What should I pay attention to in the DC withstand voltage test of film capacitors?

Film capacitors are used in analog circuits in large quantities due to their non-polarity, high insulation resistance, excellent frequency characteristics (wide frequency response), and low dielectric loss.

Especially in the part of signal cross-connection, capacitors with good frequency characteristics and very low dielectric loss must be used to ensure that the signal will not be too distorted when transmitted.

The quality of film capacitors is high, and it is very important to carry out DC withstand voltage test before leaving the factory, and we also need to pay attention to some places when conducting tests.

1. The load voltage should meet the requirements of the film capacitor manufacturer for the DC withstand voltage at present and in the future (the DC voltage borne by the withstand voltage test is provided by the separately developed DC high-voltage power supply) 2. The guarantee of the test system can ensure that the DC high voltage does not pose a threat or injury to the operator, that is, to ensure that personal injury is not caused.

3. The anti-electromagnetic interference ability of the system can ensure that the system can withstand the electromagnetic interference in the external harsh working environment and will not affect the operation, especially the test circuit and signal processing circuit, that is, to ensure that the test system does not blow problems.

4. The leakage current detection accuracy, which is used in the actual production of customers, is related to the parameter performance of the final product.

5. The processing ability of the test signal, and the detection result of the leakage current should be accurately converted, so that the equipment control unit can process the film capacitor in time.

Ensure the reliability of the test system, reduce the failure rate of the system, and enhance its redundancy.

7. The display of test results is observable, and the cost should be controlled.

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Hello dear, the high-voltage capacitor withstand voltage test should follow certain safety specifications, and some professional testing equipment is required, the following are the test steps:1Confirm that the capacitor is isolated and disconnected from the power supply2

Use a multimeter to detect if the charge on the capacitor has been released3Connect the high-voltage power supply to the positive and negative ends of the capacitor, and adjust the normal voltage according to the rated withstand voltage of the capacitor4Keep the capacitor in a high-voltage state and observe whether it leaks or is damaged, and measure its withstand voltage time when the same brother is liquid5

The capacitor is discharged with a high-voltage discharger and waits for the capacitor charge to be released6Check the capacitor for damage or leakage7Clean the test area in a timely manner and turn off the high-voltage power supply.

The above steps need to strictly follow the electrical safety regulations, and it is recommended that professional and technical personnel carry out the high-voltage capacitor withstand voltage test.

Summary. The method of the high-voltage capacitor withstand voltage test is to connect the capacitor in series with a resistor, and then directly connect to the output end of the withstand voltage meter, turn on the withstand voltage meter, slowly increase the voltage, and the voltage when the withstand voltage meter alarms (capacitance breakdown) is the withstand voltage value of the capacitor. Withstand voltage testing of capacitors is usually destructive and should be done with caution.

The method of high-voltage capacitor withstand voltage test is to connect the capacitor in series with a resistor, and then directly connect to the output end of the withstand voltage meter, turn on the withstand voltage meter, and slowly increase the voltage of the electric Xiangsen voltage, and the voltage when the withstand voltage meter alarms (capacitance breakdown) is the withstand voltage value of the capacitor. Voltage resistance test on capacitors is usually destructive due to ignition, so be careful.

1.Use a multimeter to test the resistance at both ends directly. If you use a pointer meter, like most capacitors, you can see the process of the pointer swinging from small to large.

See if the resistor is a regression to infinity. 2.Yes, it is connected in series in the 220V AC mains to see if the lamp with bucket bubbles can be lit normally.

Determine whether the capacitor still has capacity. Initial testing is normal.

Summary. Hello Dear Hello is a pleasure to serve you according to your questions. The steps of the high-voltage capacitor withstand voltage test are as follows:

1. First, determine the rated voltage, rated capacitance and quality of the capacitor, and check whether there is damage or leakage on the surface of the capacitor. 2. Select the appropriate high-voltage power supply and test instrument according to the regulations, connect the capacitor into the circuit, and carry out the grounding protection of the power device. 3. Start the high-voltage capacitor withstand voltage test, first charge the capacitor to times its rated voltage, hold it for 1 minute, and check whether there is corona discharge on the surface of the capacitor.

4. If there is no corona discharge on the surface of the capacitor, charge the capacitor to 2 times of its rated voltage, hold it for 1 minute, and check whether there is corona discharge on the surface of the capacitor again. 5. If there is still no corona discharge on the surface of the capacitor, charge the capacitor to times its rated voltage, keep it for 1 minute, and check whether there is corona discharge on the surface of the capacitor again. 6. If there is corona discharge on the surface of the capacitor, the capacitor has not passed the high-voltage capacitor withstand voltage test and should be eliminated or repaired.

7. If there is no corona discharge on the surface of the capacitor, the capacitor has passed the high-voltage capacitor withstand voltage test and can be put into use.

Hello dear and happy to serve you, according to your questions about the spring. The steps of the high-voltage capacitor withstand voltage test are as follows: 1. First, determine the rated voltage, rated capacitance and quality of the capacitor, and check whether there is damage or leakage on the surface of the capacitor.

2. Select the appropriate high-voltage power supply and test instrument according to the regulations, connect the capacitor into the circuit, and carry out the grounding protection of the power device. 3. Start the high-voltage capacitor withstand voltage test, first charge the capacitor to times its rated voltage, keep it for 1 minute, and check whether there is corona discharge on the surface of the capacitor. 4. If there is no corona discharge on the surface of the capacitor, charge the capacitor to 2 times of its rated voltage, hold it for 1 minute, and check again whether there is corona discharge on the surface of the capacitor.

5. If there is still no corona discharge on the surface of the capacitor, charge the capacitor to times its rated voltage, keep it for 1 minute, and check whether there is corona discharge on the surface of the capacitor again. 6. If there is corona discharge on the surface of the capacitor, the capacitor has not passed the high-voltage capacitor withstand voltage test and should be eliminated or repaired. 7. If there is no corona discharge on the surface of the capacitor, the capacitor has passed the high-voltage capacitor withstand voltage test and can be put into use.

It should be noted that when conducting the high-voltage capacitor withstand voltage test, necessary safety measures should also be taken to prevent the occurrence of electric shock accidents.

You need to test the capacitor after buying it, if so, test its leakage current can be, test it with a leakage current tester, the voltage is set according to the nominal voltage of the capacitor, the time is 60 seconds, the positive and negative poles of the instrument are connected to the positive and negative poles of the capacitor (don't connect it in reverse), and then start, if the leakage current displayed after the time is up, the leakage current of the capacitor is qualified, and the withstand voltage is generally no problem.

Capacitance measurement of its true withstand voltage value requires a professional measuring instrument: TV characteristic tester. Moreover, it is necessary to disassemble the capacitor, separate the core inside, take the positive foil inside to measure (the capacitor withstand voltage, in fact, the positive foil withstand voltage inside), and also need to configure a special solution (low-voltage and high-voltage capacitors, the configured solution will be different).

To tell you a simple way, the withstand voltage of a capacitor, generally you use its nominal voltage times the voltage (low voltage times. High voltage times,),Test with leakage current tester,If the leakage current is within the standard range, and the product is not hot,then there is absolutely no problem with the withstand voltage of this capacitor.

1. It is necessary to use a special instrument, capacitance withstand voltage tester to measure the withstand voltage value, and if the pressure exceeds the withstand voltage value, misoperation will cause capacitance.

2. Capacitance withstand voltage tester is sold in some electronic equipment manufacturers, and you can contact the manufacturer directly to purchase it if necessary.

3. Test principle. The following diagram shows a simple schematic diagram of a capacitance withstand voltage tester.

Hipot testing refers to the testing of the withstand voltage capacity of various electrical installations, insulating materials, and insulating structures.

The process of applying a high voltage to an insulating material or insulating structure without damaging the properties of the insulating material is called a hipot test.

Generally speaking, the main purpose of the hipot test is to check the ability of the insulation to withstand the operating voltage or overvoltage, and then to check whether the insulation performance of the product equipment meets the safety standards.

Capacitor withstand voltage test: It is to expose the capacitor product to a very harsh electrical environment, if the acidity meter can maintain a normal condition under this harsh electrical environment, it can be determined that it can maintain a very normal condition under the normal environment.

Normally, after product design, production, quality assurance and maintenance, pressure test is required to ensure that the product meets safety standards in all aspects.

Different products have different technical specifications, AC and DC withstand voltage test is basically to add a higher than normal working voltage to the product test, this voltage must last for a specified period of time.

If the leakage current of a component is kept within the specified range within the specified time, it can be determined that the component is operating under normal conditions and should be very safe.

Good design and well-chosen insulation materials can protect the user from accidental electric shock.

The basic principle of the hipot test: a higher than normal operating voltage is applied to the insulator of the device under test for a specified period of time, and if the insulation between them is good enough, the voltage applied to it will only produce a small leakage current.

If the leakage current of a DUT insulator is maintained within the specified range for a specified period of time, it can be determined that the DUT can operate safely under normal operating conditions.

When performing a withstand voltage test, the measurement standard varies depending on the technical specifications of the tested product.

For the general equipment under test, the withstand voltage test is to measure the leakage current between the live wire and the casing, and the basic regulations are: double the working voltage of the measured object plus 1000V as the standard voltage for the test.

Some products may have a test voltage higher than this specified value.

According to the provisions of IEC61010, the test voltage must gradually rise to the required test voltage value (such as 5kV, etc.) within 5s, and ensure that the test voltage value is stably added to the tested insulator for not less than 5s.

At the end of the test, the test voltage must be gradually reduced to zero within a specified period of time.

The withstand voltage value of the electrolytic capacitor is a design nominal value, indicating that this type of capacitor can work below this voltage for a long time, if it is to be tested, it is to apply a voltage that exceeds this value at both ends of the capacitor (for example: the capacitor with a nominal withstand voltage of 200V applies 500V for a minute or a few minutes without discharging or bursting, etc., it means that it can work for a long time under the voltage of 200V, the above example is only a hypothetical value, in order to be able to visually understand the withstand voltage parameters, The specific applied voltage depends on the manufacturer's standard, and it may not be a one-by-one inspection, but only a sampling inspection). This is a common practice for inspecting capacitors, so there is no way to measure the nominal withstand voltage value of a capacitor if it is not known during use.

However, you can use the method of comparison: measure the capacitance of the capacitor, and then compare the volume of the capacitor with the same capacitance with the nominal withstand voltage, and the same volume and size may be the same withstand voltage value. This gives a rough estimate of the withstand voltage value.

Since the package form may vary from manufacturer to manufacturer, this comparison error is large, so please use it carefully and reduce the voltage as much as possible to avoid the risk of capacitor bursting.

There are two methods for capacitor withstand voltage test, one is the AC withstand voltage method, which is generally used for the withstand voltage test of AC capacitors, such as the AC withstand voltage test value of power capacitors is 2 times of the rated voltage, and the time is 1 minute. Due to the large amount of current flowing through the capacitor during the AC withstand voltage test, the AC withstand voltage test requires very large equipment, and it is generally used for factory testing in manufacturing plants. The other is to use the DC withstand voltage test, because there is no capacitive current during the DC withstand voltage test, the capacity of the test equipment can be very small, which is relatively easy to achieve in the field, and the withstand voltage test can also be carried out on some polarized capacitors (such as electrolytic capacitors).

The withstand voltage test is a destructive test, once the breakdown, the capacitor will be scrapped, and explosion-proof measures should also be taken when the withstand voltage test is carried out on the large capacitor. Therefore, the withstand voltage test should be carried out with caution.

To measure capacitance or other equipment, you need to use an withstand voltage tester to gradually increase the voltage, and after reaching the breakdown, you can select a fixed value as the withstand voltage value.

Measuring the capacitance withstand voltage is a destructive measurement, you can directly hit the withstand voltage to the breakdown, and the withstand voltage deviation of a batch of capacitors will not be very large.