Corona discharge circuit for ion mobility spectrometry and ion mobility spectrometry equipment

Abstract

The utility model relates to the technical field of ion mobility spectrometry, and discloses a corona discharge circuit for ion mobility spectrometry and ion mobility spectrometry equipment, the circuit comprises a power supply circuit, a single-chip microcomputer, a waveform generation circuit, a drive circuit and a transformer circuit, the power supply circuit is respectively connected with the single-chip microcomputer, the waveform generation circuit and the drive circuit; the input end of the single-chip microcomputer is connected with an upper computer, the output end of the single-chip microcomputer is connected with the input end of the waveform generation circuit, the output end of the waveform generation circuit is connected with the input end of the drive circuit, the output end of the drive circuit is connected with the input end of the transformer circuit, and the output end of the transformer circuit is connected with a corona needle and a corona needle aiming electrode. By generating the bipolar ionization source, a set of electrodes can generate positive and negative ions at the same time, and the ionization diversity and efficiency are greatly improved, so that more types of ion information can be captured, and ion components in a sample can be analyzed more comprehensively.

Description

TECHNICAL FIELD

[0001] The utility model relates to ion mobility spectrum technical field, concretely relates to a kind of for ion mobility spectrum's corona discharge circuit and ion mobility spectrum equipment. BACKGROUND

[0002] Now ion mobility spectrum (IMS) adopts corona discharge ion source and is divided into direct current corona discharge and pulse corona discharge two kinds, they can only produce single polarity ion. Under the action of direct current voltage, negative polarity corona or positive polarity corona is gathered in the space charge near tip electrode. In negative polarity corona, when electron causes collision ionization, electron is driven to the space far from tip electrode, and forms negative ion, and positive ion is gathered in the place close to electrode surface, and the ion produced here can react with sample, and vice versa.

[0003] Since single polarity ion source can only produce single polarity ion (positive ion or negative ion), it cannot capture all ion species possibly existing in sample in the same time. In complex sample analysis, this limitation is particularly obvious, because sample often contains positive and negative ions simultaneously, and single polarity ion source cannot comprehensively reflect the existence and distribution of these ions, so that it can cause one-sidedness of analysis result. SUMMARY

[0004] Therefore, the utility model provides a kind of for ion mobility spectrum's corona discharge circuit and ion mobility spectrum equipment to solve the problem that single polarity ion source can only produce single polarity ion, cannot capture all ion species possibly existing in sample in the same time, so that it can cause one-sidedness of analysis result.

[0005] First, the utility model provides a kind of for ion mobility spectrum's corona discharge circuit, and the circuit includes: power supply circuit, single-chip microcomputer, waveform generation circuit, drive circuit and transformer circuit, wherein,

[0006] The power supply circuit is connected with the single-chip microcomputer, the waveform generation circuit and the drive circuit respectively;

[0007] The input end of the single-chip microcomputer is connected with host computer, the output end of the single-chip microcomputer is connected with the input end of the waveform generation circuit, the output end of the waveform generation circuit is connected with the input end of the drive circuit, the output end of the drive circuit is connected with the input end of the transformer circuit, and the output end of the transformer circuit is connected with corona needle and corona needle counter electrode.

[0008] The corona discharge circuit for ion mobility spectrum provided by the utility model can generate bipolar ionization source, so that positive and negative ions are generated simultaneously by one set of electrodes, the diversity and efficiency of ionization are greatly improved, more kinds of ion information can be captured, and ion components in samples can be comprehensively analyzed.

[0009] In an alternative embodiment, the waveform generating circuit comprises a programmable waveform generator and a crystal oscillator, wherein,

[0010] The power input pin of the programmable waveform generator is connected with the power supply circuit, the signal input pin of the programmable waveform generator is connected with the single-chip microcomputer, the clock input pin of the programmable waveform generator is connected with the crystal oscillator, and the output pin of the programmable waveform generator is connected with the input end of the driving circuit.

[0011] In an alternative embodiment, the driving circuit comprises a driving chip, a first transistor, a second transistor, a first capacitor and a diode, wherein,

[0012] The power input pin of the driving chip is connected with the power supply circuit, the control signal input pin of the driving chip is connected with the output pin of the programmable waveform generator, the first output pin of the driving chip is connected with the control end of the first transistor, the second output pin of the driving chip is connected with the control end of the second transistor, the high-end floating power pin of the driving chip is connected with the cathode of the diode and one end of the first capacitor respectively, and the anode of the diode is connected with the power supply circuit.

[0013] The first end of the first transistor is connected with an external power supply, the second end of the first transistor is connected with the first end of the second transistor, the high-end floating ground end of the driving chip, the other end of the first capacitor and the input end of the transformer circuit respectively, and the second end of the second transistor is grounded.

[0014] In an alternative embodiment, the transformer circuit comprises a second capacitor, a third capacitor and a transformer, wherein,

[0015] The first input end of the transformer is connected with one end of the second capacitor and one end of the third capacitor respectively, the second input end of the transformer is grounded, the first output end of the transformer is connected with a corona needle, and the second output end of the transformer is connected with a corona needle counter electrode.

[0016] The other ends of the second capacitor and the third capacitor are connected between the second end of the first transistor and the first end of the second transistor.

[0017] In an alternative embodiment, the power supply circuit comprises: a voltage reduction circuit and a voltage stabilizing circuit, wherein,

[0018] The input end of the voltage reduction circuit is connected with an external power supply, the output end of the voltage reduction circuit is connected with the input end of the voltage stabilizing circuit, and the output end of the voltage stabilizing circuit is connected with the single-chip microcomputer, the waveform generating circuit and the driving circuit respectively.

[0019] In an alternative embodiment, the voltage reduction circuit comprises: a voltage reduction chip, a digital potentiometer, a first resistor and a second resistor, wherein,

[0020] The power supply input pin of the voltage reduction chip is connected with an external power supply, the switch pin of the voltage reduction chip is connected with one end of the first resistor and the input end of the voltage stabilizing circuit respectively, and the feedback pin of the voltage reduction chip is connected with the other end of the first resistor and one end of the second resistor respectively.

[0021] The input pin of the digital potentiometer is connected with the single-chip microcomputer, and the output pin of the digital potentiometer is connected with the other end of the second resistor.

[0022] In an alternative embodiment, the voltage stabilizing circuit comprises: a linear voltage stabilizer, a first inductor, a second inductor and a fourth capacitor, wherein,

[0023] The input pin of the linear voltage stabilizer is connected with the switch pin of the voltage reduction chip, and the output pin of the linear voltage stabilizer is connected with one end of the first inductor and the power supply input pin of the driving chip respectively.

[0024] The other end of the first inductor is connected with the power supply input pin of the single-chip microcomputer, the power supply input pin of the programmable waveform generator, the power supply input pin of the crystal oscillator and one end of the fourth capacitor respectively, and the other end of the fourth capacitor is connected with the ground pin of the linear voltage stabilizer through the second inductor.

[0025] In the second aspect, the utility model provides a kind of ion mobility spectrometry equipment, including the corona discharge circuit for ion mobility spectrometry of above-mentioned first aspect or any alternative implementation thereof.

[0026] The ion mobility spectrometry equipment provided by the utility model has a relatively simple design of the corona discharge circuit for ion mobility spectrometry, and can realize an efficient ionization process in a small space. Therefore, when the corona discharge circuit for ion mobility spectrometry in the above embodiment is applied to the ion mobility spectrometry equipment, the overall size of the ion mobility spectrometry equipment can be reduced, making the ion mobility spectrometry equipment more portable and easy to detect quickly in different situations. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the description of the specific embodiments or the prior art. Obviously, the drawings described below are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0028] Figure 1 is a principle block diagram of a corona discharge circuit for ion mobility spectrometry according to an embodiment of the present application;

[0029] Figure 2 is another principle block diagram of a corona discharge circuit for ion mobility spectrometry according to an embodiment of the present application;

[0030] Figure 3 is a schematic diagram of a voltage reduction circuit according to an embodiment of the present application;

[0031] Figure 4 is a schematic diagram of a voltage stabilizing circuit according to an embodiment of the present application;

[0032] Figure 5 is a schematic diagram of a waveform generating circuit according to an embodiment of the present application;

[0033] Figure 6 is a schematic diagram of a single-chip microcomputer according to an embodiment of the present application;

[0034] Figure 7 is a schematic diagram of a driving circuit according to an embodiment of the present application;

[0035] Figure 8 is a schematic diagram of a transformer circuit according to an embodiment of the present application. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0037] In the description of the present application, it should be noted that the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0038] In the description of the utility model, it is necessary to explain that, unless there is definite stipulation and limitation, the terms "mounting", "connecting", "connection" should be understood in a broad sense, for example, it can be fixed connection, or it can be detachable connection, or it can be integrally connected, it can be mechanical connection, or it can be electrical connection, it can be directly connected, or it can be indirectly connected through intermediate medium, it can be the communication between two elements, it can be wireless connection, or it can be wired connection, for ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0039] In addition, the technical features involved in the different embodiments of the utility model described below can be combined with each other as long as there is no conflict.

[0040] The utility model provides a kind of for ion mobility spectrum corona discharge circuit, by generating bipolar ionization source, make a set of electrode simultaneously produce positive and negative ions, enhance the ionization diversity and efficiency, reach the purpose of comprehensive analysis sample ion composition. Figure 1 As shown in the figure, the corona discharge circuit for ion mobility spectrum includes: power supply circuit, single-chip microcomputer, waveform generating circuit, drive circuit and transformer circuit.

[0041] Among them, power supply circuit is connected with single-chip microcomputer, waveform generating circuit and drive circuit respectively.The input end of single-chip microcomputer is connected with host computer, the output end of single-chip microcomputer is connected with the input end of waveform generating circuit, the output end of waveform generating circuit is connected with the input end of drive circuit, the output end of drive circuit is connected with the input end of transformer circuit, the output end of transformer circuit is connected with corona needle and corona needle electrode.Corona needle and corona needle electrode are not shown in the figure. Figure 1

[0042] Specifically, first, in order to circuit can work, need a 24V power supply, 24V power supply is converted into 5V power supply for single-chip microcomputer, waveform generating circuit and drive circuit power supply after power supply circuit processing.Perfect power supply loop, single-chip microcomputer receives the waveform file issued by host computer, and then transmits the waveform file to waveform generating circuit, so that waveform generating circuit generates a 5V amplitude square wave.Waveform generating circuit transmits square wave to drive circuit, so that drive circuit outputs a square wave with amplitude Vo.Amplitude Vo square wave is converted into high-voltage alternating current signal by transformer circuit.The two ends of alternating current high voltage are respectively connected with corona needle and corona needle electrode, and the electrons near the needle tip will be ionized into the positive and negative ions required for detection.The Vo voltage range is controlled at about 7-11V.

[0043] ​The utility model provides a kind of for ion mobility spectrum's corona discharge circuit, by generating bipolar ionization source, make a set of electrode simultaneously produce positive and negative ions, greatly improve the diversity and efficiency of ionization, so that more kinds of ion information can be captured, so that the ion composition in sample can be more comprehensive analysis.The interaction of positive and negative ions also helps to balance the charge distribution in electric field, reduce the discharge instability caused by charge accumulation, so as to ensure the stability and reliability of ionization process.In addition, from the angle of environmental protection and energy saving, bipolar ionization source also has certain advantages.In some cases, it can help to reduce harmful by-products generated during ionization, such as ozone and nitrogen oxides, etc.This is because the interaction of positive and negative ions can promote the progress of certain chemical reactions, thereby reducing the generation of harmful substances.At the same time, by optimizing the ionization process and controlling ionization parameters, AC corona ionization source can also have higher energy utilization efficiency, reduce energy consumption and operating cost.

[0044] In an alternative embodiment, as shown in Figure 2 The power supply circuit includes a step-down circuit and a voltage stabilizing circuit. The input end of the step-down circuit is connected to an external power supply, the output end of the step-down circuit is connected to the input end of the voltage stabilizing circuit, and the output end of the voltage stabilizing circuit is connected to the single-chip microcomputer, the waveform generating circuit, and the driving circuit.

[0045] Specifically, as shown in Figure 3 The step-down circuit includes a step-down chip U1, a digital potentiometer U2, a first resistor R1, and a second resistor R2. The power supply input pin of the step-down chip U1 is connected to a 24V power supply, the switch pin of the step-down chip U1 is connected to one end of the first resistor R1 and the input end of the voltage stabilizing circuit, and the feedback pin of the step-down chip U1 is connected to the other end of the first resistor R1 and one end of the second resistor R2. The input pin of the digital potentiometer U2 is connected to the single-chip microcomputer, and the output pin of the digital potentiometer U2 is connected to the other end of the second resistor R2.

[0046] As shown in Figure 4 The voltage stabilizing circuit includes a linear voltage stabilizer U3, a first inductor L2, a second inductor L3, and a fourth capacitor C31. The input pin of the linear voltage stabilizer U3 is connected to the switch pin of the step-down chip U1, and the output pin of the linear voltage stabilizer U3 is connected to one end of the first inductor L2 and the power supply input pin of the driving chip. The other end of the first inductor L2 is connected to the power supply input pin of the single-chip microcomputer, the power supply input pin of the programmable waveform generator, the power supply input pin of the crystal oscillator, and one end of the fourth capacitor C31, and the other end of the fourth capacitor C31 is connected to the ground pin of the linear voltage stabilizer U3 through the second inductor L3.

[0047] In the embodiment of the utility model, 24V power supply passes through a DC-DC step-down chip U1, the feedback pin of step-down chip U1 chip is connected with two feedback resistors respectively, and output voltage is adjusted through feedback resistor. This circuit uses digital potentiometer U2 in series with feedback resistor, and the resistance of digital potentiometer U2 is adjusted through external I2C communication, so as to change the resistance of feedback resistor, thereby making the output Vo voltage range control in 7-11V or so. Voltage Vo is converted into 5V through linear voltage regulator U3, and the voltage is converted into 5V to supply power for single-chip microcomputer, waveform generating circuit and driving circuit. Among them, the voltage at +5VA node supplies power for driving chip, and the voltage at +5VD node supplies power for single-chip microcomputer, programmable waveform generator and crystal oscillator. In addition, the model of step-down chip U1 is TPS54202. The model of digital potentiometer U2 is TPL0404A-10DC. The model of linear voltage regulator U3 is LM78M05.

[0048] In an alternative embodiment, as shown in Figure 5 The waveform generating circuit includes a programmable waveform generator U7 and a crystal oscillator X1. Among them, the power input pin of programmable waveform generator U7 is connected with power supply circuit, the signal input pin of programmable waveform generator U7 is connected with single-chip microcomputer U6, the clock input pin of programmable waveform generator U7 is connected with crystal oscillator X1, and the output pin of programmable waveform generator U7 is connected with the input end of driving circuit.

[0049] Specifically, the function of single-chip microcomputer U6 is to input program to programmable waveform generator U7. As shown in Figure 5 And Figure 6 The 2 / 3 / 4 pins of single-chip microcomputer U6 are connected with the 7 / 6 / 8 pins of programmable waveform generator U7, and waveform file is transmitted through I2C communication mode. The waveform file is uploaded to single-chip microcomputer U6 before the corona discharge circuit for ion mobility spectrometry is used, and then transmitted to programmable waveform generator U7 by single-chip microcomputer U6, so that programmable waveform generator U7 generates a square wave with a frequency of 24KHZ and an amplitude of 5V, as shown in Figure 5 Among them, the model of programmable waveform generator U7 is AD9833. The model of single-chip microcomputer U6 is CH552G.

[0050] In an alternative embodiment, as shown in Figure 7As shown, the driving circuit comprises a driving chip U5, a first transistor Q1, a second transistor Q2, a first capacitor C9 and a diode D2. The power input pin of the driving chip U5 is connected with the power circuit, the control signal input pin of the driving chip U5 is connected with the output pin of the programmable waveform generator U7, the first output pin of the driving chip U5 is connected with the control end of the first transistor Q1, the second output pin of the driving chip U5 is connected with the control end of the second transistor Q2, the high-end floating power pin of the driving chip U5 is connected with the cathode of the diode D2 and one end of the first capacitor C9 respectively, and the anode of the diode D2 is connected with the power circuit. The first end of the first transistor Q1 is connected with the external power supply, the second end of the first transistor Q1 is connected with the first end of the second transistor Q2, the high-end floating ground end of the driving chip U5, the other end of the first capacitor C9 and the input end of the transformer circuit respectively, and the second end of the second transistor Q2 is grounded.

[0051] Specifically, the waveform generation circuit delivers a square wave with a frequency of 24KHZ and an amplitude of 5V to the driving circuit. The driving chip U5 and the two transistors on the right side form a half-bridge driving circuit. The +5V square wave signal is output by the half-bridge driving circuit as a square wave with an amplitude of Vo. The first transistor Q1 and the second transistor Q2 are MOS tubes, and the model number is AP68N06.

[0052] In an alternative embodiment, as shown in Figure 8 As shown, the transformer circuit comprises a second capacitor C11, a third capacitor C12 and a transformer T1. The first input end of the transformer T1 is connected with one end of the second capacitor C11 and one end of the third capacitor C12 respectively, the second input end of the transformer T1 is grounded, the first output end of the transformer T1 is connected with the corona needle, and the second output end of the transformer T1 is connected with the corona needle counter electrode. The other ends of the second capacitor C11 and the third capacitor C12 are connected between the second end of the first transistor Q1 and the first end of the second transistor Q2.

[0053] Specifically, the square wave output by the driving circuit is converted into symmetrical positive and negative square waves through a set of DC blocking capacitors C11 and C12, and then converted into high-voltage alternating current signals HV_A and HV_B through the transformer T1. The voltage difference between HV_A and HV_B is positively correlated with Vo, and the peak-to-peak value can be controlled at about 1.3KV to 2.6KV by adjusting the digital potentiometer U2. The high-voltage alternating current signals HV_A and HV_B are respectively connected with the corona needle and the corona needle counter electrode, and the electrons near the needle tip are ionized by high voltage to form the positive and negative ions required for detection.

[0054] The utility model provides a kind of ion mobility spectrometry equipment, including the corona discharge circuit for ion mobility spectrometry in above-mentioned embodiment.

[0055] Specifically, since the corona discharge circuit design for ion mobility spectrometry is relatively simple, an efficient ionization process can be achieved in a small space.

[0056] Although the embodiments of the present application are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the appended claims.

Claims

1. A corona discharge circuit for ion mobility spectrometry, characterized in that The circuit includes: a power supply circuit, a single chip microcomputer, a waveform generation circuit, a drive circuit and a transformer circuit, wherein: The power supply circuit is respectively connected to the single chip microcomputer, the waveform generating circuit and the driving circuit; The input end of the single-chip microcomputer is connected to the host computer, the output end of the single-chip microcomputer is connected to the input end of the waveform generating circuit, the output end of the waveform generating circuit is connected to the input end of the driving circuit, the output end of the driving circuit is connected to the input end of the transformer circuit, and the output end of the transformer circuit is connected to the corona needle and the corona needle-to-electrode.

2. The corona discharge circuit for ion mobility spectrometry according to claim 1, wherein The waveform generating circuit includes: a programmable waveform generator and a crystal oscillator, wherein: The power input pin of the programmable waveform generator is connected to the power supply circuit, the signal input pin of the programmable waveform generator is connected to the single-chip microcomputer, the clock input pin of the programmable waveform generator is connected to the crystal oscillator, and the output pin of the programmable waveform generator is connected to the input end of the driving circuit.

3. The corona discharge circuit for ion mobility spectrometry according to claim 2, characterized in that The driving circuit includes: a driving chip, a first transistor, a second transistor, a first capacitor and a diode, wherein: The power input pin of the driver chip is connected to the power circuit, the control signal input pin of the driver chip is connected to the output pin of the programmable waveform generator, the first output pin of the driver chip is connected to the control end of the first transistor, the second output pin of the driver chip is connected to the control end of the second transistor, the high-end floating power pin of the driver chip is respectively connected to the cathode of the diode and one end of the first capacitor, and the anode of the diode is connected to the power circuit; The first end of the first transistor is connected to an external power supply, the second end of the first transistor is respectively connected to the first end of the second transistor, the high-end floating ground end of the driver chip, the other end of the first capacitor and the input end of the transformer circuit, and the second end of the second transistor is grounded.

4. The corona discharge circuit for ion mobility spectrometry according to claim 3, characterized in that The transformer circuit includes: a second capacitor, a third capacitor and a transformer, wherein: The first input end of the transformer is connected to one end of the second capacitor and one end of the third capacitor respectively, the second input end of the transformer is grounded, the first output end of the transformer is connected to the corona needle, and the second output end of the transformer is connected to the corona needle electrode; The other ends of the second capacitor and the third capacitor are connected between the second end of the first transistor and the first end of the second transistor.

5. The corona discharge circuit for ion mobility spectrometry according to claim 4, characterized in that: The power supply circuit includes: a step-down circuit and a voltage stabilizing circuit, wherein: The input end of the step-down circuit is connected to an external power supply, the output end of the step-down circuit is connected to the input end of the voltage stabilizing circuit, and the output end of the voltage stabilizing circuit is respectively connected to the single chip microcomputer, the waveform generating circuit and the driving circuit.

6. The corona discharge circuit for ion mobility spectrometry according to claim 5, characterized in that: The step-down circuit includes: a step-down chip, a digital potentiometer, a first resistor and a second resistor, wherein: The power input pin of the step-down chip is connected to an external power supply, the switch pin of the step-down chip is connected to one end of the first resistor and the input end of the voltage stabilizing circuit respectively, and the feedback pin of the step-down chip is connected to the other end of the first resistor and one end of the second resistor respectively; The input pin of the digital potentiometer is connected to the single chip microcomputer, and the output pin of the digital potentiometer is connected to the other end of the second resistor.

7. The corona discharge circuit for ion mobility spectrometry according to claim 6, characterized in that: The voltage stabilizing circuit includes: a linear voltage stabilizer, a first inductor, a second inductor and a fourth capacitor, wherein: The input pin of the linear regulator is connected to the switch pin of the buck chip, and the output pin of the linear regulator is connected to one end of the first inductor and the power input pin of the driver chip respectively; The other end of the first inductor is respectively connected to the power input pin of the microcontroller, the power input pin of the programmable waveform generator, the power input pin of the crystal oscillator and one end of the fourth capacitor, and the other end of the fourth capacitor is connected to the ground pin of the linear regulator through the second inductor.

8. An ion mobility spectrometry device, characterized in that The invention comprises a corona discharge circuit for ion mobility spectrometry according to any one of claims 1 to 7.

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