after the product produced last month, the high-voltage ceramic capacitor 50kv 5000pf went offline, and carried out various technical tests as usual. the quality inspector was full of doubts: he gong, this batch of goods has quality problems!
although lao he is not scared, but listening to this is still a tight heart. because of this model of products, 咱 thousands of monthly production, if the quality has problems, it does have a profound impact! so i will not say anything, look at the quality inspection room look again!
first discharge the instrument, turn the switch to the lowest position, take out a 50kv502k high-voltage ceramic capacitor from the box, put the screws on both ends, clamp the capacitor with the clip, slowly put it into the transformer oil, and put it on the test column. after checking the grounding line and other aspects of the work in place, i came to the meter, turned on the switch, and pressed the voltage test button.
the torque switch rotates clockwise little by little. i turn the voltage up from 0. after 40kv, the transformer oil starts to move. this is the normal reaction. 50kv, 60kv, the capacitor does not have any abnormal reaction. transformer oil start to react more enthusiastically. 70kv, still normal, but just arrived at 71kvdc, the instrument suddenly jumped the table, the voltage button is off, the voltage on the meter is zero!
is it really a problem with the quality of the capacitor itself? you know, this capacitor is designed with a pressure resistance greater than 100kvdc. it is impossible to drop the chain at 70kvdc? don't panic, come again!
after the instrument was discharged, i turned on the power switch again. after the torque switch was turned to zero, the voltage button was pressed. the test started again. i found that the capacitor was just rising again. similarly, when the meter jumps at 71kvdc, the voltage display returns to zero! that is to say, the capacitor is not burned, but the problem of the instrument itself. unscrew the four screws and press the finger on the 4040 integrated block. mom, it is hot!
it turns out that the problem is on this ic. this ic has a solid barrier, so each time the voltage rises to 71kvdc, the instrument starts automatic protection. hurry to change the ic and test again!
80kvdc....85kvdc...90kvdc...95kvdc...100kvdc...test normal, false alarm! celebrate our high-quality high-voltage capacitors! this batch of high-pressure ceramics capacitor, completely normal! quality ok!