Hrmmmmm, I'm wondering if I mis-read the pinout on the LM338... looking at this:
**broken link removed**
what pins are A, B, and C?
I didn't initially see that it said "top view" on the left part, and so I assumed the view was from (what I call) the bottom; the part where you can see the insulating rings around the pins as shown in the diagram. If you look at it from the (much clearer) 3D view on the right, what do pins A, B, and C -- my markup -- correspond to? I have it wired with A as Input (2) and B as Adjust (1). C is quite unambiguous, and I have it wired as the Output (3). Do I have a different idea of what the "top" of the TO-3 is (and thus am reading it correctly) or are they essentially showing an x-ray view through the can?
I wired it up and plugged it in for about 10-15 seconds, with ~53VDC in; it never got hot or smoked or anything, but the output pin read dead 0.0mV. Also of note, I did briefly short the output to ground as I was trying to get my leads on the connectors -- I bumped the ground alligator clip and it snapped to the next tooth, allowing it to touch the output pin. I very quickly rectified this, but, assuming I have the LM338 wired correctly, would this have permanently killed the 338?
If I did get it backwards, would the LM338 be fried from this, or would some sort of internal protection just shut it off, so that rewiring it correctly would resolve the problem? I don't want to rewire it yet in case I do have it correct, and I'd rather not have to dremel out the mounting holes in the board to accommodate reversal of the TO-3 -- especially if I do have it right currently.
P.S.: When I put the meter on the input pin, it reads the full 53V (and the 3300µF holds a ~53V charge for quite some time after I shut off power)
P.P.S.: What could I wire up to the cap so that it safely drains when power is not being applied to the circuit, without affecting current draw or the filtering capability of the cap while the circuit is powered?