@Rod Stewart posted:Bob; it's doubtful the cap is the problem IMO. Those boards have all worked perfectly for me, even with 1000 uF caps installed. I would bet the problem is the 317T since everything else looks good. From the pix the center pin soldering looks a bit suspicious, though from the bottom it might be just fine. I would recheck that for sure. If that doesn't solve the problem i would cut out the 317 and put in a new one. They are pretty cheap after all.
Several months back another gentleman was building a few of these and had some troubles. It turned out the pack of bulk 317's he bought had several defective ones. Seems hard to believe I know, it sure seemed odd to me. Don't think I have ever had a bad one. Worth checking.
Rod
Rod,
Here is the bottom of the PCB. The regulator is from DigiKey, LM317TG. I am a novice at this type of soldering. However, I have built about a dozen of these, using the 470uf and they are all installed and working flawlessly. Nevertheless, I am no expert!
@gunrunnerjohn posted:The cap should make no difference in the output current. That is a LM317 regulator, right? It looks OK visually, but I can assure you that many people have built the same board and are using them, so something is amiss.
What voltage to you get measuring directly across the capacitor at the two arrows?
John,
The voltage across the cap, with 17.5 V AC in, is 2.3V DC. I have no idea if that is good or bad.
Thanks to both for your prompt replies.
Bob
