IN0, and one proportional valve drive signal output terminal OUT0.

[0047] In some embodiments of the present application, three segmented valve drive circuits are integrated in the drive chip. Therefore, correspondingly, the drive chip has three segmented valve control signal input terminals (IN1, IN2, IN3) and three segmented valve drive signal output terminals (OUT1, OUT2, OUT3). The circuit structures of the three segmented valve drive circuits are the same.

[0048] The proportional valve drive circuit includes a voltage comparator and a first switch circuit. The first input terminal of the voltage comparator is connected to the proportional valve control signal input terminal IN0 of the drive chip, the second input terminal of the voltage comparator is connected to the feedback input terminal FB of the drive chip, the output terminal of the voltage comparator is connected to the control terminal of the first switch circuit, and one end of the switch path of the first switch circuit is connected to the power supply terminal VCC of the drive chip, and the other end of the switch path of the first switch circuit is connected to the proportional valve drive signal output terminal OUT0 of the drive chip.

[0049] The power supply terminal VCC of the drive chip is used to connect to the power supply VDD (such as a 24V DC power supply). The proportional valve control signal input terminal IN0 is used to connect to the control chip to receive the proportional valve control signal sent by the control chip. The proportional valve drive signal output terminal OUT0 is used to connect to the proportional valve to output a drive current to the proportional valve. The feedback input terminal FB is used to connect to the proportional valve drive current feedback circuit. The proportional valve drive current feedback circuit is used to collect the drive current of the proportional valve and feedback it to the feedback input terminal FB of the drive chip.

[0050] When the signal at the first input terminal (such as the non-inverting input terminal) of the voltage comparator is greater than the signal at the second input terminal (such as the inverting input terminal), the output terminal of the voltage comparator outputs a high level to the control terminal of the first switch circuit, and the switch path of the first switch circuit is turned on, and the current provided by the power supply terminal VCC is transmitted through the first switch circuit to the proportional valve drive signal output terminal OUT0.

[0051] When the signal at the first input terminal (such as the non-inverting input terminal) of the voltage comparator is less than the signal at the second input terminal (such as the inverting input terminal), the output terminal of the voltage comparator outputs a low level to the control terminal of the first switch circuit, and the switch path of the first switch circuit is turned off, and the current provided by the power supply terminal VCC cannot be transmitted to the proportional valve drive signal output terminal OUT0.

[0052] The sectional valve drive circuit includes a second switch circuit. The control terminal of the second switch circuit is connected to the sectional valve control signal input terminal of the drive chip, one end of the switch path of the second switch circuit is connected to the power supply terminal VCC of the drive chip, and the other end of the switch path of the second switch circuit is connected to the sectional valve drive signal output terminal of the drive chip.

[0053] The sectional valve control signal input terminal is used to receive the sectional valve control signal sent by the control chip. The sectional valve drive signal output terminal is used to connect to the sectional valve to output a drive current to the sectional valve.

[0054] When the control terminal of the second switch circuit receives a high level signal, the switch path of the second switch circuit is turned on, and the current provided by the power supply terminal VCC is transmitted through the second switch circuit to the sectional valve drive signal output terminal.

[0055] When the control terminal of the second switch circuit receives a low-level signal, the switch path of the second switch circuit is turned off, and the current provided by the power supply terminal VCC cannot be transmitted to the segmented valve drive signal output terminal through the second switch circuit.

[0056] The solenoid valve drive circuit of this embodiment includes a drive chip, and the drive chip includes several proportional valve drive circuits and several segmented valve drive circuits; the proportional valve drive circuit is used to drive the proportional valve to operate, and the proportional valve drive circuit includes a voltage comparator and a first switch circuit; the first input terminal of the voltage comparator is connected to the proportional valve control signal input terminal of the drive chip, the second input terminal of the voltage comparator is connected to the feedback input terminal of the drive chip, the output terminal of the voltage comparator is connected to the control terminal of the first switch circuit, and one end of the switch path of the first switch circuit is connected to the power supply terminal VCC of the drive chip, and the other end is connected to the proportional valve drive signal output terminal of the drive chip; the segmented valve drive circuit is used to drive the segmented valve to operate; the segmented valve drive circuit includes a second switch circuit, the control terminal of the second switch circuit is connected to the segmented valve control signal input terminal of the drive chip, one end of the switch path of the second switch circuit is connected to the power supply terminal VCC of the drive chip, and the other end of the switch path of the second switch circuit is connected to the segmented valve drive signal output terminal of the drive chip. Therefore, the solenoid valve drive circuit of this embodiment integrates several proportional valve drive circuits and several segmented valve drive circuits in the drive chip, simplifies the circuit design, reduces the circuit occupation space, reduces the difficulty of circuit layout and wiring, and solves the technical problem of complex circuits in the prior art.

[0057] In some embodiments of this application, the first switch circuit includes a first switching transistor N1, a second switching transistor P1, etc., as shown in Figure 2 shown.

[0058] The control terminal of the first switching transistor N1 is connected to the output terminal of the voltage comparator IC2A, one end of the switch path of the first switching transistor N1 is connected to the power supply terminal VCC of the drive chip through a first voltage dividing circuit, and the other end of the switch path of the first switching transistor N1 is grounded.

[0059] The control terminal of the second switching transistor P1 is connected to the voltage dividing node of the first voltage dividing circuit, one end of the switch path of the second switching transistor P1 is connected to the power supply terminal VCC of the drive chip, and the other end of the switch path of the second switching transistor P1 is connected to the proportional valve drive signal output terminal OUT0 of the drive chip.

[0060] The first voltage dividing circuit includes a resistor R7 and a resistor R9, and the connection node (voltage dividing node) of the resistor R7 and the resistor R9 is connected to the control terminal of the second switching transistor P1.

[0061] The first switching transistor N1 is a high-conduction-voltage-drop switching transistor, and the second switching transistor P1 is a low-conduction-voltage-drop switching transistor.

[0062] For example, the first switching transistor N1 is an NPN type transistor, and the second switching transistor P1 is a PNP type transistor.

[0063] When the signal at the first input terminal of the voltage comparator is greater than the signal at the second input terminal, the output terminal of the voltage comparator outputs a high level to the control terminal of the first switching transistor N1. The switching path of the first switching transistor N1 is turned on, and the switching path of the second switching transistor P1 is turned on. The current provided by the power supply terminal VCC is transmitted through the second switching transistor P1 to the proportional valve drive signal output terminal OUT0.

[0064] When the signal at the first input terminal of the voltage comparator is less than the signal at the second input terminal, the output terminal of the voltage comparator outputs a low level to the control terminal of the first switching transistor N1. The first switching transistor N1 is turned off, and the second switching transistor P1 is turned off. The current provided by the power supply terminal VCC cannot be transmitted to the proportional valve drive signal output terminal OUT0.

[0065] By designing the first switching circuit to include the first switching transistor N1 and the second switching transistor P1, the circuit structure is simple and it is convenient to control the on and off.

[0066] In some embodiments of the present application, the drive chip includes three segmented valve drive circuits, three segmented valve control signal input terminals (IN1, IN2, IN3), and three segmented valve drive signal output terminals (OUT1, OUT2, OUT3). The circuit structures of the three segmented valve drive circuits are exactly the same. Each segmented valve drive circuit is used to drive the operation of a segmented valve.

[0067] Next, taking one of the segmented valve drive circuits as an example, the structure of the second switching circuit will be described.

[0068] In some embodiments of the present application, the second switching circuit includes a third switching transistor N5, a fourth switching transistor P3, etc., as shown in Figure 2 shown.

[0069] The control terminal of the third switching transistor N5 is connected to the segmented valve control signal input terminal IN1 of the drive chip. One end of the switching path of the third switching transistor N5 is connected to the power supply terminal VCC of the drive chip through the second voltage dividing circuit, and the other end of the switching path of the third switching transistor N5 is grounded.

[0070] The control terminal of the fourth switching transistor P3 is connected to the voltage dividing node of the second voltage dividing circuit. One end of the switching path of the fourth switching transistor P3 is connected to the power supply terminal VCC of the drive chip, and the other end of the switching path of the fourth switching transistor P3 is connected to the segmented valve drive signal output terminal OUT2 of the drive chip.

[0071] The second voltage dividing circuit includes a resistor R39 and a resistor R40. The connection node (voltage dividing node) of the resistor R39 and the resistor R40 is connected to the control terminal of the fourth switching transistor P3.

[0072] The third switching transistor N5 is a high on - voltage - drop switching transistor, and the fourth switching transistor P3 is a low on - voltage - drop switching transistor.

[0073] For example, the third switching transistor N5 is an NPN - type triode, and the fourth switching transistor P3 is a PNP - type triode.

[0074] When the control terminal of the third switching transistor N5 receives a high - level signal, the switching path of the third switching transistor N5 conducts, the switching path of the fourth switching transistor P3 conducts, and the current provided by the power supply terminal VCC is transmitted to the sectional valve drive signal output terminal OUT1 through the fourth switching transistor P3.

[0075] When the control terminal of the third switching transistor N5 receives a low - level signal, the third switching transistor N5 turns off, the fourth switching transistor P3 turns off, and the current provided by the power supply terminal VCC cannot be transmitted to the sectional valve drive signal output terminal OUT1 through the switching path of the fourth switching transistor P3.

[0076] By designing the second switching circuit to include the third switching transistor N5 and the fourth switching transistor P3, the circuit structure is simple and it is convenient to control the on - off.

[0077] In some embodiments of the present application, the driving chip further includes a power - on switch detection circuit for detecting whether there is power at the power supply terminal VCC of the driving chip.

[0078] The power - on switch detection circuit includes a fifth switching transistor N9. The control terminal of the fifth switching transistor N9 is connected to the power supply terminal VCC of the driving chip. One end of the switching path of the fifth switching transistor N9 is grounded, and the other end of the switching path of the fifth switching transistor N9 is connected to the power - on switch detection output terminal DET2 of the driving chip.

[0079] The power - on switch detection output terminal DET2 of the driving chip is connected to a DC power supply (such as a 5V DC power supply) through a pull - up resistor R68.

[0080] The fifth switching transistor N9 is a high on - voltage - drop switching transistor. For example, the fifth switching transistor N9 is an NPN - type triode.

[0081] When there is power at the power supply terminal VCC, the control terminal of the fifth switching transistor N9 is at a high level, the switching path of the fifth switching transistor N9 conducts, and the power - on switch detection output terminal DET2 of the driving chip is at a low level.

[0082] When there is a power outage at the power supply terminal VCC, the control terminal of the fifth switching transistor N9 is at a low level, the switching path of the fifth switching transistor N9 turns off, and the power - on switch detection output terminal DET2 of the driving chip is at a high level.

[0083] Therefore, by designing a power switch detection circuit, it is convenient to detect whether there is power at the power supply terminal VCC of the drive chip, and a detection signal is output through the power switch detection output terminal DET2 to notify other devices. For example, the power switch detection output terminal DET2 is connected to a control chip to send the detection signal to the control chip, facilitating the control chip to know whether there is power at the power supply terminal VCC of the drive chip.

[0084] In some embodiments of the present application, the power supply terminal VCC of the drive chip is connected to the power supply VDD through a temperature control switch. Therefore, through the power switch detection circuit, the on and off states of the external temperature control switch can be detected.

[0085] One end of the power supply terminal VCC of the drive chip is connected to an external temperature control switch, and the other end of the temperature switch is connected to the power supply VDD. The power switch detection circuit is used to detect the on and off of the temperature control switch.

[0086] In some embodiments of the present application, the drive chip further includes a segmented valve detection circuit.

[0087] The segmented valve detection circuit includes a sixth switching tube N6. The control end of the sixth switching tube N6 is grounded through a first voltage dividing resistor R46, and the control end of the sixth switching tube N6 is connected to the other end of the switching path of the fourth switching tube through a second voltage dividing resistor. A third voltage dividing resistor is connected in parallel at both ends of the switching path of the fourth switching tube. One end of the switching path of the sixth switching tube N6 is grounded, and the other end of the switching path of the sixth switching tube N6 is connected to the segmented valve detection output terminal DET1 of the drive chip.

[0088] The segmented valve detection output terminal DET1 of the drive chip is connected to a DC power supply (such as a 5V DC power supply) through a pull-up resistor R48.

[0089] The control end of the sixth switching tube N6 is respectively connected to the segmented valve drive signal output terminals OUT1, OUT2, and OUT3 through the second voltage dividing resistor.

[0090] The sixth switching tube N6 is a high-conduction voltage-drop switching tube. For example, the sixth switching tube N6 is an NPN-type triode.

[0091] When the fourth switching tube is turned on, the third voltage dividing resistor is short-circuited, and the second voltage dividing resistor and the first voltage dividing resistor divide the voltage of the power supply terminal VCC. The control end of the sixth switching tube N6 is at a high level, the switching path of the sixth switching tube N6 is turned on, and the segmented valve detection output terminal DET1 of the drive chip is at a low level.

[0092] When the fourth switching transistor is turned off, the third voltage-dividing resistor, the second voltage-dividing resistor, and the first voltage-dividing resistor divide the voltage of the power supply terminal VCC. The control terminal of the sixth switching transistor N6 is at a low level, the switching path of the sixth switching transistor N6 is turned off, and the segment valve detection output terminal DET1 of the driving chip is at a high level.

[0093] The resistance value of the third voltage-dividing resistor is much larger than the resistance values of the second voltage-dividing resistor and the first voltage-dividing resistor.

[0094] By the level of the segment valve detection output terminal DET1, it can be known whether the fourth switching transistor is conducting, and the level of the segment valve driving signal output terminal can also be known, and whether the output driving current is normal can be known.

[0095] Designing the above segment valve detection circuit can simply and conveniently know whether the fourth switching transistor is conducting, and can also know the level of the segment valve driving signal output terminal, and further can know whether the driving current output by the segment valve driving circuit is normal.

[0096] In some embodiments of the present application, the driving chip further includes an undervoltage detection circuit and a fault output circuit.

[0097] The undervoltage detection circuit, its detection terminal is connected to the power supply terminal VCC of the driving chip, and its output terminal outputs an undervoltage signal.

[0098] The fault output circuit, its input terminal is connected to the output terminal of the undervoltage detection circuit. The output terminal of the fault output circuit is connected to the fault alarm output terminal FAULT of the driving chip.

[0099] The undervoltage detection circuit can be implemented by a comparator. For example, the non-inverting input terminal of the comparator is connected to the power supply terminal VCC of the driving chip, the inverting input terminal of the comparator is connected to a reference voltage (provided by a DC power supply), and the output terminal of the comparator outputs an undervoltage signal. When the comparator outputs a high level, it means that the voltage at the power supply terminal VCC is normal; when the comparator outputs a low level, it means that the power supply terminal VCC is undervoltage.

[0100] After receiving the undervoltage signal, the fault output circuit outputs a fault alarm signal to the fault alarm output terminal FAULT, notifying the control chip in time, facilitating the control chip to know the voltage state of the power supply terminal VCC, so as to take measures in time when the power supply terminal VCC is undervoltage.

[0101] By designing the undervoltage detection circuit and the fault output circuit, it can conveniently detect the voltage state of the power supply terminal VCC, and when it is detected that the power supply terminal VCC is undervoltage, a fault alarm signal is output in time.

[0102] In some embodiments of the present application, a fault output circuit includes a seventh switching transistor N2. The control terminal of the seventh switching transistor N2 is connected to the output terminal of an undervoltage detection circuit. One end of the switching path of the seventh switching transistor N2 is grounded, and the other end of the switching path of the seventh switching transistor N2 is connected to the fault alarm output terminal FAULT of a driving chip.

[0103] The fault alarm output terminal FAULT of the driving chip is connected to a DC power supply (such as a 5V DC power supply) through a pull-up resistor R2.

[0104] When the control terminal of the seventh switching transistor N2 receives a high level, the switching path of the seventh switching transistor N2 is turned on, and the fault alarm output terminal FAULT of the driving chip is at a low level.

[0105] When the control terminal of the seventh switching transistor N2 receives a low level, the switching path of the seventh switching transistor N2 is turned off, and the fault alarm output terminal FAULT of the driving chip is at a high level.

[0106] By designing the above-mentioned fault output circuit, the circuit structure is simple and it is convenient to control the on-off.

[0107] In some embodiments of the present application, in order to ensure the safety of the driving chip, the driving chip further includes at least one of an over-temperature protection circuit, an over-current protection circuit, a short-circuit protection circuit, and an open-circuit protection circuit.

[0108] The over-temperature protection circuit is used to detect whether the temperature of the driving chip exceeds a temperature threshold and output an over-temperature signal. For example, the over-temperature protection circuit can be implemented by a temperature acquisition unit and a comparator. The comparator compares the magnitude of the temperature signal acquired by the temperature acquisition unit with the temperature threshold. When the temperature signal is greater than the temperature threshold, an over-temperature signal of a high level (or a low level) is output.

[0109] The over-temperature protection circuit can be used to detect whether the temperatures of the second switching transistor and the fourth switching transistor exceed the temperature threshold. For example, the over-temperature protection circuit detects whether the temperatures of the triodes P1, P3, and P4 exceed the temperature threshold, and outputs an over-temperature signal when the temperature threshold is exceeded.

[0110] The over-current protection circuit is used to detect whether the current of the driving chip exceeds a threshold and output an over-current signal. For example, the over-current protection circuit can be implemented by a sampling resistor and a comparator. The comparator compares the magnitude of the sampling voltage on the sampling resistor with the threshold voltage. When the sampling voltage is greater than the threshold voltage, an over-current signal of a high level (or a low level) is output.

[0111] The over-current protection circuit can be used to detect whether the currents of the second switching transistor and the fourth switching transistor exceed the threshold. For example, the over-current protection circuit detects whether the currents at the triodes P1, P3, and P4 exceed the threshold, and outputs an over-current signal when the threshold is exceeded.

[0112] A short - circuit protection circuit is used to detect whether the proportional valve drive circuit and the segmented valve drive circuit are short - circuited. When it detects that the proportional valve drive circuit or the segmented valve drive circuit is short - circuited, it outputs a short - circuit signal of high level (or low level).

[0113] Specifically, the short - circuit protection circuit is used to detect whether the second switching transistor and the fourth switching transistor are short - circuited. For example, the short - circuit protection circuit is used to detect whether the triodes P1, P3, and P4 are short - circuited. When there is a short - circuit, it outputs a short - circuit signal.

[0114] An open - circuit protection circuit is used to detect whether the proportional valve drive circuit and the segmented valve drive circuit are open - circuited. When it detects that the proportional valve drive circuit or the segmented valve drive circuit is open - circuited, it outputs an open - circuit signal of high level (or low level).

[0115] Specifically, the open - circuit protection circuit is used to detect whether the second switching transistor and the fourth switching transistor are open - circuited. For example, the open - circuit protection circuit is used to detect whether the triodes P1, P3, and P4 are open - circuited. When there is an open - circuit, it outputs an open - circuit signal.

[0116] The input ends of the fault output circuit are respectively connected to the output ends of the over - temperature protection circuit, the over - current protection circuit, the short - circuit protection circuit, and the open - circuit protection circuit, so as to output a fault signal to the fault alarm output end FAULT of the drive chip in a timely manner.

[0117] In some embodiments of the present application, the power supply terminal VCC of the drive chip is grounded through a decoupling capacitor C13. The decoupling capacitor C13 is used to filter out signal interference.

[0118] The decoupling capacitor C13 is used to filter out the coupling signal interference existing after the power supply VDD passes through the external temperature control switch and the wiring harness to the power supply terminal VCC.

[0119] In some embodiments of the present application, all ports (pins) of the drive chip are evenly divided into two columns for layout. The pin allocation is reasonable, making the wiring more reasonable.

[0120] In some embodiments of the present application, the drive chip includes a proportional valve drive circuit and three segmented valve drive circuits. The circuit structures of the three segmented valve drive circuits are exactly the same.

[0121] Figure 1 CN1 in [reference] is a terminal block, which is convenient for the drive chip to connect to the temperature control switch, the proportional valve, the segmented valve, etc.

[0122] In some embodiments of the present application, the driving chip includes 16 ports (or pins). Among them, ports 1 to 8 are arranged in a column (for example, arranged in a column from top to bottom), and ports 16 to 9 are arranged in another column (for example, arranged in another column from top to bottom), and the two columns of ports are arranged opposite to each other; for example, port 1 is arranged opposite to port 16, port 2 is arranged opposite to port 15,..., port 8 is arranged opposite to port 9, as shown in Figure 3 shown.

[0123] Port 1 is the feedback input terminal FB, port 2 is the power supply terminal VCC, port 3 is the proportional valve drive signal output terminal OUT0, port 4 is the floating terminal NC, port 5 is the segmented valve drive signal output terminal OUT1, port 6 is the segmented valve drive signal output terminal OUT2, port 7 is the segmented valve drive signal output terminal OUT3, and port 8 is the ground terminal GND.

[0124] Port 9 is the ground terminal GND, port 10 is the fault alarm output terminal FAULT, port 11 is the segmented valve detection output terminal DET1, port 12 is the power switch detection output terminal DET2, port 13 is the segmented valve control signal input terminal IN3, port 14 is the segmented valve control signal input terminal IN2, port 15 is the segmented valve control signal input terminal IN1, and port 16 is the proportional valve control signal input terminal IN0.

[0125] With the above port arrangement of the driving chip, the port arrangement is reasonable, avoiding interference between ports and ensuring the normal operation of the driving chip.

[0126] The driving chip has the following ports: feedback input terminal FB (port 1), power supply terminal VCC (port 2), floating terminal NC (port 4), ground terminal GND (port 8), ground terminal GND (port 9), fault alarm output terminal FAULT (port 10), segmented valve detection output terminal DET1 (port 11), power switch detection output terminal DET2 (port 12).

[0127] Proportional valve control signal input terminal IN0 (port 16), proportional valve drive signal output terminal OUT0 (port 3), segmented valve control signal input terminal IN1 (port 15), segmented valve drive signal output terminal OUT1 (port 5), segmented valve control signal input terminal IN2 (port 14), segmented valve drive signal output terminal OUT2 (port 6), segmented valve control signal input terminal IN3 (port 13), segmented valve drive signal output terminal OUT3 (port 7).

[0128] The first segmented valve drive circuit is correspondingly connected to the segmented valve control signal input terminal IN1 (port 15) and the segmented valve drive signal output terminal OUT1 (port 5) for driving the segmented valve 1 (or called segmented valve C).

[0129] The second sectional valve drive circuit is correspondingly connected to the sectional valve control signal input terminal IN2 (port 14) and the sectional valve drive signal output terminal OUT2 (port 6), and is used to drive the sectional valve 2 (or sectional valve A).

[0130] The third sectional valve drive circuit is correspondingly connected to the sectional valve control signal input terminal IN3 (port 13) and the sectional valve drive signal output terminal OUT3 (port 7), and is used to drive the sectional valve 3 (or sectional valve B).

[0131] Among them, the second sectional valve drive circuit and the third sectional valve drive circuit are shown in Figure 2 The first sectional valve drive circuit is not shown in Figure 2 and its circuit structure is exactly the same as that of the second sectional valve drive circuit and the third sectional valve drive circuit.

[0132] The second sectional valve drive circuit includes a third switching transistor N5 and a fourth switching transistor P3. Both ends of the switching path of the fourth switching transistor P3 are connected in parallel with a third voltage-dividing resistor R38. One end of the switching path of the fourth switching transistor P3 is connected to the power supply terminal VCC of the driving chip, and the other end is connected to the control terminal of the sixth switching transistor N6 through a second voltage-dividing resistor R42. The other end of the switching path of the fourth switching transistor P3 is connected to the sectional valve drive signal output terminal OUT2 of the driving chip.

[0133] The third sectional valve drive circuit includes a third switching transistor N7 and a fourth switching transistor P4. Both ends of the switching path of the fourth switching transistor P4 are connected in parallel with a third voltage-dividing resistor R50. One end of the switching path of the fourth switching transistor P4 is connected to the power supply terminal VCC of the driving chip, and the other end is connected to the control terminal of the sixth switching transistor N6 through a second voltage-dividing resistor R43. The other end of the switching path of the fourth switching transistor P4 is connected to the sectional valve drive signal output terminal OUT3 of the driving chip.

[0134] The driving chip of this embodiment supports one proportional valve drive circuit and three sectional valve drive circuits. In addition, it has a fault alarm output terminal FAULT, a sectional valve detection output terminal DET1, and a power switch detection output terminal DET2. FAULT, DET1, and DET2 are all designed with open-drain inside, which is convenient for being compatible with different external voltage inputs (the highest voltage cannot exceed the VCC voltage). The pin assignment fully considers the convenience of layout and wiring, the reasonable distribution of GND pins, and the isolation of input signals and output signals. Among them, the feedback terminal FB receives the sampling signal of the three-pin proportional valve drive.

[0135] On the basis of integrating a series of transistors and resistors, the driving chip also integrates a single-channel comparator IC2A, which greatly simplifies the circuit. Therefore, the layout and wiring of the PCB are more reasonable, and the occupied space is also greatly reduced.

[0136] The drive chip uses an SOP16 package (similar to SSOP16, DIP16, etc.), integrating a proportional valve drive circuit and three segmented valve drive circuits. The drive chip also has protection and detection functions, such as valve open circuit and short circuit detection, power input switch detection, overcurrent, chip over-temperature protection, and single-pin fault discrimination output function.

[0137] The solenoid valve drive circuit of this embodiment is applicable to the drive of the proportional valve and multi-way segmented valve of the water heater. It combines the current discrete device drive scheme composed of multiple triodes and peripheral circuits into an integrated chip, and reduces external devices, the difficulty of circuit layout and wiring, and the device occupation area through reasonable pin allocation, so that the circuit can obtain consistent electrical performance under different PCBAs. At the same time, valve open circuit, short circuit detection, power input switch detection, overcurrent, chip over-temperature protection, and single-pin fault discrimination output functions are added under the SOP16 package. The perfect protection and detection mechanism enhances the reliability of the key circuit, which cannot be achieved by discrete devices.

[0138] The solenoid valve drive circuit of this embodiment integrates a proportional valve drive circuit and three segmented valve drive circuits into one chip, reducing the number of peripheral circuit devices, simplifying the circuit, and adding various protection and detection functions. At the same time, the pins of the chip are rationally allocated, making the wiring more reasonable and avoiding performance differences caused by layout and wiring of different PCBAs. It is suitable for placement and wiring on a single-sided board with a lower cost.

[0139] The solenoid valve drive circuit of this embodiment greatly simplifies the circuit design. At the same time, compared with the discrete scheme, the detection performance is increased and the circuit occupation space is reduced; the integrated scheme and the reasonable allocation of pins simplify the PCB layout and wiring, and reduce the wiring requirements, greatly increasing the reliability and performance consistency of the circuit.

[0140] Embodiment 2

[0141] Based on the solenoid valve drive circuit in Embodiment 1, this Embodiment 2 proposes a water heater including the solenoid valve drive circuit described above.

[0142] The water heater of this embodiment integrates several proportional valve drive circuits and several segmented valve drive circuits in the drive chip, simplifies the circuit design, reduces the circuit occupation space, and reduces the difficulty of circuit layout and wiring, solving the technical problem of complex circuits in the prior art.

[0143] The water heater is provided with several proportional valves (such as one proportional valve) and several segmented valves (such as three segmented valves). Both the proportional valve and the segmented valve belong to solenoid valves and are driven by the proportional valve drive circuit and the segmented valve drive circuit in the drive chip.

[0144] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. Solenoid valve drive circuit, characterized in that: include: A driver chip, comprising: A plurality of proportional valve driving circuits, wherein the proportional valve driving circuits include a voltage comparator and a first switch circuit; The first input end of the voltage comparator is connected to the proportional valve control signal input end of the driving chip, the second input end of the voltage comparator is connected to the feedback input end of the driving chip, the output end of the voltage comparator is connected to the control end of the first switch circuit, one end of the switch path of the first switch circuit is connected to the power supply end of the driving chip, and the other end is connected to the proportional valve drive signal output end of the driving chip; Several segmented valve driving circuits, each segmented valve driving circuit includes a second switching circuit; a control end of the second switching circuit is connected to a segmented valve control signal input end of the driving chip, one end of a switch path of the second switching circuit is connected to a power supply end of the driving chip, and the other end is connected to a segmented valve driving signal output end of the driving chip.

2. The solenoid valve driving circuit according to claim 1, characterized in that: The first switch circuit includes a first switch tube and a second switch tube; The control end of the first switch tube is connected to the output end of the voltage comparator, one end of the switch path of the first switch tube is connected to the power supply end of the driving chip through a first voltage divider circuit, and the other end is grounded; The control end of the second switch tube is connected to the voltage dividing node of the first voltage dividing circuit, one end of the switch path of the second switch tube is connected to the power supply end of the driving chip, and the other end is connected to the proportional valve driving signal output end of the driving chip.

3. The solenoid valve driving circuit according to claim 1, characterized in that: The second switch circuit includes a third switch tube and a fourth switch tube; The control end of the third switch tube is connected to the segmented valve control signal input end of the driving chip, one end of the switch path of the third switch tube is connected to the power supply end of the driving chip through the second voltage divider circuit, and the other end is grounded; The control end of the fourth switch tube is connected to the voltage dividing node of the second voltage dividing circuit, one end of the switch path of the fourth switch tube is connected to the power supply end of the driving chip, and the other end is connected to the segmented valve driving signal output end of the driving chip.

4. The solenoid valve driving circuit according to claim 1, characterized in that: The driver chip also includes: A power switch detection circuit, comprising a fifth switch tube, wherein a control end of the fifth switch tube is connected to a power supply end of the driver chip, one end of a switch path of the fifth switch tube is grounded, and the other end is connected to a power switch detection output end of the driver chip; The power switch detection output terminal of the driving chip is connected to a DC power supply through a pull-up resistor.

5. The solenoid valve driving circuit according to claim 3, characterized in that: The driver chip also includes: The segmented valve detection circuit comprises a sixth switch tube, wherein the control end of the sixth switch tube is grounded through a first voltage-dividing resistor, and the control end of the sixth switch tube is connected to the other end of the switch path of the fourth switch tube through a second voltage-dividing resistor, and the two ends of the switch path of the fourth switch tube are connected in parallel with a third voltage-dividing resistor; one end of the switch path of the sixth switch tube is grounded, and the other end is connected to the segmented valve detection output end of the driving chip; The segmented valve detection output terminal of the driving chip is connected to a DC power supply through a pull-up resistor.

6. The solenoid valve driving circuit according to claim 1, characterized in that: The driver chip also includes an undervoltage detection circuit and a fault output circuit; The undervoltage detection circuit has a detection end connected to the power supply end VCC of the driver chip and an output end outputting an undervoltage signal; The fault output circuit has an input end connected to the output end of the undervoltage detection circuit, and an output end connected to the fault alarm output end of the driving chip.

7. The solenoid valve driving circuit according to claim 1, characterized in that: The driving chip also includes at least one of an over-temperature protection circuit, an over-current protection circuit, a short-circuit protection circuit, and an open-circuit protection circuit.

8. The solenoid valve driving circuit according to any one of claims 1 to 7, characterized in that: All ports of the driving chip are evenly arranged in two columns.

9. The solenoid valve driving circuit according to claim 8, characterized in that: The driver chip includes 16 ports; wherein ports 1 to 8 are arranged in one column, and ports 16 to 9 are arranged in another column; the ports in the two columns are arranged opposite to each other; Port 1 is the feedback input terminal FB, port 2 is the power supply terminal VCC, port 3 is the proportional valve drive signal output terminal OUT0, port 4 is the floating terminal NC, port 5 is the segmented valve drive signal output terminal OUT1, port 6 is the segmented valve drive signal output terminal OUT2, port 7 is the segmented valve drive signal output terminal OUT3, and port 8 is the ground terminal; Port 9 is the ground terminal, port 10 is the fault alarm output terminal FAULT, port 11 is the sectional valve detection output terminal DET1, port 12 is the power switch detection output terminal DET2, port 13 is the sectional valve control signal input terminal IN3, port 14 is the sectional valve control signal input terminal IN2, port 15 is the sectional valve control signal input terminal IN1, and port 16 is the proportional valve control signal input terminal IN0.

10. A water heater, characterized in that: The invention comprises the solenoid valve driving circuit as claimed in any one of claims 1 to 9.

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