Designing a Connector for High current DC and Ethernet 1

[danfe358]

Hello!

I want to design a connector which is to carry up to 4kW of power by 28-160 volt DC and that has a four twisted pair ethernet (8 cables) gigabit communication link.

It must have some mechanical properties which hinders me from choosing a standard connector, which is the reason I have to design it, the receptacle and the cable itself from scratch. These are however not the problem.

My problem is that I know nothing of properties that makes a connector reliable, interference free, of the right size for good transmission, cooling, wear surfaces, coatings, crosstalk etc. etc. and would very much like to get some pointers from some experienced engineers of what to watch out for, performance indicators and general tips. Literature for further reading on the topic is also much appreciated.

With warm regards,
Daniel

 

[danfe358]

For starters, I need to know what the electrical requirements for such a connector could be?

My area is really the mechanical part, but I realize I really need to brush up on my electrical skills to pull this project off.

Thanks,
D

 

[IRstuff]

You could start by studying 38999 military connectors.

TTFN

FAQ731-376
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[ScottyUK]

Have a look at Harting's HAN series of connectors. They are modular and could do what you're asking from an electrical perspective apart from the undisclosed 'special requirements' which make you want to design it yourself (because the college lecturer says so?).


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If we learn from our mistakes I'm getting a great education!

 

[danfe358]

Well, I guess it does'nt really matter if you know the other properties. It would not hurt to get suggestions here either - The connector is to be self-releasing by signal from operator or internal computer. Also it should accomodate some kind of "immobilizer" so that it prevents engine (block starter or fuel pump) start when connected. No extra electronics or weight but the extreme necessary are to be imposed on the recieving body. Thats why everything needs to be inside the connector, and also why this type of connector is kinda hard to find.

It also need to look flashy..

Your suggestions helped me impose demands for voltage drop across connection, vibration demands and emi leakage attenuation. What more may be of importance?

Many thanks!

 

[VEBill]

IRstuff has provided a good starting point with the pointer to 38999.

PEI Genesis offers a wide range of military style connectors (evolved from 38999).

You'll need to narrow down the voltage window. 4kw at 28 volts is a crazy 142 amps, at 160 volts is a sane 25 amps.

Somewhere I've seen layard-release connectors. These remind me of the sort of connectors that pulled off the side of the Saturn V rocket.

You will not be able to design a reliable connector from scratch. You can certainly design a connector from scratch, but it will not be reliable. Not without a PhD in materials science.

Perhaps you could incorporate the sockets, pins, and housings from an off-the-shelf connector, and then just design the outer mechanical shell to meet your mechanical needs.

The 38999 series offer so many combinations that you can probably find exactly what you need from that series.

Ethernet through these sorts of connectors works fine, even gigabit. Just use the smaller pins and keep each pair together.

 

[MacGyverS2000]

It is to be self-releasing by signal from operator or internal computer.

It should accomodate some kind of "immobilizer" so that it prevents engine (block starter or fuel pump) start when connected.

No extra electronics or weight but the extreme necessary are to be imposed on the recieving body.

It needs to look flashy.

Thats why everything needs to be inside the connector, and also why this type of connector is kinda hard to find.

Please tell me we're being punked...

You want a "flashy" connector that accomplishes a mechanical release as well as act as an electrical immobilizer, all without extra electronics or weight.

And how, exactly, did you plan on getting around the laws of physics? I have to be reading this incorrectly...

Dan - Owner

http://www.Hi-TecDesigns.com

 

[danfe358]

Sorry, english is not my mother tongue. No emphasism on "flashy", it was a childish expression - functional items that does their job are flashy enough.

The weight constraint is on the reciever side, but the "glove" or connector with cable may only be limited to what is possible to carry by hand. So the electronics should preferrably be placed inside this.

Nevermind the immobilizer, but if you have suggestions for the release mechanism or further comments on connector design - I'm all ears.

Complementing a 38999 connector with a mechanical shell is definately a concept, but I also want to investigate a complete design as well.

The connectors for the Saturn V or similar is what I was first searching for, but I can find no information about this or the Layard as mentioned above.

I've studied some connectors for fighter jets which have a simple hinge like design that is simply held in place by the cable which acts as a lever against the body. When a actuator pushes on the connectors, its CG changes and it slides right out of the frame. Not sure however if this would work in a high vibration environment. The connector must not release prematurely.

 

[VEBill]

"self-releasing" is a poor choice of words unless you plan to embedded, for example, a solenoid within the connector. I've assumed that you don't really mean that, and that you're actually looking for something similar to a lanyard release connector.

If you Google "lanyard release connector" you will find hits from ITT Canon and Amphenol. Although their products tend to cost hundreds and hundreds of dollars, that's nothing compared to what you would spend trying to reinvent something similar.

You've listed no requirement that couldn't be met by the military type connectors such as 38999 series or similar.

I've studied some connectors for fighter jets .... Not sure however if this would work in a high vibration environment. The connector must not release prematurely.

Huh? How high is "high"? There are different curves (vibration amplitude vs. frequency) for different platforms, but jet aircraft are still considered a tough vibration environment.