I'm building a Vicol Shigaclone (anyone interested can see the thread under Digital Source). The PS boards are built to support either a L7808 or LT1085/86 style regulator in a standard layout. I was building mine with a LT1085 and discovered only too late that the adjust pin cap (used to improve ripple rejection) was installed backwards. When I powered things up I noticed immediately the output voltage started at near the expected value, but then gradually started dropping.
It was only after pulling the power and going over the installation again that I found the reversed cap. I gave that one up as possibly damaged. I pulled it and replaced it with another (oriented correctly this time) and on power up things look nice and stable from a Vout POV - but I haven't scoped it yet. Would this cap reversal have damaged any aspect of operation for the regulator?
It was only after pulling the power and going over the installation again that I found the reversed cap. I gave that one up as possibly damaged. I pulled it and replaced it with another (oriented correctly this time) and on power up things look nice and stable from a Vout POV - but I haven't scoped it yet. Would this cap reversal have damaged any aspect of operation for the regulator?
Most probably only the cap will be a loss. Regulators usually have a very 'binary' failure behaviour: If they fail, they do so completely, if they still produce a regulated output, they are probably fine.
Rundmaus
Rundmaus
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