Following on from my earlier post about using the 3M IDC plug to interface all five lines between J3 of the EVAL1 and J4 of the SMPS1200A400, I have now tried a different approach, involving different tools and skills, and less money. Purifi provides a spare JST EHR-7 plug housing, which can be used to plug into J5 of the SMPS1200, as
@Zak66 did, above. But, with a bit of work, you can use it, plus a second one, to get the five-wire interface to J4. For this, you just need an additional EHR-7 plug body, and the two extra jumper wires, described, before. First, use a sharp knife or safety razor blade to shave off the five protruding ridges of the housing (four short and one long):
Yielding:
Next, you need to thin down the thick side of the housing - the one with all the openings. I did this by rubbing it on an emery board (fine sand-paper on a cardboard stick) for 30-60 seconds. This will make plastic dust in the openings of the plug housing - just blow it out. You want to remove maybe 0.5mm, just enough that it will slip into the SMPS1200 J4 socket,
smoothly.
[The photos are of a plug housing before I trimmed off the ridges.]
Try fitting it into the socket to judge when you've done enough. Note the orientation, carefully. Don't push it in all the way, or you might not get it back out! If it is tight, rub it down a bit more. I tried several times before I was satisfied. Do this for two EHR-7 housings.
Viewed from the ends, the two of them will fit like this, with the "plain" sides facing together, and the sides with openings facing out:
And into J4 like this:
Remove these housings from the J4 socket and insert the existing crimps of the five jumper wires (from the EVAL1, J3) into the corresponding holes, for p1, 2, 3, 6 and 10, as listed before. NOTE THAT THE END HOLES ARE EMPTY! You will use the center five positions, only.
Here is mine, with some small shrink tubing I had (red on pin 1 (V+) and grey on pin 2 (V-), with a bit of black to keep all wires together):
And here it is plugged fully into J4:
It works great! But, YOU must take care to plug it in the right way around - there is no polarization of the plugs in the socket. Note how there are three wires on the end towards the left of the socket, and only one at the right. In my case, with the red shrink-tube on wire #1, it's like the red stripe on a ribbon cable. One could add a little square of red tape on the face of the socket by there to indicate that the red wire is to be on that end. [The PCB silkscreen also indicates this by the white point just under that pin position - #1.]
Having said and done all of this, if you have to buy additional housings (I had a spare EHR-7 for this), you could just get a pair of EHR-5 (five long instead of seven long), and skip trimming off the four short ridges on the ends. Keeping those side ridges on the EHR-5 should ensure that it will insert centered in the socket. You still need to trim off the long ridge on each one, and thin down the sides, though that should be slightly easier with a 5-position plug than with the 7-way.
Finally, you could make this
polarized with two EHR-
7, by keeping just the 'back' ridge on one end of each (same end when paired!) and cut out the lock tab of SMPS1200A400 J4 on the corresponding end (I recommend it be the pin 9-10 end). Then it should insert in only one orientation.
EDIT 02/22/20:
Final advice on this. Whether one uses 7-pin, or 5 pin housings, an easy way to 'polarize' the assembly is simply to pry out the center tab of the odd numbered (front) row. This works as an indicator and partial insertion block. But, it can be made even better by looping a tiny zip-tie through that opening - then there will be no chance of inserting it, wrongly. A zip-tie with 1.8mm wide band, like Panduit PLT.6SM-C or PLT.6SM-M, would be ideal here. Mine is a typical 4" tie. A bit big, but it did work without modification.
