The first-mentioned style (let's call this "TE-styled" based from the manufacturer's abbreviated name) I can easily check for shorts with a multimeter after crimping the cable(s), but the second-mentioned style ("Kobiconn-styled") I have to insert a header far enough into the connector to make contact for use the multimeter. While I could insert it all the way, it makes it that much harder to remove once finished.
So I had thought of making something that would it make it much quicker and easier to check for shorts for the Kobiconn-styled connectors, and there's a bag of red/green LEDs that aren't being used for anything, so I grabbed what I needed for the project along with an unused LM317M.
It took a bit to design the board, but once I was done and checked it a couple times, I sent the design out to OSH Park. It took a bit of time, but once I received the PCBs, I was a bit awestruck - mainly from just seeing something that I designed look so professional.
Standard order of 3 boards, top of the board, and the bottom.
I soldered the voltage regulator on first, then the resistors, and then the LEDs before the 10-pin header (which was actually 16-pin, but I trimmed it down). I didn't take into account of the minimum length of the resistor with bent legs, so I had them close to the board on one side and angled upward on the opposite side.
The completed board with test cable attached.
I also had gotten a case and drilled the necessary holes to mount the board, but wanted to leave the final assembly for when I was at work, considering the voltage regulator is ESD sensitive. I then tested the board to make sure everything worked just right, and the green side of the LED was much brighter than I expected - flooding the nearby LEDs.
Power on, pins 1 and 2 shorted, pins 1 and 6 shorted, and all pins shorted.
When designing, I realised that I used a bad reference, which caused me to mis-mark the top-left pin as pin 1 and the bottom-right pin as pin 10. It was the last thing I fixed before sending it out. While I could have fixed the LEDs to correspond correctly, I didn't feel like taking the time to.
Not long after I completed the test, I realised that there were some 3mm LEDs at work as well, and in quite a large quantity. I wasn't too happy with myself, considering I had just spent about 15 USD for the test board, but I was determined to make it better.
The next set of boards.
If you're paying attention, you'll notice that "R3" is missing. I had omitted it because I figured that I would just lower the voltage appropriately and the power LED would light without needing a resistor. I should have given another day before sending the design out, considering I would've caught the mistake.
When testing this version of the board, none of the LEDs (beside the power LED) lit up, and I was confused, trying whatever I could to diagnose the problem. When I was about to give up, I saw a very quick flash and was quite confused, trying a few thing before shorting the legs of the LED, which is when I realised my mistake - the forward voltage of the LED is 2 volts, which is what I had the regulator output.
No other pictures for this version...
I was a bit stressed, now that I've spent another 8 USD in addition to the previous 15. I think I played with the adjustable voltage regulator unit that I made and found that I couldn't make 4 volts from 5.2, so I looked at all the adaptors that I had and coming across the adaptor from the Ikea lamp. I measured the output voltage, and it was just barely over 4 volts (4.02), which I figured would be more than enough, so I went back to my computer to design another revision.
Since the supplied voltage would be exactly what was needed, I only needed one resistor for the power LED, which helped make the board that much smaller. I decided to get rid of the ground pad that I had with the previous revision, since there wasn't going to be anything ESD sensitive on the board. When I received the boards, I set one on the soldering station, and the other two in the pile of tools and stuff next to my benchtop power supply.
It sat for a while, since the company had just moved buildings and I wasn't entirely operational yet (mainly the fact that I didn't have a need to make any ribbon cables). When I was doing the Windows 10 upgrade on Melty, I was bored and decided to solder the parts and then work on whatever I could. I forgot to take a picture of the boards themselves, but it's not horribly different from the previous version.
Parts soldered.
For testing, I didn't feel like messing with the cables because the cable from the adaptor wasn't very long (maybe about 15cm at most?), so I just clipped it together with some alligator clips to my "testing" cable (it's a cable that normally "connects" to my benchtop power supply and is inserted into a couple breadboard holes), stuck a couple of the legs into the appropriate holes, and carefully fed the legs through the power holes of the PCB.
Not entirely the best idea, but I didn't care too much.
After plugging in the cable to the adaptor, the power LED lit up, which was nice to see, but didn't mean anything at all to me. Before I was actually able to properly test it, the ends of the test cable had a mind of its own and wanted to short themselves while I tried to set it up. I tested pins 1 and 2 as usual, and the tested all the pins which gave a good result, as all test LEDs were the same brightness.
Pin 1 and 2 short test, and all pins short test (camera app I use has a weird glitch that crops the image weird when viewing right after taking).
I was quite pleased that I didn't muck up as badly this time, and proceeded to drill the new mounting holes in the case, as well as the holes for the on-off switch and the hole for the cable. I took the parts to work and did the final assembly not long after.
Completed unit, and switch in the on position.
I was going to cover the other holes with electrical tape, but I forgot and didn't care after the board was mounted to the case. I also realised that I mounted the switch backwards (I wanted on to be toward the board), but considering I used the anti-torque washer, I didn't care to have extra holes.
After 30 USD, I think I learned to be entirely certain well enough.
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