How to check the quality of capacitors?

Hello, the inspection of the capacitor: the capacitor works poorly or fails, which will weaken the high-voltage spark, and the power-off contact is often burned, the inspection method is: remove the distributor cover ** high-voltage line, 5-7 mm away from the cylinder body, open the ignition switch, toggle the breakpoint contact to check the high-voltage flashover, and then remove the capacitor wire, check the high-voltage flashover, at this time the spark should be greatly weakened, such as the two high-voltage flashovers are not much different, indicating that the capacitor is invalid and should be replaced.

1. Observation. This method is suitable for larger electrolytic capacitors or CBB capacitors and other types, this kind of capacitor damage is usually accompanied by shell deformation or rupture, especially the electrolytic capacitor is easy to bulge, leakage, as long as you see the capacitor in this situation, all should be replaced, so as not to damage other circuits when the equipment is running.

Second, the digital multimeter measurement, you can use the capacitance level to directly measure the capacitance value, the display of the volume value and the nominal value are about the same size as normal, otherwise it is regarded as damage.

1.Now the digital multimeter generally has a capacitance level, as long as the nominal capacitance value on the capacitor, the multimeter gear can be dialed to the appropriate range, for the non-polar capacitance can be directly measured without distinguishing the red and black pen, the reading value and the nominal value are about the same size as normal, and the display capacity value can be regarded as damage if it is obviously small or there is no reading.

2.For polarized capacitance, you only need to connect the red meter pen to the positive pole of the capacitor and the black pen to the negative pole of the capacitor, and the difference between the reading and the nominal value is not much as normal, otherwise it is bad.

3. Pointer multimeter measurement. Use the resistance level of the pointer multimeter to roughly judge the quality of the capacitor. Dial the pointer meter to the R 1K gear or R 100 gear, and select the gear according to the capacitance value, the larger the capacity, the smaller the gear selected.

1.For polarized capacitors, use the black watch pen to connect the positive pole of the capacitor, and the red watch pen to connect the negative pole of the capacitor, at the moment of touch, you can see that the pointer quickly swings to the right, and gradually recovers to the left to the resistance infinity, the swing amplitude can be compared with the new capacitor, the larger the capacity, the greater the amplitude. If the pointer does not return, the capacitor has leakage and cannot be used.

2.For non-polar capacitance, there is no need to distinguish between red and black pencils, it can be measured in front and back, if the pointer does not swing, it means that the internal open circuit of the capacitor has failed. If the swing amplitude is small compared to the normal value or does not return, it can be regarded as a decrease in capacitance and leakage, and cannot be used.

The above is a simple capacitance detection method, which can roughly judge the quality of the capacitance, and if you want to accurately measure the parameters of the capacitance, there is a special instrument digital bridge, but this is an instrument that can only be accessed by professionals.

Checking the quality of a capacitor is mainly to judge its voltage and ability to pass current.

To check how to check the good looks of the capacitor, and to check the quality of the capacitor, you can use the electric test for two levels.

Usually, the quality of the capacitor, the meter can only check whether there is leakage between the capacitor plates, whether it can withstand the rated voltage, that is, whether it can still be counted as a "capacitor" under the rated voltage, or whether the capacitor has a large change in capacitance.

As for the actual capacitance of this capacitor, especially the capacitor with a small capacitance, the current inspection method should use a "bridge", or a special meter (usually an internal meter based on the "bridge") to measure its capacitance.

Methods to detect the quality of capacitance:

Method 1: Pointer multimeter measurement.

1. Check the quality of the electrolytic capacitor with the resistance file of the multimeter.

The two leads of the electrolytic capacitor are positive and negative, when checking its quality, for the electrolytic capacitor with low withstand voltage (6V or L0V), the resistance gear should be placed in the R 100 or R 1K gear, and the red watch pen should be connected to the negative end of the capacitor, and the black watch pen should be connected to the positive end, then the multimeter pointer will swing, and then return to the zero position or near the zero position. Such electrolytic capacitors are good. The larger the capacity of the electrolytic capacitor, the longer the charging time and the slower the pointer swings.

2. Use a multimeter to judge the positive and negative leads of electrolytic capacitors Some electrolytic capacitors with low withstand voltage, if the positive and negative leads are not clearly marked, they can be judged according to the characteristics of small leakage current (large resistance value) when it is connected positively and large leakage current when it is reversed. The specific method is to touch the two leads of the capacitor with a red and black watch pen, remember the size of the leakage current (resistance value) (the resistance value indicated when the pointer swings back and stops), and then shorts the positive and negative leads of the capacitor, and then measures the leakage current after the red and black watch pens are reversed.

The indication of the low leakage current is used as a criterion, and the lead that comes into contact with the black stylus is the positive end of the electrolytic capacitor. This method makes it difficult to distinguish the polarity of electrolytic capacitors with low leakage current.

3. Check the variable capacitor with a multimeter The variable capacitor has a set of fixed pieces and a group of moving pieces. Use the multimeter resistance file to check whether there is a touch between the moving and fixed pieces, use the red and black watch pens to connect the moving piece and the fixed piece respectively, rotate the shaft handle, and the meter pointer does not move, indicating that there is no short circuit (touching the piece) between the moving and fixed pieces; If the pointer wiggles, it means that the capacitor has a short circuit.

4. Use the resistance file of the multimeter to roughly identify the quality of capacitors with capacitance above 5000pf.

The multimeter resistance level can roughly identify the quality of capacitors above 5000pf (those below 5000pf can only judge whether the capacitor is broken down). When checking, put the resistance range at the high end of the range, and the two meter pens are in contact with the two ends of the capacitor, then the pointer quickly swings and then recovers, reverses the connection, the swing amplitude is greater than the first time, and then recovers. Such capacitors are good.

1. Use a pointer multimeter for detection.

Adjust the multimeter first, select the corresponding position, connect the black one on one side and the red one on the other, and then you can test it. If the needle inside moves, but eventually returns to the zero position, it means that it is normal and can continue to be used.

2. Detect with a digital multimeter diode.

There is also a digital watch, which can be adjusted to the second gear, and then connected to the pen, and it can be detected. If it makes a dripping sound, it means that it is broken and needs to be replaced with a new one.

3. Direct detection with capacitors.

The first thing to choose is to choose the gear, and then to connect the electric pen, if it is infinite, it means that it is leaking and needs to be repaired before you can continue to use it.

Different capacitance of the capacitance choose different resistors to connect the capacitor to the multimeter pen (regardless of positive and negative), if the needle is biased positively and negatively, the capacitor feet are reversed, and the pointer is deflected and slowly returns to the 0 position, indicating that the capacitance is good (generally the multimeter can not measure the capacitance of the capacitance, but the multimeter of FM50 can measure the capacitance capacity).

How to measure the quality of small capacitance?

1. Detect the small capacitance below 10pf because the capacity of the fixed capacitor below 10pf is too small, and measure it with a multimeter, which can only qualitatively check whether there is leakage, internal short circuit or breakdown. When measuring, you can choose to use the multimeter R 10K block, and use the metal rod of the two meters to connect the two pins of the capacitor at will, and the resistance value should be infinity. If the measured resistance value (the indicator swings to the right) is zero, it means that the capacitor is damaged by leakage or internal breakdown.

2. For the above fixed capacitors, the R 10K block of the multimeter can be used to directly test whether the capacitor has a charging process and whether there is an internal short circuit or leakage, and the capacity of the capacitor can be estimated according to the amplitude of the pointer swinging to the right.

How to test the quality of electrolytic capacitors?

1. Because the capacity of electrolytic capacitors is much larger than that of general fixed capacitors, the appropriate range should be selected for different capacities when measuring. As a rule of thumb, the capacitance between 1 and 47 F can be measured in R 1k stops, and the capacitance greater than 47 F can be measured in R 100 stops.

If you want to effectively check the quality of the capacitor, you can use a fuel gauge to check it reasonably, or you can try to use it to check its normal condition, so when you usually test the electricity, you must follow the correct way to achieve a safer effect.

1. External inquiry auscultation.

1. If it is found that the capacitor shell is deformed and the polyester capacitor is swollen and bulging, it is clarified that the insulating medium or electrode inside the capacitor must be damaged, and the operation should be withdrawn immediately and replaced with a new one.

2. If it is found that the high-voltage porcelain bottle of the capacitor is flashing and bursting or has shown oil injection, overflowing the internal insulating medium, etc., it should also be distinguished as a capacitor damage, and the damaged products should be properly disposed of and recovered and replaced with new ones.

3. The capacitor should not have any sound during normal operation. If you hear an abnormal "crackling", "crackling" discharge sound or "buzzing" noise, it is clear that there must be a defect inside the capacitor, and it should be stopped for further inspection or replacement with a new product.

4. When the capacitor is operating, if it is found that the capacitor switch of the group is tripping or the high-voltage ** safe wire is blown out, it should be withdrawn from the operation, and the capacitor can be put into operation again after finding out that the capacitor has no defects.

Second, the insulating shake meter inspection method.

Discharge and unconnect the external wiring of the capacitor to be tested.

Choose a megohmmeter with the appropriate voltage level for the capacitor operating voltage (general torque: 500 volts or 1000 volts megohmmeter below 1000 volts; 1000 volts or more use a 1000 volt or 2500 volt megohmmeter) to measure the insulation resistance of the capacitor.

1. Check the quality of electrolytic capacitors with pointer multimeter resistance: this method is suitable for capacitors with low withstand voltage values, such as electrolytic capacitors below 6V or 10V. First, turn the pointer multimeter to the resistance position, the gear is r times 1k, and then connect the red watch pen to the negative end of the capacitor, and the black watch pen to its positive end.

Pay attention to the change of the pointer of the multimeter while connecting. The hands will oscillate, and after discharge, they will return to or near the zero scale. The occurrence of runout recovery zero proves that the capacitance is good, and vice versa.

2. Check the quality of the electrolytic capacitor in the diode file of the digital multimeter: this method is suitable for the situation that the electrolytic capacitor is broken down. Put the digital multimeter on the diode file, and connect the two meter pens to both ends of the electrolytic capacitor, at this time you need to listen to whether the digital multimeter emits a dripping sound, if not, it proves that the capacitor is good and has not been broken down.

Hello, the inspection of the capacitor: the capacitor works poorly or fails, which will weaken the high-voltage spark, and the power-off contact is often burned, the inspection method is: remove the distributor cover ** high-voltage line, 5-7 mm away from the cylinder body, open the ignition switch, toggle the breakpoint contact to check the high-voltage flashover, and then remove the capacitor wire, check the high-voltage flashover, at this time the spark should be greatly weakened, such as the two high-voltage flashovers are not much different, indicating that the capacitor is invalid and should be replaced.

1. Use the multimeter resistance file to check whether the moving and fixed pieces touch the pieces, and use the red and black watch pens to connect the moving pieces and the fixed pieces respectively.

2. Rotate the shaft handle, and the meter pointer does not move, indicating that there is no short circuit between the moving and fixed pieces. If the pointer wiggles, it means that the capacitor has a short circuit.

3. The resistance file of the multimeter can roughly identify the quality of the capacitor above 5000pf, and the capacitor below 5000pf can only judge whether the capacitor is broken down.

4. When checking, put the resistance range at the high end of the range, and the two meter pens are in contact with the two ends of the capacitor, then the pointer swings quickly, and then recovers.

How to check the quality of capacitors? 1.

When a large electrolytic capacitor or CBB capacitor is damaged, the shell is usually deformed or cracked, especially the electrolytic capacitor is prone to bulging and leakage. Capacitors in this case are damaged.

Measured with a digital multimeter. The capacitance value can be measured directly using the capacitance level, and the display of the capacitance value is about the same size as the nominal value, which is considered normal, otherwise it is considered damaged.

Measure with a pointer multimeter, and use the resistance level of the pointer multimeter to roughly judge the quality of the capacitor.

Capacitor inspection: the capacitor work is poor or invalid, will weaken the high-voltage spark, the power-off contact is often burned, the inspection method is: remove the distributor cover ** high-voltage line, 5-7 mm away from the cylinder body, open the ignition switch, dial the breakpoint contact to check the high-voltage flashover, and then remove the capacitor wire to check the high-voltage flashover, at this time the spark should be greatly weakened, such as the two high-voltage flashovers are not much different, indicating that the capacitor is invalid and should be replaced.