Beijing Zhongdian Beiyuan Electronic Technology Co., Ltd
Contact person: Manager Wang
Company telephone: 010-62014289
Mobile phone: 13718362325
website: www.cebytronic.com
Email: weihuakeji@163.com
Address: No.32, Yanqi street, Yanqi Industrial Development Zone, Huairou District, Beijing
For a good capacitor, when a DC voltage is applied at both ends of the capacitor, the current will reach a large value instantaneously, which is close to 0 for the resistance. With the charging process going on, the current will gradually decrease. Theoretically, the two plates of the capacitor should be completely insulated, so the above charging process results Should be the current to zero, reflected on the resistance, should return to zero (that is, the current equals zero position). But in fact, all the capacitor plates are not completely insulated, so there will be a small current under the applied voltage, which is called the "leakage current" of the capacitor, which is that the needle can not completely return to.. Why. The amount of the multimeter needle return indicates the size of leakage current. If the multimeter returns more, the leakage current will be small, and if the return is less, the leakage current will be large. Leakage current should not be too large, otherwise it will cause some abnormal phenomena of the circuit, and it will not work normally when it is serious. When the leakage current is large, the capacitor will be much hotter than normal.
(1) The needle is quickly set to zero or close to zero, and then slowly go back and stop somewhere. It shows that the capacitor is basically in good condition. The closer the return position to the ∞ point, the better its quality is. If it is far away, it means that there is more leakage.
(2) The needle will not move soon after it is set to zero (0) or close to zero, indicating that a short circuit fault has occurred between the two plates of the capacitor, and the capacitor can not be reused.
(3) When the two electrodes of the probe and the capacitor start to be connected, the needle does not move at all, indicating that the internal wiring of the capacitor has been disconnected (generally occurs at the connection between the electrode and the plate), so it can not be used again.
