Megameter with universal measurement range

Abstract

The utility model discloses a megohmmeter with a universal measurement range, which belongs to a megohmmeter and comprises a current measurement module and a voltage measurement module, the current measurement module and the voltage measurement module are both connected into a main control module, the main control module is further connected into a high-frequency switching power supply, the high-frequency switching power supply is connected into a booster circuit, and the booster circuit is connected into a voltage doubling circuit. The voltage doubling circuit is used for being connected to the output end, and the voltage doubling circuit is connected to the high-frequency switching power supply through the constant-voltage feedback control circuit in a constant-voltage feedback control mode. By designing a modularized current measurement module and a modularized voltage measurement module, voltage and current signals of an acquisition area can be measured independently, and a main control module can obtain a resistance value of a measured part through operation by signal amplification, filtering isolation and the like in combination with a pulse width modulation control power supply to output a voltage value. Light weight design of the megohmmeter is facilitated, and the measurement range is wider.

Description

Megohmmeter with a universal measurement range Technical Field

[0001] This utility model relates to a megohmmeter, and more specifically, it relates to a megohmmeter with a universal measurement range. Background Technology

[0002] A megohmmeter, commonly known as a megohmmeter or insulation resistance tester, is a portable instrument specifically designed to measure the insulation resistance of electrical equipment. It tests the performance of insulating materials by applying high-voltage direct current and is a core tool for electrical safety testing. However, existing megohmmeters are limited by their own circuit components, resulting in a generally small measurement range, typically reaching a maximum of 20 GΩ. With the increasing lightweight design of current megohmmeters, this measurement range is often compromised. Therefore, further research and improvement of the aforementioned lightweight circuit design for these megohmmeters are necessary. Summary of the Invention

[0003] One of the objectives of this invention is to address the aforementioned shortcomings by providing a megohmmeter with a universal measurement range, thereby resolving the technical problems of existing megohmmeters, such as limited measurement range and lack of circuit expandability.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] This utility model provides a megohmmeter with a universal measurement range, comprising a current measurement module and a voltage measurement module. The current measurement module includes a current sampling circuit connected to a data acquisition terminal, and the current sampling circuit is connected to an isolation circuit, which is connected to a filter circuit. The filter circuit is connected to a first signal amplification circuit, which is connected to a main control module. The isolation circuit is also connected to the filter circuit via a zero-adjustment circuit. The voltage measurement module includes a voltage sampling circuit connected to a data acquisition terminal, and the voltage sampling circuit is connected to a second signal amplification circuit, which is connected to the main control module. The main control module is also connected to a high-frequency switching power supply for outputting a pulse width modulation (PWM) signal to the high-frequency switching power supply. The high-frequency switching power supply is connected to a boost circuit, which is connected to a voltage multiplier circuit. The voltage multiplier circuit is connected to the output terminal, and the voltage multiplier circuit also has constant voltage feedback control connected to the high-frequency switching power supply via a constant voltage feedback control circuit.

[0006] As a preferred embodiment, a further technical solution is that the main control module is also connected to an LCD screen, a Bluetooth module, and a USB communication module.

[0007] A further technical solution is that the main control module is used to receive the current signal collected by the current measurement module and the voltage signal collected by the voltage measurement module, and output the value to be displayed on the LCD screen, and transmit it to a third-party device through the Bluetooth module or USB communication module.

[0008] Compared with the prior art, one of the beneficial effects of this utility model is that by designing modular current and voltage measurement modules, the voltage and current signals of the acquisition area can be measured separately. Through signal amplification and filtering isolation, combined with pulse width modulation to control the power supply output voltage value, the main control module can calculate the resistance value of the measured part, thereby effectively improving the measurement range of the megohmmeter to up to 30GΩ. Furthermore, the modular acquisition circuit makes it easier to design a lightweight megohmmeter, such as a handheld measurement structure, which is not only easy to operate but also suitable for use in more places. It can also be expanded based on existing circuits. Attached Figure Description

[0009] Figure 1 is a schematic circuit block diagram illustrating an embodiment of the present invention. Detailed Implementation

[0010] The present invention will be further described below with reference to the accompanying drawings.

[0011] Referring to Figure 1, one embodiment of this utility model is a megohmmeter with a universal measurement range, comprising a current measurement module and a voltage measurement module. As shown in the figure, the aforementioned current measurement module includes a current sampling circuit connected to the acquisition terminal, and the current sampling circuit is connected to an isolation circuit, which in turn is connected to a filter circuit. The filter circuit is connected to a first signal amplification circuit, which is connected to the main control module. The isolation circuit is also connected to the filter circuit via a zero-adjustment circuit. The aforementioned voltage measurement module includes a voltage sampling circuit connected to the acquisition terminal, which is connected to a second signal amplification circuit, which is connected to the main control module. More importantly, the aforementioned main control module is also connected to a high-frequency switching power supply for outputting a pulse width modulation (PWM) signal to the high-frequency switching power supply. The high-frequency switching power supply is connected to a boost circuit, which is connected to a voltage multiplier circuit. The voltage multiplier circuit is connected to the output terminal, and the voltage multiplier circuit also has constant voltage feedback control connected to the high-frequency switching power supply via a constant voltage feedback control circuit. Furthermore, to facilitate signal transmission and display of measurement results, the aforementioned main control module can also be connected to a liquid crystal display screen and peripheral circuits such as a Bluetooth module and a USB communication module.

[0012] The aforementioned main control module is used to receive the current signal collected by the current measurement module and the voltage signal collected by the voltage measurement module, and output the value to be displayed on the LCD screen, and transmit it to a third-party device via Bluetooth or USB communication module.

[0013] In this embodiment, by designing modular current and voltage measurement modules, the voltage and current signals of the acquisition area can be measured separately. Through signal amplification, filtering, and isolation, combined with pulse width modulation to control the power supply output voltage value, the main control module can calculate the resistance value of the measured part, thereby effectively improving the measurement range of the megohmmeter. Furthermore, the modular acquisition circuit facilitates the lightweight design of the megohmmeter, such as setting it as a handheld measurement device, which is not only easy to operate but also suitable for use in more places. It can also be extended based on existing circuits.

[0014] As mentioned above, the circuits in the above embodiments function as follows:

[0015] In the power supply circuit section, the power supply circuit provides power to the entire unit and also has the ability to forcibly cut off the high-voltage output power. The high-frequency switching power supply consists of a boost circuit composed of a transformer and a control chip. The main control chip provides PWM control signals, and the control chip provides high-frequency switching signals to control the duty cycle of the power supply output, thereby controlling the output voltage.

[0016] The constant voltage feedback control circuit consists of megohm-level resistors connected in series to divide the voltage, which, together with the power supply, boosts and stabilizes the voltage, and quickly feeds back the output voltage signal.

[0017] The voltage multiplier circuit amplifies the boosted voltage to the required 1kV and filters it into a stable DC voltage.

[0018] The current sampling circuit uses precision resistors to measure current in different ranges. At the same time, in order to reduce the influence of the on-resistance of the switching chip, a MOSFET with low on-resistance is used for conduction control.

[0019] The first and second signal amplification circuits use negative feedback to amplify the current sampling signal.

[0020] The isolation circuit is added to isolate the sampled voltage because the measured signal is small and easily affected by the input and output resistance of the circuit.

[0021] The zero-adjustment circuit is set up to adjust the zero point to address the zero-point drift issue in some gear positions.

[0022] The filter circuit is a low-pass filter circuit that effectively filters out stray interference signals.

[0023] The voltage measurement circuit measures the output voltage and the external voltage.

[0024] Other peripheral circuits include USB communication ports, Bluetooth communication modules, and buzzer alarm circuits.

[0025] The circuits used in this invention are all existing finished circuits, and no improvements have been made to the circuits themselves. Therefore, the principle of the circuits will not be explained separately. Those skilled in the art can refer to similar circuits in the prior art under the guidance of this specification, just as the inventors have done, to achieve the above-mentioned technical objectives of this invention in the same way.

[0026] In addition to the above, it should be noted that the terms "one embodiment," "another embodiment," and "embodiment" used in this specification refer to specific features, structures, or characteristics described in connection with that embodiment, which are included in at least one embodiment described in the general description of this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in connection with any embodiment, the intention is to suggest that implementing such a feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of this utility model.

[0027] Although the present invention has been described herein with reference to several illustrative embodiments, it should be understood that many other modifications and implementations can be devised by those skilled in the art, which will fall within the scope and spirit of the principles disclosed herein. More specifically, various variations and modifications can be made to the components and / or layout of the subject matter combination within the scope of the disclosure, drawings, and claims. Besides variations and modifications to the components and / or layout, other uses will be apparent to those skilled in the art.

Claims

1. A megohmmeter with a universal measurement range, characterized in that: The system includes a current measurement module and a voltage measurement module. The current measurement module includes a current sampling circuit connected to a data acquisition terminal. The current sampling circuit is connected to an isolation circuit, which is connected to a filter circuit. The filter circuit is connected to a first signal amplification circuit, which is connected to a main control module. The isolation circuit is also connected to the filter circuit via a zero-adjustment circuit. The voltage measurement module includes a voltage sampling circuit connected to a data acquisition terminal. The voltage sampling circuit is connected to a second signal amplification circuit, which is connected to the main control module. The main control module is also connected to a high-frequency switching power supply for outputting a pulse width modulation (PWM) signal to the high-frequency switching power supply. The high-frequency switching power supply is connected to a boost circuit, which is connected to a voltage multiplier circuit. The voltage multiplier circuit is connected to the output terminal. The voltage multiplier circuit also has constant voltage feedback control connected to the high-frequency switching power supply via a constant voltage feedback control circuit.

2. The megohmmeter with a universal measurement range according to claim 1, characterized in that: The main control module is also connected to an LCD screen, a Bluetooth module, and a USB communication module.

3. The megohmmeter with a universal measurement range according to claim 1, characterized in that: The main control module is used to receive the current signal collected by the current measurement module and the voltage signal collected by the voltage measurement module, and output the value to be displayed on the LCD screen, and transmit it to a third-party device through the Bluetooth module or USB communication module.

Images