Connector and Wire Type Question - Page 1
Forum section: electronics / projects

author: bostonman
author_rank: Super Contributor
timestamp: October 21, 2021, 01:44:07 am
content: I have a few questions.I purchased a Logic Analyzer and it came with connectors, cables, and ends that connect to an IC pin extender.I'm assuming these wires are going to break from use, so I'd like to buy some spares. The wire is amazingly flexible; it bends similar to cooked spaghetti. In the attached pictures, does anyone know what type of connector this is, what type of wire would be so flexible, and pins to tie into IC pin extenders?

author: xrunner
author_rank: Super Contributor
timestamp: October 21, 2021, 02:11:00 am
content: Typically called "dupont" connector, probably 0.1" (2.54mm) pitch, very common.https://forum.digikey.com/t/dupont-connectors-and-how-to-find-them-from-digi-key/3315If you want to make your own you can get the crimp pins (male and female) and a crimping tool. For super flexible wire get silicone insulated wire.

author: bostonman
author_rank: Super Contributor
timestamp: October 21, 2021, 02:17:17 am
content: QuoteDoes it also have to do with number of strands? I meant to include this in my question.This wire is amazingly flexible, and the only stuff I may have ever seen was called Noodle Wire.

author: xrunner
author_rank: Super Contributor
timestamp: October 21, 2021, 02:41:01 am
content: Quote from: bostonman on October 21, 2021, 02:17:17 amYea of course but I just buy the gauge of stranded wire I need, I don't think about the # of strands. Small wire might have seven strands I'm really not sure exactly, but I can check.QuoteI have some of this 30 AWG silicone insulated wire from Adafruit -https://www.adafruit.com/product/2001That stuff is super-flexible. For logic probe wire you don't need a large gauge wire of course.

author: bostonman
author_rank: Super Contributor
timestamp: October 21, 2021, 02:46:06 am
content: This is a big help.I plan to be careful, but I sense with enough use (and mistakes), that a wire is going to break, get crushed, etc...I assume the pins at the end are typical socket pins that just slide over an IC pin extender?On a side note (and I'll gladly start a new thread, but believe it's a waste), do IC pin extenders (if that's the correct name) come with different amounts of tension? The ones I have seem to have lots of tension and fear the IC chips will crack.

author: tooki
author_rank: Super Contributor
timestamp: October 21, 2021, 04:18:16 am
content: Quote from: bostonman on October 21, 2021, 01:44:07 amThe name of the original connector series, the series cloned and marketed as “DuPont” by the Chinese, is the Mini-PV series from Amphenol (formerly Berg).There are many compatible connector series, like Molex C-Grid III, Molex SL, and AMP AMPMODU Mod I, II, and IV series. (Compatible in the sense that assembled connectors are fully compatible for mating; the components to make a connector (housings, contacts, etc) are not interchangeable at all.)As far as wire goes, that’s likely an extra-fine-strandedPVCsilicone.It’s too glossy to be silicone.(Edit: on second look, I noticed that it says “200°C” on it, so it has to be silicone.) For 24awg, it’d be somewhere in the ballpark of 40-120 strands. For example, look at the datasheet below. It’s a european-spec ultra-fine-stranded 0.25mm2(slightly thicker than 24awg, which is ~0.21mm2) which uses 128 strands.Standard 24awg stranding is 7 strands, and thus very noticeably stiffer. 19 strands is already better, but the really high strand counts are preferable. But another issue is that the finer stranding tends to be paired with softer insulation, even if it’s the same insulation material. There are many types of PVC and silicone which vary significantly in rigidity and in how much they hold a shape when bent.I do not recommend the 30awg silicone from adafruit: though it is thin and thus doesn’t exert much force of its own, it tends to hold a shape rather than just flop loosely like I like in a test lead. It behaves like very thin wire, not like yarn or thread.I’ve made many leads using 24awg fine-stranded silicone from AliExpress that uses 40 strands, and it’s day-and-night better than ordinary jumper leads. It also takes a shape a bit, but not as strongly as the adafruit stuff. As long as you don’t crease it, it’ll stay looking nice. (Roll it on a table under a stiff object like a PCB to remove a crease.) In fact, this is what I used to make a better set of leads for my el-cheapo logic analyzer.There exists true test lead wire, in both PVC and silicone, which is ultra flexible and doesn’t take a shape, remaining floppy. But beware that a lot of vendors, even ones you wouldn’t suspect, sell ordinary silicone as test lead wire, even though it’s not. (For example, avoid Cal-Test wire.) Stäubli and Lapp both make excellent thin test lead wires.

author: MarkF
author_rank: Super Contributor
timestamp: October 21, 2021, 05:47:05 am
content: I bought this set from Amazon that seem okay for the ones I've used so far:https://www.amazon.com/gp/product/B0774NMT1S/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1--> NOTE THE WIRE GAUGE: 18-26AWG <--You can also get pre-made jumpers from Adafruit and replace a wire when it breaks:https://www.adafruit.com/product/266Adafruit has different lengths (3", 6" and 12") and different male/female connector choices.

author: tooki
author_rank: Super Contributor
timestamp: October 21, 2021, 10:03:15 pm
content: Quote from: MarkF on October 21, 2021, 05:47:05 amAlmost certainly incorrect. The product description says it’s DuPont, but then says it’s JST SM (which is a totally different connector type). The pictures show DuPont. So the specs are highly suspect to begin with.DuPont-style connectors come with contacts in three gauge ranges: 18-20awg, 22-26awg, and 28-32awg. So yes, the connector system supports a wide range, but an individual contact does not.Most of the DuPont terminals I’ve gotten from China were for 22-26awg, but one batch I suspect was for 28-32, or perhaps for something like 24awg but with thin insulation. Most vendors don’t tell you what they’re actually sending you. Sometimes if you ask…Anyhow, this set most likely comes with contacts for 22-26awg.Quote from: MarkF on October 21, 2021, 05:47:05 amThose are just ordinary cheap DuPont cables at a huge markup. They’re not the highly flexible wire the OP expressly wants.

author: Benta
author_rank: Super Contributor
timestamp: October 21, 2021, 10:51:41 pm
content: @bostonman:Why do you think they are going to break? I've used this kind of super-soft, multistranded silicon wire for decades in measurement setups. It doesn't break, unless you hack a meat cleaver through it.If your Logic Analyzer manufacturer is of a reputable brand, you'll be able to get replacements in 20+ years if needed.

author: bostonman
author_rank: Super Contributor
timestamp: October 22, 2021, 01:58:19 am
content: I'm not as concerned about the wire, but I feel the constant twisting of the wires will cause them to break out of the connector.

author: tooki
author_rank: Super Contributor
timestamp: October 22, 2021, 02:07:42 am
content: Quote from: bostonman on October 22, 2021, 01:58:19 amI don’t think they’re nearly as fragile as you suspect. Those contacts have likely been crimped correctly, which in these connectors means the wire is strain relieved in the contact itself, and the fairly deep recess in the housing provides additional strain relief.As long as you don’t handle them like a gorilla, they’ll be fine.

author: bostonman
author_rank: Super Contributor
timestamp: October 22, 2021, 02:16:42 am
content: I don't disagree and doubt I'll use this enough to weaken the connections.I mainly asked because should I place a DigiKey or Amazon order soon, I'd probably spend a few dollars and get extra parts to have on hand should they break.One thing I've learned: sometimes it's easier to have parts on hand than it is getting crippled last minute. There is nothing like being in the middle of a project, a tool breaks, and you need to address replacing it in order to continue.

author: WattsThat
author_rank: Frequent Contributor
timestamp: October 22, 2021, 03:47:11 am
content: QuoteNot sure what you’re referring to here. What’s an IC pin extender and how do “IC chips crack”? A photo of whatever this mystery device is would really be helpful to understand what your concern/question is.Another big help would be telling us which logic analyzer you purchased, the actual brand and model. Then we (might) know which grabber clips you received and the exact wire you’re looking to duplicate.

author: bostonman
author_rank: Super Contributor
timestamp: October 22, 2021, 03:53:23 am
content: These are the IC pin extenders I'm referring to (see attached). I wasn't sure of their exact name.The Logic Analyzer is:http://www.qdkingst.com/enI got the LA2016 model

author: tooki
author_rank: Super Contributor
timestamp: October 22, 2021, 03:15:19 pm
content: Quote from: bostonman on October 22, 2021, 03:53:23 amThose are called IC test clips. They exist for both DIP and some types of SMD.They’re not going to crack the chip. If anything, take a dead IC sometime and try to crack the case open; you’ll likely find it’s far harder to get into than you expected!!!Their AliExpress shop sells spare cables, 5 sets for $15, plus shipping. That’s really not a bad price IMHO.I’m about to head out, but I need to take some quality pictures of some of the custom leads I’ve made, they might give you some ideas about even better options.(In particular, for the flying lead ends, get the female contacts for D-Sub HD connectors (contact size 22). They come in a multitude of styles, and are more robust than DuPont female contacts. I just heat shrink around them.)FYI, the DIP clips are great if you constantly need to measure lots of signals off of ICs. But if you don’t have them yet, get some micrograbbers. You can use them on DIP ICs, but also on a multitude of other things. They mostly connect to the kinds of leads you already have. My favorite type so far is the SKS/Hirschmann Micro-Kleps. What I love about them is that you can twist the plunger to rotate the jaws to whatever angle you need.

author: bostonman
author_rank: Super Contributor
timestamp: October 26, 2021, 03:34:32 am
content: I like the idea of the micrograbbers.Unfortunately I don't have all the size clips I need for the various size IC chips, so the micrograbbers may be a great option.Today I finally got the chance to use my Logic Analyzer. Although the IC pin extenders I have are nice, it's quite a bit of work to set up sixteen channels.The IC pin extenders I have are both white and blue (they may be two different companies). The blue ones have a softer spring; but I only have one or two blue ones.Due to not having any experience with Logic Analyzers, and being completely confused on which IC(s) I should focus on, I sense I'll be moving the Logic Analyzer wires to different clips for different ICs.On a side note, looking at the Logic Analyzer data is pretty cool. I set up to measure all the address lines (12 of them) on a chip, and the remaining four on the data lines. I'm uncertain if I'll regret buying a 16-channel and not a 32-channel, but looking at the one IC I measured, it's clear not all the address lines are functioning. When I looked at a good computer, every pin had activity.Now I just need to figure out why.

author: james_s
author_rank: Super Contributor
timestamp: October 26, 2021, 05:47:27 am
content: Those test clips are great when you want to connect to several different ICs, for example dumping firmware from a board or programming an EEPROM. You can do the same thing with grabbers but it's tedious if you need to move between several ICs. Both have their place.

author: james_s
author_rank: Super Contributor
timestamp: October 26, 2021, 05:50:59 am
content: Quote from: bostonman on October 26, 2021, 03:34:32 amIt's possible that there's a problem with the address lines, but it's probably more likely that nothing is accessing the addresses that depend on the lines without activity. As I said in another thread, when you are looking at a system at this level, the hardware and the code the CPU is executing are inextricably linked. You cannot make sense of one without understanding the other.

author: Terry Bites
author_rank: Super Contributor
timestamp: October 26, 2021, 12:09:39 pm
content: Use the right crimp tool (not pliers) and good technique.https://www.electromaker.io/project/view/crimping-dupont-connectorsThey can accept 20-36AWG. Solid wire doesnt conform properly inside the crimp to give a gas tight wire to contact connection.This leads to oxidation and corrosion then noise and eventually loss of continuity. The more stands the more flexible and reliable the crimp will be. Typical 24AWG hookup wire is 10 strand.Only use solid wire in static wiring, like in a telephone exchange or domestic power installations.Flexing and vibration will cause solid to fatigue and lead to breakages.

author: tooki
author_rank: Super Contributor
timestamp: October 26, 2021, 02:38:59 pm
content: Quote from: Terry Bites on October 26, 2021, 12:09:39 pmThat page shows the wrong tool, and the result reflects that. (The insulation crimp is wrong, it's supposed to wrap around the insulation.)Seehttps://www.eevblog.com/forum/reviews/affordable-crimp-tools-for-small-connectors-(dupont-etc-)/

author: Doctorandus_P
author_rank: Super Contributor
timestamp: August 16, 2023, 04:31:55 pm
content: (I know it's old).A method I like is to take a 90 degree male IDC header and then clamp / screw / glue (hot snot) it to the DUT.This way you can use a standard flatcable between your LA and the DUT, and you can use all sorts of wiring on your DUT. Clamps that work good on 0.5mm pitch TQFP, qfn or vias or test pads don't really exist. And my solution is to just solder 0.2mm thin laquered wires between the upside down header and pins or pads on the DUT. It's cheap, reliable and relatively easy as my soldering iron is always hot when I'm working on electronics.DUT = Device. Under. Test.