input caps are blowing up
Dear Sir/Madam,
We have a power supply design using Tiny2. You can see the attached schema. We are facing a problem a few of our products which are running in very heavy inductive environment. There are high power motors nearby where we connect our products. The problem is generally blown capacitor C23.
Would you please give us ideas how this can happen and how to protect from it ?
Regards,
Mehmet Ali Ekici
Comments
Hello,
We did try with two parellel 10 uF but din't help. Actually PI8 shows 6.8uF we placed 10uF. I like to remind you that this problem happens 3 out of 30 devices. These 3 devices has a commonality they work near huge motors. Do you have any other suggestions ?
Regards,
If not caused by thermal, it is highly possible that the failure of the cap is caused by voltage. Higher voltage rating cap hould be tried. If hgh voltage rating cap failed also, you may have to try non polarity cap.
Regards
I guess the issue is caused by thermal ofC23, which has low ESR and ESL. Could you try a bigger size capacitor or just use two, to make sure that the issue is really caused by thermal.
if it is really caused by thermal, one possible solution is move the other input aluminum cap closer to the transformer and TNY switch. Or you can use a better aluminum cap with lower ESR and ESL.