Handheld high-frequency heating machine with protection function

Abstract

The utility model relates to the technical field of handheld high-frequency heating machines, in particular to a handheld high-frequency heating machine with a protection function, which is characterized in that a voltage detection circuit, a zero-cross detection circuit, a temperature detection circuit and a current detection circuit output feedback signals to a microcontroller, and a microcontroller power supply circuit supplies power to the microcontroller. Power is supplied to the key and the display circuit through the microcontroller; the microcontroller controls the key and display circuit and the ZVS power supply control circuit; the ZVS power supply control circuit supplies power to the ZVS heating circuit, and the ZVS heating circuit is monitored through the current detection circuit. And the temperature detection circuit controls the fan control circuit. The problems that a high-frequency heating machine in the current market is large in size, heavy in weight and difficult to use conveniently and movably are solved, the problems that components of the high-frequency heating machine are damaged under the condition of low load or no load and explode under the condition of large current are solved, and the situation that the high-frequency heating machine is subjected to no-load misoperation or damaged under the condition of low load is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of handheld high-frequency heating machines, in particular to a handheld high-frequency heating machine with a protection function. Background Art

[0002] High-frequency heating machines are an effective method for quickly heating metal parts (such as copper and iron) in the current market. However, current high-frequency heating machines all have the disadvantages of large volume, heavy weight, and inability to be moved freely. At the same time, due to the large current during use, when the product is used under no-load or low-load conditions, the components on the product circuit board will be damaged due to excessive current, and in severe cases, individual components will explode. To solve the above problems, we have further simplified the product circuit and added a product circuit detection module. When it detects that the current in the circuit exceeds the allowable current limit value, the circuit is promptly turned off to protect the product. Content of the Utility Model

[0003] In order to overcome the existing deficiencies, the utility model provides a handheld high-frequency heating machine with a protection function.

[0004] The technical solution adopted by the utility model to solve its technical problems is: a handheld high-frequency heating machine with a protection function, including a voltage detection circuit, a zero-crossing detection circuit, a temperature detection circuit, a microcontroller power supply circuit, a current detection circuit, a ZVS heating circuit, a ZVS power control circuit, a key and display circuit, and a microcontroller; the voltage detection circuit, the zero-crossing detection circuit, the temperature detection circuit, and the current detection circuit output feedback signals to the microcontroller, the microcontroller power supply circuit supplies power to the microcontroller, and supplies power to the key and display circuit through the microcontroller; the microcontroller controls the key and display circuit and the ZVS power control circuit; the ZVS power control circuit supplies power to the ZVS heating circuit, and the ZVS heating circuit is monitored through the current detection circuit; the temperature detection circuit controls the fan control circuit.

[0005] According to another embodiment of the utility model, it further includes that the voltage detection circuit is arranged in the ZVS heating circuit and includes a resistor R40, a resistor R42, a resistor R41, a capacitor C21, and a diode D15; wherein, one end of the resistor R40 is connected in the ZVS heating circuit, and the other end is connected to the resistor R42 and the resistor R41, the other end of the resistor R42 is connected to the capacitor C21 and the diode D15; the other end of the capacitor C21 is grounded together with the resistor R41, and the diode D15 is connected to the 5V of the microcontroller power supply circuit.

[0006] According to another embodiment of the present utility model, it further includes that the zero-crossing detection circuit includes an input rectifier bridge and an optical frequency isolator U2; two AC input terminals of the input rectifier bridge are respectively connected to the live wire input terminal and the neutral wire input terminal of the power supply unit, the positive voltage output terminal is connected to the input terminal of the optical frequency isolator U2 through a resistor R7, is connected to the emitter of a transistor Q1 through a capacitor C9, is connected to a negative voltage through a resistor R6 and a diode D3, the negative voltage is connected to the base of the transistor Q1, the collector of the transistor Q1 is connected to the input terminal of the optical frequency isolator U2, and one end of the output terminal of the optical frequency isolator U2 is connected to a voltage of 5V and is connected to the microcontroller through a ZERO interface, and the other end is grounded.

[0007] According to another embodiment of the present utility model, it further includes that the temperature detection circuit includes a resistor R45 and a resistor R47; both ends of the resistor R45 are shunted by a capacitor C22, one end is connected to the microcontroller through an NCT1 interface and is connected to a voltage of 5V through a resistor R44, and the other end is grounded; both ends of the resistor R47 are shunted by a capacitor C23, one end is connected to the microcontroller through an NCT2 interface and is connected to a voltage of 5V through a resistor R46, and the other end is grounded.

[0008] According to another embodiment of the present utility model, it further includes that the microcontroller power supply circuit includes a rectifier bridge and a high-input micro-power voltage regulator U1; the AC section of the rectifier bridge is connected to the neutral wire, the ground wire and the live wire, outputs a positive voltage of 12V and outputs a voltage of 5V through a resistor R3 and the high-input micro-power voltage regulator U1, and the output negative voltage is grounded; the ground terminal of the high-input micro-power voltage regulator is grounded; the output voltage of 12V supplies power to the key and display circuit through the microcontroller, and the output voltage of 5V supplies power to the microcontroller.

[0009] According to another embodiment of the present utility model, it further includes that the current detection circuit includes an operational amplifier U3, and the working current of the ZVS heating circuit is converted into a voltage signal through resistors R33 and R34 and sent to the operational amplifier U3 through interfaces ZGND, PGND, and GND, and after being amplified by the operational amplifier U3, it is fed back and connected to the microcontroller through an interface CUR.

[0010] According to another embodiment of the present utility model, it further includes that the ZVS heating circuit is powered by the ZVS power control circuit through the interface ZVS-12V, and is connected to the current detection circuit through the interfaces ZGND, PGND, and GND. It includes chip U4, transformer T1, inductor L1, and inductor L2. One end of the inductor L2 is connected to the ground wire, and the other end is connected to the live wire, the neutral wire, and a rectifier bridge. The high-voltage alternating current is converted into low-voltage alternating current through the inductor L2 and then forms a DC low voltage through full-bridge rectification, which is converted into a VOL voltage signal that can be detected by the voltage detection circuit, and then connected to the inductor L1 and the voltage detection circuit. The other end of the inductor L1 is connected to the primary winding of the transformer T1. Between the primary winding of the T1 transformer and the gate drive chip U4, there are transistor Q6, transistor Q7, diode D13, and diode D14.

[0011] According to another embodiment of the present utility model, it further includes that the ZVS power control circuit includes transistor Q3 and transistor Q2. The base of the transistor Q3 is connected to the interface ZVA PWR through the resistor R11, the emitter is grounded, and the collector is connected to the gate of the transistor Q2 through the resistor R10. The source of the transistor Q2 is connected to the interface ZVS-12V to supply power to the ZVS heating circuit, and the drain is powered by the microcontroller power circuit through the voltage of 12V.

[0012] According to another embodiment of the present utility model, it further includes that the key and display circuit includes a lamp board interface and a key. The lamp board interface is connected to the microcontroller through the interfaces LED1 and LED2, and the key is connected to the microcontroller through the interface KEY.

[0013] According to another embodiment of the present utility model, it further includes that the microcontroller selects chip U5. The chip interface 5 of the chip U5 is connected to the ZVS power control circuit, the interface 7 is connected to the fan control circuit, the interface 9 is connected to the current detection circuit, the interface 10 is connected to the voltage detection circuit, the interface 17 is connected to the zero-crossing detection circuit, the interfaces 15, 14, and 13 are connected to the key and display circuit, and the interfaces 12 and 11 are connected to the temperature detection circuit.

[0014] The beneficial effects of the present utility model are as follows: it solves the problems that the high-frequency heating machines on the current market are large in volume, heavy in weight, and difficult to be used conveniently and movably. At the same time, it solves the problems that product components are damaged in the high-frequency heating machine under low-load or no-load conditions, and components explode under large current, and avoids the situation of no-load misoperation or product damage under low load. Description of the Drawings

[0015] The present utility model will be further described below in conjunction with the drawings and embodiments.

[0016] Figure 1is the schematic diagram of the present utility model;

[0017] Figure 2 is the circuit diagram of the present utility model;

[0018] Figure 2 (a) is Figure 2 the partial enlarged view of the current detection circuit in

[0019] Figure 2 (b) is Figure 2 the partial enlarged view of the microcontroller circuit in

[0020] Figure 2 (c) is Figure 2 the partial enlarged view of the microcontroller power supply circuit in

[0021] Figure 2 (d) is Figure 2 the partial enlarged view of the zero-crossing detection circuit in

[0022] Figure 2 (e) is Figure 2 the partial enlarged view of the temperature detection circuit in

[0023] Figure 2 (f) is Figure 2 the partial enlarged view of the detection circuit of the ZVS power control circuit in

[0024] Figure 2 (g) is Figure 2 the partial enlarged view of the voltage detection circuit in Detailed implementation manners

[0025] As Figure 1 is the structural schematic diagram of the present utility model, a handheld high-frequency heating machine with a protection function, including a voltage detection circuit, a zero-crossing detection circuit, a temperature detection circuit, a microcontroller power supply circuit, a current detection circuit, a ZVS heating circuit, a ZVS power control circuit, a key and display circuit, and a microcontroller; the voltage detection circuit, the zero-crossing detection circuit, the temperature detection circuit, and the current detection circuit output feedback signals to the microcontroller, the microcontroller power supply circuit supplies power to the microcontroller and supplies power to the key and display circuit through the microcontroller; the microcontroller controls the key and display circuit and the ZVS power control circuit; the ZVS power control circuit supplies power to the ZVS heating circuit, and the ZVS heating circuit is monitored through the current detection circuit; the temperature detection circuit controls the fan control circuit.

[0026] Specifically, the current detection circuit is used to detect the heating current, the voltage detection circuit is used to detect the input voltage, and the zero-crossing detection circuit is used to detect the input power frequency; the microcontroller sends instructions to the ZVS heating control circuit after detecting the power supply voltage frequency and normal temperature, and the current detection circuit feeds back the working current to the microcontroller. The microcontroller sends instructions to the key and display indication circuit according to the real-time parameters, so that the LED lights display the status.

[0027] According to another embodiment of the present invention, it further includes that the voltage detection circuit is arranged in the ZVS heating circuit and includes a resistor R40, a resistor R42, a resistor R41, a capacitor C21 and a diode D15; wherein, one end of the resistor R40 is connected to the ZVS heating circuit, and the other end is connected to the resistor R42 and the resistor R41. The other end of the resistor R42 is connected to the capacitor C21 and the diode D15; the other end of the capacitor C21 is grounded together with the resistor R41, and the diode D15 is connected to 5V of the microcontroller power supply circuit.

[0028] According to another embodiment of the present invention, it further includes that the zero-crossing detection circuit includes an input rectifier bridge and an optical frequency isolator U2; the two AC input terminals of the input rectifier bridge are respectively connected to the live wire input terminal and the neutral wire input terminal of the power supply unit. The positive voltage output terminal is connected to the input terminal of the optical frequency isolator U2 through a resistor R7, connected to the emitter of the transistor Q1 through a capacitor C9, connected to the negative voltage through a resistor R6 and a diode D3, the negative voltage is connected to the base of the transistor Q1, the collector of the transistor Q1 is connected to the input terminal of the optical frequency isolator U2, and one end of the output terminal of the optical frequency isolator U2 is connected to 5V, connected to the microcontroller through the ZERO interface, and the other end is grounded.

[0029] According to another embodiment of the present invention, it further includes that the temperature detection circuit includes a resistor R45 and a resistor R47; both ends of the resistor R45 are connected in parallel with a capacitor C22, one end is connected to the microcontroller through the NCT1 interface and connected to 5V through a resistor R44, and the other end is grounded; both ends of the resistor R47 are connected in parallel with a capacitor C23, one end is connected to the microcontroller through the NCT2 interface and connected to 5V through a resistor R46, and the other end is grounded.

[0030] According to another embodiment of the present utility model, it further includes that the microcontroller power supply circuit includes a rectifier bridge and a high-input micro-power voltage regulator U1; the AC section of the rectifier bridge is connected to the neutral wire, ground wire and live wire, outputs a positive voltage of 12V and outputs a voltage of 5V through a resistor R3 and the high-input micro-power voltage regulator U1, and the output negative voltage is grounded; the ground terminal of the high-input micro-power voltage regulator is grounded; the output voltage of 12V supplies power to the key and display circuit through the microcontroller, and the output voltage of 5V supplies power to the microcontroller.

[0031] According to another embodiment of the present utility model, it further includes that the current detection circuit includes an operational amplifier U3, and the working current of the ZVS heating circuit is converted into a voltage signal through resistors R33 and R34 and sent to the operational amplifier U3 through interfaces ZGND, PGND, GND, and after being amplified by the operational amplifier U3, it is fed back to the microcontroller through interface CUR.

[0032] According to another embodiment of the present utility model, it further includes that the ZVS heating circuit is powered by the ZVS power supply control circuit through interface ZVS-12V, and is connected to the current detection circuit through interfaces ZGND, PGND, GND, and includes a chip U4, a transformer T1, an inductor L1, and an inductor L2; one end of the inductor L2 is connected to the ground wire, one end is connected to the live wire, neutral wire, and rectifier bridge; the high-voltage alternating current is converted into low-voltage alternating current through the inductor L2 and then forms a DC low voltage through full-bridge rectification and is converted into a VOL voltage signal that can be detected by the voltage detection circuit, and then is connected to the inductor L1 and the voltage detection circuit; the other end of the inductor L1 is connected to the primary winding of the transformer T1, and between the primary winding of the T1 transformer and the gate drive chip U4, there are a transistor Q6, a transistor Q7, a diode D13 and a diode D14.

[0033] According to another embodiment of the present utility model, it further includes that the ZVS power supply control circuit includes a transistor Q3 and a transistor Q2. The base of the transistor Q3 is connected to interface ZVA PWR through a resistor R11, the emitter is grounded, and the collector is connected to the gate of the transistor Q2 through a resistor R10. The source of the transistor Q2 is connected to interface ZVS-12V to supply power to the ZVS heating circuit, and the drain is powered by the microcontroller power supply circuit through a voltage of 12V.

[0034] According to another embodiment of the present utility model, it further includes that the key and display circuit includes a lamp board interface and keys. The lamp board interface is connected to the microcontroller through interfaces LED1 and LED2, and the keys are connected to the microcontroller through interface KEY.

[0035] According to another embodiment of the present utility model, it further includes that the microcontroller selects chip U5. The chip interface 5 of chip U5 is connected to the ZVS power control circuit, interface 7 is connected to the fan control circuit, interface 9 is connected to the current detection circuit, interface 10 is connected to the voltage detection circuit, interface 17 is connected to the zero-crossing detection circuit, interfaces 15, 14, and 13 are connected to the key and display circuit, and interfaces 12 and 11 are connected to the temperature detection circuit.

[0036] In the specific operation process, when it is detected that the P3 key is pressed, the microcontroller turns on the transistor Q3 to supply power to the ZVS heating control circuit with the 12V power supply to start the ZVS heating circuit to work under the state that the input power supply voltage frequency and temperature are both normal. When power is applied, the current flowing through the inductor L1 is zero. The power supply makes the transistors Q6 and Q7 in the ZVS heating circuit conduct through the resistors R15 and R16, and the current of the inductor L1 gradually increases. Due to the difference in the characteristics of the two switching tubes, the currents flowing into the two switching tubes will be different. Assuming that the current of the transistor Q6 is greater than the current of the transistor Q7, the gate voltage of the transistor Q6 is higher than the gate voltage of the transistor Q7. Through the two diodes D13 and D14, the voltage at one end of the transformer T1 is lower than the voltage at the other end. Therefore, the transformer T1 will generate an induced voltage, and thus a positive feedback is formed through the transformer T1 to make the transistor Q6 conduct and the transistor Q7 cut off, completing the startup process. After the ZVS current starts, the working current generated is converted into a voltage signal through the resistors R33 and R34, and then amplified by the operational amplifier U3 and fed back to the microcontroller for sampling, preventing the current of the ZVS heating control circuit from being too large and burning out the circuit, and being able to effectively identify no-load heating and perform protection.

[0037] The above description is illustrative rather than restrictive to the present utility model. Those of ordinary skill in the art understand that without departing from the spirit and scope defined by the appended claims, many modifications, changes or equivalents can be made, but all will fall within the protection scope of the present utility model.

Claims

1. A handheld high-frequency heating machine with a protection function, characterized in that It includes a voltage detection circuit, a zero-crossing detection circuit, a temperature detection circuit, a microcontroller power supply circuit, a current detection circuit, a ZVS heating circuit, a ZVS power control circuit, a key and display circuit, and a microcontroller; the voltage detection circuit, the zero-crossing detection circuit, the temperature detection circuit, and the current detection circuit output feedback signals to the microcontroller, the microcontroller power supply circuit supplies power to the microcontroller, and supplies power to the key and display circuit through the microcontroller; the microcontroller controls the key and display circuit and the ZVS power control circuit; the ZVS power control circuit supplies power to the ZVS heating circuit, and the ZVS heating circuit is monitored through the current detection circuit; the temperature detection circuit controls the fan control circuit.

2. The hand-held high-frequency heating machine with a protection function according to claim 1, characterized in that, The voltage detection circuit is arranged in the ZVS heating circuit and includes a resistor R40, a resistor R42, a resistor R41, a capacitor C21, and a diode D15; wherein, one end of the resistor R40 is connected to the ZVS heating circuit, and the other end is connected to the resistor R42 and the resistor R41, the other end of the resistor R42 is connected to the capacitor C21 and the diode D15; the other end of the capacitor C21 is grounded together with the resistor R41, and the diode D15 is connected to the 5V of the microcontroller power supply circuit.

3. The handheld high-frequency heating machine with a protection function according to claim 1, characterized in that, The zero-crossing detection circuit includes an input rectifier bridge and an optical frequency isolator U2; the two AC input terminals of the input rectifier bridge are respectively connected to the live wire input terminal and the neutral wire input terminal of the power supply unit, the positive voltage output terminal is connected to the input terminal of the optical frequency isolator U2 through a resistor R7, is connected to the emitter of a transistor Q1 through a capacitor C9, is connected to the negative voltage through a resistor R6 and a diode D3, the negative voltage is connected to the base of the transistor Q1, the collector of the transistor Q1 is connected to the input terminal of the optical frequency isolator U2, one end of the output terminal of the optical frequency isolator U2 is connected to the voltage 5V and is connected to the microcontroller through the ZERO interface, and the other end is grounded.

4. The hand-held high-frequency heating machine with a protection function according to claim 1, characterized in that, The temperature detection circuit includes a resistor R45 and a resistor R47; both ends of the resistor R45 are shunted with a capacitor C22, one end is connected to the microcontroller through the NCT1 interface and is connected to the voltage 5V through a resistor R44, and the other end is grounded; both ends of the resistor R47 are shunted with a capacitor C23, one end is connected to the microcontroller through the NCT2 interface and is connected to the voltage 5V through a resistor R46, and the other end is grounded.

5. The handheld high-frequency heating machine with a protection function according to claim 1, characterized in that, The microcontroller power supply circuit includes a rectifier bridge and a high-input micro-power voltage regulator U1; the AC section of the rectifier bridge is connected to the neutral wire, the ground wire, and the live wire, outputs a positive voltage of 12V and outputs a voltage of 5V through a resistor R3 and the high-input micro-power voltage regulator U1, and the output negative voltage is grounded; the ground terminal of the high-input micro-power voltage regulator is grounded; the output voltage of 12V supplies power to the key and display circuit through the microcontroller, and the output voltage of 5V supplies power to the microcontroller.

6. The handheld high-frequency heating machine with a protection function according to claim 1, characterized in that, The current detection circuit includes an operational amplifier U3, and converts the working current of the ZVS heating circuit into a voltage signal through resistors R33 and R34 through interfaces ZGND, PGND, and GND and transmits it to the operational amplifier U3, and the operational amplifier U3 feeds back and connects to the microcontroller through the interface CUR after amplification.

7. The hand-held high-frequency heating machine with a protection function according to claim 1, characterized in that, The ZVS heating circuit is powered by the ZVS power control circuit through the interface ZVS-12V, and is connected to the current detection circuit through the interfaces ZGND, PGND, and GND. It includes the chip U4, the transformer T1, the inductor L1, and the inductor L2. One end of the inductor L2 is connected to the ground wire, and the other end is connected to the live wire, the neutral wire, and the rectifier bridge. The high-voltage alternating current is converted into low-voltage alternating current through the inductor L2 and then forms a DC low voltage through full-bridge rectification and is converted into a VOL voltage signal that can be detected by the voltage detection circuit, and then is connected to the inductor L1 and the voltage detection circuit. The other end of the inductor L1 is connected to the primary winding of the transformer T1. The primary winding of the T1 transformer is connected to the gate drive chip U4, and there are the transistor Q6, the transistor Q7, the diode D13, and the diode D14 between them.

8. The hand-held high-frequency heating machine with a protection function according to claim 1, characterized in that, The ZVS power control circuit includes the transistor Q3 and the transistor Q2. The base of the transistor Q3 is connected to the interface ZVA PWR through the resistor R11, the emitter is grounded, and the collector is connected to the gate of the transistor Q2 through the resistor R10. The source of the transistor Q2 is connected to the interface ZVS-12V to supply power to the ZVS heating circuit, and the drain is powered by the microcontroller power circuit through the voltage 12V.

9. The handheld high-frequency heating machine with a protection function according to claim 1, characterized in that, The key and display circuit includes a lamp board interface and keys. The lamp board interface is connected to the microcontroller through the interfaces LED1 and LED2, and the keys are connected to the microcontroller through the interface KEY.

10. The hand-held high-frequency heating machine with a protection function according to claim 1, characterized in that, The microcontroller selects the chip U5. The chip interface 5 of the chip U5 is connected to the ZVS power control circuit, the interface 7 is connected to the fan control circuit, the interface 9 is connected to the current detection circuit, the interface 10 is connected to the voltage detection circuit, the interface 17 is connected to the zero-crossing detection circuit, the interfaces 15, 14, and 13 are connected to the key and display circuit, and the interfaces 12 and 11 are connected to the temperature detection circuit.

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