Calibration device for oscilloscope current probe

Abstract

The application discloses a calibrating device for an oscilloscope current probe and particularly relates to the field of current probes. The device comprises a groove opened along the radial direction of a shell, a gear arranged in the groove, a connecting seat connected to the gear, a rotating shaft of an adjustable capacitor penetrating through the bottom of the groove and extending into the shell, a sleeve sleeved with the shell and located outside the groove, an annular push plate connected to the inner wall of the sleeve and located in the groove, a gear rack matched with the gear and arranged along the circumferential direction of the annular push plate, the gear rack being fixed on the side wall of the annular push plate, and a gap formed between the gear and the gear rack. The rotation is realized by the meshing of the gear rack and the gear, the annular gear rack and the gear are in fixed-ratio transmission, the speed and the angle of the rotating annular gear rack are directly corresponding to the rotating speed and the rotating angle of the gear, and compared with the rotation of a screwdriver, the control precision can be improved.

Description

Technical Field

[0001] This application relates to the field of current probes, and more particularly to a calibration device for an oscilloscope current probe. Background Technology

[0002] An oscilloscope current probe is a measurement tool used in conjunction with an oscilloscope. It consists of a BNC connector, probes, and a grounding clip. It utilizes a specific principle to convert the current signal in the circuit under test into a voltage signal that the oscilloscope can recognize, enabling non-contact measurement. With a current probe, users can observe the waveform, amplitude, frequency, and other parameters of the current on the oscilloscope without damaging the circuit connections, providing important information for circuit analysis and fault diagnosis.

[0003] New or long-used current probes may exhibit overcharging or undercharging, requiring calibration. To calibrate, connect the BNC connector to an oscilloscope, and connect the probe and ground clip to the standard signal and ground respectively. Set the attenuation ratio on the probe to 10X. Observe the oscilloscope waveform and adjust the probe's compensation capacitor by rotating the shaft in the BNC connector to match the probe to the oscilloscope. The probe screw is typically a screw, and screwdriver rotation relies on hand force and angle control, which can easily result in inconsistent rotation speeds and significant deviations, leading to low control accuracy. Utility Model Content

[0004] The main objective of this application is to provide a calibration device for an oscilloscope current probe, which aims to solve the problem of low adjustment accuracy of the compensation capacitor in existing oscilloscope current probes.

[0005] To achieve the above objectives, this application provides a calibration device for an oscilloscope current probe. The current probe includes a BNC connector, which includes a housing. An adjustable capacitor is disposed inside the housing. The calibration device includes: a groove formed radially along the housing, a gear disposed within the groove, a connecting seat connected to the gear, the connecting seat extending through the bottom of the groove into the housing, and connected to the rotating shaft of the adjustable capacitor; a sleeve is fitted over the housing, located outside the groove; a ring pusher plate is connected to the inner wall of the sleeve, the ring pusher plate is located within the groove, and a rack adapted to the gear is disposed circumferentially along the ring pusher plate, the rack being fixed to the side wall of the ring pusher plate, with a gap formed between the gear and the rack.

[0006] Optionally, a spring is fitted inside the groove, with the spring located between the ring push plate and the connecting seat, and the spring located below the rack.

[0007] Optionally, the groove includes a first groove and a second groove; the size of the first groove is adapted to the gear, the gear is located in the first groove, and the depth of the first groove is less than the depth of the second groove; the second groove is annular in shape, and the spring and rack are located in the second groove.

[0008] Optionally, the opening end of the first groove is covered with a cover, the width of which is the same as the width of the first groove; the length of the sleeve is greater than the width of the second groove and less than the sum of the lengths of the first and second grooves; one end of the sleeve is fitted with the outer wall of the shell and the other end is fitted with the outer wall of the cover.

[0009] Optionally, the cover includes a cover plate, with an insert plate vertically connected to the cover plate. The insert plate is fixed to the inner sidewall of the first groove, and the opening of the first groove is on the cover plate.

[0010] Optionally, the rack is conical in shape, and the gear is conical in shape.

[0011] Compared with the prior art, the beneficial effects of this application are as follows: This invention relates to a calibration device for an oscilloscope current probe. The gap between the gear and rack prevents accidental rotation of the sleeve when calibration is not required, thus reducing the error rate. The rotation is achieved through the meshing of the rack and gear; the ring rack and gear operate on a fixed ratio, meaning the speed and angle of rotation of the ring rack directly correspond to the speed and angle of rotation of the gear. Compared to using a screwdriver, this improves control precision. Furthermore, the outer diameter of the sleeve is larger than the diameter of the rotating shaft. Based on the lever principle, the lever arm is longer when rotating the ring rack, requiring only a smaller pushing force to rotate the gear. Compared to the short lever arm of a screwdriver, this is more labor-saving and improves operational efficiency. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of an oscilloscope current probe; Figure 2 This is a schematic diagram of the structure of a calibration device for an oscilloscope current probe according to this application; Figure 3 This is a schematic diagram of the internal structure of a calibration device for an oscilloscope current probe according to this application; Figure 4 This is a cross-sectional view of a calibration device for an oscilloscope current probe according to this application.

[0013] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0015] It is worth noting that, such as Figure 1 As shown, the oscilloscope current probe includes a BNC connector 1, with a wire 2 connected to the BNC connector 1. One end of the wire is connected to a probe 3, and a grounding clip 4 is electrically connected to the side of the probe. An adjustable capacitor 5 is fixedly installed inside the BNC connector 1, and a probe screw 6 is threaded onto the adjustable capacitor 5, extending out of the housing 7 of the BNC connector 11. The compensation capacitor is a variable capacitor. Currently, technicians adjust the adjustable capacitor 5 by rotating the probe screw 6 with a screwdriver or other tools, thereby changing the capacitance of the capacitor. The problem with this method is that when the screwdriver is used directly, the force is only applied to the probe screw 6. If the force is too great or the angle is off, the probe screw 6 can easily be damaged. In addition, the rotation of the screwdriver depends on the hand force and angle control, which can easily result in "fluctuations in rotation speed" and large deviations, leading to low control accuracy. To solve the above problems, this invention sets a calibration device on the probe screw 6 instead of a screwdriver. Rotating the probe screw 6 only requires installing the calibration device on the housing 7 of the BNC connector 1; the rest of the structure remains unchanged.

[0016] An embodiment of this utility model provides a calibration device for an oscilloscope current probe. The current probe includes a BNC connector 1, and an adjustable capacitor 5 is disposed within the housing 7 of the BNC connector 1. Figure 2-4 As shown, the calibration device includes: a groove 8 is provided radially along the housing 7, a gear 9 is provided in the groove 8, a connecting seat 10 is connected to the gear 9, the connecting seat 10 extends into the housing 7 through the bottom of the groove 8, and is connected to the probe screw 6 of the adjustable capacitor 5; a sleeve 11 is fitted over the housing 7, the sleeve 11 is located outside the groove 8, a ring push plate 12 is connected to the inner wall of the sleeve 11, the ring push plate 12 is located in the groove 8, a rack 13 adapted to the gear 9 is provided along the circumference of the ring push plate 12, the rack 13 is fixed on the side wall of the ring push plate 12, and a gap is formed between the gear 9 and the rack 13.

[0017] In this embodiment, a sleeve 11 is fitted over the housing 7 of the BNC connector 1. The sleeve 11 is connected to a rack 13 via a ring pusher plate 12, and a gear 9 is installed inside the housing 7, creating a gap between the gear 9 and the rack 13. The gear 9 is connected to the rotating shaft of the adjustable capacitor 5. When the adjustable capacitor 5 needs adjustment, the sleeve 11 is pushed, causing the rack 13 to approach and mesh with the gear 9. Rotating the sleeve 11 causes the rack 13 to rotate, thereby rotating the rotating shaft of the adjustable capacitor 5. After calibration, the sleeve 11 is pushed back to its initial position. During this process, the gap between the gear 9 and the rack 13 prevents accidental rotation of the sleeve 11 when calibration is not required, thus reducing the error rate. The rotation achieved by the meshing of the rack 13 and the gear 9 is a fixed-ratio transmission. The speed and angle of the rotation of the rack 13 directly correspond to the rotation speed and angle of the gear 9 (e.g., for every 1 revolution of the rack 13, the gear 9 rotates 2 revolutions). The ring gear 13 (with a fixed ratio) improves control precision compared to the rotation of a screwdriver. Furthermore, the outer diameter of the sleeve 11 is larger than the diameter of the rotating shaft. According to the lever principle, the lever arm of the ring gear 13 is longer when rotating, requiring only a smaller pushing force to drive the gear 9. Compared to the short lever arm of a screwdriver, this is more labor-saving and improves operational efficiency.

[0018] Furthermore, a spring 14 is fitted inside the groove 8. The spring 14 is located between the ring push plate 12 and the connecting seat 10, and is located below the rack 13. The groove 8 includes a first groove 81 and a second groove 82. The cross-section of the first groove 81 is circular, and its size is adapted to the gear 9. The gear 9 is located inside the first groove 81. The depth of the first groove 81 is less than the depth of the second groove 82. The shape of the second groove 82 is annular, and the spring 14 and the rack 13 are located inside the second groove 82.

[0019] In this embodiment, a step is formed between the first groove 81 and the second groove 82. A spring 14 is installed in the second groove 82, located between the ring push plate 12 and the step (the inner wall of the second groove 82). By pushing the ring push plate 12, the rack 13 is driven to approach and mesh with the gear 9, compressing the spring 14. When calibration is complete, the sleeve 11 is released, and under the restoring force of the spring 14, the rack 13 can separate from the gear 9 and return to its original position. Due to the force of the spring 14 between the ring push plate 12 and the step, the sleeve 11 will not move when the force is small, thus avoiding overcharging or undercharging caused by accidental contact with the sleeve 11.

[0020] For example, the rack 13 is conical in shape, and the gear 9 is a bevel gear. The diameter of the rack 13 increases along the pushing direction of the sleeve 11 (i.e., the direction of the rack 13 toward the gear 9), and the diameter of the end of the gear 9 near the bottom of the groove 8 is smaller than the diameter of the other end. The rotation of the rack 13 and the gear 9 is less likely to interfere with other parts, thus reducing the space occupied.

[0021] Furthermore, a cover body 15 is attached to the open end of the first groove 81, and the width of the cover body 15 is the same as the width of the first groove 81; the length of the sleeve 11 is greater than the width of the second groove 82, but less than the sum of the lengths of the first groove 81 and the second groove 82; one end of the sleeve 11 is fitted to the outer wall of the housing 7, and the other end is fitted to the outer wall of the cover body 15. Specifically, the cover body 15 includes a cover plate 151, and an insert plate 152 is vertically connected to the cover plate 151. The insert plate 152 is fixed to the inner wall of the first groove 81, and the cover plate 151 is at the opening of the first groove 81. The cover plate 151 is installed on the outside of the first groove 81 to facilitate the installation of the gear 9 and the connecting column.

[0022] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A calibration device for an oscilloscope current probe, characterized in that, The current probe includes a BNC connector, which includes a housing, and an adjustable capacitor is installed inside the housing. The calibration device includes: a groove is formed radially along the housing, a gear is disposed in the groove, a connecting seat is connected to the gear, the connecting seat extends through the bottom of the groove into the housing, and is connected to the rotating shaft of an adjustable capacitor; The housing is fitted with a sleeve, which is located outside the groove; The inner wall of the sleeve is connected to a ring push plate, which is located in a groove. A rack adapted to the gear is arranged along the circumference of the ring push plate. The rack is fixed on the side wall of the ring push plate, and a gap is formed between the gear and the rack.

2. The calibration device for an oscilloscope current probe according to claim 1, characterized in that, A spring is fitted inside the groove. The spring is located between the ring push plate and the connecting seat, and is located below the rack.

3. The calibration device for an oscilloscope current probe according to claim 2, characterized in that, The groove includes a first groove and a second groove; The size of the first groove is adapted to the gear, the gear is located in the first groove, and the depth of the first groove is less than the depth of the second groove; The second groove is annular in shape, and the spring and rack are located within the second groove.

4. The calibration device for an oscilloscope current probe according to claim 3, characterized in that, The opening end of the first groove is covered with a cover, and the width of the cover is the same as the width of the first groove. The length of the sleeve is greater than the width of the second groove, but less than the sum of the lengths of the first and second grooves; One end of the sleeve is fitted to the outer wall of the shell, and the other end is fitted to the outer wall of the cover.

5. The calibration device for an oscilloscope current probe according to claim 4, characterized in that, The cover includes a cover plate, and an insert plate is vertically connected to the cover plate. The insert plate is fixed to the inner side wall of the first groove, and the opening of the first groove is on the cover plate.

6. The calibration device for an oscilloscope current probe according to claim 1, characterized in that, The rack is conical in shape, and the gear is also conical in shape.

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