Space charged particle electrostatic charge measuring device

Abstract

The invention relates to a space charged particle electrostatic charge measuring device, which comprises a Faraday cup used for receiving space charged particles and converting the charge quantity of the space charged particles into instantaneous peak voltage; the peak voltage detection circuit is used for measuring the peak voltage after the Faraday cup receives the space charged particles; the signal conditioning and digital sampling circuit is used for conditioning and sampling the peak voltage and converting the peak voltage into digital quantity; and the digital circuit is used for collecting the digital quantity of the peak voltage and converting the digital quantity into a charge quantity value. The instantaneous peak voltage generated when the Faraday cup receives the space charged particles is detected through the peak voltage detection circuit, the charge quantity of the space charged particles is obtained through calculation of the digital circuit, and the device has the advantages of being high in measurement speed and measurement efficiency, simple in circuit structure, low in cost and convenient to apply and popularize.

Description

Technical Field

[0001] The invention relates to the technical field of charge measurement, and in particular to a device for measuring the electrostatic charge of space charged particles. Background Art

[0002] The measurement of static charge of space particles has great application value in the military field. For example, monitoring the charge changes of the oil and gas circuits of fighter jets, monitoring the health of fighter jet engines and performing maintenance as needed; monitoring the static safety of the refueling process of military aerial refueling tankers by measuring the static charge; monitoring the changes in the static charge in the exhaust gas of missiles and rocket engines, and then judging the health of missiles and rocket engines; monitoring the static charge during the loading and unloading and transportation of military oil, to ensure the safety and timeliness of the oil used by military aircraft, tanks, war vehicles, ships, submarines, etc.; in addition, by monitoring the dynamic information such as the static charge, particle velocity, concentration and particle size of powder particles when they move with the airflow in the pipeline, it can be applied to the static safety monitoring in the production process of military ammunition to reduce safety hazards.

[0003] Electrostatic charge sensors (space charged particle electrostatic charge measurement devices) are widely used and important in the military field. As the forefront of the electrostatic monitoring system, the electrostatic charge sensor is the core component of the entire electrostatic monitoring system. The quality of its performance and the accuracy of the data obtained directly affect the accuracy of the entire oil and gas circuit electrostatic monitoring system of military aircraft, tanks, war vehicles, ships, submarines, etc., as well as the accuracy of the working status of the monitored components. If the accuracy of the electrostatic charge monitoring data is insufficient, it is easy to cause false alarms in the monitoring system and misjudgment of the actual status of the oil and gas circuits. Therefore, electrostatic charge measurement and calibration technology is widely used in the field of national defense and is of great significance.

[0004] Traditional electrostatic charge measurement uses a micro-ammeter with high input impedance to continuously measure static electricity. The instantaneous current i generated by the discharge through its input resistance R is integrated with the measurement time to calculate the electrostatic charge. The measurement is based on the following formula:

[0005]

[0006] The scheme of using a Faraday cup with a transimpedance amplifier current measurement circuit integrates the current generated by the input charge to measure the charge value. The measurement process of this scheme is relatively slow. Due to the presence of non-ideal discharge resistance in the measurement system, an input charge leakage path is formed, causing the charge measurement value to be smaller than the actual value, and it is difficult to correct and compensate through subsequent data processing. In addition, due to the complexity of the measurement circuit of this scheme, the device is large in size and high in cost, and is not suitable for pulse jet type space charged particle charge measurement. Summary of the invention

[0007] In order to solve the technical problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a device for measuring the electrostatic charge of charged particles in space, which has the characteristics of being simple and efficient, fast in measuring speed, low in cost and easy to promote and apply.

[0008] In order to achieve the above-mentioned object of the invention, the present invention provides a device for measuring the electrostatic charge of charged particles in space, comprising:

[0009] A Faraday cup, used for receiving space-charged particles and converting the charge of the space-charged particles into an instantaneous peak voltage;

[0010] A peak voltage detection circuit, used for measuring the peak voltage after the Faraday cup receives the charged particles in space;

[0011] A signal conditioning and digital sampling circuit, used for conditioning and sampling the peak voltage and converting it into a digital quantity;

[0012] The digital circuit is used to collect the digital value of the peak voltage and convert it into a charge value.

[0013] According to a technical solution of the present invention, the peak voltage detection circuit includes:

[0014] A voltage divider circuit, a first end of which is connected to the second end of the Faraday cup and a second end of which is grounded;

[0015] an operational amplifier, a non-inverting input terminal of which is connected to the third terminal of the voltage divider circuit;

[0016] a diode, an anode of which is connected to the output terminal of the operational amplifier, and a cathode of which is connected to the inverting input terminal of the operational amplifier;

[0017] A voltage peak holding capacitor has a first end connected to the cathode of the diode and a second end grounded; the input end of the signal conditioning and digital sampling circuit is connected to the first end of the voltage peak holding capacitor.

[0018] According to a technical solution of the present invention, the voltage divider circuit includes:

[0019] A first voltage-dividing capacitor, a first end of which is connected to the second end of the Faraday cup;

[0020] A second voltage-dividing capacitor has a first end connected to the second end of the first voltage-dividing capacitor and a second end grounded.

[0021] According to a technical solution of the present invention, the calculation formula of the charge Q of the space charged particles is:

[0022]

[0023] Among them, CF Represents the equivalent capacitance of the Faraday cup, C 1 represents the capacitance value of the first voltage divider capacitor, C 2 represents the capacitance value of the second voltage divider capacitor, V F2 Represents the peak voltage collected by the signal conditioning and digital sampling circuit.

[0024] According to a technical solution of the present invention, it also includes:

[0025] a first discharge switch, a first end of which is connected to the first end of the Faraday cup and a second end of which is grounded;

[0026] A second discharge switch has a first end connected to the output end of the peak voltage detection circuit and a second end connected to the ground.

[0027] According to a technical solution of the present invention, the measuring method comprises the following steps:

[0028] Step S1, turning off the first discharge switch and the second discharge switch;

[0029] Step S2, receiving the spatial charged particles through the Faraday cup, conditioning and sampling the peak voltage of the peak voltage detection circuit through the signal conditioning and digital sampling circuit, and converting it into a digital value;

[0030] Step S3, collecting the digital value of the peak voltage through the digital circuit and converting it into a charge value;

[0031] Step S4: After a single measurement is completed, the stored charge is released by closing the first discharge switch and the second discharge switch to perform the next measurement.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention proposes a device for measuring the electrostatic charge of charged particles in space, comprising a Faraday cup, a peak voltage detection circuit, a signal conditioning and digital sampling circuit and a digital circuit. The peak voltage detection circuit is used to replace the transimpedance amplifier in the traditional device for measuring the electrostatic charge of charged particles in space. The charge of the charged particles is converted into an instantaneous peak voltage through the Faraday cup and input into the peak voltage detection circuit. The instantaneous peak voltage of the input charge is maintained and measured through the peak voltage detection circuit. Compared with the traditional measurement method, the measurement speed of the measuring device of the present invention is faster, and the problem of small measurement value caused by charge leakage during the measurement process is avoided.

[0034] In the present invention, the peak voltage detection circuit has a simple structure, a small circuit scale, and a high measurement efficiency. It does not require electronic components such as precision high-value resistors required by traditional transimpedance amplifiers, and is easy to make into a handheld portable measuring instrument with low cost and easy to promote and apply. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 A schematic diagram of the structure of a device for measuring the electrostatic charge of space-charged particles provided in one embodiment of the present invention is shown;

[0037] Figure 2 The figure schematically shows the structure of a peak voltage detection circuit according to an embodiment of the present invention.

[0038] The corresponding relationship between the reference numerals and component names is as follows:

[0039] 1. Faraday cup; 2. Peak voltage detection circuit; 3. Signal conditioning and digital sampling circuit; 4. Digital circuit; 5. First discharge switch; 6. Second discharge switch; 7. Space charged particles. DETAILED DESCRIPTION

[0040] The description of the embodiments of this specification should be combined with the corresponding drawings, which should be considered as part of the complete specification. In the drawings, the shape or thickness of the embodiments may be enlarged and indicated for simplification or convenience. Furthermore, the parts of each structure in the drawings will be described separately. It is worth noting that the elements not shown in the drawings or not described in words are in a form known to ordinary technicians in the relevant technical field.

[0041] The description of the embodiments herein and any reference to directions and orientations are only for the convenience of description and are not to be construed as any limitation on the scope of protection of the present invention. The following description of the preferred embodiments may involve combinations of features, which may exist independently or in combination, and the present invention is not particularly limited to the preferred embodiments. The scope of the present invention is defined by the claims.

[0042] like Figure 1 As shown, a device for measuring the electrostatic charge of charged particles in space of the present invention comprises a Faraday cup 1, a peak voltage detection circuit 2, a signal conditioning and digital sampling circuit 3 and a digital circuit 4.

[0043] The Faraday cup 1 is used to receive the spatial charged particles 7 and convert the charge of the spatial charged particles 7 into an instantaneous peak voltage. The peak voltage detection circuit 2 is used to measure the peak voltage after the Faraday cup 1 receives the spatial charged particles 7. The signal conditioning and digital sampling circuit 3 is used to condition and sample the peak voltage and convert it into a digital quantity. The digital circuit 4 is used to collect the digital quantity of the peak voltage and convert it into a charge value for display, transmission, storage, etc.

[0044] The device for measuring the electrostatic charge of charged particles in space of the present invention improves the traditional electrostatic charge measurement method based on a high-input impedance microammeter into one that uses a peak voltage detection circuit to measure the instantaneous voltage generated by the electrostatic charge. It has many advantages in the measurement of the charge of charged particles in space by pulse jet type. Through the above device, the measurement of the charge of charged particles in space at the kilovolt level can be achieved.

[0045] In one embodiment of the present invention, Figure 2 As shown, the peak voltage detection circuit 2 includes:

[0046] A voltage divider circuit, a first end of which is connected to the second end of the Faraday cup 1 and a second end of which is grounded;

[0047] The non-inverting input terminal of the operational amplifier OPAMP is connected to the third terminal of the voltage divider circuit;

[0048] The anode of the diode D1 is connected to the output terminal of the operational amplifier OPAMP, and the cathode of the diode D1 is connected to the inverting input terminal of the operational amplifier OPAMP;

[0049] Voltage peak holding capacitor C 3 The first end is connected to the cathode of diode D1, and the voltage peak holding capacitor C 3 The second end of the signal conditioning and digital sampling circuit 3 is connected to the voltage peak holding capacitor C 3 The first end of the connection.

[0050] In one embodiment of the present invention, the voltage divider circuit includes a first voltage divider capacitor C 1 and the second voltage divider capacitor C 2 , the first voltage divider capacitor C 1 The first end of the Faraday cup 1 is connected to the second end of the second voltage-dividing capacitor C 2 The first end of the first voltage dividing capacitor C 1 The second end of the second voltage divider capacitor C 2 The second end is grounded.

[0051] The above device can realize the measurement of the charge amount of charged particles in space at the kilovolt level.

[0052] In the present invention, the first voltage-dividing capacitor C 1and the second voltage divider capacitor C 2 A voltage divider circuit is formed to convert the output voltage of the Faraday cup 1 into a voltage that the operational amplifier can withstand. The peak value of the voltage after voltage division can be maintained at the voltage peak holding capacitor C through the operational amplifier and the diode. 3 superior.

[0053] The device for measuring the electrostatic charge of charged particles in space provided by the present invention comprises the following steps:

[0054] Step S1, turning off the first discharge switch 5 and the second discharge switch 6;

[0055] Step S2, receiving the spatial charged particles 7 through the Faraday cup 1, conditioning and sampling the peak voltage of the peak voltage detection circuit 2 through the signal conditioning and digital sampling circuit 3, and converting it into a digital value;

[0056] Step S3, collecting the digital value of the peak voltage through the digital circuit 4 and converting it into a charge value;

[0057] The calculation formula for the electrostatic charge carried by charged particles in space is:

[0058]

[0059] Among them, C 1 Represents the first voltage-dividing capacitor C 1 Capacitance value, C 2 Represents the second voltage-dividing capacitor C 2 Capacitance value, V F2 It represents the peak voltage collected by the signal conditioning and digital sampling circuit 3.

[0060] like Figure 2 As shown, the Faraday cup 1 plays the role of receiving the charged particles 7 in space, and the equivalent circuit model of the Faraday cup 1 is a capacitor C F After the electrostatic charge Q carried by the space charged particle 7 is absorbed by the Faraday cup 1, a potential V is established on the electrode of the Faraday cup 1. F1 , potential V F1 The capacitance C of Faraday cup 1 F and the capacitance C of the voltage divider capacitor in the peak voltage detection circuit 2 1 , C 2 Related.

[0061] Peak voltage detection circuit 2 will V F1 C 1 , C 2 The peak value of the voltage after proportional voltage division is maintained at the voltage peak holding capacitor C 3 After the post-stage signal conditioning and digital sampling circuit 3 measures VF2, the input charge value Q can be obtained through linear conversion.

[0062] Step S4: After a single measurement is completed, the stored charge is released by closing the first discharge switch 5 and the second discharge switch 6 to perform the next measurement.

[0063] In the conventional current measurement circuit using a Faraday cup in combination with a transimpedance amplifier, the current decreases as the measurement time increases due to the presence of leakage current in the non-ideally distributed leakage path of the input path, resulting in an error in the measurement result compared to the actual result. The present invention uses instantaneous voltage value to measure the charge, has a fast measurement speed, does not need to consider the influence of leakage current in the non-ideally distributed leakage path of the input path, has a fast measurement speed, and has high measurement accuracy.

[0064] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0065] Finally, it should be noted that the above is a preferred embodiment of the present invention. It should be pointed out that although the preferred embodiment of the present invention has been described, for those skilled in the art, once the basic creative concept of the present invention is known, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention. Therefore, the attached claims are intended to be interpreted as including the preferred embodiment and all changes and modifications that fall within the scope of the embodiments of the present invention.

Claims

1. A device for measuring the electrostatic charge of charged particles in space, characterized in that: include: A Faraday cup (1) for receiving spatially charged particles (7) and converting the charge of the spatially charged particles (7) into an instantaneous peak voltage; A peak voltage detection circuit (2) for measuring the peak voltage after the Faraday cup (1) receives the spatially charged particles (7); A signal conditioning and digital sampling circuit (3) is used to condition and sample the peak voltage and convert it into a digital quantity; The digital circuit (4) is used to collect the digital value of the peak voltage and convert it into a charge value.

2. The device for measuring the electrostatic charge of space-charged particles according to claim 1, characterized in that: The peak voltage detection circuit (2) comprises: A voltage divider circuit, a first end of which is connected to the second end of the Faraday cup (1) and a second end of which is grounded; an operational amplifier, a non-inverting input terminal of which is connected to the third terminal of the voltage divider circuit; a diode, an anode of which is connected to the output terminal of the operational amplifier, and a cathode of which is connected to the inverting input terminal of the operational amplifier; A voltage peak holding capacitor has a first end connected to the cathode of the diode and a second end connected to ground; an input end of the signal conditioning and digital sampling circuit (3) is connected to the first end of the voltage peak holding capacitor.

3. The device for measuring the electrostatic charge of space-charged particles according to claim 2, characterized in that: The voltage divider circuit comprises: A first voltage-dividing capacitor, a first end of which is connected to the second end of the Faraday cup (1); A second voltage-dividing capacitor has a first end connected to the second end of the first voltage-dividing capacitor and a second end grounded.

4. The device for measuring the electrostatic charge of space-charged particles according to claim 3, characterized in that: The calculation formula for the charge Q of the space charged particle (7) is: Among them, C F represents the equivalent capacitance value of the Faraday cup (1), C1 represents the capacitance value of the first voltage-dividing capacitor, C2 represents the capacitance value of the second voltage-dividing capacitor, V F2 Indicates the peak voltage collected by the signal conditioning and digital sampling circuit (3).

5. The device for measuring the electrostatic charge of space-charged particles according to claim 1, characterized in that: Also includes: A first discharge switch (5), a first end of which is connected to the first end of the Faraday cup (1), and a second end of which is grounded; A second discharge switch (6) has a first end connected to the output end of the peak voltage detection circuit (2) and a second end connected to the ground.

6. The device for measuring the electrostatic charge of space-charged particles according to claim 5, characterized in that: The measurement method includes the following steps: Step S1, turning off the first discharge switch (5) and the second discharge switch (6); Step S2, receiving the spatially charged particles (7) through the Faraday cup (1), conditioning and sampling the peak voltage of the peak voltage detection circuit (2) through the signal conditioning and digital sampling circuit (3), and converting it into a digital quantity; Step S3, collecting the digital value of the peak voltage through the digital circuit (4) and converting it into a charge value; Step S4: After a single measurement is completed, the stored charge is released by closing the first discharge switch (5) and the second discharge switch (6) to perform the next measurement.

Images