Pulse generating circuit, pulse generator, time-of-flight mass spectrometer and electronic device

Abstract

The present invention provides a pulse generating circuit, a pulse generator, a time-of-flight mass spectrometer and an electronic device, the circuit comprising: a first direct current power supply, which is connected to a switch control module through a series high-voltage resistor and an energy storage module, the switch control module comprising a switch tube and a plurality of switches; a pulse driving module, connected to the switch tube, for generating a spike signal with alternating positive and negative polarities to turn on or off the switch tube; a plurality of photoelectric trigger modules, correspondingly connected to the switches, for generating a trigger signal for controlling the switch to open or close; a pulse output module, connected to the switch control module, for forming a positive pulse output circuit or a negative pulse output circuit according to the opening or closing of a plurality of the switches when the switch tube is turned on, and using the output circuit to generate a positive pulse signal or / and a negative pulse signal. Compared with a traditional high-voltage switch, it does not require heating power or a complex driving circuit, and also has the advantages of very short recovery time and low jitter.

Description

Technical Field

[0001] The present invention relates to the technical field of mass spectrometry analysis, and in particular to a pulse generating circuit, a pulse generator, a time-of-flight mass spectrometer and electronic equipment. Background Art

[0002] Matrix-assisted laser decomposition ion source means that in a tiny area, at a very short time interval, the laser provides high energy to the sample and heats them very quickly, which can avoid the decomposition of heat-sensitive compounds. The matrix molecules can effectively absorb the energy of the laser and indirectly transfer it to the sample molecules to be ionized. Since the process of laser bombardment of the sample is completed in an extremely short time, a high-voltage electric field and a nanosecond-level mutation electric field are required to cooperate with the laser pulse, so that the ionized ions can leave the sample plate after laser bombardment, delay in the high-voltage electric field, and quickly accelerate in the nanosecond-level mutation electric field, and then be transmitted to the mass analyzer. Such a high-voltage mutation electric field requires a very fast pulse circuit switching and a high-voltage power supply.

[0003] When a mass spectrometer analyzes different charged particles, a pulse generating circuit needs to use pulse signals of different polarities. However, existing pulse generating circuits can only generate pulse signals of a single polarity and cannot generate positive ions and / or negative ions required for sample ionization detection. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a pulse generating circuit, a pulse generator, a time-of-flight mass spectrometer and an electronic device, so as to solve the problem that the pulse generating circuit in the prior art can only generate a unipolar pulse signal.

[0005] To achieve the above-mentioned object and other related objects, the present invention provides a pulse generating circuit, comprising:

[0006] A first DC power supply is connected to a switch control module via a series high-voltage resistor, an energy storage module, and the switch control module includes at least one switch tube and a plurality of switches;

[0007] A pulse driving module, connected to the switch tube, for generating a spike signal with alternating positive and negative polarities to turn on or off the switch tube;

[0008] A plurality of photoelectric trigger modules, connected to the switches correspondingly, for generating trigger signals for controlling the switches to open or close;

[0009] The pulse output module is connected to the switch control module and is used to form a positive pulse output circuit or a negative pulse output circuit according to the opening or closing of multiple switches when the switch tube is turned on, and use the output circuit to generate a positive pulse signal and / or a negative pulse signal.

[0010] Another object of the present invention is to provide a pulse generator, comprising: the above-mentioned pulse generating circuit and a high-voltage synthesis circuit, wherein the high-voltage synthesis circuit is connected to the pulse generating circuit to output a high-voltage positive pulse signal and / or a high-voltage negative pulse signal.

[0011] Another object of the present invention is to provide a time-of-flight mass spectrometer, comprising: the above-mentioned pulse generator.

[0012] Another object of the present invention is to provide an electronic device, comprising: the above-mentioned pulse generating circuit, or the above-mentioned pulse generator, or the above-mentioned time-of-flight mass spectrometer.

[0013] As described above, the pulse generating circuit, pulse generator, time-of-flight mass spectrometer and electronic device of the present invention have the following beneficial effects:

[0014] By controlling the states of different switches in the switch control module, a positive pulse output circuit or a negative pulse output circuit is formed in different closed and open states of the switch, thereby generating a positive pulse signal or a negative pulse signal. Compared with traditional high-voltage switches, the present invention does not require heating power or complex driving circuits and has the advantages of very short recovery time and low jitter. At the same time, the present invention is simple to control and the circuit structure is more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Shown is a structural block diagram of a pulse generating circuit provided by the present invention;

[0016] Figure 2 A circuit diagram showing an embodiment of a pulse generating circuit provided by the present invention;

[0017] Figure 3 A circuit diagram showing an embodiment of a pulse generating circuit providing a positive pulse signal according to the present invention;

[0018] Figure 4 A circuit diagram showing an embodiment of a pulse generating circuit providing a negative pulse signal according to the present invention;

[0019] Figure 5 Shown is a circuit diagram of a photoelectric trigger module in a pulse generating circuit provided by the present invention;

[0020] Figure 6 Shown is a circuit diagram of a pulse driving module in a pulse generating circuit provided by the present invention;

[0021] Figure 7 Shown is a circuit diagram of a high voltage synthesis circuit provided by the present invention. DETAILED DESCRIPTION

[0022] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0023] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0024] The term "pulse generator" refers to a device suitable for applying voltage to electrodes of an accelerator. A pulse generator typically includes multiple voltage sources (eg, high voltage sources) and switches (eg, high speed (rise time less than 1 ms) / high voltage switches).

[0025] See also Figure 1 , is a structural block diagram of a pulse generating circuit provided by the present invention, comprising:

[0026] A first DC power supply 5, which is connected to a switch control module 2 via a series high-voltage resistor and an energy storage module, wherein the switch control module 2 includes at least one switch tube 21 and a plurality of switches 22;

[0027] The pulse driving module 1 is connected to the switch tube 21 and is used to generate a spike signal with alternating positive and negative polarities to turn on or off the switch tube;

[0028] A plurality of photoelectric trigger modules 3, correspondingly connected to the switch 22, for generating a trigger signal for controlling the switch to open or close;

[0029] The pulse output module 4 is connected to the switch control module 2 and is used to form a positive pulse output circuit or a negative pulse output circuit according to the opening or closing of multiple switches when the switch tube is turned on, and use the output circuit to generate a positive pulse signal and / or a negative pulse signal.

[0030] Specifically, the number of the switching tubes is preferably one. Reducing the number of switching tubes also reduces the number of pulse driving modules. The switching tube is driven to be turned on or off by the same pulse driving circuit. When the switching tube is turned on, the states of different switches are controlled to be opened or closed to form a positive pulse output circuit or a negative pulse output circuit respectively. The time when the switches are alternately opened and closed is utilized to output positive pulse signals and / or negative pulse signals. In addition, in this embodiment, the output positive pulse signals and / or negative pulse signals will not affect each other (peak voltage), thereby avoiding the phenomenon of reduced pulse peak voltage caused by the output of bipolar pulse signals.

[0031] The switch control module 2 may include a variety of circuit structures, which are described in detail as follows:

[0032] In the first case, for example, the switch control module 2 includes at least one switch tube, a first switch, a second switch, a third switch and a fourth switch. In the on state of the switch tube, when the first switch and the fourth switch are closed and the second switch and the third switch are disconnected, the first DC power supply forms a positive pulse output circuit through the energy storage module, the fourth switch, the first switch and the load in sequence; in the on state of the switch tube, when the second switch and the third switch are closed and the first switch and the fourth switch are disconnected, the first DC power supply forms a negative pulse output circuit through the second switch and the third switch coupled to the ground by the energy storage module and the load.

[0033] See Figure 2 Compared with the existing bipolar pulse generating circuit, the present embodiment has a simple structure and uses fewer components. For example, the same pulse driving module, the same energy storage module, the same load, and the same series high-voltage resistor are used, which greatly reduces the number of components. Secondly, the present embodiment is simple to control. For example, it only needs to control the switching of the switch. Thirdly, compared with the traditional high-voltage switch, it does not require heating power or complex driving circuits. At the same time, it also has the advantages of very short recovery time and low jitter. The use of the above switch greatly reduces the production cost of the circuit. In addition, the requirements for the ideal degree of component characteristics are relatively low. Under the condition of only using lower device parameters, a rising edge pulse or a falling edge pulse of less than 200nS can be generated, which greatly reduces the object cost and the dependence on device parameters.

[0034] The second situation, for example, is different from the above implementation in that the first switch and the third switch constitute a single-pole double-throw switch, that is, without changing the original function, the single-pole double-throw switch is used to achieve replacement, which reduces the number of switches and further reduces the production cost. The source of the switch tube is connected to an input end of the single-pole double-throw switch and the first end of the third resistor, the drain of the switch tube is connected to the other input end of the single-pole double-throw switch and the second end of the second resistor, and the gate of the switch tube is connected to a pulse driving module. The single-pole double-throw switch determines whether the load outputs a positive pulse signal or / and a negative pulse signal by selecting the input end to be closed.

[0035] In the third case, for example, the control module 2 can also be composed of a switch tube, a first switch and a fourth switch, the drain of the switch tube is connected to one end of the fourth switch and the second end of the second resistor, the other end of the fourth switch and the first end of the second resistor are connected to the energy storage module, the gate of the switch tube is connected to the pulse driving module, the source of the switch tube is connected to one end of the first switch and the first end of the third resistor, and the other end of the first switch outputs a positive pulse signal through the load.

[0036] See Figure 3 , which is a circuit diagram of an embodiment of a pulse generating circuit for generating a positive pulse signal provided by the present invention. In this embodiment, the positive pulse signal can be output stably. Compared with the traditional high-voltage switch, it does not require heating power or complex driving circuits. It also has the advantages of very short recovery time and low jitter. The use of the above switch greatly reduces the production cost of the circuit; the requirements for the ideal degree of component characteristics are low. Under the condition of only using lower device parameters, a rising edge pulse of less than 200nS can be generated, which greatly reduces the object cost and dependence on device parameters.

[0037] In the fourth case, for example, the control module 2 can also be composed of a switch tube, a second switch and a third switch, the source of the switch tube is connected to one end of the second switch and the first end of the third resistor, and the other end of the second switch and the second end of the third resistor are grounded; the drain of the switch tube is connected to one end of the third switch and the second end of the second resistor, the gate of the switch tube is connected to the pulse driving module, and the other end of the third switch outputs a negative pulse signal through the load.

[0038] See Figure 4, which is a circuit diagram of an embodiment of a pulse generating circuit for generating a negative pulse signal provided by the present invention. In this embodiment, the negative pulse signal can be output stably. Compared with the traditional high-voltage switch, it does not require heating power or complex driving circuits. It also has the advantages of very short recovery time and low jitter. The use of the above switch greatly reduces the production cost of the circuit; the requirements for the ideal degree of component characteristics are low. Under the condition of only using lower device parameters, a falling edge pulse of less than 200nS can be generated, which greatly reduces the object cost and dependence on device parameters.

[0039] In other embodiments, in the first case, the switch tube Q1 is an IGBT transistor, and the pulse output module outputs a pulse signal. For example, when the switch tube Q1 is turned on, when the second switch K2 and the third switch K3 are disconnected at the same time and the first switch K1 and the fourth switch K4 are closed at the same time, the DC high voltage passes through the energy storage module, the closed fourth switch K4 and the turned-on switch tube Q1, and the pulse output module generates a positive pulse (rising edge pulse) signal through the first switch K. When the switch tube Q1 is turned on, when the second switch K2 and the third switch K3 are closed at the same time and the first switch K1 and the fourth switch K4 are disconnected, the high voltage signal passing through the energy storage module is coupled to GND through the third switch K3, thereby prompting the pulse output module to generate a negative pulse (pull-down pulse) signal, wherein the amplitude of this pulse is determined by the voltage of PIEHV after energy storage, and the width is determined by the closing time of the switch control module.

[0040] In this embodiment, by controlling the states of different switches in the switch control module, a positive pulse output circuit or a negative pulse output circuit is formed in different closed and open states of the switch, thereby generating a positive pulse signal or a negative pulse signal. Compared with traditional high-voltage switches, the present invention does not require heating power or complex driving circuits, and has the advantages of very short recovery time and low jitter. At the same time, the present invention is simple to control and the circuit structure is more stable.

[0041] See also Figure 2 , is a circuit diagram of an embodiment of a pulse generating circuit provided by the present invention, comprising:

[0042] The series high-voltage resistor includes a first resistor R1, a second resistor R2 and a third resistor R3 connected in series in sequence, wherein an energy storage module is provided between the first resistor R1 and the second resistor R2, and the energy storage module includes multiple parallel capacitors, for example, capacitor C1, capacitor C2, capacitor C3, capacitor C4, capacitor C5, capacitor C6 and capacitor C7 are connected in parallel in sequence, a first end of capacitor C7 is connected to a unipolar high-voltage DC power supply PIEHV through the series first resistor R1, and a second end of capacitor C7 is grounded.

[0043] In this embodiment, the first resistor R1 preferably has a resistance of 1KΩ, and the first resistor R1 has a first end and a second end. According to the specific requirements of the circuit output pulse, other load modules (such as variable resistors, etc.) can also be used, or the number of resistors can be increased to increase or decrease the resistance.

[0044] In addition, the seven capacitors C1 to C7 are preferably 15KV withstand voltage, 0.01μF capacitors, capable of outputting 15,000V DC high voltage. According to the specific requirements of the circuit output pulse, other energy storage modules can also be used, or the number of capacitors can be increased to increase or decrease the capacitance value.

[0045] The second resistor R2 is connected in parallel with the first freewheeling tube (freewheeling diode) D1, and the second resistor R2 and the first freewheeling tube D1 form a freewheeling loop. For example, the first freewheeling tube D1 is connected in parallel to the two ends of the fourth switch K4 and the second resistor R2, and forms a freewheeling loop with them, so that the fourth switch K4 consumes in the loop in a freewheeling current manner, thereby protecting the components in the circuit from being damaged. In addition, the freewheeling circuit is also connected in parallel to the output end of the fourth switch K4. For example, the first output end (5) and the second output end (8) of the fourth switch K4 are correspondingly connected to the cathode foot and the anode foot of the first freewheeling tube D1, wherein the second resistor R2 is preferably a resistor with a resistance of 750KΩ. According to the specific requirements of the circuit output pulse, other load modules can also be used, or the number of resistors can be increased to increase or decrease the resistance. The first freewheeling tube D1 is preferably a diode with a withstand voltage of 5KV. According to the specific requirements of the circuit output pulse, diodes with better parameters can also be used to increase its withstand voltage.

[0046] The switch tube Q1 is an IGBT transistor, connected between the second resistor R2 and the third resistor R3, wherein the drain of the IGBT tube Q1 is connected to the second end of the second resistor R2, the source of the IGBT tube Q1 is connected to the first end of the third resistor R3, the second end of the third resistor R3 is grounded, the second freewheeling tube D2 and the third resistor R3 also form a freewheeling loop, the anode pin of the second freewheeling tube D2 is grounded, and the cathode pin of the second freewheeling tube D2 is connected to the first end of the third resistor R3. In addition, the freewheeling loop is also connected in parallel to the output end of the second switch K2, for example, the first output end (5) and the second output end (8) of the second switch K2 are correspondingly connected to the cathode pin and the anode pin of the second freewheeling tube D2.

[0047] The second end of the second resistor R2 is connected to the second output end (8) of the third switch K3, the first end of the third resistor R3 is connected to the second output end (8) of the first switch K1, the first output end (5) of the third switch K3 and the first output end (5) of the first switch K1 are connected to the load resistor R4, and the other end of the load resistor R4 forms a pulse output end HVPo to output a positive pulse signal or a negative pulse signal; the two input ends of the first switch K1 and the third switch K3 are commonly connected to a photoelectric trigger module, and the opening or closing of the first switch K1 and the third switch K3 is controlled by an external trigger signal.

[0048] In this embodiment, the first switch K1 and the fourth switch K4 are preferably domestic HE24-1A83-02 single-pole single-throw normally open switches with a withstand voltage of 20KV, and other switch components that meet the conditions can also be selected. In this embodiment, the first switch K1 and the fourth switch K4 are domestic HE24-1A83-02 single-pole single-throw normally open switches. The fourth switch K4 and the first switch K1 both have 4 pins, and are controlled on and off by a photoelectric trigger module. The second switch K2 and the third switch K3 are preferably domestic DBT72410 single-pole single-throw normally closed switches, and other switch components that meet the conditions can also be selected. In this embodiment, the second switch K2 and the third switch K3 are domestic DBT72410 single-pole single-throw normally closed switches. The second switch K2 and the third switch K3 both have 4 pins, and are controlled on and off by a photoelectric trigger module.

[0049] In this embodiment, the total purchase cost of the high-voltage switch tube Q1 and the high-voltage switches K1 to K4 is about one thousand yuan. Compared with other high-voltage switches, which often require a purchase cost of tens of thousands of yuan, the purchase cost of the pulse generating circuit in this embodiment is lower. For the bipolar pulse generating circuit, the purchase cost of the high-voltage switch is reduced by an order of magnitude, thereby greatly reducing the manufacturing cost of the pulse generating circuit, which is conducive to widespread use. In addition, each high-voltage switch is controlled by a photoelectric trigger module, and the input and output of the optical coupler are isolated from each other, and the electrical signal transmission has the characteristics of unidirectionality, so it has good electrical insulation and anti-interference capabilities; at the same time, the input end of the optical coupler is a low-resistance element working in the current mode, so it has a strong common-mode suppression capability; therefore, the signal-to-noise ratio is greatly improved.

[0050] The first DC power supply, that is, the unipolar high-voltage DC power supply PIEHV signal is connected to one end of the switch tube after being connected in series with the first high-voltage resistor and the second high-voltage resistor; at this time, the pulse signal source sends a rising edge trigger signal, and generates a peak signal through the pulse drive circuit to drive the high-voltage switch tube Q1 so that the pulse output end is pulled down to ground, thereby enabling the pulse output end to obtain a PIEHV pull-down (falling edge) pulse signal.

[0051] The positive electrode of the first DC power supply is connected to the first end of the first resistor R1 and the first end of the second resistor R2, and the energy storage module is connected between the second end of the first resistor R1 and the first end of the second resistor R2; at the same time, the second end of the first resistor R1 is also connected to the cathode foot of the first freewheeling tube D1; the second end of the second resistor R2 and the anode foot of the first freewheeling tube D1 are connected to the drain foot of the IGBT tube Q1 and the second output end (8) of the third switch K3; the source foot of the IGBT tube Q1 is connected to the first output end (5) of the second switch K2, and the first output end (5) of the third switch K3 is connected to the first end of the load resistor R4, and the second end of the load resistor R4 is the pulse output end. By controlling the fourth switch K4 and the first switch K1 to be disconnected, and controlling the second switch K2 and the third switch K3 to be closed, when the pin of the IGBT tube Q1 is triggered to be turned on, a negative pulse signal is output at the pulse output end HVPo of the load resistor R4.

[0052] The fourth switch K4 and the first switch K1 are controlled to be closed at the same time by the photoelectric trigger module, and the second switch K2 and the third switch K3 are opened at the same time. At the same time, the driving signal sent by the pulse driving module triggers Q1 to turn on, and a positive pulse signal is generated at the pulse output terminal HVPo of the load resistor R4 through the first output terminal (5) of the first switch K1.

[0053] See also Figure 5 , is a circuit diagram of a photoelectric trigger module in a pulse generating circuit provided by the present invention, comprising:

[0054] The anode pin of the light-emitting diode in the photocoupler U1 is connected to a voltage of +5V, the cathode pin of the light-emitting diode is connected to an external trigger signal B through a fifth resistor R5, the anode pin of the photosensitive diode is connected to the collector of the transistor Q2 and the input end (pin 2) of the switch K through a seventh resistor R7, the input end (pin 1) of the switch K is connected to a 24V power supply, and a third freewheeling diode D3 is connected in parallel between pins 1 and 2 of the switch; the cathode pin of the photosensitive diode is connected to the base of the transistor Q2, and a sixth resistor R6 is connected in series between the emitter and the base of the transistor Q2.

[0055] Here, it should be noted that each switch K is connected to a corresponding photoelectric trigger module for triggering the closing and opening of the switch. Figure 2 As shown, the anode foot of the third freewheeling tube (freewheeling diode) D3 is connected to the pin 2 of the switch K, and the cathode foot of the third freewheeling diode D3 is connected to the pin 1 of the switch, in order to prevent the high-voltage reverse current induced by the coil inside the switch at the moment of power failure of the short-circuit coil current of the switch, thereby ensuring the normal operation of the coil inside the switch.

[0056] Specifically, when the input terminal (base) of the transistor Q2 is suspended, the pull-down resistor R6 is used to ensure that the base of the transistor Q2 can be reliably cut off.

[0057] When the light-emitting diode is turned on, the photosensitive diode in the photocoupler U1 receives the light signal, so the photocoupler is in the on state and outputs a high level. Since the high level is input to the base of the transistor Q2, the emitter of the transistor Q2 is grounded, so that the transistor Q2 is turned on to amplify the electrical signal. By turning on the base and emitter of the transistor Q2, the collector of the transistor Q2 is grounded, which causes the coil in the switch to be energized, thereby closing the switch K. When the light-emitting diode is not emitting light, the photosensitive diode in the photocoupler U1 cannot receive the light signal, so the photocoupler is in the off state and outputs a low level. Since the low level is input to the base of the transistor Q2, the emitter of the transistor Q2 is grounded, so that the transistor Q2 is turned off, causing the coupling inductor in the switch to be de-energized, thereby opening the switch K.

[0058] Therefore, the conduction or cutoff of the optocoupler U1 can be controlled by the external trigger signal B to realize the opening or closing of the control switch K. The photoelectric trigger module has the advantages of unidirectional signal transmission, complete electrical isolation between the input and output ends, and no effect of the output signal on the input end. It has the advantages of strong anti-interference ability, stable operation, no contacts, long service life and high transmission efficiency.

[0059] See also Figure 6 , is a circuit diagram of a pulse driving module in a pulse generating circuit provided by the present invention, comprising:

[0060] A pulse signal source, a signal capture unit, a power amplification unit and a signal coupling unit, wherein the pulse signal source generates a pulse signal, the signal capture unit is connected to the pulse signal source, and generates a group of signals with the same amplitude and opposite phase according to the rising edge signal in the pulse signal, and the power amplification unit is connected to the signal capture unit and the signal coupling unit in sequence, amplifies the group of signals and couples to generate a peak signal to drive the switch tube.

[0061] The pulse signal source is Figure 6 In the TTL Trig, the signal capture unit is the signal capture chip U2, and the preferred model is SN74LV3GU04; the power amplifier unit is the power amplifier chip U3, and the preferred model is SN75372. The pulse signal source TTLTrig forms a freewheeling circuit through a parallel freewheeling diode D4 and a resistor R8 to connect to the pin 1A of the signal capture chip. The rising edge signal generated by the capture pulse signal source triggers a group of signals with the same amplitude (voltage) and opposite phase. The pin 1Y is connected to the pin 1A of the power amplifier chip to amplify the group of differential signals. The output end of the power amplifier chip is connected to the signal coupling unit to generate a peak signal to drive the high-voltage switch tube Q1.

[0062] It should be noted that the diode D4 is preferably of BYV968, and the resistor R8 is preferably of 1.5KΩ.

[0063] The signal coupling unit includes two coupling capacitors (capacitor C8 and capacitor C9) and a coupling inductor T1. The two output ends (pin 1out and pin 2out) of the power amplifier chip U3 are each connected to one end of a coupling capacitor (capacitor C8 and capacitor C9), and the other ends of the two coupling capacitors (capacitor C8 and capacitor C9) are correspondingly connected to the two ends of the input stage of the coupling inductor T1.

[0064] Specifically, the coupling inductor T1 and two coupling capacitors are connected in parallel to form an LC coupling circuit, and the two signals amplified at the output end of the power amplifier unit U3 are connected to the input end of the primary coil of the coupling inductor T through the coupling circuit, so that the secondary coil of the coupling inductor T can output a peak signal.

[0065] In addition, based on the above circuit, it also includes two clamping diodes arranged at the input end of the coupling inductor T1. For example, a clamping diode D5 is provided between the capacitor C8 and one input end of the coupling inductor T1, the cathode leg of the clamping diode D5 is connected between the capacitor C8 and one input end of the coupling inductor T1, and the anode leg of the clamping diode D5 is grounded; a clamping diode D6 is provided between the capacitor C9 and the other input end of the coupling inductor T1, the anode leg of the clamping diode D6 is connected between the capacitor C9 and the other input end of the coupling inductor T1, and the cathode leg of the clamping diode D6 is grounded.

[0066] Specifically, when the cathode pin of the clamping diode D6 is grounded, the potential of the anode pin of the clamping diode D6 is higher than the ground, and the clamping diode D6 will be turned on to pull down its potential, that is, the anode pin circuit is clamped to zero potential or below zero potential; when the anode pin of the clamping diode D5 is grounded, the potential of the cathode pin of the clamping diode D5 is higher than the ground, and the clamping diode D6 will be cut off, and its potential will not be affected by any effect of the clamping diode D5.

[0067] In some other embodiments, a photoelectric coupling unit is provided between the signal capturing unit and the power amplifying unit, such as Figure 6 As shown, the photoelectric coupling unit U4 is a photoelectric coupling chip of model HCPL-0600, which realizes isolation between the DC circuit and the AC circuit and is compatible with TTL signals.

[0068] Specifically, pin A of the photoelectric coupling chip is connected between the signal capture unit and the signal capture unit through the eleventh resistor R11 to realize photoelectric coupling. At the same time, pin 3Y of the signal capture unit is connected to pin k of the photoelectric coupling chip to provide it with a captured pulse signal. Pin out of the photoelectric coupling chip is externally connected to the INTO interface and the load resistor R12. The load resistor R12 is connected in parallel with a grounded decoupling capacitor C22. The decoupling capacitor C22 can suppress the noise generated by load changes.

[0069] In this embodiment, the external INTO interface of the optocoupler chip U4 is used to reflect the pulse signal source output by the pin 3Y of the signal capture chip U2, so as to realize real-time detection of the pulse signal source. For example, a work log can be generated according to the pulse signal source through the external INTO interface to prevent the inability to effectively handle the fault when it occurs.

[0070] In other embodiments, the MOS transistor Q3 is a consumption-closed N-channel, wherein the gate and source of the MOS transistor Q3 are correspondingly connected to the negative end (negative output end) and the positive end (positive output end) of the output stage of the coupling inductor T1, and the drain of the MOS transistor Q3 is connected to the resistor R9. The MOS transistor Q3 is used to isolate the coupling inductor T1 and the switch transistor Q1, and the drain current is controlled by adjusting the gate voltage of the MOS transistor Q3. The current passes through the resistor R9 to limit the current, thereby preventing the current flowing through the tube base from being too large, and the current of the resistor R9 is used to turn on the switch transistor Q1.

[0071] Specifically, the diode D7 is connected in parallel between the gate and drain of the MOS tube Q3, wherein the anode pin of the diode D7 is connected to the gate of the MOS tube Q3, and the cathode pin of the diode D7 is connected to the drain of the MOS tube Q3, for voltage stabilization. When the switch tube Q1 is not turned on, its gate is connected to the pull-down resistor R10 to ensure that the switch tube Q1 can be turned off. When it is turned on, the resistor R9 and the resistor R10 form a voltage divider; at the same time, the emitter junction of the switch tube Q1 is connected in parallel with the resistor R10 to prevent a small current from passing through the base of the tube and causing mis-conduction.

[0072] In this embodiment, through the MOS tube Q3 and the diode D7, when the secondary coil of the coupled inductor T1 outputs a falling edge pulse signal, the falling edge pulse signal can be refluxed to the MOS tube Q3 through the diode D7, ensuring that the MOS tube Q3 is cut off, so that the MOS tube Q3 is only effective for the rising edge pulse signal, and when the secondary coil of the coupled inductor T1 outputs a rising edge pulse signal, the unidirectional conduction characteristic of the MOS tube Q3 turns on the switch tube Q1 through the resistor R9.

[0073] It should be noted that the switch in this embodiment adopts a photoelectric isolation driving mode, which can avoid feedback and interference that may be generated by the output end to the input end; it has strong noise and interference suppression capabilities; and has the advantages of durability, high reliability and high speed. In addition, the pulse drive module corresponding to the switch tube adopts a passive driving mode, that is, the switch tube Q1 can be driven without a DC high-voltage power supply.

[0074] See also Figure 7 , is a circuit diagram of a high voltage synthesis circuit provided by the present invention, the high voltage synthesis circuit comprising:

[0075] A pulse input terminal, a second DC power supply, a bipolar high-voltage pulse output terminal and a high-voltage power supply output terminal; the pulse input terminal is connected to the output terminal of the pulse generating circuit, the pulse input terminal is connected to the first terminal of the first shunt and the second shunt through a first filtering module, the second DC power supply is connected to the first terminal of the first shunt and the second shunt through a series resistor, the second terminal of the first shunt is connected to the bipolar high-voltage pulse output terminal, and the second terminal of the second shunt is connected to the high-voltage power supply output terminal.

[0076] The first filter module is composed of a tenth capacitor C10, an eleventh capacitor C11, a twelfth capacitor C12 and a thirteenth capacitor C13, the tenth capacitor C10, the eleventh capacitor C11, the twelfth capacitor C12 and the thirteenth capacitor C13 are connected in series in sequence, and the first end of the first filter module, that is, the first end of the tenth capacitor C10, is connected to the pulse input end ( Figure 2 The pulse output terminal HVPo in the circuit may also adopt other filter module structures or select capacitors of other quantities and sizes, preferably capacitors with a withstand voltage of 40KV and 4000pF, according to the output requirements of the circuit.

[0077] The first shunt includes a thirteenth resistor R13 and a fourteenth resistor R14 in parallel, the second end of the first filtering module (capacitor C13) is connected to the first end of the thirteenth resistor R13 and the fourteenth resistor R14 (the first shunt), the second end of the thirteenth resistor R13 and the fourteenth resistor R14 (the first shunt) outputs a bipolar high-voltage pulse signal, and the resistance values ​​of the thirteenth resistor R13 and the fourteenth resistor R14 are preferably 1KΩ.

[0078] The second shunt consists of three resistors, a fifteenth resistor R15, a sixteenth resistor R16, and a seventeenth resistor R17, which are connected in series in sequence. The three resistors have a first end and a second end, respectively. The resistance values ​​of the fifteenth resistor R15 and the sixteenth resistor R16 are preferably 35 MΩ, and the resistance value of the seventeenth resistor R17 is 1 KΩ. The output end of the seventeenth resistor R17 (the second shunt) is the output end of the high-voltage power supply.

[0079] Therefore, in this embodiment, Figure 2 The pulse output terminal HVPo inputs a positive pulse or a negative pulse to one end of the tenth capacitor C10 through the pulse input terminal HVP PLS in, and is divided into two paths through the other end of the thirteenth capacitor C13, one of which is connected to the first end of the first shunt, and the other is connected to the first end of the second shunt, and the second end of the first shunt is connected to the bipolar high-voltage pulse output terminal HVP PULSE OUT to output a high-voltage negative pulse or a high-voltage positive pulse; the second DC power supply input terminal HVP IN is connected to the first end of the second shunt, and the second end of the second shunt is connected to the high-voltage power supply output terminal HVP OUT, thereby outputting high-voltage DC power.

[0080] Finally, a second filtering module (filter) is arranged before the second output terminal HVP OUT to filter the pulse part of the voltage so that the second output terminal HVP OUT can output a stable DC voltage.

[0081] The second filtering module of the present embodiment is preferably composed of 8 capacitors with the same capacitance connected in parallel, the fourteenth capacitor C14, the fifteenth capacitor C15, the sixteenth capacitor C16, and the seventeenth capacitor C17 are connected in series in sequence to form a first series group, the eighteenth capacitor C18, the nineteenth capacitor C19, the twentieth capacitor C20, and the twenty-first capacitor C21 are connected in series in sequence to form a second series group, the two series groups are connected in parallel, and the fourteenth capacitor C14 and the eighteenth capacitor C18 are connected in parallel to the ground, and the seventeenth capacitor C17 and the twenty-first capacitor C21 are connected in parallel between the fifteenth resistor R15 and the sixteenth resistor R16, and the selected 8 capacitors are all capacitors with a precision grade of 102M.

[0082] In addition, a protection circuit may be provided at the first end of the second shunt. For details, see the arrangement of the protection resistors (the eighteenth resistor R18, the nineteenth resistor R19, the twentieth resistor R20, and the twenty-first resistor R21) connected in series and the inductor L1. In addition, there are many other circuit arrangements, which are commonly used structures in the industry and will not be described in detail in this embodiment.

[0083] In addition, a twenty-second resistor R22 and a twenty-third resistor R23 may be connected in series between the first end of the second shunt and the second DC power input terminal HVP IN.

[0084] When the pulse input terminal inputs a 0~±15KV, 10us level pulse signal to HVP_PLS_in, the second DC power supply input terminal HVP_IN inputs an adjustable DC high voltage of 0~30KV, and a pull-down pulse is coupled into it through the four series-connected capacitors in the first filtering module, wherein the pull-down pulse is mixed with the high voltage and then output through the first shunt, namely HVP_PULSE_OUT (HVP_PULSE_OUT=HVP_IN-HVP_PLS_in, HVP_PLS_in is the pulse amplitude), and the HVP_OUT output remains unchanged as HVP_IN.

[0085] When the second DC power input terminal HVP_IN inputs a high voltage of 30KV, if the pulse input terminal couples a pulse signal of 10KV→0, the high-voltage power output terminal HVP_OUT outputs a DC high voltage of 30KV, and the bipolar high-voltage pulse output terminal HVP_PULSE_OUT outputs a pulse high voltage of 30KV→20KV.

[0086] By adjusting the positive and negative polarity pulse signals of the pulse input terminal, the bipolar high-voltage pulse output terminal HVPPULSE OUT finally outputs a high-voltage positive pulse or / and a high-voltage negative pulse.

[0087] In other embodiments, the present invention provides a time-of-flight mass spectrometer, including: the above-mentioned pulse generator, which will not be described in detail here.

[0088] In some embodiments, the TOF analyzer may receive ions from an upstream stage of a mass spectrometer, for example, in some embodiments, the mass spectrometer may be an MS / MS analyzer in which the TOF analyzer receives ions from an upstream quadrupole analyzer. A mass spectrometer according to the present teachings may be employed in various applications (e.g., mass spectrometric detection of proteins, metabolites, food contamination, environmental toxins) in time periods shorter than those achieved by conventional mass spectrometers.

[0089] In other embodiments, the present invention provides an electronic device, including: the above-mentioned pulse generating circuit, or the above-mentioned pulse generator, or the above-mentioned time-of-flight mass spectrometer, which will not be described in detail here.

[0090] In summary, the present invention forms a positive pulse output circuit or a negative pulse output circuit in different closed and open states of the switch by controlling the states of different switches in the switch control module, thereby generating a positive pulse signal or a negative pulse signal. Compared with the traditional high-voltage switch, the present invention does not require heating power or a complex driving circuit, and has the advantages of very short recovery time and low jitter. At the same time, the present invention is simple to control and the circuit structure is more stable. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has a high industrial utilization value.

[0091] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A pulse generating circuit, characterized in that: include: A first DC power supply is connected to a switch control module via a series high-voltage resistor, an energy storage module, and the switch control module includes at least one switch tube and a plurality of switches; A pulse driving module, connected to the switch tube, for generating a spike signal with alternating positive and negative polarities to turn on or off the switch tube; A plurality of photoelectric trigger modules, connected to the switches correspondingly, for generating trigger signals for controlling the switches to open or close; A pulse output module, connected to the switch control module, is used to form a positive pulse output circuit or a negative pulse output circuit according to the opening or closing of a plurality of the switches when the switch tube is turned on, and to generate a positive pulse signal and / or a negative pulse signal by using the output circuit; The series high-voltage resistor includes a second resistor and a third resistor connected in series in sequence, the second resistor is connected to a first DC power supply, and the third resistor is grounded; the switch control module includes a first switch to a fourth switch, and the pulse output module includes a load; in the on-state of the switch tube, when the first switch and the fourth switch are closed and the second switch and the third switch are disconnected, the first DC power supply forms a positive pulse output circuit through the energy storage module, the fourth switch, the first switch and the load; in the on-state of the switch tube, when the second switch and the third switch are closed and the first switch and the fourth switch are disconnected, the first DC power supply forms a negative pulse output circuit through the second switch and the third switch coupled to the ground by the energy storage module and the load; The source of the switch tube in the negative pulse output loop is connected to one end of the second switch and the first end of the third resistor, and the other end of the second switch and the second end of the third resistor are grounded; the drain of the switch tube is connected to one end of the third switch and the second end of the second resistor, the gate of the switch tube is connected to the pulse driving module, and the other end of the third switch outputs a negative pulse signal through a load; or The drain of the switch tube in the positive pulse output loop is connected to one end of the fourth switch and the second end of the second resistor, the other end of the fourth switch and the first end of the second resistor are connected to the energy storage module, the gate of the switch tube is connected to the pulse driving module, the source of the switch tube is connected to one end of the first switch and the first end of the third resistor, and the other end of the first switch outputs a positive pulse signal through a load.

2. The pulse generating circuit according to claim 1, characterized in that: The series high-voltage resistor also includes a first resistor, which is connected in series between the first DC power supply and the second resistor.

3. The pulse generating circuit according to claim 2, characterized in that: The energy storage module is connected between the first resistor and the second resistor, and the energy storage module includes a plurality of parallel capacitors.

4. The pulse generating circuit according to claim 2 or 3, characterized in that: The second resistor is connected in parallel with a first freewheeling diode.

5. The pulse generating circuit according to claim 2 or 3, characterized in that: The third resistor is connected in parallel with a second freewheeling tube.

6. The pulse generating circuit according to claim 1, characterized in that: Also includes: The first switch and the third switch constitute a single-pole double-throw switch, the source of the switch tube is connected to an input end of the single-pole double-throw switch and a first end of the third resistor, the drain of the switch tube is connected to another input end of the single-pole double-throw switch and a second end of the second resistor, the gate of the switch tube is connected to a pulse driving module, and the single-pole double-throw switch determines whether the load outputs a positive pulse signal or / and a negative pulse signal by selecting the input end to be closed.

7. The pulse generating circuit according to claim 1, characterized in that: The switch control module is composed of a switch tube, a second switch and a third switch, the source of the switch tube is connected to one end of the second switch and the first end of the third resistor, and the other end of the second switch and the second end of the third resistor are grounded; the drain of the switch tube is connected to one end of the third switch and the second end of the second resistor, the gate of the switch tube is connected to the pulse driving module, and the other end of the third switch outputs a negative pulse signal through a load; or The switch control module is composed of a switch tube, a first switch and a fourth switch. The drain of the switch tube is connected to one end of the fourth switch and the second end of the second resistor, the other end of the fourth switch and the first end of the second resistor are connected to the energy storage module, the gate of the switch tube is connected to the pulse driving module, the source of the switch tube is connected to one end of the first switch and the first end of the third resistor, and the other end of the first switch outputs a positive pulse signal through a load.

8. The pulse generating circuit according to claim 1, characterized in that: The photoelectric trigger module includes a photoelectric coupler and a transistor, wherein the positive input end of the photoelectric coupler is connected to the power supply voltage, the negative input end thereof is connected to the external trigger signal, the positive output end thereof is connected to the collector of the transistor and the control end of the switch, the negative output end thereof is connected to the base of the transistor, and the emitter of the transistor is grounded.

9. The pulse generating circuit according to claim 8, characterized in that: A third freewheeling tube is connected in parallel to the control end of the switch.

10. The pulse generating circuit according to claim 1, characterized in that: The pulse driving module comprises: A pulse signal source, used for generating a pulse signal; A signal capture unit, connected to the output end of the pulse signal source, and used to generate a group of differential signals with the same amplitude and opposite phase according to the pulse signal; A power amplification unit connected to the output end of the signal capture unit and used to amplify the group of differential signals; The signal coupling unit is connected to the output end of the power amplification unit and is used to couple the amplified differential signal to generate a peak signal for driving the switch tube.

11. The pulse generating circuit according to claim 10, characterized in that: The signal coupling module at least includes a coupling inductor and two coupling capacitors. The two output ends of the power amplification unit are respectively connected to one end of a coupling capacitor, and the other ends of the two coupling capacitors are correspondingly connected to the two input ends of the coupling inductor.

12. The pulse generating circuit according to claim 11, characterized in that: A clamping diode is provided between the coupling capacitor and the coupling inductor.

13. The pulse generating circuit according to claim 11 or 12, characterized in that: The output end of the coupled inductor has a MOS tube and a voltage regulator tube, the negative output end of the coupled inductor is connected to the anode pin of the voltage regulator tube and the gate of the MOS tube, the positive output end of the coupled inductor is connected to the source of the MOS tube, and the drain of the MOS tube is connected to the cathode pin of the voltage regulator tube.

14. The pulse generating circuit according to claim 10, characterized in that: A photoelectric coupling unit is provided between the signal capturing unit and the power amplifying unit.

15. A pulse generator comprising: A pulse generating circuit and a high-voltage synthesis circuit as described in any one of claims 1 to 14 are used, and the high-voltage synthesis circuit is connected to the pulse generating circuit to output a high-voltage positive pulse signal and / or a high-voltage negative pulse signal.

16. According to the pulse generator of claim 15, the high-voltage synthesis circuit includes a pulse input terminal, a second DC power supply, a bipolar high-voltage pulse output terminal and a high-voltage power supply output terminal; the pulse input terminal is connected to the output terminal of the pulse generating circuit, the pulse input terminal is connected to the first end of the first shunt and the second shunt through a first filtering module, the second DC power supply is connected to the first end of the first shunt and the second shunt through a series resistor, the second end of the first shunt is connected to the bipolar high-voltage pulse output terminal, and the second end of the second shunt is connected to the high-voltage power supply output terminal.

17. The pulse generator of claim 16, further comprising: A second filter module, one end of the second filter module is grounded, and the other end of the second filter module is connected to the high voltage power supply output end.

18. The pulse generator according to claim 16 or 17, wherein the first ends of the first shunt and the second shunt are grounded via a protective resistor and an inductor.

19. A time-of-flight mass spectrometer, characterized in that: Comprising the pulse generator described in any one of claims 15 to 18.

20. An electronic device comprising: Using the pulse generating circuit described in any one of claims 1 to 14, or using the pulse generator described in any one of claims 15 to 18: Or use the time-of-flight mass spectrometer described in claim 19.

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