CN110764017A - A detection method for quickly determining a short circuit of an electronic device in a parallel circuit - Google Patents

Abstract

The invention belongs to the technical field of electronics, and particularly relates to a detection method for quickly determining short circuit of an electronic device of a parallel circuit. The impedance of the parallel circuit is measured by using the impedance level of the LCR digital bridge, and the minimum point of the impedance is the position of the short-circuit device in the circuit; the parallel circuit is a circuit formed by connecting a plurality of pure resistors, a plurality of pure capacitors or a plurality of pure inductors in parallel, or a circuit formed by connecting resistors, capacitors and inductors in parallel in a mixed manner, or other parallel circuits which can judge whether the device is short-circuited or not through the impedance. The invention has fast detection speed and is not limited by the number and the type of the parallel devices.

Description

A detection method for quickly determining a short circuit of an electronic device in a parallel circuit

technical field

The invention belongs to the technical field of electronics, and in particular relates to a method for detecting a short circuit of an electronic device.

Background technique

In various electronic circuits, there will be different numbers and types of electronic components used in parallel, especially for circuits that use parallel devices on a large scale, such as a large number of transducers used in electromagnetic wave or sound wave transmission or reception. Parallel connection, parallel connection of LED lights, etc., sometimes thousands of devices of the same or different types are used in parallel. Due to improper welding and installation or during use, one or several parallel devices will inevitably be damaged, resulting in a short circuit, and the entire equipment or system cannot work normally.

In a resistance parallel circuit, if there is a short circuit in the resistance, the position of the short circuit resistance cannot be determined with a multimeter. For circuits that are connected in parallel by inductors or capacitors or mixed in parallel by resistors, capacitors, and inductors, the multimeter cannot be used, because measuring the inductance with a multimeter is a short circuit. Other measurement methods require special instruments and the detection process is cumbersome. It takes a long time to determine the position of short-circuit devices, and the efficiency of determining the short-circuit position of large-scale parallel devices is low.

SUMMARY OF THE INVENTION

Aiming at the shortcomings of the above detection technology, the purpose of the present invention is to provide a detection method for quickly determining the short circuit of an electronic device in a parallel circuit.

In the detection method for quickly determining the short circuit of an electronic device in a parallel circuit provided by the present invention, the impedance measurement file of the LCR digital bridge that meets certain accuracy and frequency requirements is used to detect and confirm the short circuit device of the parallel electronic device under test, and the minimum impedance point is The location of the shorting device in the circuit. The present invention can not only be used for circuits in which multiple pure resistors, multiple pure capacitors or multiple pure inductances are connected in parallel, see Figures 2, 3, and 4; but also can be used in circuits where resistors, capacitors, and inductors are mixed in parallel, see Figure 1; It can also be used in other parallel circuits that can determine whether the device is short-circuited or not through the magnitude of the impedance. The invention has high detection speed and is not limited by the number and type of parallel and short-circuit devices.

In the present invention, the LCR digital bridge used is a conventional instrument used in the field of electronics, but the bridge must have an impedance Z measurement file, and the LCR digital bridge and a parallel circuit with a short-circuit device form a detection system; the impedance Z measurement range should be within 0.0001Ω—99.99MΩ, the accuracy should reach 0.1%, and the measurement frequency should be continuous or have a fixed frequency point within 1KHz. For the short-circuit detection of some parallel devices working in a fixed frequency or frequency domain, the measurement frequency range of the LCR digital bridge used should be satisfied.

In the present invention, a circuit composed of resistors, capacitors and inductances in parallel, see FIG. 1, a circuit composed of a plurality of pure resistors in parallel, referring to FIG. 2, a circuit composed of a plurality of pure capacitors in parallel, referring to FIG. 3, a circuit composed of a plurality of pure inductances For the parallel circuit, see Figure 4, use the test terminals of the above-mentioned LCR digital bridge to connect with terminals A and B (two test points) in Figure 1, Figure 2, Figure 3, and Figure 4, and terminals C and D (two test points), respectively. test points), and test the impedances Z _AB and Z _CD at both ends. If Z _AB < Z _CD , it means that the A and B terminals are close to the short-circuit device, then start from the A and B terminals to move the measurement points quickly or in a leaping manner, and press The trend of impedance reduction is to find the minimum impedance point, at this time, the position of the short-circuit device is between the two measurement points. If Z _AB > Z _CD , starting from the C and D terminals, find the position of the short-circuit device by the same method as above.

In the present invention, for other parallel circuits that can determine whether the device is short-circuited through the magnitude of the impedance, the position of the short-circuit device can be determined by the above detection method.

In the present invention, for the short-circuit detection of some parallel devices operating at a fixed frequency (such as ultrasonic transducers in parallel) or in the frequency domain, the above method can also be used to determine the position of the short-circuit device, and the measurement frequency of the LCR digital bridge used should be consistent with the operating frequency of the device.

The detection method for quickly determining the short circuit of a parallel electronic device according to the present invention is not only suitable for all parallel circuits that determine whether the device is short-circuited or not by the magnitude of impedance, but also has no specific requirements for the form and impedance size of the detected parallel short-circuit device, and the detection process It will not cause secondary damage to the original circuit.

Description of drawings

FIG. 1 is a schematic diagram of a mixed parallel circuit of resistance, capacitance and inductance in the present invention.

FIG. 2 is a schematic diagram of a pure resistance parallel circuit in the present invention.

FIG. 3 is a schematic diagram of a pure capacitor parallel circuit in the present invention.

FIG. 4 is a schematic diagram of a purely inductive parallel circuit in the present invention.

Detailed ways

Referring to Figure 1, for a circuit in which a resistor, capacitor, and inductor are mixed in parallel, if one or several devices are short-circuited, the specific detection and determination methods are as follows:

First, select an LCR digital bridge, the parameters are set in the impedance Z measurement file, and the frequency is 1KHz.

Secondly, use the two measurement probes of the LCR digital bridge to connect to the A, B terminals, and C and D terminals of Figure 1 respectively, and test the values of the impedance Z _AB and Z _CD at both ends. The specific values can be obtained from the LCR digital bridge. read on the display. If Z _AB < Z _CD , it means that the A and B terminals are close to the short-circuit device, then start from the A and B terminals to move the measuring points rapidly or in a leaping manner, and find the minimum impedance point according to the trend of impedance reduction. is the location of the short-circuit device. If Z _AB > Z _CD , starting from the C and D terminals, find the position of the short-circuit device with the same method as above. If there are multiple devices short-circuited, use the above method to check one by one.

For the parallel circuits of pure resistance, capacitance and inductance shown in FIG. 2, FIG. 3, and FIG. 4 of the present invention, and the parallel circuit that can determine whether the device is short-circuited or not by the magnitude of the impedance, the position of the short-circuit device can also be determined by the above method.

For devices that work at a certain frequency, such as an ultrasonic transmitting array composed of n 40KHz ultrasonic transducers in parallel, if there are short-circuit transducers, the above method can also be used to detect, but the frequency of the LCR digital bridge should be 40KHz. .

Claims (3)

1. a detection method for determining the short circuit of parallel circuit electronic device is characterized in that, utilize LCR digital bridge impedance profile to measure the impedance of parallel circuit, and impedance minimum point is the position of short circuit device in circuit; Described parallel circuit is A circuit in which multiple pure resistors, multiple pure capacitors or multiple pure inductors are connected in parallel, or a circuit in which resistors, capacitors, and inductors are mixed in parallel, or a parallel circuit that can determine whether the device is short-circuited or not through the magnitude of the impedance. 2. the detection method that can quickly determine the short circuit of parallel electronic devices according to claim 1, is characterized in that, described LCR digital bridge and the parallel circuit that has short circuit device form detection system, the impedance profile measurement range of LCR digital bridge In 0.0001Ω-99.99MΩ, the accuracy reaches 0.1%, and the measurement frequency should be continuous or have a fixed frequency point within 1KHz. 3. the detection method that can quickly determine the short circuit of parallel electronic devices according to claim 1, it is characterized in that, for resistance, capacitance, inductance mixed parallel circuit, or for a plurality of pure resistance parallel circuits, a plurality of pure capacitance parallel circuits A circuit or a plurality of circuits with pure inductance in parallel, use the test end of the LCR digital bridge to connect with the test points A and B of the circuit under test, as well as the test points C and D, respectively, and test the impedance Z _AB at both ends. and Z _CD ; if Z _AB < Z _CD , it means that the A and B terminals are close to the short-circuit device, then start from the A and B terminals to move the measuring point rapidly or in a leaping manner, and find the minimum impedance point according to the trend of impedance reduction. At this time, the two The position between the measuring points is the position of the short-circuit device; if Z _AB > Z _CD , start from the C and D terminals, and use the same method as above to find the position of the short-circuit device.

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