How to judge the quality of a large 15000μF capacitor with a multimeter
How to judge the quality of a 15000μF large capacitor with a multimeter
To determine the quality of a 15000μF large capacitor by charging and discharging using a multimeter's resistance setting, this method is not feasible because the test current of a multimeter's resistance setting is generally very small (μA level). To measure such a large capacitance, charge and discharge long time. If you want to judge the quality of a 15000μF capacitor, the simple way is to use the diode or capacitor setting of a digital multimeter. These two methods are introduced below.
1. Use the capacitance setting of a digital multimeter to directly measure the capacity.
Use the capacitance scale of a digital multimeter to directly measure the capacitance.
Many digital multimeters today can measure capacitances below 20mF ("mF" here is read as "millifarad", 1mF = 1000μF) (previous multimeters could only measure capacitance up to 200μF), so to judge the quality of a 15000μF capacitor, The capacitance can be measured directly using the capacitance scale of a multimeter.
The 4700μF electrolytic capacitor measured by the multimeter.
Use a DT9975 digital multimeter to measure the capacitance of a 4700μF (since there is no 15000μF capacitor) capacitor. The displayed reading is 4.502mF, which is 4502μF. Since the error of electrolytic capacitors is large, the displayed capacity is normal. When measuring a large-capacity electrolytic capacitor, if it does not exceed the range, but the displayed reading is always "1", it means that the capacitor has a large leakage or has been damaged by breakdown. If the measured capacitance is much smaller than the nominal value, it means that the electrolyte inside the capacitor has dried up and it is generally not suitable for use.
2. Use a digital multimeter to judge whether the diode is good or bad.
If you do not have a digital multimeter that can measure large-capacity capacitance, you can also use the diode setting of an ordinary digital multimeter to simply judge the quality of the capacitor. Since the test current of the diode gear is relatively large (mostly more than 1mA), diode gear measurement can quickly measure whether a large capacitor is broken down or damaged. When measuring, use the multimeter pen to touch the two pins of the capacitor. If the capacitor is a good capacitor, the reading displayed on the diode scale may be "0.000" in the first ten seconds. After that, the displayed reading will gradually increase until it is displayed as "0.000". 1". If during measurement, the multimeter displays a reading of 0.000 for a long time (or the reading is always very small), it means that the capacitor is damaged.
