Adapter Box for (all) your Lab needs - Page 1
Forum section: electronics / projects

author: dangrie
author_rank: Contributor
timestamp: November 10, 2018, 09:36:00 am
content: Hi,I just wanted to show off and get feedback on my latest Project that I cobbled together in the last 2 Days. It is a "universal" Adapter Box that simply gives multiple connection points with the most common connector types seen in a lab environment.The complete thing is highly inspired by the "Monsieur Adapteur" by felitek.de which appeared in EEVBlog #606. I wanted to have one, but sadly the Project is discontinued. Although all Files are available for this Project, I had some trouble sourcing some of the used components, so I spun my own.I was surprised to not easily find 100 similar projects, so I wonder I you know of any? Also: What do you think of the Layout, Connector choice, and other design decisions? I would be happy to get some feedback before ordering the first set of Boards. Think something like this is useful?All resources and documentation can be found on GitHub:https://github.com/dangrie158/AdapterBox/blob/master/README.md

author: t1d
author_rank: Super Contributor
timestamp: November 10, 2018, 12:20:48 pm
content: I think that is rather neat and well done. You might swap places, with the BNC and Banana Socket sections. This would put the tallest component in the middle, giving better access to the lower Banana Socket components.Also, you may want to use the multi-connection type Banana Sockets. They provide more attachment options.Both of the Banana type connectors, the single and multi, can be directly bolted to the PCB. You just need to create big pads, for the post nut to seat on and make contact. No need, for the wire washer, or soldering. I added a layer of solder, to the pad, to give it extra strength, so the nut would not scrap it off. Here's the idea...When you are bolting on the multi-connection type Banana Sockets, raise one of the plastic nuts and insert a small screwdriver, in the post's side-hole. Tighten the plastic nut, just with very slight hand pressure. Use the screwdriver to hold the post's hole in the proper direction, to allow access, when in use. Then, tighten the securing nut. Repeat, for the other posts. You will not need the backing plate.I am sure that you know that Banana sockets pair holes are set on 19mm centers.

author: Dave
author_rank: Super Contributor
timestamp: November 10, 2018, 12:37:12 pm
content: Personally, I don't see it being useful in any scenario.If I need to connect something, I'd rather just crimp a couple of connectors onto a cable than have a bulky box sitting on my table. Most of the time you need more than 2 wires anyway.The BNC on there seems pointless, because you're not going to maintain the characteristic impedance with this thing.

author: Richard Crowley
author_rank: Super Contributor
timestamp: November 10, 2018, 12:59:44 pm
content: Quote from: Dave on November 10, 2018, 12:37:12 pmWith something like this, you don't have to stop and get the connectors and crimp them on.With something like this, you don't have to waste a couple of crimp connectors for something temporary.QuoteThe concept is applicable to to a large number of wires.QuoteIf you are interfacing to banana or any of those other connectors, then impedance is not important for the experiment. Essentially by definition.

author: Dave
author_rank: Super Contributor
timestamp: November 10, 2018, 01:21:27 pm
content: For a quick test, I'd simply use croc clips or J-hooks.I don't mind spending 5 minutes to crimp a couple of custom cables together, if I'm going to be using them for a day or two. You'd have to waste a lot of connectors to outweigh the cost of such adapter.Fair point on the BNC.

author: 001
author_rank: Super Contributor
timestamp: November 10, 2018, 02:20:39 pm
content: Awesome cute projectI build similar from oil can years ago

author: cgroen
author_rank: Unknown
timestamp: November 10, 2018, 02:26:47 pm
content: Brilliant idea(now is just the question, are you planning on making a small batch to sell, and if so, do you ship to Denmark)

author: dangrie
author_rank: Contributor
timestamp: November 10, 2018, 03:34:27 pm
content: Thank you very much for the constructive criticism and feedback.Quote from: t1d on November 10, 2018, 12:20:48 pmThat totally makes sense! Thanks, I did not think if this. I just moved some stuff around and updated all files (See the github Link and also the updated images in my first Post.Quote from: t1d on November 10, 2018, 12:20:48 pmI don't quite understand what you mean by multi-connection type? Do you mean 2 Banaplugs in 1 Case with the standard spacing?Quote from: t1d on November 10, 2018, 12:20:48 pmYes, the Banana Plugs are spaced 19mm apart in both directions.Quote from: Dave on November 10, 2018, 12:37:12 pmStopping a prototyping session because I have to "quickly" crimp a pair of cables was exactly what drove me into wanting something like this. Of course a crimped cable is always superior to having to dick around with adapters, but when I just need to temporarily power my project via jumper cables and only have a plug pack or benchtop supply I now don't have to look for contacts, housing, crimping tool, heat shrink etc. but can simply plug in my banana plugs into one end and attach the jumper cables on the other. I also do not waste a set of rather expensive banana connectors. Also I do have a much nicer way to connect my crocodile clips to any other cable. I find especially crocodile clips to be unreliable when simply connected to pin-headers or banana jacks or plugs.Quote from: cgroen on November 10, 2018, 02:26:47 pmThanks! I did not currently plan to "manufacture" these in any way, but since I probably have some space PCBs and other parts and live in Germany, shipping should not be a problem. I plan to order the first batch of PCBs this weekend and can keep you updated. If you want, send me a PM and we'll figure something out

author: cgroen
author_rank: Unknown
timestamp: November 10, 2018, 03:37:47 pm
content: PM sent Daniel

author: gdewitte
author_rank: Unknown
timestamp: November 10, 2018, 03:38:44 pm
content: I recently built something similar (and also based on the Monsieur Adaptateur that I had purchased a few years ago and found very handy). I ditched the BNC figuring I could always use one of those BNC-to-banana plug adapters if needed, and added an Anderson Powerpole panel mount.

author: t1d
author_rank: Super Contributor
timestamp: November 10, 2018, 08:21:13 pm
content: Quote from: dangrie on November 10, 2018, 03:34:27 pmLook at the third/down picture of the "Multi-Connection Banana Socket," in my prior post. Look at the one with the nut raised. You will see that you can insert a wire, into the hole in the post, and tighten the nut, to secure the wire. With the grommet-style Banana Connector that you have specified, you do not have that additional option. Does that make sense?If you make space for the multi-type, the grommet type will be accommodated, too, and the user can choose whichever they like.Just a suggestion...

author: t1d
author_rank: Super Contributor
timestamp: November 10, 2018, 08:28:25 pm
content: I have made a custom PCB library part, in Kicad, for the multi-type Banana Socket, if that is the CAD program that you are using... I think that I up-sized the hole, to accommodate the grommet-style type, too, but open the editor and double-check the hole diameter, just to make sure.If you are using Eagle, there may be a converter out there, to adapt the file. I think that I have seen such a thing.

author: t1d
author_rank: Super Contributor
timestamp: November 10, 2018, 08:48:59 pm
content: If using the multi-type, you will need to adjust the positive and negative orientation, of the individual component, to face the holes, to the side of the box.For either style, you presently have...+ +- -This orientation would give more options...+ -- +By alternating the orientation, you add another direction to turn the Banana Plugs... Presently, they can only be oriented in perpendicular, to the box. If you space all the holes at 19mm centers and modify the orientations, as I suggest, they could be plugged in perpendicular, or parallel, to the box.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: November 10, 2018, 09:29:15 pm
content: It needs a couple male banana plugs sticking out the side so you can plug it into meters and such. You can also cheat and put an SO-239 female UHF connector on it, with a female banana jack 3/4" away. That gives you the 239 plus the ability to accept 3/4" dual banana plugs using the center of the 239.

author: Gixy
author_rank: Regular Contributor
timestamp: November 11, 2018, 07:50:45 am
content: I have Something very similar. As I use it mainly for power supply connections, I have no BNC plug but USB female socket instead, and a LED to indicate power on.

author: dangrie
author_rank: Contributor
timestamp: November 11, 2018, 01:52:54 pm
content: Quote from: t1d on November 10, 2018, 08:21:13 pmThanks. I will make sure to leave enough space so one can fit whichever socket they preferDo you have a link or Part# for the posts you used? they look awesome.Quote from: t1d on November 10, 2018, 08:48:59 pmThats a good point, going to update the board right now. Having more options is kind of the whole reason for the box.Quote from: gdewitte on November 10, 2018, 03:38:44 pmGreat, do you have som pictures? Do you know of any PCB-mount poles? However, I think I'm too limited in space with the form factor I'm targeting.Quote from: Conrad Hoffman on November 10, 2018, 09:29:15 pmI thought about that but ditched the idea since this would mean I would always have sticking out poles connected to potentially high voltage and always risking shorting them. So I decided to just plug in a banana-cable to connect to meters and power supplies.Quote from: Gixy on November 11, 2018, 07:50:45 amUSB may be a good option, I will check if I can fit it nicely. BNC is kind of important for me, since I have lots of BNC cables with different ends I can use for probing and now also powering, etc.I also thought about the LED. How do you drive it with the varying input voltages? I thought about using an LM234 as a constant current source over a wide voltage range (certainly the 2-30V I use 99% of the time). It would also be protected up to 20V of reverse voltage which would help keep the circuit simple.

author: t1d
author_rank: Super Contributor
timestamp: November 11, 2018, 04:33:28 pm
content: Quote from: dangrie on November 11, 2018, 01:52:54 pmThis is what I bought. They were the cheapest, at the time. But, I see some cheaper, today. So, shop around.Also, there are a lot of different styles, of this same thing. I think I started with a search for "Speaker Banana Jacks." Adding "Speaker" seems to narrow the search, better.https://www.ebay.com/itm/Banana-Plug-Terminal-Connector-Amplifier-Jack-Audio-Speaker-Adapter-Dual-Cable/282398851657?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

author: gdewitte
author_rank: Unknown
timestamp: November 11, 2018, 05:41:17 pm
content: Here are two pictures of my home-built version: one 3/4 view showing the Powerpole panel mount end and the other 3/4 view showing the 5.5mm DC jack panel mount end. The box is a Hammond 1591 I had originally purchased for another project. I replaced its top cover with a piece of PC project board (ground plane on one side and solder pads on the other; I cut a length-wise break in the ground plane with my Dremel to make positive and negative sides). The Powerpoles use Anderson Autogrips from Hardened Power Systems (https://www.portableuniversalpower.com/our-products/anderson-autogrips/) for the panel mount.

author: t1d
author_rank: Super Contributor
timestamp: November 11, 2018, 05:47:46 pm
content: Quote from: gdewitte on November 11, 2018, 05:41:17 pmReally nice job!I take it that you just cut through the copper and not completely through the board. I think the line down the middle, that I am seeing, was made with a marker, as opposed to it being a cut's shadow... Correct?

author: gdewitte
author_rank: Unknown
timestamp: November 11, 2018, 05:59:33 pm
content: Correct: only milled through the copper on the ground plane side; the line on the pad side was for reference.

author: t1d
author_rank: Super Contributor
timestamp: November 11, 2018, 07:46:03 pm
content: Quote from: gdewitte on November 11, 2018, 05:59:33 pmI must laugh... I know myself... I would have way over-thought this... Designed a custom PCB, paid for it, waited for it, etc... When all I needed was a positive and negative plane.Simply excellent, pun intended, on your part... A single piece of copper clad, divided, and a few holes...Quirky, on mine. lol

author: gdewitte
author_rank: Unknown
timestamp: November 11, 2018, 09:11:27 pm
content: Quote

author: gdewitte
author_rank: Unknown
timestamp: November 11, 2018, 09:13:04 pm
content: And, clearly, I need to work on the correct method for inserting a quote

author: Microcheap
author_rank: Frequent Contributor
timestamp: November 11, 2018, 10:05:04 pm
content: Neat, I would just add maybe a micro USB connector for completeness

author: Gixy
author_rank: Regular Contributor
timestamp: November 11, 2018, 10:41:19 pm
content: Quote from: dangrie on November 11, 2018, 01:52:54 pmYes, simple current source (LM234 or opamp)

author: dangrie
author_rank: Contributor
timestamp: November 12, 2018, 04:19:39 pm
content: Quote from: t1d on November 11, 2018, 07:46:03 pmSo basically what I'm doing nowHowever, for me, designing is more fun than building and having the final product is just a nice side-effectI just updated the files with all your suggestions: Power LED, better layout of the banana jacks, enough space for bigger banana posts with cable screw clamp, USB connector (Vout)I'm going to order 10 of the boards now, I think I'm now where I wanted to be with the project

author: timgiles
author_rank: Regular Contributor
timestamp: December 29, 2018, 08:38:16 pm
content: Having just built one, there are three issues:1. No pin 1 dot for the LM on the bottom side of the PCB2. The BNC locator pins will not both fit in at the same time, the holes on the PCB are too far apart3. No LED in BOM (not critical but the BOM should be complete)Otherwise I get about 0.2 Ohms resistance between each connector - and the only connector that gives me anything above 20Meg when connecting between +ve and -ve is the green terminals. I suspect this is within manufactures tolerance.

author: dangrie
author_rank: Contributor
timestamp: January 01, 2019, 06:21:05 pm
content: Quote from: timgiles on December 29, 2018, 08:38:16 pmThanks for the extensive feedback. I fixed all the issues you mentioned, let me know if you find anything else.FYI: I fixed the wrong BNC footprint by widening the mounting holes with a 3mm drill and scraped off some of the solder mask around the holes to be able to solder the pins in place.

author: t1d
author_rank: Super Contributor
timestamp: January 09, 2019, 04:15:02 am
content: Quote from: dangrie on January 01, 2019, 06:21:05 pmIt sounds like you have a final design. Please post your design files, in whatever format you created them... KiCad? Eagle? Etc. I am looking at building this and having your board printed might be easier than working with perf board.Great project. Thanks.

author: newbie666
author_rank: Regular Contributor
timestamp: January 09, 2019, 08:55:45 am
content: The files are on his github:https://github.com/dangrie158/AdapterBox

author: t1d
author_rank: Super Contributor
timestamp: January 09, 2019, 09:09:37 am
content: Quote from: newbie666 on January 09, 2019, 08:55:45 amDoh, I must have missed that. Thank you, for the pointer.Edit: Those seem to be only the gerbers. Any chance of getting the source files? I would like to make some modifications... To use the components I have on hand, for example.I think I might add a switch to bring the LED in and out of line, too.I am already gathering components out of their bins <g>.

author: dangrie
author_rank: Contributor
timestamp: January 09, 2019, 09:21:35 am
content: Quote from: newbie666 on January 09, 2019, 08:55:45 amThanks for pointing that out, didn't have time to respond until now...The current HEAD in the master branch should alwyas point to the latest non-development version (pass DRC, ERC, consistent BOM, renders, etc...)

author: newbie666
author_rank: Regular Contributor
timestamp: January 09, 2019, 09:22:47 am
content: Board directory contains both .sch and .brd files (Eagle):https://github.com/dangrie158/AdapterBox/tree/master/Board@dangrie: awesome project docs, I think I'll build myself one as well, I'm just thinking about swapping usb-a for usb-c connector

author: t1d
author_rank: Super Contributor
timestamp: January 09, 2019, 11:06:38 am
content: Quote from: newbie666 on January 09, 2019, 09:22:47 amThanks, again, for the additional pointer. But, I am not seeing what I expected... I thought that I would just be able to download the board and schematic files. However, I seem to be finding their actual code. I know how to plug the files into a project, but I do not know how to deal with the code. A little help, please and thank you...

author: newbie666
author_rank: Regular Contributor
timestamp: January 09, 2019, 11:19:55 am
content: you need to:- either clone the repo (in terminal type "git clonehttps://github.com/dangrie158/AdapterBox.git")- in main repo directory on github (https://github.com/dangrie158/AdapterBox) click on green clone or download button and then select Download ZIPeither way you'll have all the files on your PC / Mac. Then navigate to the Boards folder and you can open the files in eagle as usual.

author: t1d
author_rank: Super Contributor
timestamp: January 10, 2019, 12:31:02 am
content: Quote from: newbie666 on January 09, 2019, 11:19:55 amThanks, Newbie, this is what I had expected to find and it worked well. I have done this method, in the past. I don't know why I couldn't find it, this time.Dangrie - I like your solution for connecting the banana socket pads on only one plane (just top, or just bottom) to assign them to the correct network. Clever.

author: bernie79
author_rank: Contributor
timestamp: January 13, 2019, 05:08:45 am
content: Maybe this can be made commercial..Sorry, could not resist.Nice to see several ideas to solve this problem that has everyone

author: dangrie
author_rank: Contributor
timestamp: January 19, 2019, 08:38:30 am
content: Quote from: bernie79 on January 13, 2019, 05:08:45 amWell on that note:I decided to put it on Tindie, so you can get a unit via this link:https://www.tindie.com/products/dangrie158/adapterbox/