Master valve driving chip for gas water heater and gas water heater

Abstract

The utility model discloses a main control valve drive chip for gas water heater and gas water heater, main control valve drive chip includes drive signal input pin, drive signal output pin, power supply pin, main control valve drive circuit, main control valve drive circuit includes first switch tube, second switch tube, and the control end of first switch tube is connected drive signal input pin, and one end of the switch passage of first switch tube is connected power supply pin through voltage division circuit, and the other end is grounded, and the control end of second switch tube is connected voltage division circuit's voltage division node, and one end of the switch passage of second switch tube is connected power supply pin, and the other end of the switch passage of second switch tube is connected drive signal output pin. The utility model integrates main control valve drive circuit in drive chip, has simplified the circuit design, avoided component dispersion, reduced the circuit occupied space, reduced the difficulty of circuit layout wiring, solved the technical problem of component dispersion, large occupied space and complex circuit in the prior art.

Description

Technical Field

[0001] This utility model belongs to the field of circuit technology, specifically, it relates to a main control valve drive chip for a gas water heater and a gas water heater. Background Technology

[0002] In gas water heaters, the main control valve is used to control the on / off state of the main gas pipeline. In the design of the gas water heater's control board, various solenoid valve drive circuits are essential. Among these multiple solenoid valve drive circuits for different purposes, the main control valve drive circuit, as the main switching path of the gas water heater, needs to be designed separately. It forms a double safety mechanism with other valve drive circuits to prevent gas leakage caused by damage to a single valve drive circuit.

[0003] In current computer board designs, the main control valve drive circuit uses a discrete component solution consisting of multi-stage transistors and peripheral circuits. This results in dispersed components, numerous potential failure points, a lack of independent protection functions, and difficulties in PCB layout and routing. Furthermore, this part of the circuit is a high-frequency, high-current concentrated area within the entire PCBA, making component layout and routing issues highly susceptible to EMC and overall system reliability problems.

[0004] Existing discrete drive solutions for main control valves have problems such as component dispersion, high requirements for layout and routing, lack of device detection and protection functions, and also occupy more PCB area, and inconsistent performance of the same circuit in different PCBAs. Utility Model Content

[0005] This invention provides a main control valve drive chip for gas water heaters, which solves the technical problems of scattered components and large space occupation in the prior art.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0007] The main control valve driver chip for gas water heaters includes:

[0008] The drive signal input pin IN is used to connect to the control unit of the gas water heater;

[0009] The drive signal output pin OUT is used to connect to the main control valve of the gas water heater.

[0010] The power supply pin VCC is used to connect to the power supply.

[0011] The main control valve drive circuit includes a first switching transistor and a second switching transistor;

[0012] The control terminal of the first switching transistor is connected to the drive signal input pin IN, one end of the switching path of the first switching transistor is connected to the power supply pin VCC through a voltage divider circuit, and the other end of the switching path of the first switching transistor is grounded.

[0013] The control terminal of the second switching transistor is connected to the voltage divider node of the voltage divider circuit, one end of the switching path of the second switching transistor is connected to the power supply pin VCC, and the other end of the switching path of the second switching transistor is connected to the drive signal output pin OUT.

[0014] In some embodiments of this application, the drive signal output pin OUT is connected to the cathode of the freewheeling diode, and the anode of the freewheeling diode is grounded.

[0015] In some embodiments of this application, the main control valve drive chip further includes:

[0016] The valve detection output pin DET1 is used to connect to the control unit of the gas water heater, and it is connected to the DC power supply through the first pull-up resistor.

[0017] The main control valve detection circuit includes a third switching transistor. The control terminal of the third switching transistor is grounded through a first resistor, and the control terminal of the third switching transistor is connected to the other end of the switching path of the second switching transistor through a second resistor. A third resistor is connected in parallel across the two ends of the switching path of the second switching transistor. One end of the switching path of the third switching transistor is grounded, and the other end is connected to the valve detection output pin DET1.

[0018] In some embodiments of this application, the main control valve drive chip further includes:

[0019] The alarm output pin FAULT is used to connect to the control unit of the gas water heater, and it is connected to the DC power supply through a second pull-up resistor.

[0020] An over-temperature detection circuit is used to detect whether the temperature of the second switching transistor exceeds a temperature threshold, and outputs an over-temperature signal when the temperature threshold is exceeded.

[0021] The fault output circuit has its input terminal connected to the output terminal of the over-temperature protection circuit, and its output terminal connected to the alarm output pin FAULT.

[0022] In some embodiments of this application, the main control valve drive chip further includes:

[0023] An overcurrent detection circuit is used to detect whether the current in the switching path of the second switching transistor exceeds the overcurrent threshold. When the overcurrent threshold is exceeded, an overcurrent signal is output and transmitted to the input terminal of the fault output circuit.

[0024] In some embodiments of this application, the main control valve drive chip further includes:

[0025] A short-circuit detection circuit is used to detect whether the second switching transistor is short-circuited. When a short circuit is detected, a short-circuit signal is output and transmitted to the input terminal of the fault output circuit.

[0026] In some embodiments of this application, the main control valve drive chip further includes:

[0027] An open-circuit detection circuit is used to detect whether the second switch is open-circuited. When an open circuit is detected, an open-circuit signal is output and transmitted to the input terminal of the fault output circuit.

[0028] In some embodiments of this application, all pins of the main control valve drive chip are arranged in two columns on an average basis.

[0029] In some embodiments of this application, the main control valve drive chip includes 8 pins; wherein pins 1 to 4 are arranged in one column, and pins 8 to 5 are arranged in another column;

[0030] Pin 1 and pin 8 are arranged opposite each other, pin 2 and pin 7 are arranged opposite each other, pin 3 and pin 6 are arranged opposite each other, and pin 4 and pin 5 are arranged opposite each other.

[0031] Pin 1 is the ground pin, pin 2 is the drive signal output pin OUT, pin 3 is the ground pin, pin 4 is the drive signal input pin IN, pin 5 is the valve detection output pin DET1, pin 6 is the alarm output pin FAULT, pin 7 is the power supply pin VCC, and pin 8 is the ground pin.

[0032] A gas water heater, including the aforementioned main control valve drive chip.

[0033] Compared with the prior art, the advantages and positive effects of this utility model are as follows: The main control valve drive chip and gas water heater of this utility model include a drive signal input pin IN, a drive signal output pin OUT, a power supply pin VCC, and a main control valve drive circuit. The main control valve drive circuit includes a first switching transistor N3 and a second switching transistor P2. The control terminal of the first switching transistor N3 is connected to the drive signal input pin IN, one end of the switching path of the first switching transistor N3 is connected to the power supply pin VCC through a voltage divider circuit, and the other end of the switching path of the first switching transistor N3 is grounded. The control terminal of the second switching transistor P2 is connected to the voltage divider node of the voltage divider circuit, one end of the switching path of the second switching transistor P2 is connected to the power supply pin VCC, and the other end of the switching path of the second switching transistor P2 is connected to the drive signal output pin OUT. Therefore, the main control valve drive chip of this utility model integrates the main control valve drive circuit into the drive chip, simplifying the circuit design, avoiding component dispersion, reducing the circuit space occupied, reducing the difficulty of circuit layout and wiring, and solving the technical problems of component dispersion, large space occupation, and complex circuit in the prior art.

[0034] Other features and advantages of this utility model will become clearer after reading the detailed description of the embodiments of this utility model in conjunction with the accompanying drawings. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the circuit structure of one embodiment of the main control valve drive chip proposed in this utility model;

[0037] Figure 2 This is the internal circuit schematic of the main control valve drive chip;

[0038] Figure 3 This is a diagram illustrating the pin assignments and pin functions of the main control valve driver chip. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0040] It should be noted that in the description of this utility model, the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. These are used merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] Furthermore, it should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0042] Example 1

[0043] The main control valve driver chip for gas water heaters in this embodiment includes a drive signal input pin IN, a drive signal output pin OUT, a power supply pin VCC, and a main control valve drive circuit, etc. (See [link]) Figures 1 to 3 As shown.

[0044] The drive signal input pin IN is used to connect to the control unit of the gas water heater and receive control signals sent by the control unit.

[0045] The drive signal output pin OUT is used to connect to the main control valve of the gas water heater, outputting drive current to the main control valve to drive its operation.

[0046] The power supply pin VCC is used to connect to the power supply (such as a +12V DC power supply) and receive electrical energy from it. The power supply pin VCC is grounded through capacitor C11 to filter out signal interference.

[0047] The main control valve drive circuit includes a first switching transistor N3 and a second switching transistor P2.

[0048] The control terminal of the first switching transistor N3 is connected to the drive signal input pin IN. One end of the switching path of the first switching transistor N3 is connected to the power supply pin VCC through a voltage divider circuit, and the other end of the switching path of the first switching transistor N3 is grounded.

[0049] The control terminal of the second switch P2 is connected to the voltage divider node of the voltage divider circuit. One end of the switching path of the second switch P2 is connected to the power supply pin VCC, and the other end of the switching path of the second switch P2 is connected to the drive signal output pin OUT.

[0050] The voltage divider circuit includes resistors R29 and R24. The connection node (voltage divider node) of resistors R29 and R24 is connected to the control terminal of the second switching transistor P2.

[0051] The first switch N3 is a high on-state voltage drop switch, and the second switch P2 is a low on-state voltage drop switch.

[0052] For example, the first switching transistor N3 is an NPN transistor, and the second switching transistor P2 is a PNP transistor.

[0053] When the drive signal input pin IN receives a high-level signal from the control unit, the control terminal of the first switch N3 receives a high-level signal, the switching path of the first switch N3 is turned on, the switching path of the second switch P2 is turned on, and the current provided by the power supply pin VCC is transmitted to the drive signal output pin OUT through the switching path of the second switch P2, and then transmitted to the main control valve.

[0054] When the drive signal input pin IN receives a low-level signal from the control unit, the control terminal of the first switch N3 receives a low-level signal, the first switch N3 is turned off, the second switch P2 is turned off, and the current provided by the power supply pin VCC cannot be transmitted to the drive signal output pin OUT through the switching path of the second switch P2.

[0055] The main control valve drive chip for a gas water heater in this embodiment includes a drive signal input pin IN, a drive signal output pin OUT, a power supply pin VCC, and a main control valve drive circuit. The main control valve drive circuit includes a first switching transistor N3 and a second switching transistor P2. The control terminal of the first switching transistor N3 is connected to the drive signal input pin IN. One end of the switching path of the first switching transistor N3 is connected to the power supply pin VCC through a voltage divider circuit, and the other end of the switching path of the first switching transistor N3 is grounded. The control terminal of the second switching transistor P2 is connected to the voltage divider node of the voltage divider circuit. One end of the switching path of the second switching transistor P2 is connected to the power supply pin VCC, and the other end of the switching path of the second switching transistor P2 is connected to the drive signal output pin OUT. Therefore, the main control valve drive chip for a gas water heater in this embodiment integrates the main control valve drive circuit into the drive chip, simplifying the circuit design, avoiding component dispersion, reducing the circuit space occupied, reducing the difficulty of circuit layout and wiring, and solving the technical problems of component dispersion, large space occupation, and complex circuit in the prior art.

[0056] By designing the first switching transistor N3 and the second switching transistor P2, the on / off control of the line between the power supply pin VCC and the drive signal output pin OUT is realized. The circuit structure is simple and easy to control the on / off state.

[0057] In some embodiments of this application, the drive signal output pin OUT is connected to the cathode of the freewheeling diode D5, and the anode of the freewheeling diode D5 is grounded.

[0058] The main control valve of the gas water heater is a solenoid valve. The drive signal output pin OUT is connected to one end of the main control valve coil, and the other end of the coil is grounded. When the switching path of the second switching transistor P2 is turned on, the current supplied by the power supply pin VCC is transmitted through the switching path of the second switching transistor P2 to the drive signal output pin OUT, and then flows to the coil of the main control valve to power the coil, and then flows to ground. When the coil is de-energized, the reverse electromotive force generated by the coil causes the freewheeling diode D5 to conduct in the forward direction. The coil current flows through ground, the freewheeling diode D5, and then back to the coil.

[0059] The freewheeling diode D5 provides the direction of freewheeling flow. By releasing the current through the freewheeling diode D5, the current gradually decays, ensuring the safety of the main control valve.

[0060] In some embodiments of this application, the main control valve driver chip further includes a valve detection output pin DET1 and a main control valve detection circuit.

[0061] The valve detection output pin DET1 is used to connect to the control unit of the gas water heater through the current limiting resistor R49, and it is connected to a DC power supply (such as a +5V DC power supply) through the first pull-up resistor R48.

[0062] The main control valve detection circuit includes a third switch transistor N6. The control terminal of the third switch transistor N6 is grounded through a first resistor R46, and the control terminal of the third switch transistor N6 is connected to the other end of the switching path of the second switch transistor P2 through a second resistor R41. A third resistor R23 is connected in parallel across the two ends of the switching path of the second switch transistor P2. One end of the switching path of the third switch transistor N6 is grounded, and the other end of the switching path of the third switch transistor N6 is connected to the valve detection output pin DET1.

[0063] The third switch, N6, is a high on-state voltage drop switch. For example, the third switch, N6, is an NPN transistor.

[0064] When the second switch P2 is turned on, the third resistor R23 is short-circuited. The second resistor R41 and the first resistor R46 divide the voltage of the power supply pin VCC. The control terminal of the third switch N6 is at a high level, the switching path of the third switch N6 is turned on, and the valve detection output pin DET1 is at a low level.

[0065] When the second switch P2 is turned off, the third resistor R23, the second resistor R41, and the first resistor R46 divide the voltage of the power supply pin VCC. The control terminal of the third switch N6 is at a low level, the switching path of the third switch N6 is turned off, and the valve detection output pin DET1 is at a high level.

[0066] The resistance of the third resistor R23 is much greater than the resistance of the second resistor R41, and much greater than the resistance of the first resistor R46.

[0067] The above-mentioned main control valve detection circuit is designed so that the control unit can easily and conveniently determine whether the second switch P2 is conducting by checking the level of the valve detection output pin DET1, as well as the level of the drive signal output pin OUT, and thus determine whether the drive current output by the main control valve drive circuit is normal.

[0068] In some embodiments of this application, the main control valve drive chip also includes an alarm output pin FAULT, an over-temperature detection circuit, a fault output circuit, etc.

[0069] The alarm output pin FAULT is used to connect to the control unit of the gas water heater through the current-limiting resistor R5, and it is connected to a DC power supply (such as a 5V DC power supply) through the second pull-up resistor R2.

[0070] The over-temperature detection circuit is used to detect whether the temperature of the second switch P2 exceeds the temperature threshold, and outputs an over-temperature signal when the temperature threshold is exceeded.

[0071] The fault output circuit has its input terminal connected to the output terminal of the over-temperature protection circuit, and its output terminal connected to the alarm output pin FAULT.

[0072] After receiving the over-temperature signal, the fault output circuit outputs a fault alarm signal to the alarm output pin FAULT to promptly notify the control chip, so that the control chip can know the temperature status of the second switching transistor P2 in a timely manner and take timely measures.

[0073] By designing an over-temperature detection circuit and a fault output circuit, the temperature status at the second switching transistor P2 can be easily detected. When the temperature of the second switching transistor P2 exceeds the temperature threshold, a fault alarm signal is output in a timely manner.

[0074] In some embodiments of this application, the over-temperature protection circuit includes a temperature acquisition unit and a comparator. The temperature acquisition unit is used to acquire the temperature of the second switching transistor P2, and the comparator is used to compare the temperature signal acquired by the temperature acquisition unit with the temperature threshold. When the temperature signal is greater than the temperature threshold, the comparator outputs a high-level (or low-level) over-temperature signal.

[0075] In some embodiments of this application, the fault output circuit includes a fourth switching transistor. The control terminal of the fourth switching transistor is connected to the output terminal of the over-temperature protection circuit. One end of the switching path of the fourth switching transistor is grounded, and the other end of the switching path of the fourth switching transistor is connected to the alarm output pin FAULT.

[0076] When the control terminal of the fourth switch receives a high level, the switching path of the fourth switch is turned on, and the alarm output pin FAULT is at a low level.

[0077] When the control terminal of the fourth switch receives a low level, the switching path of the fourth switch is turned off, and the alarm output pin FAULT goes high.

[0078] The fault output circuit described above has a simple structure and is easy to control for switching on and off.

[0079] In some embodiments of this application, the main control valve drive chip further includes an overcurrent detection circuit.

[0080] The overcurrent detection circuit is used to detect whether the current in the switching path of the second switching transistor P2 exceeds the overcurrent threshold. When the overcurrent threshold is detected, an overcurrent signal is output and transmitted to the input terminal of the fault output circuit.

[0081] For example, an overcurrent detection circuit includes a sampling resistor and a comparator. The sampling resistor is connected in series with the switching path of the second switching transistor P2. The comparator is used to compare the sampled voltage across the sampling resistor with the voltage overcurrent threshold (the voltage overcurrent threshold is the product of the current overcurrent threshold and the sampling resistor). When the sampled voltage is greater than the voltage overcurrent threshold, the comparator outputs a high-level (or low-level) overcurrent signal.

[0082] By designing an overcurrent detection circuit, the current in the switching path of the second switching transistor P2 can be easily detected. When the current in the switching path of the second switching transistor P2 exceeds the overcurrent threshold, an overcurrent signal is output and transmitted to the fault output circuit in a timely manner. The fault output circuit outputs a fault alarm signal in a timely manner so as to notify the control unit in a timely manner.

[0083] In some embodiments of this application, the main control valve drive chip further includes a short-circuit detection circuit.

[0084] The short-circuit detection circuit is used to detect whether the second switch P2 is short-circuited. When a short circuit is detected in the second switch P2, a short-circuit signal is output and transmitted to the input terminal of the fault output circuit.

[0085] For example, a short-circuit detection circuit includes a voltage measurement unit and a first voltage comparator. The voltage measurement unit measures the voltage between the collector and emitter (CE) of the second switch P2. The first voltage comparator compares the measured voltage with a preset short-circuit voltage threshold. When the measured voltage is less than the short-circuit voltage threshold, it indicates that the CE of the second switch P2 is short-circuited, and the first voltage comparator outputs a high-level (or low-level) short-circuit signal.

[0086] By designing a short-circuit detection circuit, it is easy to detect whether the second switch P2 is short-circuited. When a short circuit is detected in the second switch P2, a short-circuit signal is output and transmitted to the fault output circuit in a timely manner. The fault output circuit outputs a fault alarm signal in a timely manner so as to notify the control unit in a timely manner.

[0087] In some embodiments of this application, the main control valve drive chip further includes an open-circuit detection circuit.

[0088] The open-circuit detection circuit is used to detect whether the second switch P2 is open. When the second switch P2 is detected to be open, it outputs an open-circuit signal and transmits it to the input terminal of the fault output circuit.

[0089] For example, the open-circuit detection circuit includes a voltage measurement unit and a second voltage comparator. The voltage measurement unit is used to measure the voltage between the collector and emitter (CE) of the second switch P2. The second voltage comparator is used to compare the measured voltage with a preset open-circuit voltage threshold. When the measured voltage is greater than the open-circuit voltage threshold, it indicates that the CE of the second switch P2 is open, and the second voltage comparator outputs a high-level (or low-level) open-circuit signal.

[0090] By designing an open-circuit detection circuit, it is easy to detect whether the second switch P2 is open. When an open circuit is detected in the second switch P2, an open-circuit signal is output and transmitted to the fault output circuit in a timely manner. The fault output circuit outputs a fault alarm signal in a timely manner so as to notify the control unit in a timely manner.

[0091] The input terminals of the fault output circuit are connected to the output terminals of the over-temperature detection circuit, over-current detection circuit, short-circuit detection circuit, and open-circuit detection circuit, respectively, so as to output the fault signal to the alarm output pin FAULT in a timely manner.

[0092] In some embodiments of this application, all pins of the main control valve driver chip are arranged in two columns on an average basis, and the pin allocation of the main control valve driver chip is reasonable, making the wiring more reasonable.

[0093] In some embodiments of this application, the main control valve drive chip includes 8 pins (ports); wherein pins 1 to 4 are arranged in one column (arranged in one column from top to bottom), and pins 8 to 5 are arranged in another column (arranged in another column from top to bottom), and the two columns of pins are arranged opposite each other.

[0094] Pin 1 is positioned opposite pin 8, pin 2 is positioned opposite pin 7, pin 3 is positioned opposite pin 6, and pin 4 is positioned opposite pin 5. See below. Figure 3 As shown.

[0095] Pin 1 is the ground pin GND, pin 2 is the drive signal output pin OUT, pin 3 is the ground pin GND, pin 4 is the drive signal input pin IN, pin 5 is the valve detection output pin DET1, pin 6 is the alarm output pin FAULT, pin 7 is the power supply pin VCC, and pin 8 is the ground pin GND.

[0096] The main control valve drive chip uses the above-mentioned pin layout. The pin layout is reasonable, avoiding interference between pins and ensuring the normal operation of the main control valve drive chip.

[0097] The main control valve driver chip in this embodiment has a drive signal input pin IN, a drive signal output pin OUT, an alarm output pin FAULT, and a valve detection output pin DET1. Both Fault and DET1 are internally open-drain designs, which facilitates compatibility with different external voltage inputs (the maximum voltage cannot exceed VCC voltage). The pin allocation fully considers the convenience of layout and routing. Pins 1, 3, and 8 are defined as GND pins. The reasonable distribution of GND pins isolates the input signal at pin 4 (drive signal input pin IN) from the output signal at pin 2 (drive signal output pin OUT). In addition, pin 6 is used as a fault output signal, and pin 5 is used as a valve open circuit detection signal.

[0098] The main control valve driver chip in this embodiment integrates a series of transistors and resistors, and also eliminates the electrolytic capacitor. Therefore, the layout and wiring on the PCB are more reasonable and the space occupied is greatly reduced.

[0099] The main control valve driver chip in this embodiment integrates the main control valve driver circuit in an SOP8 package (similar to SSOP8, DIP8, etc.). The chip has a reasonable pin allocation order and features valve open circuit and short circuit detection, overcurrent and chip over-temperature protection, and single-pin fault identification output functions.

[0100] The main control valve driver chip in this embodiment integrates the main control valve driver circuit into a single chip, simplifying the circuit design while increasing device detection and protection functions. At the same time, the reasonable allocation of pins simplifies the PCB layout and routing, reduces routing requirements, improves circuit reliability, and reduces design risks.

[0101] The main control valve driver chip in this embodiment is suitable for driving the main control valve of a gas water heater. It integrates the current discrete device driving scheme, which uses multi-stage transistors and peripheral circuits, into a single integrated chip. Through reasonable pin allocation, it reduces external components, simplifies circuit layout and wiring, reduces device footprint, and ensures consistent electrical performance across different PCBAs. Furthermore, it adds valve open-circuit and short-circuit detection, overcurrent and chip over-temperature protection, and single-pin fault identification output functions within an SOP8 package. This comprehensive protection and detection mechanism enhances the reliability of critical circuits—features that discrete devices cannot provide or achieve.

[0102] The main control valve drive chip in this embodiment integrates the main control valve drive circuit into a single chip, optimizing space while adding multiple protection and detection functions. In addition, the number of peripheral circuit components is reduced, making the circuit simpler. Furthermore, the chip's pins are rationally allocated, making its routing and layout simpler and greatly reducing design risks. It is suitable for placement and routing on a low-cost single-sided board.

[0103] Example 2

[0104] Based on the design of the main control valve drive chip in Embodiment 1, Embodiment 2 proposes a gas water heater, including a control unit (MCU) and the aforementioned main control valve drive chip.

[0105] Gas water heaters are equipped with a main control valve to control the on / off state of the main gas pipeline. The main control valve is a solenoid valve, and its operation is driven by a main control valve driver chip.

[0106] The gas water heater in this embodiment integrates the main control valve drive circuit into the drive chip, which simplifies the circuit design, avoids component dispersion, reduces the circuit space occupied, reduces the difficulty of circuit layout and wiring, and solves the technical problems of component dispersion, large space occupation, and complex circuit in the prior art.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions 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 this utility model.

Claims

1. A main control valve drive chip for gas water heaters, characterized in that: include: The drive signal input pin IN is used to connect to the control unit of the gas water heater; The drive signal output pin OUT is used to connect to the main control valve of the gas water heater. The power supply pin VCC is used to connect to the power supply. The main control valve drive circuit includes a first switching transistor and a second switching transistor; The control terminal of the first switching transistor is connected to the drive signal input pin IN, one end of the switching path of the first switching transistor is connected to the power supply pin VCC through a voltage divider circuit, and the other end of the switching path of the first switching transistor is grounded. The control terminal of the second switching transistor is connected to the voltage divider node of the voltage divider circuit, one end of the switching path of the second switching transistor is connected to the power supply pin VCC, and the other end of the switching path of the second switching transistor is connected to the drive signal output pin OUT.

2. The master valve drive chip of claim 1, wherein: The drive signal output pin OUT is connected to the cathode of the freewheeling diode, and the anode of the freewheeling diode is grounded.

3. The main control valve drive chip according to claim 1, characterized in that: The main control valve drive chip also includes: The valve detection output pin DET1 is used to connect to the control unit of the gas water heater, and it is connected to the DC power supply through the first pull-up resistor. The main control valve detection circuit includes a third switching transistor. The control terminal of the third switching transistor is grounded through a first resistor, and the control terminal of the third switching transistor is connected to the other end of the switching path of the second switching transistor through a second resistor. A third resistor is connected in parallel across the two ends of the switching path of the second switching transistor. One end of the switching path of the third switching transistor is grounded, and the other end is connected to the valve detection output pin DET1.

4. The main control valve drive chip according to claim 3, characterized in that: The main control valve drive chip also includes: The alarm output pin FAULT is used to connect to the control unit of the gas water heater, and it is connected to the DC power supply through a second pull-up resistor. An over-temperature detection circuit is used to detect whether the temperature of the second switching transistor exceeds a temperature threshold, and outputs an over-temperature signal when the temperature threshold is exceeded. The fault output circuit has its input terminal connected to the output terminal of the over-temperature detection circuit, and its output terminal connected to the alarm output pin FAULT.

5. The main control valve drive chip according to claim 4, characterized in that: The main control valve drive chip also includes: An overcurrent detection circuit is used to detect whether the current in the switching path of the second switching transistor exceeds the overcurrent threshold. When the overcurrent threshold is exceeded, an overcurrent signal is output and transmitted to the input terminal of the fault output circuit.

6. The main control valve drive chip according to claim 4, characterized in that: The main control valve drive chip also includes: A short-circuit detection circuit is used to detect whether the second switching transistor is short-circuited. When a short circuit is detected, a short-circuit signal is output and transmitted to the input terminal of the fault output circuit.

7. The main control valve drive chip according to claim 4, characterized in that: The main control valve drive chip also includes: An open-circuit detection circuit is used to detect whether the second switch is open-circuited. When an open circuit is detected, an open-circuit signal is output and transmitted to the input terminal of the fault output circuit.

8. The master valve drive chip according to any one of claims 1 to 7, characterized in that: All pins of the main control valve drive chip are arranged in two columns on average.

9. The master valve drive chip of claim 8, wherein: The main control valve drive chip includes 8 pins; pins 1 to 4 are arranged in one column, and pins 8 to 5 are arranged in another column. Pin 1 and pin 8 are arranged opposite each other, pin 2 and pin 7 are arranged opposite each other, pin 3 and pin 6 are arranged opposite each other, and pin 4 and pin 5 are arranged opposite each other. Pin 1 is the ground pin, pin 2 is the drive signal output pin OUT, pin 3 is the ground pin, pin 4 is the drive signal input pin IN, pin 5 is the valve detection output pin DET1, pin 6 is the alarm output pin FAULT, pin 7 is the power supply pin VCC, and pin 8 is the ground pin.

10. A gas water heater characterised by: Includes the main control valve drive chip as described in any one of claims 1 to 9.

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