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Electronics => Open Source Hardware => Topic started by: MiDi on December 21, 2017, 08:28:58 am

Title: 4-wire short - DIY
Post by: MiDi on December 21, 2017, 08:28:58 am
I make it short: it's just a short :D
Project is in Public Domain and the actual project files are on Github (https://github.com/EleDes/4-wire-short).

This item is intended for use with DMMs capable of 4-wire measurement.

Features:
- standard 19mm space between plugs
- low thermal emf design
- gold plated quality plugs
- easy pull out with handle
- low resistance: <5mOhm between HI and LO plugs

Should be suitable for all devices with standard jacks (like Keithley 2000-Series)

NOT SUITABLE FOR DEVICES WITH:
- jacks are even / flush mount with the front panel (e.g. Fluke 8846A)
- inner contacts of the jacks are heavy recessed (e.g. Keysight 344xxA-Series)


The plugs are a bit shorter than standard bananas and the pullout needs some space at the bottom.

Borderline:
Keithley DMM7510 (only small elevation of jacks from front panel)

Review from Dave (https://www.youtube.com/watch?v=eGFaOsKh9CQ#t=29m36s)
Discussion (https://www.eevblog.com/forum/blog/eevblog-1069-mailbag/)

xDevs (https://www.youtube.com/watch?v=pUceB_7kmZU#t=1h44m20s)

There is a new batch international available on ebay germany - just search for "4-wire short" (include the quotation marks).

All gone to: Australia, Sweden, Taiwan, Japan, Great Britain, Spain, Austria, Germany, Russia, USA, Netherlands


Front 3d
(https://github.com/EleDes/4-wire-short/blob/master/19mmx19mm/images/4-wire%20short%20square%204mm%20front%203d.png?raw=true)

Back 3d
(https://github.com/EleDes/4-wire-short/blob/master/19mmx19mm/images/4-wire%20short%20square%204mm%20back%203d.png?raw=true)

Front assembled
(https://github.com/EleDes/4-wire-short/blob/master/19mmx19mm/images/4-wire%20short%20square%204mm%20top%20front%20assembled.jpg?raw=true)

Back assembled
(https://github.com/EleDes/4-wire-short/blob/master/19mmx19mm/images/4-wire%20short%20square%204mm%20back%20assembled.jpg?raw=true)
Title: Re: 4-wire short - DIY
Post by: perdrix on February 10, 2018, 01:28:04 am
I bought one - like it.  Did you consider doing one for the 3458A which has different spacing for the sockets?

Dave
Title: Re: 4-wire short - DIY
Post by: Insatman on February 10, 2018, 05:47:22 am
Where did you source the gold plated plugs?  I've been looking for those for another project
Title: Re: 4-wire short - DIY
Post by: MiDi on February 10, 2018, 08:29:53 am
I bought one - like it.  Did you consider doing one for the 3458A which has different spacing for the sockets?
Thanks for the feedback, Dave!
I thought about doing one (https://www.eevblog.com/forum/metrology/copper-binding-post-shorting-straps-for-low-thermal-emf-alloytempering/msg1389043/#msg1389043) for my 3457A (3458A and others should have the same spacing), but would prefere a PCB only Version.
As it turned out there is already a design with PCB only (https://www.eevblog.com/forum/metrology/copper-binding-post-shorting-straps-for-low-thermal-emf-alloytempering/msg1389056/#msg1389056).
But if there is enough demand for my design idea (https://www.eevblog.com/forum/metrology/copper-binding-post-shorting-straps-for-low-thermal-emf-alloytempering/?action=dlattach;attach=383475;image), would think about doing it.

Where did you source the gold plated plugs?
Got the Multi-Contact SA404 22.1054 from german distributor voelkner (https://www.voelkner.de/products/89322/Messerleiste-Stecker-gerade-Stift-4mm-Messing-Staeubli-SA404-1St..html?ref=43&products_model=D27608&gclid=EAIaIQobChMIyfa4lPSa2QIV9TLTCh2aHQEREAkYASABEgIXk_D_BwE), conrad (https://www.conrad.de/de/messerleiste-stecker-gerade-stift-o-4-mm-messing-staeubli-sa404-1-st-730896.html?WT.mc_id=google_pla&WT.srch=1&ef_id=UNBuVQAAUpDQi1y5:20180210081952:s&gclid=EAIaIQobChMIyfa4lPSa2QIV9TLTCh2aHQEREAkYAiABEgL3XvD_BwE&hk=SEM&insert_kz=VQ&s_kwcid=AL!222!3!231682502060!!!g!!) has them too, but higher price - but not shure if they sell to your country.
Perhaps a search could turn out a distributor for you - if there is no option, could buy for you - send me a PM.
Title: Re: 4-wire short - DIY
Post by: perdrix on February 12, 2018, 03:08:16 pm
OK Thank you, I ordered Mark Sims' (Texaspyro) PCB version from Oshpark

Dave
Title: Re: 4-wire short - DIY
Post by: Insatman on February 13, 2018, 01:38:12 am

Where did you source the gold plated plugs?
Got the Multi-Contact SA404 22.1054 from german distributor voelkner (https://www.voelkner.de/products/89322/Messerleiste-Stecker-gerade-Stift-4mm-Messing-Staeubli-SA404-1St..html?ref=43&products_model=D27608&gclid=EAIaIQobChMIyfa4lPSa2QIV9TLTCh2aHQEREAkYASABEgIXk_D_BwE), conrad (https://www.conrad.de/de/messerleiste-stecker-gerade-stift-o-4-mm-messing-staeubli-sa404-1-st-730896.html?WT.mc_id=google_pla&WT.srch=1&ef_id=UNBuVQAAUpDQi1y5:20180210081952:s&gclid=EAIaIQobChMIyfa4lPSa2QIV9TLTCh2aHQEREAkYAiABEgL3XvD_BwE&hk=SEM&insert_kz=VQ&s_kwcid=AL!222!3!231682502060!!!g!!) has them too, but higher price - but not shure if they sell to your country.
Perhaps a search could turn out a distributor for you - if there is no option, could buy for you - send me a PM.
[/quote]

I'd be interested in buying one of your 4 terminal shorts plus 8 more contacts.  PM me if interested and we'll try and work something out.
Title: Re: 4-wire short - DIY
Post by: cowasaki on June 21, 2018, 06:57:01 pm
MiDi, would you happen to have any of these left?
Title: Re: 4-wire short - DIY
Post by: MiDi on June 22, 2018, 07:42:41 pm
At the moment there are no more left.
But if there is a couple demand, I would do another batch.
Do you want only one or more?
Title: Re: 4-wire short - DIY
Post by: cowasaki on June 22, 2018, 07:45:38 pm
Just one.
Title: Re: 4-wire short - DIY
Post by: BNElecEng on June 22, 2018, 08:26:22 pm
Count me in if you are planning another run please.
Title: Re: 4-wire short - DIY
Post by: MiDi on June 26, 2018, 10:40:47 pm
I decided to make another batch, but it would take a couple of weeks...

They are not suitable for all devices: The plugs are a bit shorter than standard bananas and the pullout needs some space at the bottom.

If the jacks are even with the front panel or the inner contact of the jacks are heavy recessed, they are not suitable for that device!
Title: Re: 4-wire short - DIY
Post by: cowasaki on June 26, 2018, 10:52:39 pm
I decided to make another batch, but it would take a couple of weeks...

They are not suitable for all devices: The plugs are a bit shorter than standard bananas and the pullout needs some space at the bottom.

If the jacks are even with the front panel or the inner contact of the jacks are heavy recessed, they are not suitable for that device!

I have a Keithley 2100 and a couple of PM2525s I can't actually recall if either of them are so will check tomorrow.
Title: Re: 4-wire short - DIY
Post by: MiDi on June 27, 2018, 05:16:09 am

I have a Keithley 2100 and a couple of PM2525s I can't actually recall if either of them are so will check tomorrow.

Keithley 2100 should be fine.
PM2525 I saw do not have 4 terminals and even if they would, they are of type "flush mount" and not suitable.

Not suitable:
Keysight 34470A

Borderline:
Keithley DMM7510
Title: Re: 4-wire short - DIY
Post by: cowasaki on June 27, 2018, 05:19:24 am

I have a Keithley 2100 and a couple of PM2525s I can't actually recall if either of them are so will check tomorrow.

Keithley 2100 should be fine.
PM2525 I saw do not have 4 terminals and even if they would, they are of type "flush mount" and not suitable.

I was answering whilst watching TV and didn't really give it a thought.  The PM2525 has 3 terminals plus the DIN socket :)  You'd think I would remember having 2 of them although they get much less use now!!  This would really have been for the Keithley though anyway.
Title: New batch
Post by: MiDi on July 17, 2018, 09:25:40 pm
Started the new batch today.
It will take a couple of days to finish.
I give an update, when they are ready for shipping.
Title: New batch awailable
Post by: MiDi on July 19, 2018, 09:54:01 am
New batch is internationally awailable on ebay germany - just search for "4-wire short"!
Title: Re: 4-wire short - DIY
Post by: Navarro on July 19, 2018, 03:42:51 pm
Are they suitable for the 34401A, MiDi?
Title: Re: 4-wire short - DIY
Post by: MiDi on July 19, 2018, 03:54:18 pm
Are they suitable for the 34401A, MiDi?

Sorry, they are not suitable for the 344xxA-Series, they are to short to fit accurately into the heavily recessed jacks.
Title: Re: 4-wire short - DIY
Post by: ap on September 17, 2018, 06:28:51 am
I bought one - like it.  Did you consider doing one for the 3458A which has different spacing for the sockets?

This design is not suitable for the 3458A for EMF reasons. Nothing beats a copper wire as specified by Keysight for short adjustment/calibration.
Title: Re: 4-wire short - DIY
Post by: cvanc on September 17, 2018, 10:17:10 am
Ordered; thanks very much!
Title: Re: 4-wire short - DIY
Post by: DC1MC on September 17, 2018, 10:43:34 am
They are so nice and cheap, I would so much need one of my Datrons, sadly they have the sockets on a 19x38 grid  |O.

If you ever make a Datron compatible lot, me and some other Datron owners will thank you and I'll buy at least one.

 Cheers,
 DC1MC
Title: Re: 4-wire short - DIY
Post by: MiDi on September 17, 2018, 11:25:50 am
They are so nice and cheap, I would so much need one of my Datrons, sadly they have the sockets on a 19x38 grid  |O.

If you ever make a Datron compatible lot, me and some other Datron owners will thank you and I'll buy at least one.

 Cheers,
 DC1MC

It is public domain, so feel free to fork it on github and modify it for your needs ;)
Making them is not that complicated, you can even solder by hand.
As I made a couple, I did it with solder paste and heat gun - faster and better finish.
Title: Re: 4-wire short - DIY
Post by: DC1MC on September 17, 2018, 11:29:25 am
They are so nice and cheap, I would so much need one of my Datrons, sadly they have the sockets on a 19x38 grid  |O.

If you ever make a Datron compatible lot, me and some other Datron owners will thank you and I'll buy at least one.

 Cheers,
 DC1MC

It is public domain, so feel free to fork it on github and modify it for your needs ;)
Making them is not that complicated, you can even solder by hand.
As I made a couple, I did it with solder paste and heat gun - faster and better finish.

There is no chance in hell to look so nice like yours, offer stands  ^-^

 Cheers,
 DC1MC
Title: Re: 4-wire short - DIY
Post by: MiDi on September 17, 2018, 11:51:39 am
There is no chance in hell to look so nice like yours, offer stands  ^-^

Ok, understood  8)
I think about it, if there will be demand for min 10 pcs, if demand for min 20pcs thinking would be omitted...
Hope that was the answer you imagined  ;)
Title: Re: 4-wire short - DIY
Post by: DC1MC on September 17, 2018, 12:01:46 pm
There is no chance in hell to look so nice like yours, offer stands  ^-^

Ok, understood  8)
I think about it, if there will be demand for min 10 pcs, if demand for min 20pcs thinking would be omitted...
Hope that was the answer you imagined  ;)

 Genau  :-+ !!!

 The problem is how can this be better announced, maybe a post in "Buy, Setll, Wanted", also I don't think that 19x36 grid it's really only for Datrons, there should be other DMM as well.
 In any case, put me on with 2, and make them 15EUR even with a thicker copper plate.

 Cheers,
 DC1MC
Title: Re: 4-wire short - DIY
Post by: MiDi on September 19, 2018, 03:32:55 pm
The problem is how can this be better announced, maybe a post in "Buy, Setll, Wanted", also I don't think that 19x36 grid it's really only for Datrons, there should be other DMM as well.
 In any case, put me on with 2, and make them 15EUR even with a thicker copper plate

Could worth a try to anounce it in buy, sell, wanted - so feel free to make advertisement for it.

If I remember right, the Datrons have screwed binding posts.
Then the question arises: would it make sense to build the short with plugs?
Better solution would be a pcb only version as mentioned at the beginning of thread...
Title: Re: 4-wire short - DIY
Post by: DC1MC on September 19, 2018, 07:35:15 pm
The problem is how can this be better announced, maybe a post in "Buy, Setll, Wanted", also I don't think that 19x36 grid it's really only for Datrons, there should be other DMM as well.
 In any case, put me on with 2, and make them 15EUR even with a thicker copper plate

Could worth a try to anounce it in buy, sell, wanted - so feel free to make advertisement for it.

If I remember right, the Datrons have screwed binding posts.
Then the question arises: would it make sense to build the short with plugs?
Better solution would be a pcb only version as mentioned at the beginning of thread...

Hello, so I'm attaching here a pair of pictures of an actual Datron device input panel. As you can see, the access it's only possible from top (or bottom) with a pcb only version (kind of like a m with veery long legs).
From left it's the case and from right it's the guard terminal.
So personally I'll lobe to have a plug version. Also wondering if it will be possible to replace the pcb with a piece of copper sheet  ;D, but with the same nice shape.

 So if you say the plugs version is doable, we can proceed with advertising it :)

 Best regards,
 DC1MC
Title: Re: 4-wire short - DIY
Post by: MiDi on September 19, 2018, 08:23:32 pm
Thought of a lollypop pcb only design, or as Dave would call it: sex on a stick ;)

This draft/idea was for my HP 3457A:
(https://www.eevblog.com/forum/metrology/copper-binding-post-shorting-straps-for-low-thermal-emf-alloytempering/?action=dlattach;attach=383475;image)
Title: Re: 4-wire short - DIY
Post by: DC1MC on September 19, 2018, 09:50:37 pm
Thought of a lollypop pcb only design, or as Dave would call it: sex on a stick ;)

This draft/idea was for my HP 3457A:
(https://www.eevblog.com/forum/metrology/copper-binding-post-shorting-straps-for-low-thermal-emf-alloytempering/?action=dlattach;attach=383475;image)

Wow, that's a really nice idea, so one insert this and rotates it in position and tighten the binding posts screws, if I understand correctly. In case of a symmetrical grid, if you make it from metal it can be used as a Ninja throwing weapon  :-DD.

Well, if you can devise the PCB/plate shape correctly for Datrons as above (sadly I suck badly at mechanical design) you will have my gratitude and a beer & onion rings kit ;) at the local Eichbaum pub if you pass sometimes trough Mannheim  ^-^.
Of course I'm willing to measure whatever you instruct me to measure on the Datron panel, I have a digital Messchieber that collects dust ;).

 Cheers,
 DC1MC
Title: Re: 4-wire short - DIY
Post by: MiDi on September 21, 2018, 06:37:18 am
Wow, that's a really nice idea, so one insert this and rotates it in position and tighten the binding posts screws, if I understand correctly. In case of a symmetrical grid, if you make it from metal it can be used as a Ninja throwing weapon  :-DD.

Well, if you can devise the PCB/plate shape correctly for Datrons as above (sadly I suck badly at mechanical design) you will have my gratitude and a beer & onion rings kit ;) at the local Eichbaum pub if you pass sometimes trough Mannheim  ^-^.
Of course I'm willing to measure whatever you instruct me to measure on the Datron panel, I have a digital Messchieber that collects dust ;).

Exactly, unscrew posts, put short in and rotate in position, screw posts.
At the moment it is just idea, has to be tested.
So first would do design for HP 3457A style posts and verify function.

There will be an option with sharp edges to throw like a ninja and an option to screw to your dremel to use as a saw  :-DD

Data needed: distances between posts, thickness of threads, thickness of insulation
Title: Re: 4-wire short - DIY
Post by: DuPe on September 26, 2018, 04:16:05 pm
@ MIDI: please see PM Folder
Title: Re: 4-wire short - DIY
Post by: DuPe on October 09, 2018, 12:11:05 pm

Hi MiDi,
arrived well packed and ... (most amazing :-) shorts great.
CheersPeter
Title: Re: 4-wire short - DIY
Post by: MiDi on October 09, 2018, 04:24:32 pm

Hi MiDi,
arrived well packed and ... (most amazing :-) shorts great.
CheersPeter

It would even short better when plugged in fully  ;)
Title: Re: 4-wire short - DIY
Post by: DC1MC on October 09, 2018, 05:24:07 pm
Any news for the flat one for Datrons, my family grew with two members, all in dire need of calibration.

 Cheers,
 DC1MC
Title: Re: 4-wire short - DIY
Post by: MiDi on October 09, 2018, 05:53:07 pm
Data needed: distances between posts, thickness of threads, thickness of insulation

At the moment I have other projects, do not expect something the next weeks...
Title: Re: 4-wire short - DIY
Post by: DC1MC on October 09, 2018, 05:57:24 pm
Data needed: distances between posts, thickness of threads, thickness of insulation

At the moment I have other projects, do not expect something the next weeks...

Then I'll do the measurements and post them here, to have them handy in case you'll find some time.

 Cheers,
 DC1MC