Impact test device for motor piezoresistor

Abstract

The utility model discloses an impact test device for a motor piezoresistor, which comprises a main power supply and a first branch power supply, the first branch power supply is variable voltage, and the first branch comprises a first direct current anode branch and a first direct current cathode branch. A capacitor module is connected in parallel between the first direct current anode branch and the first direct current cathode branch, a voltage display is connected in parallel between the first branch power supply and the capacitor module, and the voltage display is used for acquiring and recording reverse voltage value changes of a piezoresistor located on the converter. The time relay is used for controlling the time interval of switching-on and switching-off of the first branch power supply; the output end A of the first direct current anode branch is connected with the input end B of the first direct current cathode branch; the number of the output end A and the input end B is respectively one, and the output end A and the input end B are respectively and electrically connected with commutator segments of the converter. The time relay outputs voltages to the commutator segments according to different discharge gaps and different voltages, and then the internal resistance of the piezoresistor is obtained.

Description

An impact testing device for motor varistor Technical Field

[0001] This utility model relates to the field of brushed motor testing devices, and in particular to an impact testing device for motor varistor. Background Technology

[0002] During operation, a brushed DC motor generates an electromotive force (EMF) voltage that is opposite to the electrical voltage. This back EMF can cause severe arcing during commutator switching, affecting motor performance and potentially failing to meet EMC management requirements. To reduce this back EMF, it's necessary to dissipate this voltage and reduce sparking. In the industry, a varistor (DV) is typically installed on the commutator in the armature core. However, varistors are relatively fragile components, prone to cracking during manufacturing, which is difficult to detect visually. Therefore, we consider conducting a high-voltage withstand test on the varistor before it's put into use, and then testing its E10 value to assess its performance.

[0003] The E10 value refers to the reverse voltage of the varistor when a DC current of 10 mA flows through it. This parameter mainly describes the voltage withstand capability of the varistor under overcurrent surges and is a key performance indicator of strontium titanate (TSR) type varistors. E10 is mainly used to evaluate the performance of varistors in continuous overcurrent protection scenarios, such as DC motors and other devices requiring fast response. Summary of the Invention

[0004] The main purpose of this invention is to propose an impact testing device for motor varistors. The device is designed to apply a high voltage to the varistor instantaneously, so that the varistor can be tested before it is put into use, thus avoiding a large number of defects after mass production.

[0005] To achieve the above objectives, this utility model proposes an impact testing device for motor varistor, comprising:

[0006] The main power supply is 220V AC power, and inductors are connected in parallel to the positive and negative terminals of the main power supply. The inductors are used to output DC power with a predetermined voltage.

[0007] The DC power output is controlled by a predetermined DC power output through a switch QS and a control module FU.

[0008] The first power supply branch is a variable voltage power supply, and the first branch includes a first DC positive branch and a first DC negative branch.

[0009] A capacitor module is connected in parallel between the first DC positive branch and the first DC negative branch.

[0010] A voltage display is connected in parallel between the first branch power supply and the capacitor module. The voltage display is used to acquire and record the reverse voltage change of the varistor located in the converter.

[0011] The capacitor module includes a first capacitor C1, a second capacitor C2, and a third capacitor C3.

[0012] The first DC positive branch is connected to a time relay behind the capacitor module. The time relay is used to control the time interval between the power supply of the first branch being turned on and off.

[0013] The output terminal A of the first DC positive branch and the input terminal B of the first DC negative branch;

[0014] The output terminal A and the input terminal B are each provided and are electrically connected to the commutator segments of the converter.

[0015] In practical design, given that varistors consume electrical energy, when a varistor meets the predetermined requirements,

[0016] When the commutator is not installed on the motor, the output terminal A and input terminal B are directly in contact with the commutator, thus enabling the input of a predetermined voltage to the commutator.

[0017] In actual testing, the time relay determines the output voltage of the commutator based on different discharge gaps and voltages, thereby obtaining the internal resistance of the varistor.

[0018] When the resistance value of the varistor meets the requirements, the reverse voltage value recorded by the voltage display is within the predetermined range, then the varistor meets the requirements.

[0019] When the resistance value of the varistor does not meet the requirements, the reverse voltage value recorded by the voltage display will be greater than the predetermined value, thus allowing the varistor to be judged to be qualified in a timely manner.

[0020] In actual testing, this structure can be upgraded to automated equipment, that is, the commutator segments are transported by a fixture or a conveyor belt, preferably by a fixture. When the fixture is in the test position, the output terminal A and the input terminal B are respectively connected to the commutator segments, and the time relay outputs a predetermined voltage to the commutator segments to test their withstand voltage value, thereby obtaining the product qualification rate and improving the testing efficiency. Attached Figure Description

[0021] Figure 1 is a circuit diagram of this utility model;

[0022] Figure 2 is a simplified diagram of this utility model;

[0023] Figure 3 shows an example of output terminal A and input terminal B;

[0024] Figure 4 shows the second embodiment of output terminal A and input terminal B;

[0025] Figure 5 is a schematic diagram of another embodiment of directly testing the varistor of the motor.

[0026] In the picture,

[0027] 1 is the power supply for the first branch;

[0028] 2 is the commutator.

[0029] 3 represents a varistor. Detailed Implementation

[0030] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0031] It should be noted that if any directional indication (such as up, down, left, right, front, back, top, bottom, inside, outside, vertical, horizontal, longitudinal, counterclockwise, clockwise, circumferential, radial, axial, etc.) is involved in the embodiments of this utility model, the directional indication is only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0032] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0033] As shown in Figures 1 to 5, an impact testing device for a motor varistor includes:

[0034] The main power supply is 220V AC power, and inductors are connected in parallel to the positive and negative terminals of the main power supply. The inductors are used to output DC power with a predetermined voltage.

[0035] The DC power output is controlled by a predetermined DC power output through a switch QS and a control module FU.

[0036] The first power supply branch is a variable voltage power supply, and the first branch includes a first DC positive branch and a first DC negative branch.

[0037] A capacitor module is connected in parallel between the first DC positive branch and the first DC negative branch.

[0038] A voltage display is connected in parallel between the first branch power supply and the capacitor module. The voltage display is used to acquire and record the reverse voltage change of the varistor located in the converter.

[0039] The capacitor module includes a first capacitor C1, a second capacitor C2, and a third capacitor C3.

[0040] The first DC positive branch is connected to a time relay behind the capacitor module. The time relay is used to control the time interval between the power supply of the first branch being turned on and off.

[0041] The output terminal A of the first DC positive branch and the input terminal B of the first DC negative branch;

[0042] The output terminal A and the input terminal B are each provided and are electrically connected to the commutator segments of the converter.

[0043] In practical design, given that varistors consume electrical energy, when a varistor meets the predetermined requirements,

[0044] When the commutator is not installed on the motor, the output terminal A and input terminal B are directly in contact with the commutator, thus enabling the input of a predetermined voltage to the commutator.

[0045] In actual testing, the time relay determines the output voltage of the commutator based on different discharge gaps and voltages, thereby obtaining the internal resistance of the varistor.

[0046] When the resistance value of the varistor meets the requirements, the reverse voltage value recorded by the voltage display is within the predetermined range, then the varistor meets the requirements.

[0047] When the resistance value of the varistor does not meet the requirements, the reverse voltage value recorded by the voltage display will be greater than the predetermined value, thus allowing the varistor to be judged to be qualified in a timely manner.

[0048] In actual testing, this structure can be upgraded to automated equipment, that is, the commutator segments are transported by a fixture or a conveyor belt, preferably by a fixture. When the fixture is in the test position, the output terminal A and the input terminal B are respectively connected to the commutator segments, and the time relay outputs a predetermined voltage to the commutator segments to test their withstand voltage value, thereby obtaining the product qualification rate and improving the testing efficiency.

[0049] Specifically, the variable voltage range of the first branch power supply is 0-120V.

[0050] Specifically, the control discharge gap of the time relay is 10 milliseconds to 10000 milliseconds.

[0051] Specifically, the number of discharges is 1-9999.

[0052] In this embodiment of the utility model, when there are three commutator segments, there are two input terminals A and one output terminal B.

[0053] Specifically, when there are five commutator segments, there are three input terminals A and two output terminals B.

[0054] In this embodiment of the invention, the input terminal A and the output terminal B are clamping structures, which are used to clamp them in the thickness direction.

[0055] Specifically, the clamping structure is a clamp, although a contact structure can be used in automated design.

[0056] In this embodiment of the invention, the first branch power supply is connected to a variable resistor, which is used to control the voltage of the output DC power.

[0057] In actual testing, the voltage display records the conduction voltage, response time, and residual voltage for each impact.

[0058] The specific capacitor module is used for input filtering to suppress high-frequency current interference and ensure stable operation of the control module; thus, the output is smooth, reducing the stress impact of voltage surges on the varistor, and thus the reverse voltage value can be accurately obtained.

[0059] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. An impact testing device for a motor varistor, characterized in that, include: The main power supply is 220V AC power, and inductors are connected in parallel to the positive and negative terminals of the main power supply. The inductors are used to output DC power with a predetermined voltage. The DC power output is controlled by a switch QS and a control module FU to a predetermined value. A first branch power supply, which is a variable voltage, includes a first positive DC branch and a first negative DC branch. A capacitor module is connected in parallel between the first positive and first negative DC branches. A voltage display is connected in parallel between the first branch power supply and the capacitor module. The voltage display is used to acquire and record the reverse voltage change of the varistor located in the converter. The capacitor module includes a first capacitor C1, a second capacitor C2, and a third capacitor C3. A time relay is connected behind the capacitor module in the first positive DC branch. The time relay is used to control the time interval between the on and off of the first branch power supply. There is an output terminal A of the first positive DC branch and an input terminal B of the first negative DC branch. Output terminal A and input terminal B are each provided and electrically connected to the commutator segments of the converter.

2. The impact testing device for motor varistor as described in claim 1, characterized in that: The variable voltage range of the first branch power supply is 0-120V.

3. The impact testing device for motor varistor as described in claim 1, characterized in that: The control discharge gap of the time relay is 10 milliseconds to 10,000 milliseconds.

4. The impact testing device for motor varistor as described in claim 1, characterized in that: When there are three commutator segments, there are two input terminals A and one output terminal B.

5. The impact testing device for motor varistor as described in claim 1, characterized in that: When there are five commutator segments, there are three input terminals A and two output terminals B.

6. The impact testing device for motor varistor as described in claim 1, characterized in that: The input terminal A and the output terminal B are clamping structures used to clamp them in the thickness direction.

7. The impact testing device for motor varistor as described in claim 6, characterized in that: The clamping structure is a clip.

8. The impact testing device for motor varistor as described in claim 1, characterized in that: The first branch power supply is connected to a variable resistor, which is used to control the magnitude of the output DC voltage.

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