Wireless charging circuit and magnet yoke flaw detector using same

Abstract

The utility model discloses a wireless charging circuit and a magnet yoke flaw detector using the same, the charging circuit comprises a receiving coil L2, the receiving coil L2 is electrically connected with a Zener diode D3 and a rectifier diode D2 respectively; the voltage stabilizing diode D3 is electrically connected with a linear voltage regulator U7, the linear voltage regulator U7 is electrically connected with a single-chip microcomputer U6, and the rectifier diode D2 is electrically connected with a switching circuit. The magnet yoke flaw detector comprises a flaw detector body and a charging seat, a battery pack BT1 and a wireless receiving module are arranged in the flaw detector body, a wireless charging module is arranged in the charging seat, the wireless receiving module is connected with a charging circuit, and the wireless charging module is connected with a transmitting circuit. According to the utility model, a wireless induction charging mode and a contact type charging mode are mainly adopted, thereby effectively avoiding equipment fault risks.

Description

Technical Field

[0001] The utility model relates to the field of nondestructive testing and flaw detection, and in particular to a wireless charging circuit and a yoke flaw detector using the circuit. Background Art

[0002] Magnetic particle flaw detector is an instrument used to inspect surface and near-surface defects of iron products. It is widely used in the manufacturing, installation and use of pressure vessels, pressure pipes, steel, mechanical equipment, aerospace, electricity, automobiles, petroleum, chemicals, railways, bridges, etc. Magnetic particle flaw detection is also often used for important steel parts during regular equipment maintenance to detect defects such as fatigue cracks generated during use and prevent catastrophic accidents during continued use of the equipment. Magnetic particle flaw detection is a non-destructive testing method that detects defects on the surface or near the surface of ferromagnetic materials by accumulating magnetic particles in the leakage magnetic field near the defect.

[0003] In the prior art, the application with publication number CN210037705U discloses a multifunctional yoke flaw detector, which includes a yoke probe, a magnetizing power supply, and a cable connecting the yoke probe and the magnetizing power supply, and also includes a battery arranged inside the magnetizing power supply; the battery of the device can be charged by a limited mains supply or powered by an external rechargeable battery, and the charging interface is prone to water and oil ingress during a complex working process, which poses a risk of failure. Currently, there is a lack of a yoke flaw detector with wireless induction charging. Summary of the invention

[0004] The purpose of the utility model is to provide a wireless charging circuit and a yoke flaw detector using the circuit, so as to solve the problem that the conventional yoke flaw detector in the prior art has a charging interface, which is easy to get into water and oil during the complex working process and has the risk of failure.

[0005] The utility model is realized by the following technical solutions:

[0006] A wireless charging circuit includes a charging circuit and a transmitting circuit; the charging circuit includes a receiving coil L2, the receiving coil L2 is electrically connected to a voltage regulator diode D3 and a rectifier diode D2 respectively; the voltage regulator diode D3 is electrically connected to a linear voltage regulator U7, the linear voltage regulator U7 is electrically connected to a single-chip computer U6, the rectifier diode D2 is electrically connected to a switch circuit, the switch circuit includes a MOS tube Q3, a resistor R12 is arranged between the two poles of the MOS tube Q3, one end of the MOS tube Q3 is connected to a battery pack BT1, the other end of the MOS tube Q3 is electrically connected to a MOS tube Q4, the MOS tube Q4 is electrically connected to the single-chip computer U6, and the battery pack BT1 is connected to a battery voltage detection circuit. A flyback circuit scheme is adopted, and a rectifier diode D2 is arranged, and a synchronous rectifier circuit can be used instead to reduce losses.

[0007] Furthermore, the voltage detection circuit includes a resistor R13, the resistor R13 is electrically connected to a resistor R14, the resistor R14 is grounded, the resistor R14 is connected in parallel to a capacitor C8, and an interface AD_V1 is externally connected between the resistor R13 and the resistor R14.

[0008] Furthermore, the input pin of the linear regulator U7 is electrically connected to a Zener diode D3, the output pin of the linear regulator U7 is electrically connected to the microcontroller U6, the ground pin of the linear regulator U7 is grounded, a capacitor C9 is provided between the input pin and the ground pin, a capacitor C10 is provided between the output pin and the ground pin, and a capacitor C11 is provided between the ground pin and the microcontroller U6.

[0009] Furthermore, the transmitting circuit includes a transmitting coil L1, and a zero-crossing detection circuit and a capacitor C6 are connected in parallel at both ends of the transmitting coil L1; a resistor R4 is electrically connected to one end of the transmitting coil L1, and a MOS tube Q1 is electrically connected to the other end; an input current detection circuit is connected in parallel at both ends of the resistor R4, and the resistor R4 is electrically connected to a charging power supply DC1 and a linear regulator U1 respectively; the MOS tube Q1 is electrically connected in parallel with a gate drive chip U3, and the gate drive chip U3 is electrically connected to a single-chip microcomputer U2, and an overvoltage detection circuit is connected in parallel at both ends of the MOS tube Q1; the linear regulator U1 is electrically connected to the single-chip microcomputer U2; the linear regulator U1 is electrically connected to an input voltage detection circuit. The transmitting coil L1 and the capacitor C6 form a parallel resonant circuit, which is driven by the MOS tube Q1.

[0010] Furthermore, the input current detection circuit includes a current detection chip U5, the current detection chip U5 is electrically connected to a resistor R3 and a capacitor C5, the resistor R3Y and the capacitor C5 are connected in series, an external interface AD_I is connected between the resistor R3Y and the capacitor C5, and the capacitor C5 is grounded.

[0011] Furthermore, the overvoltage detection circuit includes a voltage stabilizing diode D1, the voltage stabilizing diode D1 is electrically connected to a resistor R9, the resistor R9 is electrically connected to a transistor Q2, and the transistor Q2 is grounded.

[0012] Furthermore, the zero-crossing detection circuit includes a comparator U4, the positive input end of the comparator U4 is electrically connected to a resistor R5 and a resistor R6 respectively; the resistor R5 is electrically connected to the transmitting coil L1, and the resistor R6 is grounded; the reverse input end of the comparator U4 is electrically connected to a resistor R7 and a resistor R8 respectively; the resistor R7 is electrically connected to the transmitting coil L1, and the resistor R8 is grounded; the comparator U4 is connected to a synchronization signal interface SYNC.

[0013] Furthermore, the input voltage detection circuit includes a resistor R1, the resistor R1 is electrically connected to a resistor R2, a capacitor C4 is connected in parallel across the resistor R2, and an interface AD_V2 is externally connected between the resistor R1 and the resistor R2.

[0014] Furthermore, the single chip microcomputer U2 is electrically connected to two indicator lights LED1.

[0015] A yoke flaw detector using a wireless charging circuit includes a flaw detector body and a charging base, wherein the flaw detector body and the charging base are provided with the above-mentioned wireless charging circuit; wherein, a battery pack BT1 and a charging circuit are provided in the flaw detector body, and a transmitting circuit is provided in the charging base, the flaw detector body and the charging base cooperate with each other, and the battery pack BT1 is electrically connected to a yoke probe through a control circuit.

[0016] Compared with the prior art, the beneficial effects of the utility model are:

[0017] 1. The magnetic yoke flaw detector of the utility model adopts wireless induction charging and contact charging, which effectively avoids the risk of water and oil entering the charging interface during complex working processes.

[0018] 2. The utility model has a battery voltage detection circuit in the charging circuit. The single chip microcomputer identifies the battery voltage through the battery voltage detection circuit. If the battery is not fully charged, charging is started. If the battery voltage reaches the charging protection voltage, charging is disconnected. An overvoltage detection circuit and an indicator light are provided in the transmitting circuit. The overvoltage detection circuit can protect the circuit, and the indicator light can directly feedback the charging status. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the flaw detector body and the charging base of the utility model;

[0020] Figure 2 It is the principle diagram of the transmitting circuit of the utility model;

[0021] Figure 3 It is a charging circuit schematic diagram of the utility model. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is clearly and completely described below in conjunction with the drawings of the present invention. Based on the embodiments in this application, other similar embodiments obtained by ordinary technicians in this field without making creative work should all fall within the scope of protection of this application. In addition, the directional words mentioned in the following embodiments, such as "up", "down", "left", "right", etc., are only referenced to the directions of the drawings. Therefore, the directional words used are used to illustrate rather than limit the creation of the present invention.

[0023] The utility model is further described below in conjunction with the accompanying drawings.

[0024] Embodiment 1: A wireless charging circuit, comprising a charging circuit and a transmitting circuit; Figure 3 As shown, the charging circuit includes a receiving coil L2, such as Figure 3 As shown, one end of the receiving coil L2 is electrically connected to a voltage regulator diode D3 and a rectifier diode D2, respectively, and the other end is grounded; the cathode of the voltage regulator diode D3 is electrically connected to a linear voltage regulator U7, the linear voltage regulator U7 is electrically connected to a single-chip computer U6, the cathode of the rectifier diode D2 is electrically connected to a switch circuit, the cathode of the rectifier diode D2 is grounded through a capacitor C7, and the capacitor C7 is a filter capacitor of the rectifier circuit. The switch circuit includes a MOS tube Q3, a resistor R12 is provided between the two poles of the MOS tube Q3, one end of the MOS tube Q3 is connected to a battery pack BT1, the battery pack BT1 is grounded, the other end of the MOS tube Q3 is electrically connected to a MOS tube Q4, the MOS tube Q4 is electrically connected to the single-chip computer U6, and the battery pack BT1 is connected to a battery voltage detection circuit. A flyback circuit scheme is adopted, and a rectifier diode D2 is set, and a synchronous rectifier circuit can be used instead to reduce losses.

[0025] Embodiment 2: A wireless charging circuit, wherein the voltage detection circuit comprises a resistor R13, wherein the resistor R13 is electrically connected to a resistor R14, the resistor R14 is grounded, the resistor R14 is connected in parallel to a capacitor C8, and an interface AD_V1 is externally connected between the resistor R13 and the resistor R14.

[0026] The input pin of the linear regulator U7 is electrically connected to a Zener diode D3, the output pin of the linear regulator U7 is electrically connected to the microcontroller U6, the ground pin of the linear regulator U7 is grounded, a capacitor C9 is provided between the input pin and the ground pin, a capacitor C10 is provided between the output pin and the ground pin, a stable voltage source 3.3V is externally connected between the capacitor C10 and the output pin, and a capacitor C11 is provided between the ground pin and the microcontroller U6.

[0027] The transmitting circuit includes a transmitting coil L1, such as Figure 2As shown, a zero-crossing detection circuit and a capacitor C6 are connected in parallel at both ends of the transmitting coil L1; a resistor R4 is electrically connected to one end of the transmitting coil L1, and a MOS tube Q1 is electrically connected to the other end; an input current detection circuit is connected in parallel at both ends of the resistor R4, and the resistor R4 is electrically connected to a charging power supply DC1 and a linear voltage regulator U1 respectively, and an external voltage power supply VCC is electrically connected to the connection; the input voltage of the charging power supply DC1 is 12V-24V; the MOS tube Q1 is electrically connected to a gate drive chip U3 in parallel, and the gate drive chip U3 is electrically connected to a single-chip microcomputer U2, and an overvoltage detection circuit is connected in parallel at both ends of the MOS tube Q1; the linear voltage regulator U1 is electrically connected to the single-chip microcomputer U2, and the connection method of the linear voltage regulator U1 and the single-chip microcomputer U2 is equivalent to the connection method of the above-mentioned linear voltage regulator U7 and the single-chip microcomputer U6; the linear voltage regulator U1 is electrically connected to an input voltage detection circuit.

[0028] The input current detection circuit includes a current detection chip U5, which is electrically connected to a resistor R3 and a capacitor C5, respectively. The resistor R3Y and the capacitor C5 are connected in series, an external interface AD_I is connected between the resistor R3Y and the capacitor C5, and the capacitor C5 is grounded.

[0029] The overvoltage detection circuit includes a Zener diode D1, the Zener diode D1 is electrically connected to a resistor R9, the resistor R9 is electrically connected to a transistor Q2, and the transistor Q2 is grounded. When the charge is fully charged or the connection is disconnected due to other reasons, the voltage on the MOS tube Q1 may be higher than the conduction voltage of the Zener diode D1, so that the transistor Q2 is turned on to generate an overvoltage signal, the wireless charging will be suspended, and the connection status will be re-detected.

[0030] The zero-crossing detection circuit includes a comparator U4, the positive input end of the comparator U4 is electrically connected to a resistor R5 and a resistor R6 respectively; the resistor R5 is electrically connected to the transmitting coil L1, and the resistor R6 is grounded; the reverse input end of the comparator U4 is electrically connected to a resistor R7 and a resistor R8 respectively; the resistor R7 is electrically connected to the transmitting coil L1, and the resistor R8 is grounded; the comparator U4 is connected to a synchronization signal interface SYNC; the parallel resonant zero-crossing detection circuit is output to the single-chip microcomputer as a driving synchronization signal.

[0031] The input voltage detection circuit includes a resistor R1, which is electrically connected to a resistor R2, and a capacitor C4 is connected in parallel at both ends of the resistor R2; an interface AD_V2 is externally connected between the resistor R1 and the resistor R2. The power of wireless charging is calculated by detecting the input voltage and input current, and then the pulse width of the MOS tube Q1 is adjusted according to the setting.

[0032] The single chip microcomputer U2 is electrically connected to two indicator light LEDs 1 , and the two indicator light LEDs 1 are respectively provided with current limiting resistors, one of the indicator light LEDs 1 is a red light, and the other indicator light LED 1 is a green light.

[0033] The rest is the same as Example 1.

[0034] A yoke flaw detector using a wireless charging circuit, such as Figure 1 As shown, it includes a flaw detector body and a charging base; the flaw detector body is provided with the battery pack BT1 and the charging circuit mentioned above, the charging base is provided with the transmitting circuit mentioned above, the flaw detector body and the charging base cooperate, and the battery pack BT1 is electrically connected to the yoke probe through the control circuit.

[0035] When charging the yoke flaw detector, connect the wireless receiving module on the flaw detector body to the wireless charging module of the charging base. Insert the external power plug into the charging power supply DC1 to supply power to the charging base. The single-chip microcomputer U2 starts the transmission every 5 seconds, and drives the MOS tube Q1 to turn on briefly through the gate drive chip U3, and then cuts off. Make the transmitting coil L1 and the capacitor C6 oscillate, and judge whether it is connected to the charged unit by the number of oscillations. If not connected, repeat this step. The green indicator light is on; if it is detected that it is connected, the transmission is started, and the oscillation of the transmitting coil L1 and the capacitor C6 is maintained in a resonant state through the synchronization circuit. The red indicator light is on. When the wireless charging module is charging, the linear regulator U7 can be powered by the voltage regulator diode D3, and then the linear regulator U7 supplies power to the single-chip microcomputer U6, so that the single-chip microcomputer U6 wakes up and starts. The single-chip microcomputer U6 will not be powered off during the charging process; the single-chip microcomputer identifies the battery voltage through the battery voltage detection circuit, and starts charging if it is not fully charged. Drive the MOS tube Q4 to turn on, so that the MOS tube Q3 is turned on. The charging current is output by the receiving coil L2, and passes through the rectifier diode D2 and MOS tube Q3 to the battery pack BT1. When the battery voltage reaches the charging protection voltage, the charging is disconnected. The single chip turns off the MOS tube Q4, and the MOS tube Q3 is cut off by the resistor R12 pulling up the gate voltage.

[0036] The present invention has been described in detail above. The above description is only a preferred embodiment of the present invention and should not limit the scope of implementation of the present invention. That is, all equivalent changes and modifications made within the scope of this application should still fall within the scope of the present invention.

Claims

1. A wireless charging circuit, Features: It includes a charging circuit and a transmitting circuit; the charging circuit includes a receiving coil L2, and the receiving coil L2 is electrically connected to a voltage regulator diode D3 and a rectifier diode D2 respectively; the voltage regulator diode D3 is electrically connected to a linear voltage regulator U7, the linear voltage regulator U7 is electrically connected to a single-chip computer U6, and the rectifier diode D2 is electrically connected to a switch circuit, the switch circuit includes a MOS tube Q3, a resistor R12 is arranged between the two poles of the MOS tube Q3, one end of the MOS tube Q3 is connected to a battery pack BT1, and the other end of the MOS tube Q3 is electrically connected to a MOS tube Q4, the MOS tube Q4 is electrically connected to the single-chip computer U6, and the battery pack BT1 is connected to a battery voltage detection circuit.

2. The wireless charging circuit according to claim 1, Features: The voltage detection circuit includes a resistor R13, the resistor R13 is electrically connected to a resistor R14, the resistor R14 is grounded, the resistor R14 is connected in parallel to a capacitor C8, and an interface AD_V1 is externally connected between the resistor R13 and the resistor R14.

3. The wireless charging circuit according to claim 1, Features: The input pin of the linear regulator U7 is electrically connected to a Zener diode D3, the output pin of the linear regulator U7 is electrically connected to the microcontroller U6, the ground pin of the linear regulator U7 is grounded, a capacitor C9 is provided between the input pin and the ground pin, a capacitor C10 is provided between the output pin and the ground pin, and a capacitor C11 is provided between the ground pin and the microcontroller U6.

4. The wireless charging circuit according to claim 1, Features: The transmitting circuit includes a transmitting coil L1, and a zero-crossing detection circuit and a capacitor C6 are connected in parallel at both ends of the transmitting coil L1; one end of the transmitting coil L1 is electrically connected to a resistor R4, and the other end is electrically connected to a MOS tube Q1; an input current detection circuit is connected in parallel at both ends of the resistor R4, and the resistor R4 is electrically connected to a charging power supply DC1 and a linear regulator U1 respectively; the MOS tube Q1 is electrically connected to a gate drive chip U3, the gate drive chip U3 is electrically connected to a single-chip microcomputer U2, and an overvoltage detection circuit is connected in parallel at both ends of the MOS tube Q1; the linear regulator U1 is electrically connected to the single-chip microcomputer U2; the linear regulator U1 is electrically connected to an input voltage detection circuit.

5. The wireless charging circuit according to claim 4, Features: The input current detection circuit includes a current detection chip U5, the current detection chip U5 is electrically connected to a resistor R3 and a capacitor C5, the resistor R3Y and the capacitor C5 are connected in series, an external interface AD_I is connected between the resistor R3Y and the capacitor C5, and the capacitor C5 is grounded.

6. The wireless charging circuit according to claim 4, Features: The overvoltage detection circuit includes a voltage stabilizing diode D1, the voltage stabilizing diode D1 is electrically connected to a resistor R9, the resistor R9 is electrically connected to a transistor Q2, and the transistor Q2 is grounded.

7. The wireless charging circuit according to claim 4, Features: The zero-crossing detection circuit includes a comparator U4, the positive input end of the comparator U4 is electrically connected to a resistor R5 and a resistor R6 respectively; the resistor R5 is electrically connected to the transmitting coil L1, and the resistor R6 is grounded; the reverse input end of the comparator U4 is electrically connected to a resistor R7 and a resistor R8 respectively; the resistor R7 is electrically connected to the transmitting coil L1, and the resistor R8 is grounded; the comparator U4 is connected to a synchronization signal interface SYNC.

8. The wireless charging circuit according to claim 4, Features: The input voltage detection circuit includes a resistor R1, the resistor R1 is electrically connected to a resistor R2, a capacitor C4 is connected in parallel across the resistor R2, and an interface AD_V2 is externally connected between the resistor R1 and the resistor R2.

9. The wireless charging circuit according to claim 4, Features: The single chip microcomputer U2 is electrically connected to two indicator lights LED1.

10. A yoke flaw detector using a wireless charging circuit, Features: It includes a flaw detector body and a charging base, and the flaw detector body and the charging base are provided with a wireless charging circuit as described in any one of claims 1 to 9; wherein, the battery pack BT1 and the charging circuit are arranged in the flaw detector body, and the transmitting circuit is arranged in the charging base, the flaw detector body and the charging base cooperate with each other, and the battery pack BT1 is electrically connected to the yoke probe through the control circuit.

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