Power supply circuit for electrostatic probe

Abstract

The utility model relates to the technical field of nuclear fusion, and discloses a power supply circuit for an electrostatic probe, which comprises a power supply module and a sampling module, the power supply module is connected with the electrostatic probe through the sampling module, the power supply module comprises a plurality of linear power supply branches which are input in parallel and output in series, each linear power supply branch comprises a linear voltage regulator and a voltage regulating unit, and the input end of each linear voltage regulator is connected with a corresponding external power supply; the output end of the linear voltage regulator is connected with the electrostatic probe through the voltage regulating unit, and the voltage regulating unit corresponding to the last stage of linear voltage regulator is connected between the output end of the current linear voltage regulator and the ground. And the voltage regulating unit corresponding to the previous-stage linear voltage regulator is connected between the output end of the current linear voltage regulator and the output end of the next-stage linear voltage regulator. The power supply voltage with small enough voltage ripple and high enough voltage value can be provided for the plasma acquisition device, and weak ion saturation current signals can be accurately detected.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear fusion, in particular to a power supply circuit for an electrostatic probe. BACKGROUND

[0002] In a magnetic confinement fusion device, it is of great significance to measure the parameters of the plasma, such as the electron temperature, the electron density, the ion saturation current, the floating potential and the transport flux. The detection of the plasma can be usually performed by using an electrostatic probe, a laser-induced fluorescence, a microwave reflectometer, a fast-response force sensor and the like.

[0003] In the plasma diagnosis, the power supply system of the plasma detection device needs to meet the requirements of high-voltage (for example, 150V-300V) output and high-response speed (for example, sub-microsecond level). In order to meet the requirements of high-voltage output and high-response speed, the power supply system often uses a DC / DC power module in the related art.

[0004] However, when the ion saturation current is detected by using the detection device with the DC / DC power module, the detection signal is often distorted.

[0005] Therefore, how to ensure the authenticity of the detection signal during the detection of the ion saturation current becomes a technical problem to be solved. CONTENT OF THE INVENTION

[0006] Therefore, the present application provides a power supply circuit for an electrostatic probe to solve the technical problem of how to ensure the authenticity of the detection signal during the detection of the ion saturation current in the related art.

[0007] The present application provides a power supply circuit for an electrostatic probe, which comprises a power module and a sampling module. The power module comprises a plurality of linear power branches connected in parallel and outputting in series, each of the linear power branches comprising a linear voltage stabilizer and a voltage regulating unit, the input end of each linear voltage stabilizer being connected to a corresponding external power supply, the output ends of the plurality of linear voltage stabilizers being connected to the electrostatic probe, wherein the voltage regulating unit corresponding to the last linear voltage stabilizer is connected between the output end of the current linear voltage stabilizer and the ground, and the voltage regulating unit corresponding to the last linear voltage stabilizer is connected between the output end of the current linear voltage stabilizer and the output end of the next linear voltage stabilizer. The sampling module comprises a sampling resistor and a sampling unit, the sampling resistor being connected in series between the output end of the power module and the electrostatic probe, and the sampling unit being connected to the sampling resistor.

[0008] In an embodiment, the voltage regulating unit comprises a first resistor and an adjustable resistor connected in series between the output of the current linear voltage regulator and the output of the next linear voltage regulator, and a voltage dividing terminal between the first resistor and the adjustable resistor, wherein the voltage dividing terminal is connected to the feedback terminal of the corresponding linear voltage regulator.

[0009] In an embodiment, the power supply module further comprises an input rectifying filter unit connected to the input of the linear voltage regulator, and an output filter unit connected to the output of the linear voltage regulator.

[0010] In an embodiment, the sampling unit comprises an isolation amplification chip, a filter unit and a collector, wherein the input of the isolation amplification chip is connected to the sampling resistor, and the output of the isolation amplification chip is connected to the collector through the filter unit.

[0011] In an embodiment, the power supply circuit further comprises a current limiting module connected between the output of the power supply module and the sampling module, which disconnects the connection between the power supply module and the probe when the output current of the power supply module is greater than a preset current.

[0012] In an embodiment, the current limiting module comprises a first controllable switch, a second controllable switch, a second resistor, a third resistor and a fourth resistor, wherein the control terminal of the first controllable switch is connected to the output of the power supply module through the second resistor, and the input of the first controllable switch is connected to the output of the power supply module; the input of the second controllable switch is connected to the output of the power supply module through the second resistor, and the control terminal of the second controllable switch is connected to the output of the first controllable switch; one end of the third resistor is connected to the input of the second controllable switch, and the other end of the third resistor is connected to the output of the first controllable switch, the input of the second controllable switch and one end of the fourth resistor, and the other end of the fourth resistor is grounded.

[0013] In an embodiment, the first controllable switch comprises a PNP triode, and the second controllable switch comprises an NMOS tube.

[0014] In an embodiment, each linear power supply branch further comprises a short circuit protection unit, wherein the short circuit protection unit comprises a Darlington tube, a zener diode and a fifth resistor, the anode of the zener diode is connected to the output of the linear power supply branch, and the cathode of the zener diode is connected to the control terminal of the Darlington tube; one end of the fifth resistor is connected to the external power supply, and the other end of the fifth resistor is connected to the control terminal of the Darlington tube; the input of the Darlington tube is connected to the external power supply, and the output of the Darlington tube is connected to the input of the linear voltage regulator.

[0015] In an embodiment, the linear power branch further comprises a rectifier module; an input end of the rectifier module is connected with the external power supply, and an output end is connected with an input end of the linear voltage stabilizer.

[0016] In an embodiment, the power supply circuit further comprises an overvoltage protection module, and the overvoltage protection circuit comprises a varistor and a transient voltage suppression tube connected in parallel across the electrostatic probe.

[0017] The present application has at least the following technical effects:

[0018] The power supply circuit comprises a power supply module and a sampling module; the power supply module comprises a plurality of linear power branches connected in parallel in input and in series in output, each linear power branch comprising a linear voltage stabilizer and a voltage regulating unit, an input end of each linear voltage stabilizer being connected with a corresponding external power supply, and output ends of the plurality of linear voltage stabilizers being connected with the electrostatic probe, wherein the voltage regulating unit corresponding to the last linear voltage stabilizer is connected between the output end of the current linear voltage stabilizer and the ground, and the voltage regulating unit corresponding to the last linear voltage stabilizer is connected between the output end of the current linear voltage stabilizer and the output end of the next linear voltage stabilizer; the sampling module comprises a sampling resistor and a sampling unit, the sampling resistor being connected in series between the output end of the power supply module and the electrostatic probe, and the sampling unit being connected with the sampling resistor. A plurality of linear power branches with linear voltage stabilizers are adopted, the linear voltage stabilizer can output a low-ripple power supply voltage, the linear power branches are connected in parallel in input and in series in output, each linear power branch has a voltage regulating unit capable of regulating the output voltage of the linear voltage stabilizer, the output voltages of the multiple linear voltage stabilizers are connected in series, the reverse end (i.e. the reference voltage end) of the error amplifier in the lower linear voltage stabilizer is connected with the output end of the upper linear voltage stabilizer, the voltage regulating unit dynamically adjusts the output voltage of each linear voltage stabilizer, the output voltages of the linear voltage stabilizers are adjusted to be consistent, high-voltage stability and voltage equalization control are achieved, and the sum of the output voltages is the voltage required by the plasma collection device, which can provide a power supply voltage with small enough voltage ripple and high enough voltage value for the plasma collection device, and can accurately detect the weak ion saturation flow signal when detecting the ion saturation flow. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the specific embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0020] Figure 1is a modular schematic diagram of a power supply circuit for an electrostatic probe according to an embodiment of the present application;

[0021] Figure 2 is another modular schematic diagram of a power supply circuit for an electrostatic probe according to an embodiment of the present application;

[0022] Figure 3 is an electrical schematic diagram of a power supply circuit for an electrostatic probe according to an embodiment of the present application;

[0023] Figure 4 is a waveform diagram of a collected plasma for an ion saturation current detection device according to an embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0025] As described in the above background, when detecting ion saturation current by using a detection device with a DC / DC power supply module, the detection signal is often distorted. The applicant has found that, as an important information among various parameters of boundary plasma, ion saturation current needs to be accurately detected when detecting boundary plasma. However, in a controlled nuclear fusion device, the core plasma density is extremely high, but the density of boundary plasma is low. Due to the influence of sheath effect and strong magnetic field of the controlled nuclear fusion device, the collection efficiency of the plasma detection device for plasma is reduced, resulting in that the amplitude of ion saturation current is as low as microampere level. When detecting other parameters of plasma, the signal strength is large, and accurate signals can be easily collected. For example, when the power supply of the plasma detection device uses a DC / DC power supply module, the accuracy of signal collection is not greatly affected. However, when detecting ion saturation current, the power supply of the plasma detection device uses a DC / DC power supply module, and is affected by the ripple of the DC / DC power supply module, so it is difficult to collect the true value of the ion saturation current signal. Other power supply modules are difficult to meet the requirements of stable high voltage. Based on this, the present application provides a power supply circuit for an electrostatic probe to meet the requirements of low ripple, high sampling rate and high voltage output for ion saturation current with low signal strength.

[0026] Referring to Figures 1 to 3 As shown in the figure, the power supply circuit for the electrostatic probe includes a power supply module 100 and a sampling module 200.

[0027] The power module 100 comprises multiple linear power branches 110 with parallel input and series output, each of the linear power branches 110 comprises a linear voltage regulator 111 and a voltage regulating unit 112, the input end of the linear voltage regulator 111 is connected to a corresponding external power supply, the output end of the linear voltage regulator 111 is connected to the electrostatic probe 300 through the voltage regulating unit 112, the output end of multiple linear voltage regulators 111 is connected to the electrostatic probe 300, wherein the voltage regulating unit 112 corresponding to the last linear voltage regulator 111 is connected between the output end of the current linear voltage regulator 111 and the ground, and the voltage regulating unit 112 corresponding to the last linear voltage regulator 111 is connected between the output end of the current linear voltage regulator 111 and the output end of the next linear voltage regulator 111, the voltage regulating unit 112 is used to adjust the output voltage of each linear power branch 110 to be relatively the same, and adjust the output voltage of the power module 100 to the required voltage of the electrostatic probe 300. The sampling module 200 comprises a sampling resistor 210 and a sampling unit 220, the sampling resistor 210 is connected in series between the output end of the power module 100 and the electrostatic probe 300, and the sampling unit 220 is connected in parallel with the sampling resistor 210.

[0028] In the embodiment, the power supply circuit for the electrostatic probe adopts multiple linear power branches 110 with linear voltage regulators 111, the linear voltage regulator 111 can output low-ripple power supply voltage, the linear power branches 110 are connected in parallel input and series output, each linear power branch 110 has a voltage regulating unit 112 capable of adjusting the output voltage of the linear voltage regulator 111, multiple linear voltage regulators 111 are connected in series, the reverse end (i.e. the reference voltage end) of the error amplifier in the lower linear voltage regulator 111 is connected to the output end of the upper linear voltage regulator 111, the voltage regulating unit 112 dynamically adjusts the output voltage of each linear voltage regulator 111, adjusts the output voltage of each linear voltage regulator 111 to be consistent, to realize high-voltage stability and voltage equalization control, and the sum of the output voltages is adjusted to the required voltage of the electrostatic probe 300, which can provide the electrostatic probe 300 with power supply voltage with small enough voltage ripple and high enough voltage value, and can accurately detect the weak ion saturation flow signal when detecting the ion saturation flow.

[0029] When the power supply circuit for the electrostatic probe is used for plasma collection, the waveform of the plasma as shown in Figure 4 can be obtained. It can be seen that the weak plasma signal can be accurately detected.

[0030] In an embodiment, when multiple linear voltage stabilizers 111 are connected in series, the inter-stage coupling noise, poor transient response and other conditions may be introduced, therefore, in the embodiment, the number of linear voltage stabilizers 111 is set as small as possible according to the required voltage of the electrostatic probe 300. When detecting the ion saturation current of the controlled nuclear fusion device, the power supply of the electrostatic probe 300 is required to have high voltage, low ripple, high sampling rate and other elements, for example, the voltage is required to be above 180V, the ripple voltage is required to be within 20mV, and the sampling frequency is required to be above 100k. For existing switching power supplies, for example, DC / DC power supply modules, when the output voltage is above 180V, the voltage ripple is above 1%, and the sampling frequency is low, which often affects the authenticity of the ion saturation current signal detection. Therefore, in the embodiment, the linear voltage stabilizer 111 can use a low dropout linear voltage stabilizer device with an output voltage above 90V, and when building the power supply circuit, only two linear power supply branches 110 are needed, that is, only two linear voltage stabilizers 111 connected in series can meet the required voltage of the electrostatic probe 300, and the transient response, inter-stage coupling noise and other conditions of the two linear voltage stabilizers 111 connected in series are within an acceptable range.

[0031] In an embodiment, in order to further improve the transient response capability, reduce the inter-stage coupling noise, and reduce the ripple of the output voltage, a filtering unit is arranged at the input end and the output end of the linear voltage stabilizer 111. Specifically, the filtering unit can include an input rectification filtering unit connected to the input end of the linear voltage stabilizer 111 and an output filtering unit connected to the output end of the linear voltage stabilizer 111. The input rectification filtering unit and the output filtering unit can use a capacitor for filtering. For example, the input rectification filtering unit can include a first filtering capacitor C1 connected in parallel to the input end of the linear voltage stabilizer 111, and the output filtering unit can include a second filtering capacitor C2 connected in parallel to the output end of the linear voltage stabilizer 111. The first filtering capacitor C1 can pre-filter the voltage input to the linear voltage stabilizer 111 to ensure the quality of the voltage input to the linear voltage stabilizer 111, and the second filtering capacitor C2 connected in parallel to the output end of the linear voltage stabilizer 111 can further reduce the ripple of the output voltage of the linear voltage stabilizer.

[0032] In an embodiment, in order to further improve the transient response capability and reduce the inter-stage coupling noise, the first filtering capacitor C1 and the second filtering capacitor C2 can use a ceramic capacitor array. The ceramic capacitor array can not only filter high-frequency noise, but also a ceramic capacitor array with low ESR and ESL can shorten the transient recovery time and improve the transient response capability.

[0033] In another embodiment, the turbulent flow characteristics of the boundary plasma cause the ion saturation current signal to fluctuate on a sub-microsecond time scale, such as edge-localized modes (ELMs), which often requires the linear power supply branch to have a higher dynamic response capability, therefore, a dynamic feed-forward compensation circuit can be used to shorten the response time, for example, a high-gain comparator can be used to detect the current rate of change on the plasma collection device, and its output directly drives the regulating tube of the linear voltage regulator to achieve dynamic feed-forward compensation.

[0034] In one embodiment, the voltage regulating unit 112 includes an adjustable voltage dividing circuit, the input end of the adjustable voltage dividing circuit is connected with the output end of the linear voltage regulator 111, and the voltage dividing end of the adjustable voltage dividing circuit is connected with the feedback end; the adjustable voltage dividing circuit includes a first resistor R1 and an adjustable resistor RV connected in series, and the voltage dividing end is arranged between the first resistor R1 and the adjustable resistor RV. In this embodiment, the feedback end is used as the reverse input end of the error amplifier in the linear voltage regulator 111, and the voltage dividing end of the adjustable voltage dividing circuit is connected. When a plurality of linear voltage regulators 111 are connected in parallel input and series output, the adjustable resistor RV of the voltage regulating unit 112 in the last linear power supply branch 110 is grounded, and the adjustable resistor RV of the voltage regulating unit 112 in the last linear power supply branch 110 is connected with the output end of the next linear power supply branch 110.

[0035] The output voltage of each linear voltage regulator 111 is adjusted by adjusting the resistance value of the adjustable resistor RV. In this embodiment, the adjustable resistor RV can be a precision adjustable resistor to adjust the output voltage of the linear voltage regulator 111, and the output voltages of the linear voltage regulators 111 can be adjusted to be equal, so as to realize the voltage equalization output of each linear voltage regulator 111 and prevent the damage of one or several linear voltage regulators 111 caused by the instantaneous high voltage or current mutation of the plasma.

[0036] In an embodiment, the sampling unit 220 comprises an isolation amplification chip U1, a filter circuit 221 and a collector U2; an input end of the isolation amplification chip U1 is connected with the sampling resistor 210, and an output end of the isolation amplification chip U1 is connected with the collector U2 through the filter circuit 221. The input end of the isolation amplification chip U1 is connected at both ends of the sampling resistor 210, and the isolation amplification chip U1 can electrically isolate and amplify the signal collected by the sampling resistor 210. Electrical isolation can effectively avoid interference in the signal transmission process, improve the purity of the signal and the anti-interference ability of the circuit, and also protect the subsequent circuit and equipment, prevent high voltage or abnormal signal from damaging the collector and other devices. The amplification function of the isolation amplification chip U1 can adjust the amplitude of the signal according to actual needs, so as to meet the input requirements of the collector U2. The filter circuit 221 can adopt a π-type filter circuit composed of a first filter resistor, a second filter resistor and a third filter capacitor, which can filter high-frequency noise in the signal, so that the signal entering the collector U2 is smoother and more stable. Through the cooperation of the sampling resistor 210, the isolation amplification chip U1, the filter circuit 221 and the collector U2 and the low-ripple voltage output by the linear voltage stabilizer 111, the accuracy of the collected ion saturation flow signal can be improved.

[0037] In an embodiment, as shown in Figure 2 The power supply circuit for the electrostatic probe further comprises a current limiting module 400 connected between the output end of the power supply module 100 and the sampling module 200. The current limiting module 400 acts in response to the output current of the power supply module 100 to turn on or turn off the connection between the power supply module 100 and the electrostatic probe 300. When the output current of the power supply module 100 is less than a preset current, the current limiting module 400 enables the power supply module 100 to output electric energy to the electrostatic probe 300. When the output current of the power supply module 100 is greater than the preset current, the current limiting module 400 disconnects the connection between the power supply module 100 and the electrostatic probe 300, so that the power supply module 100 stops outputting electric energy to the electrostatic probe 300.

[0038] As Figure 3As shown, the current limiting module 400 comprises a first controllable switch Q1, a second controllable switch Q2, a second resistor R2, a third resistor R3 and a fourth resistor R4; a control terminal of the first controllable switch Q1 is connected with an output terminal of the power module 100 through the second resistor R2, and an input terminal of the first controllable switch Q1 is connected with the output terminal of the power module 100; an input terminal of the second controllable switch Q2 is connected with the output terminal of the power module 100 through the second resistor R2, and a control terminal of the second controllable switch Q2 is connected with an output terminal of the first controllable switch Q1; one end of the third resistor R3 is connected with the input terminal of the second controllable switch Q2, and the other end of the third resistor R3 is connected with the output terminal of the first controllable switch Q1, the input terminal of the second controllable switch Q2 and one end of the fourth resistor R4 respectively, and the other end of the fourth resistor R4 is grounded.

[0039] As an exemplary embodiment, the preset current of the current limiting module 400 is the protection current set by the selected linear voltage regulator 111, and the preset current can be 500 mA, for example. The resistance value of the second resistor R2 is selected by presetting the preset current and the output voltage of the power module 100, and the resistance values of the third resistor R3 and the fourth resistor R4 are set by the selection of the second controllable switch Q2, so as to accurately limit the current to protect the linear voltage regulator in the power module.

[0040] The first controllable switch Q1 and the second controllable switch Q2 can comprise a MOS tube, a transistor or other switch tube. In this embodiment, the first controllable switch Q1 is a PNP type transistor, and the second controllable switch Q2 is an NMOS tube, which are taken as examples for description. The base and the emitter of the PNP type transistor are connected at two ends of the second resistor R2; the gate and the source of the NMOS tube are connected at two ends of the third resistor R3, and the gate of the NMOS tube is connected with the collector of the PNP type transistor, and the source of the NMOS tube is connected with the output terminal of the power module 110 through the second resistor R2.

[0041] The principle of the current limiting module is described below by specific examples:

[0042] The second resistor R2 connected at the output terminal of the power module 100 can be used as a current sampling resistor, and the second resistor R2 is connected between the control terminal and the input terminal of the first controllable switch Q1. When the output current of the power module 100 is small, the voltage drop of the second resistor R2 is small, and the voltage difference between the control terminal and the input terminal of the first controllable switch Q1 is small, which is less than the turn-on voltage of the first controllable switch Q1, so the first controllable switch Q1 is turned off, and the third resistor R3 and the fourth resistor R4 form a voltage divider circuit, and the control terminal and the input terminal of the second controllable switch Q2 are connected at two ends of the third resistor R3, and the voltage drop between the two ends of the third resistor R3 is V R3 = V OUT×(R3 / (R3+R4)), where V R3 V is the voltage drop across the third resistor. OUT R3 is the output voltage of the linear regulator, R4 is the resistance of the third resistor, and R5 is the resistance of the fourth resistor. The voltage drop across the third resistor R3 is greater than the turn-on voltage of the second controllable switch Q2, causing Q2 to turn on. The power supply circuit operates normally.

[0043] When the output current of the power module 100 is large, the voltage drop of the second resistor R2 is large, resulting in a large voltage difference between the control terminal and the input terminal of the first controllable switch Q1. When the voltage difference is greater than the turn-on voltage of the first controllable switch Q1, the first controllable switch Q1 is turned on, and the current flows directly through the first controllable switch Q1 to the fourth resistor R4. The third resistor R3 is effectively short-circuited. The voltage difference between the control terminal and the input terminal of the second controllable switch Q2 is less than its turn-on voltage, so the second controllable switch Q2 is turned off, and the power circuit limits the current.

[0044] like Figure 2 As shown, each of the linear power supply branches 110 further includes a short-circuit protection unit 113; the short-circuit protection unit 113 includes a Darlington transistor Q3, a Zener diode, and a fifth resistor R5; the positive terminal of the Zener diode D1 is connected to the output terminal of the linear power supply branch 110, and the negative terminal is connected to the control terminal of the Darlington transistor Q3; one end of the fifth resistor R5 is connected to the external power supply, and the other end is connected to the control terminal of the Darlington transistor Q3; one end of the Darlington transistor Q3 is connected to the input terminal of the linear regulator 111, and the other end is connected to the external power supply.

[0045] For example, the Darlington transistor Q3 is composed of two NPN transistors. The collector of the first NPN transistor is connected to the collector of the second NPN transistor, and the emitter of the first NPN transistor is connected to the base of the second NPN transistor. One end of the Zener diode D1 is connected to the output terminal of the linear power supply branch 110, and the other end is connected to the Darlington base of the Darlington transistor Q3. One end of the fifth resistor R5 is connected to the external power supply, and the other end is connected to the base of the Darlington transistor Q3. The emitter of the Darlington transistor Q3 is connected to the input terminal of the linear regulator 111, and the collector is connected to the external power supply. The short-circuit protection unit 113 and the regulating transistor contained inside the linear regulator 111 work together to reverse-bias the base-emitter junction of the Darlington transistor Q3, preventing current from entering the linear regulator 111, thus protecting the linear regulator 111 when plasma breaks up during fusion.

[0046] As an exemplary embodiment, the linear power supply branch 110 further comprises a rectification module 114; the rectification module 114 comprises a transformer, a rectifier bridge and a rectification filter circuit, wherein the transformer input end is connected with the external power supply, the output end is connected with the rectifier bridge, and the rectifier bridge is connected to the input end of the linear voltage stabilizer through the rectification filter circuit, wherein the rectification filter circuit can adopt an RC filter circuit.

[0047] As an exemplary embodiment, the electrostatic probe 300 is connected with an overvoltage protection circuit 500 at both ends. Exemplarily, the overvoltage protection circuit 500 comprises a varistor and a transient voltage suppression tube; the varistor and the transient voltage suppression tube are connected in parallel and connected in parallel with the electrostatic probe 300. It can prevent transient voltage from damaging the electrostatic probe 300 or the power supply module 100.

[0048] The above-mentioned sequence numbers of the embodiments of the present application are only for description, and do not represent the advantages and disadvantages of the embodiments.

[0049] The above-described device embodiments are only schematic, and the division of units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units or modules shown or discussed can be indirect coupling or communication connection through some interfaces, units or modules, and can be electrical or other forms.

[0050] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e. can be located in one place or distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the scheme provided in the embodiments.

[0051] In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The above integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0052] In the above-described embodiments of the present application, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0053] The above is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, which should be considered as the protection scope of the present application.

Claims

1. A power supply circuit for an electrostatic probe, characterized by, The power supply circuit comprises a power supply module and a sampling module; The power supply module comprises a plurality of linear power supply branches connected in parallel at the input and in series at the output, each linear power supply branch comprising a linear voltage regulator and a voltage regulating unit, the input of each linear voltage regulator being connected to a corresponding external power supply, the outputs of the linear voltage regulators being connected to the electrostatic probe via the voltage regulating unit, wherein the voltage regulating unit of the last linear voltage regulator is connected between the output of the current linear voltage regulator and the ground, and the voltage regulating unit of the previous linear voltage regulator is connected between the output of the current linear voltage regulator and the output of the next linear voltage regulator; The sampling module comprises a sampling resistor and a sampling unit, the sampling resistor being connected in series between the output of the power supply module and the electrostatic probe, and the sampling unit being connected to the sampling resistor.

2. The power supply circuit for electrostatic probes as claimed in claim 1, wherein, The voltage regulating unit comprises a first resistor and an adjustable resistor connected in series between the output of the current linear voltage regulator and the output of the next linear voltage regulator, and a voltage dividing terminal between the first resistor and the adjustable resistor, wherein the voltage dividing terminal is connected to the feedback terminal of the corresponding linear voltage regulator.

3. The power supply circuit for electrostatic probes as recited in claim 1, wherein, The power supply module further comprises: an input rectification and filtering unit connected to the input of the linear voltage regulator; an output filtering unit connected to the output of the linear voltage regulator.

4. The power supply circuit for electrostatic probes as recited in claim 1, wherein, The sampling unit comprises an isolation and amplification chip, a filtering unit and a collector; the input of the isolation and amplification chip is connected to the sampling resistor, and the output of the isolation and amplification chip is connected to the collector via the filtering unit.

5. The power supply circuit for an electrostatic probe according to any one of claims 1 to 4, wherein Further comprising: a current limiting module connected between the output of the power supply module and the sampling module, the current limiting module disconnecting the connection between the power supply module and the electrostatic probe when the output current of the power supply module is greater than a preset current.

6. The power supply circuit for electrostatic probes as claimed in claim 5, wherein, The current limiting module comprises a first controllable switch, a second controllable switch, a second resistor, a third resistor and a fourth resistor; the control terminal of the first controllable switch is connected to the output of the power supply module via the second resistor, and the input of the first controllable switch is connected to the output of the power supply module; the input of the second controllable switch is connected to the output of the power supply module via the second resistor, and the control terminal of the second controllable switch is connected to the output of the first controllable switch; one end of the third resistor is connected to the input of the second controllable switch, and the other end of the third resistor is connected to the output of the first controllable switch, the input of the second controllable switch and one end of the fourth resistor, and the other end of the fourth resistor is connected to the ground.

7. The power supply circuit for electrostatic probes as claimed in claim 6, wherein, The first controllable switch comprises a PNP triode, and the second controllable switch comprises an NMOS tube.

8. The power supply circuit for electrostatic probes as recited in claim 1, wherein, Each linear power supply branch further comprises a short circuit protection unit, the short circuit protection unit comprising a Darlington tube, a voltage stabilizing diode and a fifth resistor; the positive electrode of the voltage stabilizing diode is connected to the output of the linear power supply branch, and the negative electrode is connected to the control terminal of the Darlington tube; one end of the fifth resistor is connected to the external power supply, and the other end is connected to the control terminal of the Darlington tube. The input end of the Darlington tube is connected with the external power supply, and the output end is connected with the input end of the linear voltage stabilizer.

9. The power supply circuit for electrostatic probes as recited in claim 1, wherein, The linear power supply branch further comprises a rectification module, an input end of the rectification module is connected with the external power supply, and an output end of the rectification module is connected with the input end of the linear voltage stabilizer.

10. The power supply circuit for electrostatic probes as recited in claim 1, wherein, Further comprising: An overvoltage protection module, the overvoltage protection module comprises a pressure sensitive resistor and a transient voltage suppression tube connected in parallel across the electrostatic probe, and the pressure sensitive resistor and the transient voltage suppression tube are connected in parallel.

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