CN202075322U - Fast-response passive resistance differentiator with two matched ends - Google Patents

Abstract

The utility model relates to a fast-response passive resistance-capacity integrator capable of realizing the double-end matching of pulse signal integral calculation, used in conjunction with a differential probe, and applied to the measurement of high-voltage, high-current, and fast pulses. Including input matching resistor, integrating resistor, integrating capacitor, output matching resistor, input cable holder, input cover, integrator shell, connecting plate of integrating capacitor, output cover, output cable holder and casing. The integrator considers the problem of matching at both ends when connecting the measuring cable, and reduces the stray inductance of the integrating capacitor and the distributed capacitance at both ends of the integrating resistor by selecting the core-through capacitance of the screw connection method and increasing the length of the integrating resistor , which reduces the adverse influence of the integrator on the measurement waveform, expands the upper limit of the response frequency of the integrator, and is suitable for the measurement of high-voltage and high-current pulses on the order of nanoseconds to microseconds.

Description

Fast Response Passive RC Integrator with Double-End Matching

technical field

The utility model relates to a fast-response passive resistance-capacity integrator capable of realizing pulse signal integral operation and double-end matching, which is used in conjunction with a differential probe and applied to the measurement of high-voltage, high-current, and fast pulses. the

technical background

In the field of pulse power technology, for the measurement of high voltage, high current and fast pulses, differential probes are often used, such as differential capacitive voltage dividers, Rogowski coils, etc., and differential signals need to be integrated to obtain the original measured waveform. Integral operation can use both numerical integration and device integration. When using numerical integration, it is necessary to preprocess the signal before integration, such as removing zero drift, selecting the time period for integration, etc. Otherwise, the waveform after integration may be quite different from the original waveform, and the measured waveform cannot be displayed in real time by numerical integration. It is the above reasons that limit the application of numerical integration. the

The time range of high-voltage, high-current, and fast pulses is usually on the order of nanoseconds to microseconds, and device integration often uses passive resistance-capacity integrators. Due to the wide spectrum range of the measurement signal, the distribution parameters of the integrator itself and the matching at both ends will cause waveform distortion, and even the correct measured signal cannot be obtained in severe cases. In order to reduce the influence of the integrator on the measured waveform, it is necessary to optimize the parameters of the integrating device and design the structure of the integrator, especially the connection mode between the devices. For example, the utility model patent "Coaxial Passive Resistance-Capacitance Integrator" applied by Weibing of the Institute of Engineering Physics. The connection method reduces the stray inductance of the integrator and improves the upper limit of the frequency response of the integrator. the

The utility model considers the matching between the output and input ends of the integrator and the measuring cable, adopts the integrating capacitor with a core-through structure, further reduces the distributed inductance of the integrating capacitor, improves the upper limit of the frequency response of the integrator, and simultaneously increases the integrating resistance The length of the sensor reduces the influence of distributed capacitance on the measurement. the

Contents of the invention

In order to overcome the problem that the existing passive resistance-capacity integrator does not consider double-end matching, and at the same time, in order to improve the response frequency of the integrator and reduce the adverse influence of the integrator on the waveform when measuring fast signals, the utility model provides a double-end matching Fast response passive resistance-capacity integrator. The integrator considers the problem of matching at both ends when connecting the measuring cable, and reduces the stray inductance of the integrating capacitor and the distributed capacitance at both ends of the integrating resistor, reduces the adverse influence of the integrator on the measurement waveform, and expands the integrator's The upper limit of the response frequency is suitable for the measurement of high-voltage and high-current pulses on the order of nanoseconds to microseconds. the

The double-end matched fast-response passive resistance-capacitance integrator of the present utility model includes an input-end matching resistor, an integrating resistor, an integrating capacitor, an output-end matching resistor, an input-end cable seat, an input-end cover plate, an integrator shell, and an integrating capacitor The connection plate, the output end cover plate, and the output end cable seat are characterized in that: the input end cable seat is a standard cable seat, and inside the integrator, the core wires of the cable seat are connected in parallel to the shell of the integrator through a number of low inductance film resistors. The resistance value of the rear resistor is 50Ω, which is consistent with the impedance of the measuring cable. The matching resistor at the input end of the integrator is connected by screw crimping, and the cable seat at the output end is a standard cable seat. The impedance matching between the output end and the measurement cable is realized by connecting a 49Ω resistor in series, and the integrator is a coaxial structure. the

The shell of the above-mentioned integrator is formed by butting two semi-circular rings, and the integral capacitor adopts a core-through capacitor in the form of screw connection, and there is no connection between the integral capacitor and the shell of the integrator, which reduces the stray inductance of the integral capacitor. the

In the above integrator, the matching resistance at the input end is composed of 6 low-inductance film resistors with a resistance value of 300Ω connected in parallel, the integral resistor is composed of 2 to 3 low-inductance film resistors with a resistance value of several hundred Ω in series, and the integral capacitance is Core structure, the capacitance value is 4~10nF, which is determined by the integral constant of the integrator. One pole of the capacitor is the core wire of the integral capacitor, and the other pole is the fixing bolt of the capacitor. The matching resistor at the output end is a low-inductance film resistor with a resistance value of 49Ω. the

The utility model's dual-end matching fast-response passive resistance-capacity integrator is characterized in that: (1) the input end of the integrator is a standard cable seat, and inside the integrator, the core wire of the cable seat passes through several low-inductance film resistors Parallel connection to the shell of the integrator, the resistance value of the resistance after parallel connection is consistent with the impedance of the measuring cable, which avoids the refraction and reflection of the measurement signal at the input end of the integrator; (2) The matching resistor at the input end of the integrator is connected by screw crimping to avoid (3) The output end of the integrator is also a standard cable holder, and the connection between the output end and the measurement cable is realized through a series resistance between the integrating capacitor inside the integrator and the core wire of the cable holder. Impedance matching avoids the refraction and reflection of the measurement signal at the output end of the integrator; (4) The integrator is a coaxial structure, and the outer shell is made of two semi-circular butt joints, and the integral capacitor adopts a core-through capacitor with screw connection. At present, the integrating capacitor is usually several ceramic disc capacitors connected in parallel and welded to the integrating resistor, or crimped to the integrating resistor with screws, so the stray inductance connected in series with the integrating capacitor is relatively large, which will lead to distortion of the measured waveform. There is no connection between the integral resistance and the integral capacitance of the utility model, which reduces the stray inductance in series to the greatest extent and improves the upper limit of the response frequency of the integrator; (5) by increasing the length of the integral resistance to reduce the Distributed capacitance reduces the distortion of the measured waveform caused by distributed capacitance. According to the data research, the existing integrator does not consider the influence of the distributed capacitance of the integrating resistor on the measurement, but the equivalent circuit simulation shows that the distributed capacitance at both ends of the integrating resistor has a significant impact on the measured waveform, and its importance is second only to the stray capacitor of the integrating capacitor. The effect of inductance. the

Both ends of the integrator of the utility model take into account the matching with the measuring cable, and by reducing the stray inductance of the integrating device and the distributed capacitance at both ends of the integrating resistor, the upper limit of the response frequency of the integrator is improved, which overcomes the problem of measuring ns level Waveform distortion problems such as overshoot and oscillation that may occur in fast pulse signals can be used for the measurement of high voltage, high current and fast pulses. the

Description of drawings

Fig. 1 is an equivalent circuit diagram of the utility model. the

Fig. 2 is a longitudinal sectional structure diagram of the first embodiment of the utility model. the

Fig. 3 is a sectional view along I-I direction in Fig. 2 . the

Fig. 4 is a view from II-II direction in Fig. 2 . the

In the figure, 1. Input terminal matching resistor, 2. Integrating resistor, 3. Integrating capacitor, 4. Output terminal matching resistor, 5. Input terminal cable seat, 6. Input terminal cover plate, 7. Integrator shell, 8. Integrating Capacitor connection plate, 9. output end cover plate, 10. output end cable seat. the

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is further described. the

Fig. 1 is the schematic circuit diagram of the utility model. the

The resistance value of the matching resistor 1 at the input end is consistent with the impedance of the measuring cable, which is 50Ω; the value of the integral resistor 2 is between hundreds of Ω and tens of kΩ, and the value of the integral capacitor 3 is several nF. The time constant is determined; the resistance value of the matching resistor 4 at the output end is slightly lower than the impedance of the measuring cable, which is 49Ω. The main function of the matching resistor 4 at the output end is to absorb the voltage wave that is transmitted back to the integrator from the oscilloscope along the measuring cable in reverse. the

The overall size of the embodiment of the utility model is Φ26×140mm (including the cable holders at both ends), and the structure is compact, and the main components are all axisymmetric structures. the

In Fig. 2 to Fig. 4, the shell 7 of the integrator is formed by butting two semicircular rings, and the interface is a nested structure, which can effectively shield external electromagnetic radiation. the

The cable bases 5, 10 and the cover plates 6, 10 at both ends of the integrator are fixed together with screws, and the cable bases are standard products. the

The matching resistor 1 at the input end is composed of six low-inductance film resistors with a resistance value of 300Ω connected in parallel, which can effectively reduce the inductance of the matching resistor 1 at the input end. the

The integrating resistor 2 is composed of three low-inductance film resistors with a resistance value of 300Ω connected in series, which can effectively reduce the distributed capacitance at both ends of the integrating resistor. the

The integral capacitor 3 is a core-through structure with a capacitance value of 6nF. One pole of the capacitor is the core wire of the integral capacitor, and the other pole is the fixing bolt of the capacitor. The structure and connection method of the integrating capacitor 3 can effectively reduce the stray inductance of the integrating capacitor. the

The matching resistor 4 at the output end is a low-inductance film resistor with a resistance value of 49Ω. the

The main installation process of the utility model embodiment is: (1) welding together one end of the input end matching resistor 1, the core wire of the input end cable seat 5 and one end of the integrating resistor 2; (2) welding the input end after welding After the cable seat 5 and the input end cover plate 6 are fixed, fix the other end of the input end matching resistor 1 on the input end cover plate 6 with screws; (3) Tighten and fix the integral capacitor 3 on the integral capacitor connecting plate 8 , to realize the connection of the integral capacitor 3 to the ground; (4) connect the three integral resistors 2 end to end and weld them together, and weld the other end of the integral resistor 2 with the core wire of the integral capacitor 3; (5) connect the output end cable holder After 10 and the output end cover plate 9 are fixed by screws, one end of the output matching resistor 4 is welded to the core wire of the output end cable seat 10, and the other end of the resistor is welded to the core wire of the other pole of the integrating capacitor 3; (6 ) Fix the integrator shell 7 and the input end cover plate 6, the integrating capacitor connection plate 8, and the output end cover plate 9 with screws. The installation of the utility model embodiment is completed. the

Claims (3)

1. A fast-response passive resistance-capacitance integrator with double-end matching, including input-end matching resistors, integrating resistors, integrating capacitors, output-end matching resistors, input-end cable holders, input-end cover plates, integrator shells, and integrating capacitors The connection plate, the output end cover plate, and the output end cable seat are characterized in that: the input end cable seat is a standard cable seat, and inside the integrator, the core wires of the cable seat are connected in parallel to the shell of the integrator through a number of low inductance film resistors. The resistance value of the rear resistor is 50Ω, which is consistent with the impedance of the measuring cable. The matching resistor at the input end of the integrator is connected by screw crimping, and the cable seat at the output end is a standard cable seat. The impedance matching between the output end and the measurement cable is realized by connecting a 49Ω resistor in series, and the integrator is a coaxial structure. 2. The fast-response passive resistance-capacitance integrator with double-terminal matching as claimed in claim 1, characterized in that the shell is formed by butting two semi-circular rings, and the integrating capacitor adopts a core-through capacitor in a threaded connection. 3. The fast-response passive resistance-capacitance integrator of double-terminal matching as claimed in claim 1 or 2, it is characterized in that the input matching resistance is composed of 6 low-inductance film resistances with a resistance value of 300Ω in parallel, and the integral resistance is 2 ~Three low-inductance film resistors with a resistance value of hundreds of Ω are connected in series. The integral capacitor is a core-through structure with a capacitance value of 4-10nF. One pole of the capacitor is the core wire of the integral capacitor, and the other pole is the fixing bolt of the capacitor. The output matching resistor is a low-inductance film resistor with a resistance value of 49Ω. the

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