Ribbon cable with different pitches connectors

Thread Starter

fhaddad75

Joined Dec 14, 2019
4
Hi All,
I have a problem and I believe it Is simple for you but I am not experienced so I need your help. I have two devices that needs to be connected to each other with ribbon cable, one device has 2.54mm pitch connector and the other one has 1.27mm connector. I got all the connectors and now I ran into the problem, it seems that the ribbon cable for the 1.27mm connector has obviously different pitch than the 2.54mm, is there any ribbon cable in the marker that is one pitch from one side and another pitch from the other. If not then how what pitch of the ribbon cable I need to buy to use the 1.27mm connector and how can I connect two ribbon cables of different pitches together?
 

Attachments

Papabravo

Joined Feb 24, 2006
15,700
Cut two pieces, one of each pitch. Put the IDC (Insulation Displacement Connectors) on the appropriate ends. Get a piece of veector board with holes on 0.100" centers. Inset one pin for each wire. Strip the ends of the two cables without connectors and connect the corresponding wires to the pins on the vector board. Work out a method of strain relief and wrap the result.

That should work.
 

Thread Starter

fhaddad75

Joined Dec 14, 2019
4
Cut two pieces, one of each pitch. Put the IDC (Insulation Displacement Connectors) on the appropriate ends. Get a piece of veector board with holes on 0.100" centers. Inset one pin for each wire. Strip the ends of the two cables without connectors and connect the corresponding wires to the pins on the vector board. Work out a method of strain relief and wrap the result.

That should work.
Thank you so much, can you tell me what is the right pitch of the ribbon cable for the smaller connector (The 1.27mm or 0.05” one) and if possible can you please post me a link to buy it from any supplier
 

MisterBill2

Joined Jan 23, 2018
8,399
You will find that the method described requires a fair amount of space and certainly also requires some reasonably good soldering skills. And if it is for use in anything close to a modern computer system it needs to be suitable for a fairly high frequency.
Can you tell us what devices it is connecting to? And are you certain that the connections should be 1 for 1? And it is very important to get the pin numbering correct I have seen serious damage done by exchanging odd and even sides of a connector. It is possible to split the conductors apart on the closer spaced cable and insert them into the correct positions on the farther spaced connector, but it is both difficult and tedious.
 

jpanhalt

Joined Jan 18, 2008
11,088
There are also various adapters. Here's a link to some breakout boards for various pitches: https://www.digikey.com/products/en/prototyping-fabrication-products/adapter-breakout-boards/643?k=connector adapter

There are also adapters that convert from one pitch M or F connector to another pitch connector that don't require soldering.

If you go the soldering route, stripping ribbon cable can be tricky. I use a method described here: https://forum.allaboutcircuits.com/...12-pin-headers-100-times.125256/#post-1013147
 
Last edited:

Thread Starter

fhaddad75

Joined Dec 14, 2019
4
You will find that the method described requires a fair amount of space and certainly also requires some reasonably good soldering skills. And if it is for use in anything close to a modern computer system it needs to be suitable for a fairly high frequency.
Can you tell us what devices it is connecting to? And are you certain that the connections should be 1 for 1? And it is very important to get the pin numbering correct I have seen serious damage done by exchanging odd and even sides of a connector. It is possible to split the conductors apart on the closer spaced cable and insert them into the correct positions on the farther spaced connector, but it is both difficult and tedious.
You will find that the method described requires a fair amount of space and certainly also requires some reasonably good soldering skills. And if it is for use in anything close to a modern computer system it needs to be suitable for a fairly high frequency.
Can you tell us what devices it is connecting to? And are you certain that the connections should be 1 for 1? And it is very important to get the pin numbering correct I have seen serious damage done by exchanging odd and even sides of a connector. It is possible to split the conductors apart on the closer spaced cable and insert them into the correct positions on the farther spaced connector, but it is both difficult and tedious.
The devices I am working with are all from my company and I attached three photos for three of them, one of them uses Male 1.27mm 2x5Pin, the second uses 1.27 1x7pin male (molex) and the third uses 2X7 pin 1.27mm as you can see in the photos, the problem is that all of them needs to be connected to FlashPro430 device to upload the firmware that uses 2.54mm pin (the ribbon cable comes with FlashPro430 both sides 2.54mm). What I am trying to do is create this ribbon cable that connects from one side to the FlashPro430 and the other to those three devices I attached photos for. I bought the connection and I have the drawing for the pins arrangement and all the technical details is OK I don't have an issue with it. My issue is the knowledge about the connectors and ribbon cables, I thought that one type of ribbon cable would be required but apparently the smaller connectors requires different pitch ribbon so I need help of what pitch. The previous post told me to buy 0.05" ribbon and that is correct for the 0.1" connectors but for the 0.05" connectors it doesn't work, I need to know the best solution to achieve this. Hope I explained well enough and thanks
 

Attachments

MisterBill2

Joined Jan 23, 2018
8,399
There is a company that specializes in making small boards to cover assorted mismatches, and while I don't recall their name they have a good reputation. They can probably provide an adapter that will work. One more question: Is this for production, or just a one-time thing. If it is for production an adaption of the board may be a better choice. A small add-on to acomodate the other sized connector,
 

Thread Starter

fhaddad75

Joined Dec 14, 2019
4
There is a company that specializes in making small boards to cover assorted mismatches, and while I don't recall their name they have a good reputation. They can probably provide an adapter that will work. One more question: Is this for production, or just a one-time thing. If it is for production an adaption of the board may be a better choice. A small add-on to acomodate the other sized connector,
It is one time only
 

bassbindevil

Joined Jan 23, 2014
157
Can you split the cable into individual conductors at one end and carefully set them into a bigger connector, or use crimp sockets? I've seen cables made up that way for embedded PCs.
 

MisterBill2

Joined Jan 23, 2018
8,399
Splitting a cable up quickly becomes very tedious in a very short time, and getting the connections to stay in place long enough to crimp the connector is a real challenge.
 
Splitting a cable up quickly becomes very tedious in a very short time, and getting the connections to stay in place long enough to crimp the connector is a real challenge.
I would agree. A "third hand" (alligator clips on gimbal mount) would make the job easier. i.e. stripping, soldering and heat shrink tubing.
 

MisterBill2

Joined Jan 23, 2018
8,399
I have not seen a ribbon cable connector with enough room for any heat shrink tubing. And also most fine pitch ribbon cable connections are insulation displacement types, so no soldering either. The wire is simply forced into a slot in the metal blade and when all wires are in place the back piece is pressed on. That is the crimp I am talking about. Only the part with the pins gets soldered, and that into the circuit board. I have not seen a solder connector for ribbon cable.
 
In the old days, 0.1" pitch connectors, 0.050" pitch ribbon cable, each wire of the ribbon was crimped to a pin that was inserted in the housing. You "could" separate the wires.
 
Top