Electrotome and electrocoagulation output driving circuit capable of improving breakdown of power tube

Abstract

The utility model provides an electrotome electrocoagulation output drive circuit capable of improving breakdown of a power tube. The electrotome electrocoagulation output drive circuit capable of improving breakdown of the power tube is provided. Comprising an MCU square wave signal driving circuit, an MOS tube driving circuit, an MOS tube inverter circuit and an AC boost oscillation circuit. The output end of the MCU square wave signal driving circuit is connected with the input end of the MOS tube driving circuit, the output end of the MOS tube driving circuit is connected with the input end of the MOS tube inverter circuit, and the output end of the MOS tube inverter circuit is connected with the input end of the AC boost oscillation circuit; the MOS tube inverter circuit comprises an inverter unit and a resistance-capacitance absorption unit. According to the utility model, on the basis of realizing inversion from direct current to alternating current, voltage spikes generated in the switching process of the MOS tube can be effectively absorbed and inhibited, so that two ends of the MOS tube can be effectively protected from being broken down, and the problems that in an inversion circuit required by electrocoagulation output of a conventional high-frequency electrotome, a power tube is easy to be broken down by high voltage, and the power consumption is low are solved. And the normal operation of the high-frequency electrotome is influenced.

Description

TECHNICAL FIELD

[0001] The utility model relates to medical instrument technical field, concretely is a kind of electrotome electrocoagulation output drive circuit capable of improving power tube breakdown. BACKGROUND

[0002] High-frequency electrotome has been widely applied in medical field due to the advantages of fast cutting speed, good hemostatic effect, high safety and simple operation. The electrocoagulation function is one of the basic functions of high-frequency electrotome, which can output high voltage with intermittent waveform, control the temperature of tissue cells at 60-100 degrees, make the intracellular fluid evaporate without cell membrane rupture, and then make the cells shrink due to internal water loss, so as to achieve the purpose of hemostasis. In the current technology, when running the electrocoagulation mode, a higher output peak voltage is often needed to generate enough high voltage to close the blood vessels. For example, the maximum output voltage of Beijing Suojiwei ES-300 model high-frequency electrotome under spray coagulation and strong coagulation mode is 4800V, and the output peak voltage is greater than 9000V. The coagulation output of high-frequency electrotome needs to be realized by power tube (MOS tube or IGBT tube) to invert direct current to alternating current, and higher output peak voltage represents higher voltage that power tube needs to withstand, which will inevitably lead to more heat and electrostatic discharge, and thus affect the service life of inverter device, and too high peak voltage may even directly break down the MOS.

[0003] Most of the high-frequency electrotomes on the market choose high-power IGBT tubes for current inversion, because IGBT tubes generate less heat under high-voltage and high-current conditions compared with MOS tubes. However, this method cannot solve the problem of power tube breakdown from the source, because even if IGBT tubes generate less heat, there is still a risk of breakdown after a period of use. Once breakdown occurs, it will affect the normal operation of high-frequency electrotome.

[0004] In view of the above, the utility model provides an electrotome electrocoagulation output drive circuit capable of improving power tube breakdown. UTILITY MODEL CONTENTS

[0005] The utility model aims to provide an electrotome electrocoagulation output drive circuit capable of improving power tube breakdown, to solve the problem that power tube is easily broken down by high voltage in the inverter circuit required by the electrocoagulation output of existing high-frequency electrotome, which will affect the normal operation of high-frequency electrotome.

[0006] The utility model is implemented by the following technical solutions:

[0007] The utility model provides an electric knife electrocoagulation output drive circuit that can improve the breakdown of power tube, including MCU square wave signal drive circuit, MOS pipe drive circuit, MOS pipe inverter circuit and alternating -current boost oscillation circuit, the output of MCU square wave signal drive circuit connects the input of MOS pipe drive circuit, the output of MOS pipe drive circuit connects the input of MOS pipe inverter circuit, the output of MOS pipe inverter circuit connects the input of alternating -current boost oscillation circuit, and the MOS pipe inverter circuit includes inverter unit and resistance -capacity absorption unit.

[0008] In the drive circuit, the MCU square wave signal drive circuit is used to generate a signal with sufficient driving capability to drive the MOS pipe drive circuit, the MOS pipe drive circuit and the MOS pipe inverter circuit are used to realize the inversion of direct current to alternating current, and the alternating -current boost oscillation circuit is used to realize stable alternating -current output; wherein, by setting the resistance -capacity absorption unit in the MOS pipe inverter circuit, the voltage spike generated in the switching process of the MOS pipe can be effectively absorbed and suppressed, and the both ends of the MOS pipe can be effectively protected from breakdown.

[0009] Further, the MCU square wave signal drive circuit includes two pull-up resistors, an amplifier and a logic gate; the input of the amplifier is connected to the signal output by the MCU, and the output of the amplifier is connected to the input of the logic gate.

[0010] In the above scheme, the signal output by the MCU is connected to VCC through a pull-up resistor to ensure the stability of the signal at high level; the amplifier and the logic gate are used to amplify the signal to enhance its driving capability, so that the signal can drive the MOS pipe drive circuit.

[0011] Further, the MOS pipe drive circuit includes two drive chips, a multi-channel drive amplifier, four MOS pipes and two transformers; the outputs of the two drive chips are respectively connected to the inputs of the multi-channel drive amplifier, the outputs of the multi-channel drive amplifier are respectively connected to the inputs of the two MOS pipes, and the two MOS pipes are respectively located at the high side of the primary side of the two transformers, and the other two MOS pipes are respectively located at the low side of the primary side of the two transformers.

[0012] In the above scheme, the two drive chips are used to receive the signal output by the MCU square wave signal drive circuit, amplify the signal and convert it into a signal suitable for driving the MOS pipe; the multi-channel drive amplifier is used to further amplify the signal output by the two drive chips to ensure sufficient driving capability to control the MOS pipe; by the alternate conduction and cutoff of the four MOS pipes, alternating currents can be generated at the primary side of the two transformers, and the alternating currents can induce alternating voltages at the secondary side of the transformers through electromagnetic coupling, thereby forming alternating -current output.

[0013] As a further aspect of the present solution, the inverter unit comprises two MOS transistors, an input connector and an output connector; the two MOS transistors in the inverter unit are located at the secondary side of the two transformers in the MOS transistor driving circuit.

[0014] In the above solution, the input connector is used to input adjustable direct current; the two MOS transistors are located at the secondary side of the two transformers, and are used as switching elements of the output stage, which can change the way of current passing through the load by alternating conduction and cutoff, thereby realizing the conversion from direct current to alternating current.

[0015] As a further aspect of the present solution, the resistance-capacitance absorption unit comprises an intermediate connector, a resistor, two capacitors and a diode; the intermediate connector is connected with the output connector in the inverter unit, the resistor and one of the capacitors form an RC absorption circuit, and the diode and the other capacitor form a clamping circuit.

[0016] In the above solution, the RC absorption circuit can absorb the voltage spike generated when the MOS transistor switches, thereby preventing damage to the circuit. When no voltage spike is generated, the capacitor in the clamping circuit basically does not work, and is in a charging state or a voltage maintaining state; the diode in the clamping circuit is a clamping diode, which will be immediately turned on if a voltage spike is generated, so as to clamp the spike voltage to a safe range, and at the same time the capacitor starts to charge and discharge to absorb the excess energy, thereby effectively absorbing and suppressing the voltage spike generated in the switching process of the MOS transistor.

[0017] As a further aspect of the present solution, the alternating current step-up oscillation circuit comprises a transformer, two capacitors and an output connector; the primary winding of the transformer in the alternating current step-up oscillation circuit is connected to the output end of the clamping circuit, the secondary winding of the transformer in the alternating current step-up oscillation circuit is connected to the two capacitors in the alternating current step-up oscillation circuit, and the two capacitors in the alternating current step-up oscillation circuit are connected to the output connector in the alternating current step-up oscillation circuit.

[0018] In the above solution, the secondary winding of the transformer (as an inductor), the two capacitors and the output connector (as an external resistor) together form an LRC oscillation circuit to generate a stable alternating current output.

[0019] The present utility model realizes the beneficial effects of:

[0020] The utility model provides an electric knife electrocoagulation output drive circuit, through setting up MCU square wave signal drive circuit, MOS pipe drive circuit, MOS pipe inverter circuit and alternating -current boost oscillation circuit, and setting up MOS pipe inverter circuit includes inverter unit and resistance and capacity absorption unit, can effectively absorb and restrain the voltage peak produced in the switching process of MOS pipe on the basis of realizing the inversion of direct current to alternating current, and then can effectively protect the both ends of MOS pipe not to be punctured, compared with the prior art that uses high power IGBT pipe to carry out current inversion, the utility model can solve the problem of power tube breakdown from the source, instead of sacrificing the quality of power tube, even after using for a period of time, still have the anti -puncture function, thereby can continuously guarantee the working effect and quality stability of high frequency electric knife. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is the whole structure composition schematic diagram of the drive circuit that the utility model embodiment describes;

[0022] Figure 2 It is the drive circuit in the utility model embodiment MCU square wave signal drive circuit diagram;

[0023] Figure 3 It is the drive circuit in the utility model embodiment MOS pipe drive circuit diagram;

[0024] Figure 4 It is the inverter unit circuit diagram of the drive circuit in the utility model embodiment MOS pipe inverter circuit;

[0025] Figure 5 It is the resistance and capacity absorption unit circuit diagram of the drive circuit in the utility model embodiment MOS pipe inverter circuit;

[0026] Figure 6 It is the alternating -current boost oscillation circuit diagram in the drive circuit in the utility model embodiment. DETAILED DESCRIPTION

[0027] The technical scheme in the utility model embodiment will be described clearly and completely in the utility model embodiment in conjunction with the drawings.

[0028] Embodiment 1

[0029] The utility model provides an electric knife electrocoagulation output drive circuit, please refer to Figure 1 , including MCU square wave signal drive circuit, MOS pipe drive circuit, MOS pipe inverter circuit and alternating -current boost oscillation circuit;The output of MCU square wave signal drive circuit is connected with the input of MOS pipe drive circuit, the output of MOS pipe drive circuit is connected with the input of MOS pipe inverter circuit, the output of MOS pipe inverter circuit is connected with the input of alternating -current boost oscillation circuit, specifically:

[0030] Please refer to Figure 2 , MCU square wave signal drive circuit includes two pull-up resistors, amplifier IC101, logic gate IC102, VCC (5v) and VDD (15v). The MCU sends a drive signal VMCU, which is connected to VCC through a pull-up resistor. The input of the amplifier IC101 is connected to the VMCU signal, and the output of the amplifier IC101 is connected to VDD through a pull-up resistor. The input of the logic gate IC102 is connected to the output of the amplifier IC101.

[0031] Please refer to Figure 3 (in the dashed box), MOS tube drive circuit includes drive chip IC1, drive chip IC2, multi-channel drive amplifier IC3 (including channel I IC3A ~ channel VI IC3F), MOS tube I Q1, MOS tube II Q2, MOS tube III Q3, MOS tube IV Q4, transformer I T1 and transformer II T2. The output of the drive chip IC1 and the output of the drive chip IC2 are connected to the input of the multi-channel drive amplifier IC3, respectively. The output of the multi-channel drive amplifier IC3 is connected to the input of the MOS tube I Q1 and the input of the MOS tube II Q2, respectively. The MOS tube I Q1 is located on the high side of the primary side of the transformer I T1. The MOS tube II Q2 is located on the high side of the primary side of the transformer II T2. The MOS tube III Q3 is located on the low side of the primary side of the transformer I T1. The MOS tube IV Q4 is located on the low side of the primary side of the transformer II T2. Among them, there are resistance I R1, capacitance I C1 connected with drive chip IC1, resistance II R2, capacitance II C2 connected with drive chip IC2, resistance III R3, diode I D1 connected with MOS tube I Q1, resistance IV R4, diode II D2 connected with MOS tube II Q2.

[0032] MOS tube inverter circuit includes inverter unit and resistance-capacitance absorption unit. Please refer to Figure 4 (in the dashed box), the inverter unit includes MOS tube V Q5, MOS tube VI Q6, input connector J1 and output connector J2; MOS tube V Q5 is located on the secondary side of the transformer T1, and MOS tube VI Q6 is located on the secondary side of the transformer II T2. Please refer to Figure 5 (in the dashed box), the resistance-capacitance absorption unit includes intermediate connector J3, resistance IV R11, capacitance III C3, capacitance IV C4 and diode III D11; the output connector J2 in the inverter unit is connected to the intermediate connector J3 in the resistance-capacitance absorption unit. Resistance IV R11 and capacitance III C3 constitute an RC absorption circuit, and capacitance IV C4 and diode III D11 constitute a clamping circuit.

[0033] Please refer to Figure 6The AC voltage boosting oscillation circuit includes transformer III T3, capacitor V C5, capacitor VI C6 and external output connector J4; transformer III T3 is a voltage boosting transformer, the primary winding of transformer III T3 is connected to the output end of the clamping circuit, the secondary winding of transformer III T3 is connected to capacitor V C5 and capacitor VI C6, capacitor V C5 and capacitor VI C6 are connected to external output connector J4, and the secondary winding of transformer III T3 (as an inductor), capacitor V C5, capacitor VI C6 and external output connector J4 (as an external resistor) jointly form an LRC oscillation circuit.

[0034] Based on the above structure, the working process of the embodiment is as follows:

[0035] The MCU sends out a square wave driving signal V MCU, which is input into the MCU square wave signal driving circuit, and is driven by the amplifier IC101 and the logic gate IC102, so that the driving signal V MCU has the ability to drive the MOS tube driving circuit. After the driving signal V MCU reaches the MOS tube driving circuit, it is first expanded in pulse width by the driving chip IC1 and the driving chip IC2, and the resistor I R1, the capacitor I C1 and the resistor II R2 and the capacitor II C2 form delay circuits to determine the delay constants of the driving chip IC1 and the driving chip IC2. Then, the multi-channel driving amplifier IC3 amplifies and converts the level of the driving signal V MCU, so that it becomes a signal with sufficient driving ability and suitable for driving the MOS tube. Under the driving action of the driving signal V MCU:

[0036] When the MOS tube I Q1 is turned on, the current flows from VDD through the primary side coil of transformer I T1, and then reaches the ground GND through the MOS tube I Q1. At this time, since there is current flowing through the primary side of transformer I T1, the secondary side of transformer I T1 induces a voltage, so that Q5 is turned on and Q3 is turned off. When the MOS tube I Q1 is turned off, the current of the primary side of transformer I T1 gradually decreases and is consumed by resistor III R3 and diode I D1. At this time, MOS tube III Q3 is turned on to provide a low impedance path to release the energy stored in the primary side of transformer I T1, and MOS tube V Q5 is turned off. When the MOS tube II Q2 is turned on, the current flows from VDD through the primary side coil of transformer II T2, and then reaches the ground GND through the MOS tube II Q2. At this time, since there is current flowing through the primary side of transformer II T2, the secondary side of transformer II T2 induces a voltage, so that MOS tube VI Q6 is turned on and MOS tube IV Q4 is turned off. When the MOS tube II Q2 is turned off, the current of the primary side of transformer II T2 gradually decreases and is consumed by resistor IV R4 and diode II D2. At this time, MOS tube IV Q4 is turned on to provide a low impedance path to release the energy stored in the primary side of transformer II T2, and MOS tube VI Q6 is turned off.

[0037] Through the above-mentioned four MOS tubes of the alternate conduction and cut-off, the alternating current can be generated in the primary side of the two transformers, and through the electromagnetic coupling of the transformer, the alternating voltage can be induced in the secondary side, and then the DC can be inverted into AC; the input connector J1 is used for inputting 0-500v adjustable DC, and the AC obtained by inversion is output by the output connector J2. When the AC reaches the intermediate connector J3 and then reaches the RC absorption unit from the output connector J2, the RC absorption circuit and the clamping circuit absorb and suppress the voltage peak generated when the MOS tube switch. Then the AC reaches the AC boost oscillation circuit, the transformer III T3 boosts the input AC, and the boosted AC is output to the capacitor V C5 and the capacitor VI C6 through the secondary winding of the transformer III T3, and finally the stable AC is output by the external output connector J4.

[0038] In summary, the driving circuit provided by the embodiment can effectively absorb and suppress the voltage peak generated in the MOS tube switching process on the basis of realizing the inversion of DC to AC, and can effectively protect the MOS tube from being broken down, thereby meeting the demand for long-term stable and reliable operation of the high-frequency electrotome.

[0039] It should be particularly pointed out that the parts not described in detail or expanded in the above-mentioned scheme are all prior art, do not belong to the improvement of the prior art by the present application, and do not belong to the protection range of the technical scheme of the present application, therefore, this paper will not be described.

[0040] Of course, the above-mentioned content is only the preferred embodiment of the present application, and cannot be considered as limiting the scope of the embodiment of the present application. The present application is also not limited to the above examples, and the equivalent changes and improvements made by the ordinary skilled in the art within the essential scope of the present application should be attributed to the patent coverage range of the present application.

Claims

1. An electrosurgical output drive circuit for improving power transistor breakdown, characterized in that: The application relates to a driving circuit for a high-voltage inverter, which comprises an MCU square wave signal driving circuit, a MOS tube driving circuit, a MOS tube inverter circuit and an alternating-current voltage-boosting oscillation circuit; the output end of the MCU square wave signal driving circuit is connected with the input end of the MOS tube driving circuit; the output end of the MOS tube driving circuit is connected with the input end of the MOS tube inverter circuit; the output end of the MOS tube inverter circuit is connected with the input end of the alternating-current voltage-boosting oscillation circuit; the MOS tube inverter circuit comprises an inverter unit and a resistance-capacitance absorption unit.

2. The electrosurgical coagulation output driving circuit capable of improving power tube breakdown according to claim 1, wherein: The MCU square wave signal driving circuit comprises two pull-up resistors, an amplifier and a logic gate; the input end of the amplifier is connected with the signal output by an MCU; the output end of the amplifier is connected with the input end of the logic gate.

3. The electrosurgical coagulation output driving circuit capable of improving power tube breakdown according to claim 1 or 2, characterized in that: The MOS tube driving circuit comprises two driving chips, a multi-channel driving amplifier, four MOS tubes and two transformers; the output ends of the two driving chips are respectively connected with the input ends of the multi-channel driving amplifier; the output ends of the multi-channel driving amplifier are respectively connected with the input ends of the two MOS tubes, wherein the two MOS tubes are respectively located at the high side of the primary side of the two transformers; the other two MOS tubes are respectively located at the low side of the primary side of the two transformers.

4. The electrosurgical coagulation output driving circuit capable of improving power tube breakdown according to claim 3, wherein: The inverter unit comprises two MOS tubes, an input connector and an output connector; the two MOS tubes in the inverter unit are respectively located at the secondary side of the two transformers in the MOS tube driving circuit.

5. The electrosurgical coagulation output driving circuit capable of improving power tube breakdown of claim 4, wherein: The resistance-capacitance absorption unit comprises an intermediate connector, a resistor, two capacitors and a diode; the intermediate connector is connected with the output connector in the inverter unit; the resistor and one of the capacitors form an RC absorption circuit; the diode and the other capacitor form a clamping circuit.

6. The electrosurgical coagulation output driving circuit capable of improving power tube breakdown of claim 5, wherein: The alternating-current voltage-boosting oscillation circuit comprises a transformer, two capacitors and an output connector; the primary winding of the transformer in the alternating-current voltage-boosting oscillation circuit is connected with the output end of the clamping circuit; the secondary winding of the transformer in the alternating-current voltage-boosting oscillation circuit is connected with the two capacitors in the alternating-current voltage-boosting oscillation circuit; the two capacitors in the alternating-current voltage-boosting oscillation circuit are connected with the output connector in the alternating-current voltage-boosting oscillation circuit.

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