LC resonance voltage and current phase difference detection circuit

Abstract

The utility model discloses an LC resonance voltage and current phase difference detection circuit, which comprises a current detection module, a half-bridge driving module, a power supply module and a single chip microcomputer module, and is characterized in that the current detection module comprises a Hall sensor chip, a first filtering unit and a second filtering unit. According to the technical scheme, a current detection module with a Hall sensor chip as a core is used for detecting current parameters output by a half-bridge driving module, and a single-chip microcomputer module calculates the voltage and current phase difference of LC series resonance according to the current parameters and voltage parameters output by the half-bridge driving module; according to the technical scheme, the Hall sensor chip is used for replacing a current transformer, so that the circuit size of the induction cooker is reduced, and the operation loss is effectively reduced.

Description

Technical Field

[0001] This utility model relates to the field of electronic circuit technology, and more specifically to an LC resonant voltage-current phase difference detection circuit. Background Technology

[0002] An induction cooker is a common household appliance that primarily converts electrical energy into electromagnetic energy and uses the eddy current effect to heat metal components. Existing induction cookers are classified into half-bridge and full-bridge types based on their circuit topology.

[0003] For half-bridge induction cookers, the heating power cannot be adjusted by changing the PWM duty cycle; it can only be adjusted by changing the PWM frequency. Therefore, during frequency adjustment, it is necessary to detect the phase relationship between voltage and current in real time to avoid entering the capacitive region or being in phase with the LC series resonance, which could lead to overcurrent and breakdown of the switching devices. Traditional current phase detection uses constantan wire passing through a current transformer, which induces a resonant current. This current is then used by the microcontroller to detect and determine the conditions for driving the switching devices to turn on and off, resulting in a large circuit size and high operating losses for the induction cooker. Utility Model Content

[0004] To solve the above-mentioned technical problems, the purpose of this utility model is to provide an LC resonant voltage-current phase difference detection circuit.

[0005] The technical solution adopted by this utility model to solve the problem is:

[0006] An LC resonant voltage-current phase difference detection circuit includes a current detection module, a half-bridge drive module, a power supply module, and a microcontroller module. The power supply module is connected to the current detection module, the half-bridge drive module, and the microcontroller module. The microcontroller module is connected to the half-bridge drive module. The current detection module is connected to both the half-bridge drive module and the microcontroller module.

[0007] The current detection module includes a Hall sensor chip, a first filtering unit, and a second filtering unit. The Hall sensor chip is configured with a positive sampling current terminal, a negative sampling current terminal, a reference voltage terminal, and an output voltage terminal. The positive and negative sampling current terminals of the Hall sensor chip are respectively connected to the half-bridge drive module. The output voltage terminal of the Hall sensor chip is connected to the microcontroller module through the first filtering unit, and the reference voltage terminal of the Hall sensor chip is connected to the microcontroller module through the second filtering unit.

[0008] As a further improvement to the above technical solution, the Hall sensor chip is model CC6905.

[0009] As a further improvement to the above technical solution, the first filtering unit includes resistors R1, R2, R3, and R4, and capacitors C1, C2, and C3. The output voltage terminal of the Hall sensor chip is connected to ground through resistor R1 and capacitor C1. Resistor R2 is connected in parallel with capacitor C1, and capacitor C2 is connected in parallel with capacitor C1. One end of resistor R3 is connected to the connection point of resistor R1 and capacitor C1, and the other end of resistor R3 is connected to ground through resistor R4. Capacitor C3 is connected in parallel with resistor R4. The microcontroller module is connected to the connection point of resistor R3 and resistor R4.

[0010] The second filtering unit includes resistors R5 and R6 and capacitor C4. The reference voltage terminal of the Hall sensor chip is connected to ground through resistors R5 and R6 in sequence. Capacitor C4 is connected in parallel with resistor R6. The microcontroller module is connected at the connection point of resistors R5 and R6.

[0011] As a further improvement to the above technical solution, the half-bridge driver module includes a first connection terminal, a second connection terminal, a half-bridge driver chip, resistors R7, R8, R9, R10, R11, R12, R13, R14, R15, and R16, capacitors C5, C6, C7, C8, C9, C10, and C11, diodes D1, D2, D3, and D4, and switching transistors Q1 and Q2. The half-bridge driver chip is configured with a high-side input terminal, a low-side input terminal, a high-side output terminal, a low-side output terminal, a high-side offset voltage terminal, and a high-side absolute voltage terminal.

[0012] The microcontroller module is connected to the high-side input of the half-bridge driver chip via resistor R7. The high-side input of the half-bridge driver chip is connected to ground via resistor R8 and capacitor C5. The microcontroller module is connected to the low-side input of the half-bridge driver chip via resistor R9. The low-side input of the half-bridge driver chip is connected to ground via resistor R10 and capacitor C6. The low-side output of the half-bridge driver chip is connected to one end of resistor R14. The cathode of diode D3 is connected to the cathode of diode D4, the anode of diode D3 and the other end of resistor R14 are both connected to the cathode of diode D4, the anode of diode D4 is connected to ground, resistor R15 is connected in parallel with diode D4, the cathode of diode D4 is connected to the gate of switching transistor Q1, the emitter of switching transistor Q1 is connected to ground, the collector of switching transistor Q1 is connected to the first connection terminal, the two ends of resistor R16 are connected to the collector and emitter of switching transistor Q1 respectively, capacitor C8 is connected in parallel with resistor R16, and the half-bridge drive... The high-side offset voltage terminal of the chip is connected to the first connection terminal. The high-side output terminal of the half-bridge driver chip is connected to one end of the resistor R11 and the cathode of the diode D1. The anode of the diode D1 and the other end of the resistor R11 are both connected to the cathode of the diode D2. The anode of the diode D2 is connected to the high-side offset voltage terminal of the half-bridge driver chip. The resistor R12 is connected in parallel with the diode D2. The cathode of the diode D2 is connected to the gate of the switching transistor Q2. The emitter of the switching transistor Q2 is connected to the high-side offset voltage terminal of the half-bridge driver chip. The collector of transistor Q2 is connected to the power supply module. The two ends of resistor R13 are connected to the emitter and collector of transistor Q2 respectively. Capacitor C7 is connected in parallel with resistor R13. The high-side absolute voltage terminal of the half-bridge driver chip is connected to the high-side offset voltage terminal of the half-bridge driver chip through capacitor C9. Capacitors C10 and C11 are connected in series between the collector of transistor Q2 and the emitter of transistor Q1. The second connection terminal is connected to the current detection module. The connection point of capacitors C10 and C11 is connected to the current detection module.

[0013] As a further improvement to the above technical solution, the half-bridge driver chip is model FD2606.

[0014] As a further improvement to the above technical solution, this circuit also includes a human-computer interaction module, the power supply module is connected to the human-computer interaction module, and the human-computer interaction module is connected to the microcontroller module.

[0015] The human-computer interaction module includes an access port, resistors R17, R18, R19, and R20, capacitors C12 and C13, and the access port is configured with a first communication terminal and a second communication terminal.

[0016] The first communication terminal of the access port is connected to the microcontroller module through resistor R17. One end of resistor R18 is connected to the connection point between resistor R17 and the first communication terminal of the access port, and the other end of resistor R18 is connected to ground. One end of capacitor C12 is connected to the connection point between resistor R17 and the microcontroller module, and the other end of capacitor C12 is connected to ground. The second communication terminal of the access port is connected to the microcontroller module through resistor R19. One end of resistor R20 is connected to the connection point between resistor R19 and the second communication terminal of the access port, and the other end of resistor R20 is connected to ground. One end of capacitor C13 is connected to the connection point between resistor R19 and the microcontroller module, and the other end of capacitor C13 is connected to ground.

[0017] The beneficial effects of this utility model are as follows: In this technical solution, a Hall sensor chip is used as the core current detection module to detect the current parameters output by the half-bridge drive module. The microcontroller module calculates the voltage and current phase difference of the LC series resonance based on the current and voltage parameters output by the half-bridge drive module. This technical solution uses a Hall sensor chip to replace the current transformer, thereby reducing the size of the induction cooker circuit and effectively reducing operating losses. Attached Figure Description

[0018] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.

[0019] Figure 1 This is a circuit module framework diagram of this utility model;

[0020] Figure 2 This is a circuit diagram of the current detection module of this utility model;

[0021] Figure 3 This is the circuit schematic diagram of the half-bridge drive module of this utility model;

[0022] Figure 4 This is the circuit schematic diagram of the human-computer interaction module of this utility model. Detailed Implementation

[0023] This section will describe in detail the specific embodiments of the present utility model. The preferred embodiments of the present utility model are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present utility model, but they should not be construed as limiting the scope of protection of the present utility model.

[0024] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to 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.

[0025] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0026] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0027] Reference Figures 1 to 4 This application discloses an LC resonant voltage-current phase difference detection circuit. In its first embodiment, it includes a current detection module, a half-bridge drive module, a power supply module, and a microcontroller module. The power supply module outputs 310V DC voltage, 15V DC voltage, and 5V DC voltage. The power supply module is connected to the current detection module, the half-bridge drive module, and the microcontroller module, respectively. The microcontroller module is connected to the half-bridge drive module, and the current detection module is connected to both the half-bridge drive module and the microcontroller module.

[0028] The current detection module includes a Hall sensor chip, a first filtering unit, and a second filtering unit. The Hall sensor chip is configured with a positive sampling current terminal, a negative sampling current terminal, a reference voltage terminal, and an output voltage terminal. The positive and negative sampling current terminals of the Hall sensor chip are respectively connected to the half-bridge drive module. The output voltage terminal of the Hall sensor chip is connected to the microcontroller module through the first filtering unit, and the reference voltage terminal of the Hall sensor chip is connected to the microcontroller module through the second filtering unit.

[0029] Specifically, in this embodiment, the Hall sensor chip is used as the core of the current detection module to detect the current parameters output by the half-bridge drive module. The microcontroller module calculates the voltage and current phase difference of the LC series resonance based on the current and voltage parameters output by the half-bridge drive module. In this embodiment, the Hall sensor chip is used to replace the current transformer, thereby reducing the size of the induction cooker circuit and effectively reducing operating losses.

[0030] As a further preferred embodiment, in this example, the Hall sensor chip is model CC6905. This model of Hall sensor chip consists of a high-precision, low-noise linear Hall integrated circuit and a low-impedance main current conductor, manufactured using advanced BiCMOS technology. Internally, it includes a differential Hall sensor, chopper amplifier, variable gain amplifier, output polarity / sensitivity / offset, oscillator, filter, zero-point reference output, overcurrent output, and amplifier buffer output, etc. This model of Hall sensor chip adopts linear Hall sensor temperature compensation technology, which has high temperature stability characteristics. Its internally integrated differential common-mode rejection circuit allows the chip output to be unaffected by external interference magnetic signals, and the integrated dynamic offset cancellation circuit makes the chip sensitivity unaffected by external pressure and chip packaging stress.

[0031] As a further preferred embodiment, in this embodiment, the first filtering unit includes resistors R1, R2, R3, and R4, capacitors C1, C2, and C3. The output voltage terminal of the Hall sensor chip is connected to ground through resistor R1 and capacitor C1. Resistor R2 is connected in parallel with capacitor C1, and capacitor C2 is connected in parallel with capacitor C1. One end of resistor R3 is connected to the connection point of resistor R1 and capacitor C1, and the other end of resistor R3 is connected to ground through resistor R4. Capacitor C3 is connected in parallel with resistor R4. The microcontroller module is connected to the connection point of resistor R3 and resistor R4.

[0032] The second filtering unit includes resistors R5 and R6 and capacitor C4. The reference voltage terminal of the Hall sensor chip is connected to ground through resistors R5 and R6 in sequence. Capacitor C4 is connected in parallel with resistor R6. The microcontroller module is connected at the connection point of resistors R5 and R6.

[0033] Specifically, in this embodiment, the first filtering unit performs voltage divider filtering on the voltage signal output from the output voltage terminal of the Hall sensor chip, and the second filtering unit performs voltage divider filtering on the voltage signal output from the reference voltage terminal of the Hall sensor chip, thereby improving the detection accuracy of the microcontroller module on the voltage signals output from the output voltage terminal and the reference voltage terminal of the Hall sensor chip.

[0034] As a further preferred embodiment, in this embodiment, the half-bridge driver module includes a first connection terminal, a second connection terminal, a half-bridge driver chip, resistors R7, R8, R9, R10, R11, R12, R13, R14, R15, and R16, capacitors C5, C6, C7, C8, C9, C10, and C11, diodes D1, D2, D3, and D4, and switching transistors Q1 and Q2. The half-bridge driver chip is configured with a high-side input terminal, a low-side input terminal, a high-side output terminal, a low-side output terminal, a high-side offset voltage terminal, and a high-side absolute voltage terminal.

[0035] The microcontroller module is connected to the high-side input of the half-bridge driver chip via resistor R7. The high-side input of the half-bridge driver chip is connected to ground via resistor R8 and capacitor C5. The microcontroller module is connected to the low-side input of the half-bridge driver chip via resistor R9. The low-side input of the half-bridge driver chip is connected to ground via resistor R10 and capacitor C6.

[0036] The low-side output terminal of the half-bridge driver chip is connected to one end of resistor R14 and the cathode of diode D3. The anode of diode D3 and the other end of resistor R14 are both connected to the cathode of diode D4. The anode of diode D4 is connected to ground. Resistor R15 is connected in parallel with diode D4. The cathode of diode D4 is connected to the gate of switching transistor Q1. The emitter of switching transistor Q1 is connected to ground. The collector of switching transistor Q1 is connected to the first connection terminal. The two ends of resistor R16 are connected to the collector and emitter of switching transistor Q1 respectively. Capacitor C8 is connected in parallel with resistor R16. The high-side offset voltage terminal of the half-bridge driver chip is connected to the first connection terminal. The high-side output terminal of the half-bridge driver chip is connected to one end of resistor R11 and the cathode of diode D1. The anode of diode D1 and the other end of resistor R11 are both connected to the cathode of diode D3. The negative terminal of diode D2 is connected to the circuit, and the positive terminal of diode D2 is connected to the high-side offset voltage terminal of the half-bridge driver chip. Resistor R12 is connected in parallel with diode D2, and the negative terminal of diode D2 is connected to the gate of switch Q2. The emitter of switch Q2 is connected to the high-side offset voltage terminal of the half-bridge driver chip, and the collector of switch Q2 is connected to the power supply module. The two ends of resistor R13 are connected to the emitter and collector of switch Q2 respectively. Capacitor C7 is connected in parallel with resistor R13. The high-side absolute voltage terminal of the half-bridge driver chip is connected to the high-side offset voltage terminal of the half-bridge driver chip through capacitor C9. Capacitors C10 and C11 are connected in series between the collector of switch Q2 and the emitter of switch Q1. The second connection terminal is connected to the current detection module, and the connection point of capacitors C10 and C11 is connected to the current detection module.

[0037] As a further preferred embodiment, in this embodiment, the half-bridge driver chip is model FD2606. This model of half-bridge driver chip has built-in VCC and VB undervoltage protection functions to prevent the power transistor from working under too low voltage. Its logic input is compatible with both TTL and CMOS types, which facilitates interfacing with control devices. The output of this model of chip has a high pulse current buffer design with minimum driver transconductance.

[0038] As a further preferred embodiment, this embodiment also includes a human-computer interaction module, the power module is connected to the human-computer interaction module, and the human-computer interaction module is connected to the microcontroller module.

[0039] Preferably, in this embodiment, the human-computer interaction module includes an access port, resistors R17, R18, R19, and R20, capacitor C12, and capacitor C13, and the access port is configured with a first communication terminal and a second communication terminal.

[0040] The first communication terminal of the access port is connected to the microcontroller module through resistor R17. One end of resistor R18 is connected to the connection point between resistor R17 and the first communication terminal of the access port, and the other end of resistor R18 is connected to ground. One end of capacitor C12 is connected to the connection point between resistor R17 and the microcontroller module, and the other end of capacitor C12 is connected to ground. The second communication terminal of the access port is connected to the microcontroller module through resistor R19. One end of resistor R20 is connected to the connection point between resistor R19 and the second communication terminal of the access port, and the other end of resistor R20 is connected to ground. One end of capacitor C13 is connected to the connection point between resistor R19 and the microcontroller module, and the other end of capacitor C13 is connected to ground.

[0041] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the concept of this utility model and the contents of the specification and drawings of this utility model, or direct or indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. An LC resonant voltage current phase difference detection circuit, characterized by: The current detection module, the half-bridge driving module, the power module and the single-chip microcomputer module are connected with each other, the single-chip microcomputer module is connected with the half-bridge driving module, and the current detection module is connected with the half-bridge driving module and the single-chip microcomputer module. The current detection module comprises a Hall sensor chip, a first filter unit and a second filter unit, the Hall sensor chip is provided with a sampling current positive terminal, a sampling current negative terminal, a reference voltage terminal and an output voltage terminal, the sampling current positive terminal and the sampling current negative terminal of the Hall sensor chip are connected with the half-bridge driving module, the output voltage terminal of the Hall sensor chip is connected with the single-chip microcomputer module through the first filter unit, and the reference voltage terminal of the Hall sensor chip is connected with the single-chip microcomputer module through the second filter unit.

2. The LC resonant voltage current phase difference detection circuit according to claim 1, characterized in that: The Hall sensor chip is CC6905.

3. The LC resonant voltage current phase difference detection circuit according to claim 2, wherein: The first filter unit comprises resistors R1, R2, R3, R4, capacitors C1, C2 and C3, the output voltage terminal of the Hall sensor chip is connected with a ground terminal through the resistor R1 and the capacitor C1 in sequence, the resistor R2 and the capacitor C1 are connected in parallel, the capacitor C2 and the capacitor C1 are connected in parallel, one end of the resistor R3 is connected to a connection point of the resistor R1 and the capacitor C1, the other end of the resistor R3 is connected with the ground terminal through the resistor R4, the capacitor C3 is connected with the resistor R4 in parallel, and the single-chip microcomputer module is connected to a connection point of the resistor R3 and the resistor R4. The second filter unit comprises resistors R5, R6 and a capacitor C4, the reference voltage terminal of the Hall sensor chip is connected with a ground terminal through the resistor R5 and the resistor R6 in sequence, the capacitor C4 is connected with the resistor R6 in parallel, and the single-chip microcomputer module is connected to a connection point of the resistor R5 and the resistor R6.

4. The LC resonant voltage-current phase difference detection circuit according to claim 1, wherein: The half-bridge driving module comprises a first connection end, a second connection end, a half-bridge driving chip, resistors R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, capacitors C5, C6, C7, C8, C9, C10, C11, diodes D1, D2, D3, D4, a switch tube Q1 and a switch tube Q2, and the half-bridge driving chip is provided with a high-side input terminal, a low-side input terminal, a high-side output terminal, a low-side output terminal, a high-side offset voltage terminal and a high-side absolute voltage terminal. The single-chip microcomputer module is connected with the high-side input end of the half-bridge drive chip through the resistor R7, the high-side input end of the half-bridge drive chip is connected with the ground end through the resistor R8, the high-side input end of the half-bridge drive chip is connected with the ground end through the capacitor C5, the single-chip microcomputer module is connected with the low-side input end of the half-bridge drive chip through the resistor R9, the low-side input end of the half-bridge drive chip is connected with the ground end through the resistor R10, the low-side input end of the half-bridge drive chip is connected with the ground end through the capacitor C6, the low-side output end of the half-bridge drive chip is connected with one end of the resistor R14 and the negative electrode of the diode D3 respectively, the positive electrode of the diode D3 and the other end of the resistor R14 are connected with the negative electrode of the diode D4, the positive electrode of the diode D4 is connected with the ground end, the resistor R15 is connected with the diode D4 in parallel, the negative electrode of the diode D4 is connected with the gate electrode of the switching tube Q1, the emitter electrode of the switching tube Q1 is connected with the ground end, the collector electrode of the switching tube Q1 is connected with the first connecting end, the two ends of the resistor R16 are connected with the collector electrode and the emitter electrode of the switching tube Q1 in one-to-one correspondence, the capacitor C8 is connected with the resistor R16 in parallel, the high-side offset voltage end of the half-bridge drive chip is connected with the first connecting end, the high-side output end of the half-bridge drive chip is connected with one end of the resistor R11 and the negative electrode of the diode D1 respectively, the positive electrode of the diode D1 and the other end of the resistor R11 are connected with the negative electrode of the diode D2, the positive electrode of the diode D2 is connected with the high-side offset voltage end of the half-bridge drive chip, the resistor R12 is connected with the diode D2 in parallel, the negative electrode of the diode D2 is connected with the gate electrode of the switching tube Q2, the emitter electrode of the switching tube Q2 is connected with the high-side offset voltage end of the half-bridge drive chip, the collector electrode of the switching tube Q2 is connected with the power module, the two ends of the resistor R13 are connected with the emitter electrode and the collector electrode of the switching tube Q2 in one-to-one correspondence, the capacitor C7 is connected with the resistor R13 in parallel, the high-side absolute voltage end of the half-bridge drive chip is connected with the high-side offset voltage end of the half-bridge drive chip through the capacitor C9, the capacitor C10 and the capacitor C11 are connected in series between the collector electrode of the switching tube Q2 and the emitter electrode of the switching tube Q1, the second connecting end is connected with the current detection module, and the connection point of the capacitor C10 and the capacitor C11 is connected with the current detection module.

5. The LC resonant voltage current phase difference detection circuit according to claim 4, characterized in that: The model of the half-bridge drive chip is FD2606.

6. The LC resonant voltage current phase difference detection circuit according to claim 1, wherein: The power module is connected with the human-computer interaction module, and the human-computer interaction module is connected with the single-chip microcomputer module.

7. The LC resonant voltage current phase difference detection circuit according to claim 6, characterized in that: The human-computer interaction module comprises an access port, resistors R17, R18, R19, R20, capacitors C12 and C13, and the access port is provided with a first communication end and a second communication end. The first communication end of the access port is connected with the single-chip microcomputer module through the resistor R17, one end of the resistor R18 is connected with the connection point of the resistor R17 and the first communication end of the access port, the other end of the resistor R18 is connected with the ground, one end of the capacitor C12 is connected with the connection point of the resistor R17 and the single-chip microcomputer module, the other end of the capacitor C12 is connected with the ground, the second communication end of the access port is connected with the single-chip microcomputer module through the resistor R19, one end of the resistor R20 is connected with the connection point of the resistor R19 and the second communication end of the access port, the other end of the resistor R20 is connected with the ground, one end of the capacitor C13 is connected with the connection point of the resistor R19 and the single-chip microcomputer module, the other end of the capacitor C13 is connected with the ground.

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