Commoning block? - Page 1
Forum section: electronics / general

author: bsudbrink
author_rank: Frequent Contributor
timestamp: September 27, 2019, 05:26:28 pm
content: I'm restoring the linear power supply in a vintage computer and I need a couple of these parts. They are called out in the BOM as:Molex commoning block (07-01-70)The block seems to have the behavior that it shorts wires inserted into adjacent "slots" via "crimp pins". Appears to be made of black plastic (see photo). My Google Fu is failing me on this. I'd appreciate if someone could point me to where they can still be bought. Barring that, if you have a couple of spares (I'll need blocks and pins), I'll happily pay a reasonable amount.Thanks!

author: worsthorse
author_rank: Super Contributor
timestamp: September 28, 2019, 08:26:27 pm
content: Quote from: bsudbrink on September 27, 2019, 05:26:28 pmNot surprised. Figuring out molex part numbers, especially in old gear, is a real chore. Do you have any better photos or any from the side? What year is it from, roughly. I have an old molex catalog around here somewhere and will see if I can find more info.

author: bsudbrink
author_rank: Frequent Contributor
timestamp: September 28, 2019, 08:38:20 pm
content: The year would be 1977. Thanks for taking a look. I don't have another photo, but I imagine that it's pretty symmetrical. I know I could accomplish the same thing with a couple of wire nuts, but I want to "do it right".

author: worsthorse
author_rank: Super Contributor
timestamp: September 28, 2019, 08:50:16 pm
content: Quote from: bsudbrink on September 28, 2019, 08:38:20 pmOkay. I will look later today or tomorrow and post something. And I understand wanting to do it right because that will probably be the death of me.

author: drussell
author_rank: Super Contributor
timestamp: September 28, 2019, 08:59:31 pm
content: I don't recognize that particular one, but perhaps try doing parametric searches for "1 circuit" versions of things like "Terminal Block", "Terminal Junction", "Connecting Block", "Terminal Strip", etc...You essentially want to specify something like you would when you want a non-barrier version of a "barrier strip", but for contacts instead of screw terminals. I'm sure they exist for spade terminals, so why not for regular pin connectors?Digikey has some similar-ish things under "Terminal Junction Systems" but they all seem to be much fancier and rather expensive, but perhaps a place to start at least finding the terminology?I'm not sure what else the "non-barrier" version of connector junction thingies would be called...

author: Nusa
author_rank: Super Contributor
timestamp: September 28, 2019, 09:29:40 pm
content: https://www.molex.com/molex/products/datasheet.jsp?part=active/0007017051_CRIMP_HOUSINGS.xmlhttps://www.molex.com/molex/products/datasheet.jsp?part=active/0007017101_CRIMP_HOUSINGS.xmlhttps://www.ebay.com/itm/QTY-20-07-01-7101-MOLEX-10-POSITION-NUMBERED-POWER-CRIMP-HOUSING-4-45mm-/122548173462Few minutes of google-fu. Hope that helps.

author: bsudbrink
author_rank: Frequent Contributor
timestamp: September 28, 2019, 10:24:53 pm
content: Excellent. That's a start. Wrong number of positions, but a start. I'm asking the ebay seller whether his lots come with the pins. I still have no idea what they look like.

author: drussell
author_rank: Super Contributor
timestamp: September 28, 2019, 10:25:55 pm
content: "Commoning Crimp Housing" ... I wouldn't have thought of that directly....Well done.

author: bsudbrink
author_rank: Frequent Contributor
timestamp: September 28, 2019, 10:31:47 pm
content: I think part of my problem was that I was including "5 pin".

author: drussell
author_rank: Super Contributor
timestamp: September 28, 2019, 10:34:05 pm
content: Quote from: bsudbrink on September 28, 2019, 10:24:53 pmThe first of the three links posted above looks like it would be the 5-position model in your photo.I just stupidly didn't even try searching for the model number... The "07-01-70" listed in your BOM is, indeed, the part number prefix for that series. I would think you could figure out what pins fit if you had one of the housings in front of you.I'm a bit perplexed, though... You say you're repairing an old supply, but there aren't any remnants of any of these still in the unit you're working on?Sounds like quite the restoration project then. Do tell.

author: bsudbrink
author_rank: Frequent Contributor
timestamp: September 28, 2019, 10:57:33 pm
content: I'm doing a repair to a Sol20 computer. Some of them came with the "wrong" transformer installed. This results in the unregulated power on the S-100 bus being too high. 11 volts instead of 8, 22 volts instead of 16 (plus and minus). Pushing that much voltage through the regulators found on most S-100 cards will burn them up in no time. The correction, from Processor Technology, was to install a bucking transformer to decrease the voltage going to the main one. This "block" was included as part of the kit. The picture (above) is from the kit instructions. The transformer that came in the kit was common and is still being made by the same manufacturer, available at all of the "usual suspects" (DigiKey, etc.).

author: drussell
author_rank: Super Contributor
timestamp: September 28, 2019, 11:34:59 pm
content: Quote from: bsudbrink on September 28, 2019, 10:57:33 pmSo yours doesn't have the two blocks to the left and right of the power switch on the fan closure assembly?(Figure 2-1 in the System Manual)If they didn't use those blocks in some of the early kits, how are the fan and the transformer connected to the power switch and neutrals connected together on that fan plate / back panel assembly?(Figure X-1, page 204 in the SM PDF)

author: bsudbrink
author_rank: Frequent Contributor
timestamp: September 28, 2019, 11:42:47 pm
content: Ah, yes. Yes it does. I have not pulled it apart yet, I'm at the parts collection phase. I had not even carefully read the instructions yet, just the parts list. On the plus side, with everyone's help, I located a place with a few in stock:https://www.nepelectronics.com/products/07-01-7051/I guess I will go ahead and pull it apart to see what the crimp pins look like. I'm still looking for them. The vendor (above) does not have them listed.

author: drussell
author_rank: Super Contributor
timestamp: September 29, 2019, 12:10:59 am
content: Quote from: bsudbrink on September 28, 2019, 10:57:33 pmAhh, yes... That all makes perfect sense then.You intrigued me since I'm really not familiar with the Sol-20, only recognize the name, so I went to look it up. I found it even more intriguing and was amused when I realized that Jim Battle had reasonably extensive info atsol20.org. I have a functional multi-user Wang 2200 LVP system, and Jim hasthedefinitive Wang 2200 resource atwang2200.org.Great guy. I haven't conversed via e-mail for many years now but he went out of his way to provide me with some disk interface manuals, schematics and programming info that had not yet been posted to his site archive, allowing me to start to make an IDE disk interface for the ol' girl. (Well, technically I have two of 'em. I also have a 2200 MVP, which could be made into a separate working system with some kind of disk interface since I cannibalized the old 80MB CDC CMD "Phoenix" disk drive and suitcase controller decades ago.)I simply haven't had time lately to pursue the project. Someday, eventually, though! With all the(Real life and all, always interrupting, you know.)Quote from: bsudbrink on September 28, 2019, 11:42:47 pmThat's great! It is amazing what the hive mind can come up with sometimes, isn't it?I was hoping you at least had something to compare the pin type to. I expect it is a standard old-school Molex pin of one type or another. The assembly section talks about inserting the "open" side a certain direction and then inserting the pin until it locks. Certainly sounds like common style Molex pins to me, it will likely just be a matter of figuring our what size-type they are.Please consider keeping us apprised of your progress on bringing this historic relic back to life.

author: bsudbrink
author_rank: Frequent Contributor
timestamp: September 29, 2019, 12:32:50 am
content: I'm puzzled by the fact that there is no metal in the block. The function to short pins must be implemented in the pins themselves and is apparently affected by both the insertion location and the insertion orientation. I'm now reading the PS assembly instructions. I will probably disassemble the PS sufficiently to examine the blocks and pins tomorrow.P.S. Shameless plug. If you go to the "Programs" tab on Jim's web page and scroll down a little, you will see a link to my web page for my RUNENT program.

author: drussell
author_rank: Super Contributor
timestamp: September 29, 2019, 12:48:08 am
content: Quote from: bsudbrink on September 29, 2019, 12:32:50 amUgh... That would be annoying, being some oddball type of pins. Drats.Good versatility, though, I suppose. Just not what I would have expected.Thatwouldcertainly explain why the holes are numbered and why they are so specific in the assembly instructions as to which terminal holes to use for each wire.QuoteI'll be interested to hear what you find about the pins. Perhaps you could take a couple photos of the connector system for posterity?Also, congrats on becoming a man known for his file format.

author: drussell
author_rank: Super Contributor
timestamp: September 29, 2019, 02:47:04 am
content: Just a quick note after doing a bit more research on those pins...Digikey still lists the 15-position connector housing as "active" although it could be an error that it is still listed as active, (and no help since minimum order 3900 pcs at C$0.88)Mouser still has listings for the whole series (now listed as obsolete) but the datasheet copies that they host show the series were still listed active in 2016, so it may not be impossible to still find the pins if we could figure out the darn part number.The main issue is finding a catalog for that 1461 series,which I have bee^H^H^H. . . .NO! WAIT!!EUREKA!!!The pins you're looking for are the "Commoning Connector Crimp Terminal", series 1457.05-02-0049-- 14-16ga05-02-0048-- 18-22ga05-02-0091-- 24-30gaI found this drawing via Digikey while looking at the connectors and the polarizing key info screens:https://www.molex.com/pdm_docs/sd/007018051_sd.pdf... and lo and behold, in the upper right corner are some notes:I guess the bowed out sides must be able to connect to the adjacent connectors?I suppose the "polarizing key" might just block off a section to create a multi-section strip?Anyway, keep us posted... and good luck!

author: drussell
author_rank: Super Contributor
timestamp: September 29, 2019, 03:18:08 am
content: One more additional update, then I'm getting back to my own dang projects...It appears from this obsolescence notice:https://estore.heilind.com/pcn_upload/20150121_Molex_GCM_10451192.pdf... that at least several of the versions of the housings and pins were slated to be discontinued starting in 2010, but some part numbers seem to have carried on for at least a little while, perhaps to fulfill some end of life / lifetime buy orders, etc. There were actually about a zillion different versions of that connector series housings... Labelled in ink, unlabelled, raised or recessed numbering, numbering that goes from 1-5, 1-10, 1-15 and 1-20, or ones that are numbering from 5-10, 10-20, or 60-80, etc. etc.In any case, most places don't seem to have any of the crimp pins in stock, but Mouser supposedly has 1015 of the 18-22ga version in stock, although you strangely have to order them in multiples of 79, but if you can manage to shell out the USD$8.77, you can have a lifetime supply of those pins.https://www.mouser.ca/ProductDetail/Molex/05-02-0048?qs=%2Fha2pyFaduiSmRWGChcGk1WwL5HHjd4HJRhmdKhqHm0%3D

author: worsthorse
author_rank: Super Contributor
timestamp: September 29, 2019, 10:32:48 pm
content: well, why i was digging around through the catalog box, it looks like an answer was found. excellent news!

author: bsudbrink
author_rank: Frequent Contributor
timestamp: October 01, 2019, 10:21:45 pm
content: Mouser failed me. Despite their website indicating 1015 in stock, _AFTER_ I placed an order, they've just emailed me to say that they don't have any. Fortunately, Lake-View Electronics (found via MOLEX's web site) has a small stock on hand and, after talking to a real person who verified that they really do have some, I've placed an order with them that should arrive later this week.

author: bsudbrink
author_rank: Frequent Contributor
timestamp: October 21, 2019, 07:20:09 pm
content: Job done... note that the mainboard and some structure was temporarily removed to deal with a lot of unfortunate rust.Parts:Transformer wired for bucking duty:Cutout for mounting:Transformer mounted:Commoning block mounted: