Induction power supply circuit and control method

Abstract

The present invention discloses an inductive power-taking circuit and a control method, and relates to the technical field of power distribution network automation. The inductive power-taking circuit includes an energy-taking coil, a rectifier circuit, an energy storage filter circuit, a protection circuit, a voltage measurement circuit, a voltage comparison circuit, a power output control switch, a switch control circuit, a switch post-filter circuit, a switch control auxiliary circuit, a main control peripheral circuit, and a main control single-chip computer. The present invention can obtain sufficient electric energy under a small current, and realize circuit self-starting without a backup power supply. At the same time, after the main control single-chip computer is started, the low power consumption of the entire circuit is realized under the software and hardware control of the single-chip computer, and the circuit works stably under a small primary current.

Description

Technical Field

[0001] The present invention relates to the technical field of power distribution network automation, and in particular to an induction power supply circuit and a control method. Background Art

[0002] Inductive power extraction devices using current transformers are usually used in passive power supplies or power monitoring systems. This device uses the magnetic induction principle of the current transformer (CT) to extract electrical energy. The current transformer converts the energy of the main current into a lower voltage electrical energy output, which can be used to drive low-power circuits or electronic devices.

[0003] The inductive power supply equipment using current transformers is easy to disassemble and assemble, and does not require the structure of the primary equipment to be changed. It has been widely used in distribution networks. However, inductive power supply is to sense the main circuit current signal to the secondary side, which is greatly affected by the system load current. It is difficult to solve the problem of stable power supply under low current. In the case that the user circuit has no backup power supply, if the primary current is small, the power output current cannot meet the current required for the user circuit to start, which will cause the microcontroller system to fail to start normally. The commonly used inductive power supply circuits have the following problems:

[0004] (1) It is difficult to obtain power under low current, which cannot meet the needs of equipment use;

[0005] (2) The heating of the power coil and voltage stabilization circuit under high current affects the stable operation of the circuit;

[0006] (3) Without a backup power supply, the primary system cannot be started when the current is small.

[0007] Currently, no effective solution has been proposed for the problems in the related technologies. Summary of the invention

[0008] 1. Technical issues to be resolved

[0009] In view of the deficiencies in the prior art, the present invention provides an inductive power supply circuit and a control method, which have the advantage of stable operation of the circuit under a small primary current, thereby solving the problem that stable power supply under a small current is difficult.

[0010] (II) Technical solution

[0011] In order to achieve the advantage of stable operation of the circuit under the condition of small primary current, the specific technical solution adopted by the present invention is as follows:

[0012] According to one aspect of the present invention, an inductive power supply circuit is provided, which includes an energy supply coil, a rectifier circuit, an energy storage filter circuit, a voltage limiting protection circuit, a voltage stabilization output circuit, a voltage measurement circuit before voltage stabilization, a voltage measurement circuit after voltage stabilization, a filter circuit after voltage stabilization, a voltage comparison circuit, a power supply output control switch, a switch control circuit, a filter circuit after switching, a switch control auxiliary circuit, a main control peripheral circuit and a main control single chip computer;

[0013] The energy taking coil is electrically connected to the rectifier circuit, the energy storage filter circuit, the voltage limiting protection circuit, the voltage stabilization output circuit, the voltage measurement circuit before voltage stabilization, the voltage measurement circuit after voltage stabilization, the filtering circuit after voltage stabilization, the voltage comparison circuit, the power supply output control switch, the switch control circuit, the filtering circuit after the switch, the switch control auxiliary circuit, the main control peripheral circuit and the main control microcontroller in sequence.

[0014] Preferably, the rectifier circuit includes a QD terminal, a diode D4, a diode D5, a diode D7 and a diode D9; the second pin of the QD terminal is respectively connected to the cathode of the diode D4 and the anode of the diode D5, the anode of the diode D4 is grounded, the cathode of the diode D5 is connected to the cathode of the diode D7 and forms a rectifier output VO0 terminal, the anode of the diode D7 is respectively connected to the first pin of the QD terminal and the cathode of the diode D9, and the anode of the diode D9 is grounded.

[0015] Preferably, the voltage limiting protection circuit includes a diode D1, a diode D6 and a capacitor C8; the cathode of the diode D6 is respectively connected to the anode of the capacitor C8 and the cathode of the diode D1 and connected to the VIN0 terminal, and the anode of the diode D6, the cathode of the capacitor C8 and the anode of the diode D1 are all grounded.

[0016] Preferably, capacitor C8 is a polar capacitor, and capacitor C8 is used to achieve energy storage filtering; diode D1 and diode D6 are both bidirectional transient voltage suppression tubes, and the voltage limiting values ​​of diode D1 and diode D6 are both 6.5V.

[0017] Preferably, the voltage measurement circuit before voltage stabilization includes a voltage stabilizing chip VR1, a diode D11, a diode D12, a capacitor C9, a resistor R4, a resistor R10, a resistor R11, a resistor R15 and a resistor R22; the first pin of the voltage stabilizing chip VR1 is connected to the positive electrode of the diode D11 and to the VIN0 end, the negative electrode of the diode D11 is connected to the positive electrode of the diode D12, the negative electrode of the diode D12 is connected to one end of the resistor R15, the resistor R15 is connected to one end of the resistor R11, the resistor R11 is connected to one end of the resistor R22 and to the VIN- end, the other end of the resistor R22 is grounded, the second pin of the voltage stabilizing chip VR1 is connected to one end of the capacitor C9 and one end of the resistor R4 and to the VCC0 end, the other end of the capacitor C9 is grounded, the other end of the resistor R4 is connected to one end of the resistor R10 and to the VIN+ end, the other end of the resistor R10 is grounded, the other end of the capacitor C9 is grounded, and the third pin of the voltage stabilizing chip VR1 is grounded.

[0018] Preferably, capacitor C9 is a filter capacitor, and capacitor C9 is 22uF.

[0019] Preferably, the switch control circuit includes a chip U2, a diode D10, a field effect transistor Q1, a resistor R21, a capacitor C11, a capacitor C12 and a capacitor C3; the first pin of the chip U2 is connected to the cathode of the diode D10, the anode of the diode D10 is respectively connected to one end of the resistor R21, one end of the capacitor C11 and the gate of the field effect transistor Q1 and connected to the GS1 terminal, the other end of the capacitor C11 is grounded, the other end of the resistor R21 is connected to the source of the field effect transistor Q1 and connected to the VCC0 terminal, the drain of the field effect transistor Q1 is respectively connected to one end of the capacitor C12 and the anode of the capacitor C3 and connected to the VCC terminal, the other end of the capacitor C12 is connected to the cathode of the capacitor C3 and grounded, the second pin of the chip U2 is grounded, the third pin of the chip U2 is connected to the VIN+ terminal, the fourth pin of the chip U2 is connected to the VIN- terminal, and the fifth pin of the chip U2 is connected to the VCC0 terminal.

[0020] Preferably, the field effect transistor Q1 is a P-channel field effect transistor, and is in an on state when the gate voltage of the field effect transistor Q1 is lower than the source voltage of the field effect transistor Q1, otherwise, the field effect transistor Q1 is in an off state.

[0021] Preferably, the switch control auxiliary circuit includes a resistor R24, a resistor R25, a capacitor C14, a transistor Q2, and a transistor Q3; one end of the resistor R24 ​​is connected to the DIELUO terminal, the other end of the resistor R24 ​​is connected to one end of the capacitor C14, the base of the transistor Q3 and the collector of the transistor Q2, the other end of the capacitor C14 is connected to the VCC0 terminal, the collector of the transistor Q3 is connected to the GS1 terminal, the emitter of the transistor Q3 is connected to the emitter of the transistor Q2 and is grounded, the base of the transistor Q2 is connected to one end of the resistor R25, and the other end of the resistor R25 is connected to the MOSI terminal.

[0022] According to another aspect of the present invention, a control method for an induction power circuit is also provided. The control method for an induction power circuit comprises the following steps:

[0023] S1. When the main control microcontroller is powered off and stops working, the power output control switch is in the disconnected state, and the energy collection coil is used to charge the energy storage filter circuit;

[0024] S2. When the voltage of the energy storage capacitor reaches the starting voltage, the power output control switch is turned on and supplies power to the main control microcontroller and the main control peripheral circuit respectively;

[0025] S3, when the main control microcontroller is started, the program controls the main control microcontroller to output the required level, so as to control the switch control auxiliary circuit to make the main control peripheral circuit continuously turned on, and control the main control microcontroller to enter the low power consumption mode;

[0026] S4. Write a control program to ensure that the power output control switch of the main control microcontroller is continuously turned on during the wake-up period and keep the power supply voltage of the microcontroller stable to meet the continuous working requirements of the main control microcontroller.

[0027] (III) Beneficial effects

[0028] Compared with the prior art, the present invention provides an induction power supply circuit and a control method, which have the following beneficial effects:

[0029] (1) The inductive power supply circuit provided by the present invention can obtain sufficient electric energy under low current and realize self-starting of the circuit without the need for a backup power supply. At the same time, after the main control microcontroller is started, the low power consumption of the entire circuit is realized under the software and hardware control of the microcontroller, and the circuit can work stably under the condition of a small primary current. The working stability of the inductive power supply circuit is improved by removing the backup power supply, thereby reducing the overall cost of the inductive power supply working equipment.

[0030] (2) The present invention designs a current output control switch and an input energy storage capacitor voltage measurement circuit in the inductive power supply circuit. The current output function is started only when the input and output energy storage capacitor voltages are higher than the start-up threshold voltage, thereby ensuring that the circuit can be self-started even when the current is relatively small and no back power supply is required. At the same time, after the control microcontroller is started, the program control of the microcontroller and the switch control auxiliary circuit are used to achieve stable operation of the circuit when the primary current is relatively small. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 is a circuit diagram of an inductive power extraction circuit according to an embodiment of the present invention;

[0033] Figure 2 is a circuit diagram of a rectifier circuit in an induction power extraction circuit according to an embodiment of the present invention;

[0034] Figure 3 is a circuit diagram of a voltage limiting protection circuit in an induction power taking circuit according to an embodiment of the present invention;

[0035] Figure 4 is a circuit diagram of a voltage measurement circuit before voltage stabilization in an induction power taking circuit according to an embodiment of the present invention;

[0036] Figure 5 is a circuit diagram of a switch control circuit in an induction power extraction circuit according to an embodiment of the present invention;

[0037] Figure 6 is a circuit diagram of a switch control auxiliary circuit in an induction power extraction circuit according to an embodiment of the present invention;

[0038] Figure 7 is a flow chart of a control method of an induction power taking circuit according to an embodiment of the present invention;

[0039] Figure 8 is a principle block diagram of a protection circuit in an induction power extraction circuit according to an embodiment of the present invention;

[0040] Fig. 9 It is a principle block diagram of a voltage measurement circuit in an inductive power extraction circuit according to an embodiment of the present invention.

[0041] In the figure:

[0042] 1. Energy taking coil; 2. Rectification circuit; 3. Protection circuit; 301. Energy storage filter circuit; 302. Voltage limiting protection circuit; 4. Voltage measurement circuit; 401. Voltage stabilization output circuit; 402. Voltage measurement circuit before voltage stabilization; 403. Voltage measurement circuit after voltage stabilization; 404. Filter circuit after voltage stabilization; 5. Voltage comparison circuit; 6. Power supply output control switch; 7. Switch control circuit; 8. Filter circuit after switch; 9. Switch control auxiliary circuit; 10. Main control peripheral circuit; 11. Main control microcontroller. DETAILED DESCRIPTION

[0043] To further illustrate each embodiment, the present invention provides drawings, which are part of the disclosure of the present invention and are mainly used to illustrate the embodiments. They can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in this field should be able to understand other possible implementation methods and advantages of the present invention.

[0044] According to an embodiment of the present invention, an inductive power extraction circuit and a control method are provided.

[0045] The present invention is further described with reference to the accompanying drawings and specific embodiments. Figure 1 As shown, according to the inductive power taking circuit of the embodiment of the present invention, the inductive power taking circuit includes an energy taking coil 1, a rectifier circuit 2, an energy storage filter circuit 301, a voltage limiting protection circuit 302, a voltage stabilization output circuit 401, a voltage measurement circuit 402 before voltage stabilization, a voltage measurement circuit 403 after voltage stabilization, a filter circuit 404 after voltage stabilization, a voltage comparison circuit 5, a power output control switch 6, a switch control circuit 7, a filter circuit 8 after switching, a switch control auxiliary circuit 9, a main control peripheral circuit 10 and a main control microcontroller 11; the energy taking coil 1 is connected to the rectifier circuit 2, the energy storage filter circuit 301, the voltage limiting protection circuit 302, the voltage stabilization output circuit 401, the voltage measurement circuit 402 before voltage stabilization, the voltage measurement circuit 403 after voltage stabilization, the filter circuit 404 after voltage stabilization, the voltage comparison circuit 5, the power output control switch 6, the switch control circuit 7, the filter circuit 8 after switching, the switch control auxiliary circuit 9, the main control peripheral circuit 10 and the main control microcontroller 11 in sequence.

[0046] It should be noted that the present invention realizes the function of taking power through current transformer induction, the secondary turns of the energy taking coil 1 are 1000 turns, and when the primary current of the line is greater than 0.5A, the circuit can output an average current of more than 0.5mA.

[0047] The main feature of this circuit is that the main control peripheral circuit 10 is designed without backup power supply. As long as the primary loop current is greater than the minimum starting current, the main control microcontroller 11 can complete the process from power failure to self-starting. Its working principle is:

[0048] (1) When the power is turned off and the operation stops, the main control peripheral circuit 10 is in the disconnected state.

[0049] (2) After the line is powered on, the energy taking coil 1 obtains electric energy from the primary circuit to charge the energy storage filter circuit 301 .

[0050] (3) After the voltage of the energy storage capacitor reaches the starting threshold voltage, the main control peripheral circuit 10 is turned on to supply power to the main control microcontroller 11 and the main control peripheral circuit 10.

[0051] (4) After the main control microcontroller 11 is started, the power output control switch 6 is controlled to be continuously turned on through the switch control auxiliary circuit 9. At the same time, the program controls the main control microcontroller 11 to enter a low power consumption mode.

[0052] (5) The main control microcontroller 11 works in the periodic wake-up mode. After wake-up, during the full-speed operation, the voltage of the energy storage filter circuit 301 drops; when entering the low power consumption mode, the voltage rises slowly; by reasonably selecting the energy storage filter capacitor of the power supply circuit and the power supply circuit capacitor, as long as the power supply voltage of the main control microcontroller 11 does not drop below the minimum allowable voltage of the microcontroller during the wake-up period, the microcontroller system can meet the requirements of continuous operation.

[0053] It should be noted that the energy extraction coil 1 is a toroidal current transformer made of a toroidal core of nanocrystalline material. The current transformer is mounted on the primary circuit. When there is a certain AC current on the primary side, an AC current signal will be generated if the secondary side of the energy extraction coil is short-circuited. The energy extraction coil 1 is in the form of a current source, and its current is determined by the primary current. If the secondary side is not short-circuited, but connected to a load with a certain impedance, an AC voltage will be formed on the load. By processing the voltage signal, the purpose of powering the subsequent circuit can be achieved. Wind n turns of enameled wire on the core as the secondary coil, and the calculation relationship between the secondary current I2 and the primary current I1 is:

[0054]

[0055] Under the same primary current condition, the larger the number of turns, the smaller the secondary current; therefore, in order for the secondary side to obtain a relatively large current value, the number of turns cannot be too large; but considering the limited energy density of the iron core and the influence of the excitation current, when the number of turns is too small, the secondary side output voltage is too low when the primary current is small, and no energy can be obtained; therefore, taking into account the power consumption and voltage requirements of the subsequent circuit, the number of coil turns in the present invention is determined to be 1000, and when the primary current is 0.5A, the secondary output current is 0.5mA; as long as the average power consumption of the overall load is less than 0.5A, the power extraction energy can meet the circuit operation requirements.

[0056] In one embodiment, the rectifier circuit 2 includes a QD terminal, a diode D4, a diode D5, a diode D7 and a diode D9; the second pin of the QD terminal is respectively connected to the cathode of the diode D4 and the anode of the diode D5, the anode of the diode D4 is grounded, the cathode of the diode D5 is connected to the cathode of the diode D7 and forms a rectifier output VO0 terminal, the anode of the diode D7 is respectively connected to the first pin of the QD terminal and the cathode of the diode D9, and the anode of the diode D9 is grounded.

[0057] It should be noted that the rectifier circuit 2 converts AC current into DC current to supply power to the energy storage filter circuit 301; in order to facilitate wiring and achieve better heat dissipation performance, four Schottky diodes (diode D4, diode D5, diode D7 and diode D9) are used in the present invention to realize full-bridge rectification. Figure 2 As shown, Figure 2 The QD terminal on the left side is connected to the output of the energy taking coil 1, and the VO0 terminal is the rectifier output terminal.

[0058] In one embodiment, the protection circuit 3 includes a diode D1, a diode D6 and a capacitor C8;

[0059] The cathode of the diode D6 is respectively connected to the anode of the capacitor C8 and the cathode of the diode D1 and connected to the VIN0 terminal. The anode of the diode D6, the cathode of the capacitor C8 and the anode of the diode D1 are all grounded.

[0060] In one embodiment, the capacitor C8 is a polar capacitor, and the capacitor C8 is used to achieve energy storage filtering; the diode D1 and the diode D6 are both bidirectional transient voltage suppression tubes, and the voltage limiting values ​​of the diode D1 and the diode D6 are both 6.5V.

[0061] It should be noted that if Figure 8 As shown, the protection circuit 3 includes an energy storage filter circuit 301 and a voltage limiting protection circuit 302, wherein the energy storage filter circuit 301 includes a capacitor C8, and the voltage limiting protection circuit 302 includes a diode D1 and a diode D6. The rectified output voltage is a pulsating direct current. In order to meet the requirements of subsequent power supply voltage stability, an energy storage filter circuit 301 is required after the rectified output. The energy storage filter circuit 301 is an electrolytic capacitor with a relatively large capacity. The withstand voltage of the electrolytic capacitor is limited, and it will be broken down if the voltage is too high; at the same time, the subsequent voltage stabilization output circuit 401 also has requirements for the upper limit of the input voltage; therefore, in order to ensure that the circuit is not damaged when there is a large primary current in the primary line, it is necessary to limit the rectified output circuit, and a voltage limiting protection circuit 302 is added in the design. This part of the circuit is as shown in FIG. Figure 3 shown.

[0062] The capacitor C8 in the energy storage filter circuit 301 is used to realize the energy storage filter function. The diode D1 and the diode D6 in the voltage limiting protection circuit 302 are bidirectional transient voltage suppressors (TVS tubes) for voltage limiting, and the voltage limiting value is 6.5V. When the primary current is large, the energy output by the energy extraction circuit will be mainly consumed by the TVS tube. In order to ensure that the TVS tube is not damaged under high current conditions, two identical TVS tubes are set up in the circuit. Considering the maximum current of the primary line of 600A, the maximum power consumption of the TVS tube is:

[0063] W=V·I=6.5×0.6=3.9(W);

[0064] According to the conduction characteristics of the TVS tube, the voltage VIN0 on the energy storage and filter capacitor will slightly exceed the nominal conduction voltage of the TVS tube of 6.5V, and the maximum value is about 7V. The energy storage filter capacitor C8 uses a 16V / 680uF electrolytic capacitor, which can ensure safe and reliable operation.

[0065] In one embodiment, the voltage measurement circuit 4 includes a voltage stabilizing chip VR1, a diode D11, a diode D12, a capacitor C9, a resistor R4, a resistor R10, a resistor R11, a resistor R15 and a resistor R22;

[0066] A first pin of the voltage stabilizing chip VR1 is connected to the positive electrode of the diode D11 and to the VIN0 terminal, a negative electrode of the diode D11 is connected to the positive electrode of the diode D12, a negative electrode of the diode D12 is connected to one end of the resistor R15, the resistor R15 is connected to one end of the resistor R11, the resistor R11 is connected to one end of the resistor R22 and to the VIN- terminal, the other end of the resistor R22 is grounded, a second pin of the voltage stabilizing chip VR1 is connected to one end of the capacitor C9 and one end of the resistor R4 and to the VCC0 terminal, the other end of the capacitor C9 is grounded, the other end of the resistor R4 is connected to one end of the resistor R10 and to the VIN+ terminal, the other end of the resistor R10 is grounded, the other end of the capacitor C9 is grounded, and a third pin of the voltage stabilizing chip VR1 is grounded.

[0067] It should be noted that if Fig. 9 As shown, the voltage measurement circuit 4 includes a pre-stabilization voltage measurement circuit 402, a stabilization output circuit 401, a post-stabilization voltage measurement circuit 403 and a post-stabilization filtering circuit 404. The function of the stabilization output circuit 401 is to convert the higher voltage (up to 7V) on the energy storage filter capacitor into a stable voltage (3.3V) that can be used by subsequent circuits. The HT7333 low-power linear voltage regulator chip is selected in the present invention.

[0068] It should be noted that the power consumption of the main control microcontroller 11 is relatively large when it starts, generally above 2 mA. If the voltage of the energy storage capacitor is relatively low, the main control microcontroller 11 and the main control peripheral circuit 10 will be powered. At this time, if the primary current is relatively low, the current provided by the energy taking coil 1 is less than the current consumed by the main control microcontroller 11 and the main control peripheral circuit 10, and the voltage of the energy storage capacitor will quickly drop to a voltage lower than the minimum voltage required for the operation of the main control microcontroller 11, which will cause the main control microcontroller 11 to fail to start; therefore, in order to ensure that the primary current is relatively low, In order for the single-chip microcomputer system to be successfully started, the power supply to the main control microcontroller 11 and the main control peripheral circuit 10 needs to be controlled. The power supply to the main control microcontroller 11 is only turned on when the voltage on the energy storage and filter capacitors is high; when the voltage on the energy storage capacitor is higher than the minimum voltage required for the operation of the main control microcontroller 11, the main control microcontroller 11 completes the reset initialization process and enters the low power consumption mode. In the low power consumption mode, the main control microcontroller 11 consumes current at the microampere level, and the current provided by the energy extraction coil 1 can meet the operating requirements of the main control microcontroller 11. In order to realize the control of the power supply to the main control microcontroller 11 and the main control peripheral circuit 10, a circuit is designed to measure the energy storage capacitor voltage and the regulated output voltage. This part of the circuit is as follows: Figure 4 shown.

[0069] It should be noted that the static power consumption of the voltage regulator chip VR1 is in the microampere level. When the primary current is very small (the minimum primary current in the present invention is 0.5A), a stable output voltage (3.3V) can be guaranteed. In this circuit, VIN- represents the voltage on the energy storage capacitor, and VIN+ represents the voltage after voltage regulation. When the voltage of the energy storage capacitor is higher than 3.4V, VR1 outputs a stable 3.3V voltage. At this time, the value of VIN+ is:

[0070]

[0071] In the formula, the resistance value of resistor R10 is 100kΩ, the resistance value of resistor R4 is 2MΩ, and the stable output voltage of VIN+ is 0.157V. Two voltage regulator diodes are introduced into the voltage measurement circuit. The purpose is to utilize the nonlinear characteristics of the forward conduction of the voltage regulator diode to reduce the power consumption of the circuit under low voltage and the efficiency of power utilization under low primary current. In the present invention, the value of resistor R15 is 3MΩ, the value of R11 is 82kΩ, and the value of R22 is 100kΩ. The calculation relationship between the energy storage voltage VIN0 and the resistance voltage divider value VIN- is:

[0072]

[0073] In the formula, when VIN- is 0.157V, the energy storage voltage VIN0 is equal to 6.396V, which is called the startup threshold voltage.

[0074] In the present invention, VIN- and VIN+ are connected to the reverse input and the forward input of a comparator respectively, and the output of the comparator controls a power output control switch; when the energy storage voltage is lower than the start threshold voltage, the comparator outputs a high level, and the power output control switch is turned off; when the energy storage voltage is higher than the start threshold, the comparator outputs a low level, the power output control switch is turned on, and the single-chip system starts the power supply startup process. In order to ensure the stability of the output voltage, a 22uF filter capacitor C9 is connected in parallel to the output end.

[0075] In one embodiment, the switch control circuit 7 includes a chip U2, a diode D10, a field effect transistor Q1, a resistor R21, a capacitor C11, a capacitor C12 and a capacitor C3; a first pin of the chip U2 is connected to the cathode of the diode D10, a positive electrode of the diode D10 is respectively connected to one end of the resistor R21, one end of the capacitor C11 and the gate of the field effect transistor Q1 and connected to the GS1 terminal, the other end of the capacitor C11 is grounded, the other end of the resistor R21 is connected to the source of the field effect transistor Q1 and connected to the VCC0 terminal, the drain of the field effect transistor Q1 is respectively connected to one end of the capacitor C12 and the positive electrode of the capacitor C3 and connected to the VCC terminal, the other end of the capacitor C12 is connected to the negative electrode of the capacitor C3 and grounded, a second pin of the chip U2 is grounded, a third pin of the chip U2 is connected to the VIN+ terminal, a fourth pin of the chip U2 is connected to the VIN- terminal, and a fifth pin of the chip U2 is connected to the VCC0 terminal.

[0076] It should be noted that in order to realize the on-off control of the power supply of the main control microcontroller 11 in the present invention, the main control peripheral circuit 10 is used; when the voltage on the energy storage capacitor is lower than the set value, the switch is turned off, and when the energy storage voltage is higher than the set value, the switch is turned on. Figure 5 shown.

[0077] It should be noted that the field effect transistor Q1 is a P-channel field effect transistor. It is turned on when the G pole voltage of the field effect transistor Q1 is lower than the S pole voltage by 2.5V, otherwise it is cut off; when the voltage on the energy storage capacitor is lower than the starting threshold voltage, VIN- is less than VIN+, the comparator outputs a high level, D10 is cut off, and under the action of the pull-up resistor R21, the G pole is a high level, and the field effect transistor Q1 is cut off; when the energy storage voltage is higher than the starting threshold voltage, the comparator outputs a low level, D10 is turned on, the G pole is doubled to a low level, and the field effect transistor Q1 is turned on.

[0078] It should be noted that after the field effect tube Q1 is turned on, due to the large power consumption of the main control single-chip computer 11 (often greater than the output current of the energy-taking coil), the voltage on the energy storage capacitor will soon be lower than the starting threshold voltage, the comparator will switch to a high-level output, and the field effect tube Q1 will be cut off again. In this case, the single-chip computer does not have enough time to complete the startup process; in order to avoid this situation of insufficient startup time, the present invention designs a Schottky diode D10 and a capacitor C11; when the field effect tube Q1 is not turned on, under the action of the pull-up resistor R21, the capacitor C11 is charged, and the G of the field effect tube Q1 is at a high level; when the starting threshold voltage is reached and the comparator outputs a low level, the diode D10 is forward-conducted, and the capacitor C1 1 discharges rapidly, the G pole becomes low level, and the field effect tube Q1 is turned on; after the field effect tube Q1 is turned on, the voltage of the energy storage capacitor decreases after discharge, and when the comparator outputs a high level, the diode D10 is in a reverse cutoff state; the capacitor C11 is slowly charged under the action of R21 (the resistor R21 is 1M ohm, the capacitor C11 is 4.7uF, and the charging time constant is 4.7s), and the voltage on the capacitor C11 will slowly increase; and the startup process of the main control microcontroller 11 is generally completed within 200ms. During this period of time, although the voltage on the energy storage capacitor is lower than the startup threshold voltage, as long as VCC is higher than the minimum voltage for the normal operation of the main control microcontroller 11, the main control microcontroller 11 can successfully complete the startup process. The capacitor C12 and the capacitor C3 after the power output control switch Q1 have the functions of filtering and voltage stabilization, stabilizing the working voltage of the main control microcontroller 11, and improving the anti-interference ability of the circuit.

[0079] In one embodiment, the switch control auxiliary circuit 9 includes a resistor R24, a resistor R25, a capacitor C14, a transistor Q2, and a transistor Q3; one end of the resistor R24 ​​is connected to the DIELUO terminal, the other end of the resistor R24 ​​is connected to one end of the capacitor C14, the base of the transistor Q3 and the collector of the transistor Q2, the other end of the capacitor C14 is connected to the VCC0 terminal, the collector of the transistor Q3 is connected to the GS1 terminal, the emitter of the transistor Q3 is connected to the emitter of the transistor Q2 and is grounded, the base of the transistor Q2 is connected to one end of the resistor R25, and the other end of the resistor R25 is connected to the MOSI terminal.

[0080] It should be noted that after the main control microcontroller 11 completes startup, the main control microcontroller 11 enters a low power consumption state; at this time, the voltage on the energy storage capacitor will slowly rise, but due to the large power consumption during the startup process, the voltage on the energy storage capacitor will still be lower than the startup threshold voltage for a long time; if no other measures are taken, as the capacitor C11 charges, the voltage on the gate of the field effect transistor Q1 will increase, which will cause the field effect transistor Q1 to be cut off, and the main control microcontroller 11 will stop working due to power cut-off. In order to avoid the above situation, a switch control auxiliary circuit 9 is designed to control the main control microcontroller to control the power output control switch to be continuously turned on. This circuit is as shown in FIG. Figure 6shown.

[0081] It should be noted that GS1 is connected to the S pole of field effect Q1. When transistor Q3 is turned on, the S pole of field effect transistor Q1 is at a low level, and field effect transistor Q1 is turned on; DIELUO and MOSI are respectively connected to the two output control pins of the main control microcontroller; the logical relationship between the DIELUO and MOSI levels and the conduction of transistors Q2 and Q3 is shown in Table 1:

[0082] Table 1 Conducting logic relationship

[0083] DIELUO MOSI Q2 Status Q3 Status High level High level Conductivity Deadline High level Low level Deadline Conductivity Low level High level Conductivity Deadline Low level Low level Deadline Deadline

[0084] It should be noted that, as can be seen from Table 1, transistor Q3 enters the on state only when DIELUO is at a high level and MOSI is at a low level. After the master microcontroller 11 is started and initialized, the DIELUO pin is set to a high level and the MOSI pin is set to a low level, and transistor Q3 enters the on state; after the master microcontroller 11 is started and enters the low power consumption state, the pin level remains unchanged, and transistor Q3 can consistently maintain the on state in the low power consumption state, thereby ensuring that the S pole voltage of the field effect transistor Q1 is at a low level, and the field effect transistor Q1 is continuously in the on state.

[0085] It should be noted that if the main control microcontroller 11 has not completed the normal startup process, DIELUO and MOSI may be high or low at the same time, and the situation where DIELUO is high and MOSI is low will not cause the transistor Q3 to be mis-turned on, thereby avoiding the phenomenon that the main control microcontroller 11 fails to start normally when the energy storage voltage is low, causing the field effect transistor Q1 to be mis-turned on.

[0086] It should be noted that the inductive power-taking circuit provided by the present invention is used in automation equipment that needs inductive power-taking in the power system. Power is taken by induction through a current transformer, and the electric energy is stored in a storage capacitor after rectification and filtering on the secondary side of the current transformer. A power output control switch is designed between the inductive power-taking circuit and the main circuit of the subsequent user. When the voltage of the energy storage capacitor is higher than the set threshold voltage, the power output control switch is turned on to realize power supply to the subsequent user circuit. After the main control microcontroller is started, the continuous power supply operation of the main control microcontroller part is realized by reasonably designing the low power consumption mode and the output voltage of the microcontroller I / O port, as well as the switch auxiliary control circuit.

[0087] like Figure 7 According to another embodiment of the present invention, a control method for an inductive power circuit is provided. The control method for an inductive power circuit includes the following steps:

[0088] S1, when the main control microcontroller 11 is powered off and stops working, the main control peripheral circuit 10 is in a disconnected state, and the energy storage filter circuit 301 is charged by the energy taking coil 1;

[0089] S2, when the voltage of the energy storage capacitor reaches the starting voltage, the main control peripheral circuit 10 is turned on and supplies power to the main control microcontroller 11 and the main control peripheral circuit 10 respectively;

[0090] S3, when the main control single chip computer 11 is started up, the program controls the main control single chip computer 11 to output the required level, so as to control the switch control auxiliary circuit 9 so that the main control peripheral circuit 10 is continuously turned on, and controls the main control single chip computer 11 to enter the low power consumption mode;

[0091] S4. Write a control program to ensure that the power output control switch 6 of the main control microcontroller 11 is continuously turned on during the wake-up period and keep the power supply voltage of the microcontroller stable to meet the continuous working requirements of the main control microcontroller 11.

[0092] In summary, with the help of the above technical solutions of the present invention, the inductive power supply circuit provided by the present invention can obtain sufficient electric energy under low current, and realize self-starting of the circuit without the need for a backup power supply. At the same time, after the main control microcontroller is started, the low power consumption of the entire circuit is realized under the software and hardware control of the microcontroller, and the circuit is stable when the primary current is small. The working stability of the inductive power supply circuit is improved by removing the backup power supply, thereby reducing the overall cost of the inductive power supply working equipment. The present invention designs a current output control switch and an input part energy storage capacitor voltage measurement circuit in the inductive power supply circuit. The current output function is started only when the voltage of the input and output part energy storage capacitor is higher than the start-up threshold voltage, thereby ensuring that the circuit can be self-started even when the current is small and no back power supply is required. At the same time, after the control microcontroller is started, the program control of the microcontroller and the switch control auxiliary circuit realize the stable operation of the circuit when the primary current is small.

[0093] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An induction power circuit, characterized in that: The induction power extraction circuit comprises an energy extraction coil (1), a rectification circuit (2), a protection circuit (3), a voltage measurement circuit (4), a voltage comparison circuit (5), a power output control switch (6), a switch control circuit (7), a post-switch filter circuit (8), a switch control auxiliary circuit (9), a main control peripheral circuit (10) and a main control single chip computer (11); The energy extraction coil (1) is electrically connected in sequence to the rectification circuit (2), the protection circuit (3), the voltage measurement circuit (4), the voltage comparison circuit (5), the power output control switch (6), the switch control circuit (7), the post-switch filter circuit (8), the switch control auxiliary circuit (9), the main control peripheral circuit (10) and the main control single chip computer (11); The switch control circuit (7) comprises a chip U2, a diode D10, a field effect transistor Q1, a resistor R21, a capacitor C11, a capacitor C12 and a capacitor C3; The first pin of the chip U2 is connected to the cathode of the diode D10, the anode of the diode D10 is respectively connected to one end of the resistor R21, one end of the capacitor C11 and the gate of the field effect transistor Q1 and connected to the GS1 terminal, the other end of the capacitor C11 is grounded, the other end of the resistor R21 is connected to the source of the field effect transistor Q1 and connected to the VCC0 terminal, the drain of the field effect transistor Q1 is respectively connected to one end of the capacitor C12 and the anode of the capacitor C3 and connected to the VCC terminal, the other end of the capacitor C12 is connected to the cathode of the capacitor C3 and connected to the ground, the second pin of the chip U2 is grounded, the third pin of the chip U2 is connected to the VIN+ terminal, the fourth pin of the chip U2 is connected to the VIN- terminal, and the fifth pin of the chip U2 is connected to the VCC0 terminal.

2. The induction power supply circuit according to claim 1, characterized in that: The rectifier circuit (2) comprises a QD terminal, a diode D4, a diode D5, a diode D7 and a diode D9; The second pin of the QD terminal is respectively connected to the cathode of the diode D4 and the anode of the diode D5, the anode of the diode D4 is grounded, the cathode of the diode D5 is connected to the cathode of the diode D7 and forms a rectifier output VO0 terminal, the anode of the diode D7 is respectively connected to the first pin of the QD terminal and the cathode of the diode D9, and the anode of the diode D9 is grounded.

3. The induction power supply circuit according to claim 2, characterized in that: The protection circuit (3) comprises a diode D1, a diode D6 and a capacitor C8; The cathode of the diode D6 is respectively connected to the anode of the capacitor C8 and the cathode of the diode D1 and connected to the VIN0 terminal. The anode of the diode D6, the cathode of the capacitor C8 and the anode of the diode D1 are all grounded.

4. The induction power supply circuit according to claim 3, characterized in that: The capacitor C8 is a polar capacitor, and the capacitor C8 is used to achieve energy storage filtering; The diode D1 and the diode D6 are both bidirectional transient voltage suppressors, and the voltage limiting values ​​of the diode D1 and the diode D6 are both 6.5V.

5. The induction power supply circuit according to claim 4, characterized in that: The voltage measurement circuit (4) comprises a voltage stabilizing chip VR1, a diode D11, a diode D12, a capacitor C9, a resistor R4, a resistor R10, a resistor R11, a resistor R15 and a resistor R22; The first pin of the voltage stabilizing chip VR1 is connected to the positive electrode of the diode D11 and to the VIN0 terminal, the negative electrode of the diode D11 is connected to the positive electrode of the diode D12, the negative electrode of the diode D12 is connected to one end of the resistor R15, the resistor R15 is connected to one end of the resistor R11, the resistor R11 is connected to one end of the resistor R22 and to the VIN- terminal, the other end of the resistor R22 is grounded, the second pin of the voltage stabilizing chip VR1 is connected to one end of the capacitor C9 and one end of the resistor R4 and to the VCC0 terminal, the other end of the capacitor C9 is grounded, the other end of the resistor R4 is connected to one end of the resistor R10 and to the VIN+ terminal, the other end of the resistor R10 is grounded, and the third pin of the voltage stabilizing chip VR1 is grounded.

6. The induction power supply circuit according to claim 5, characterized in that: The capacitor C9 is a filter capacitor, and the capacitor C9 is 22uF.

7. The inductive power supply circuit according to claim 6, characterized in that: The field effect transistor Q1 is a P-channel field effect transistor. When the gate voltage of the field effect transistor Q1 is lower than the source voltage of the field effect transistor Q1, the field effect transistor Q1 is in the on state. Otherwise, the field effect transistor Q1 is in the off state.

8. The induction power supply circuit according to claim 7, characterized in that: The switch control auxiliary circuit (9) comprises a resistor R24, a resistor R25, a capacitor C14, a transistor Q2, and a transistor Q3; One end of the resistor R24 ​​is connected to the DIELUO terminal, the other end of the resistor R24 ​​is connected to one end of the capacitor C14, the base of the transistor Q3 and the collector of the transistor Q2, the other end of the capacitor C14 is connected to the VCC0 terminal, the collector of the transistor Q3 is connected to the GS1 terminal, the emitter of the transistor Q3 is connected to the emitter of the transistor Q2 and is grounded, the base of the transistor Q2 is connected to one end of the resistor R25, and the other end of the resistor R25 is connected to the MOSI terminal.

9. A control method for an inductive power taking circuit, used to realize the inductive power taking of the inductive power taking circuit according to any one of claims 1 to 8, characterized in that: The control method of the induction power taking circuit comprises the following steps: S1. When the main control microcontroller is powered off and stops working, the power output control switch is in the disconnected state, and the energy collection coil is used to charge the energy storage filter circuit; S2. When the voltage of the energy storage capacitor reaches the starting voltage, the power output control switch is turned on and supplies power to the main control microcontroller and the main control peripheral circuit respectively; S3, when the main control microcontroller is started, the program controls the main control microcontroller to output the required level, so as to control the switch control auxiliary circuit to make the main control peripheral circuit continuously turned on, and control the main control microcontroller to enter the low power consumption mode; S4. Write a control program to ensure that the power output control switch of the main control microcontroller is continuously turned on during the wake-up period and keep the power supply voltage of the microcontroller stable to meet the continuous working requirements of the main control microcontroller.

Images