Low voltage connector

Greets to all,

I need to pass 12V current from a chassis to a door. I would like the
door to have a spring loaded contact that would complete the circuit
when the door is closed by making contact with a flat contact in the
chassis. I'd thought such things would exist, but can't seem to find
them. I am getting desperate for a solution as the product I am
designing is already in production and without a comparable solution,
I will be forced to use grommets and run wire through the door into
the chassis.

Any help or direction is greatly appreciated.....

Dave

 

These were used in car doors at one time.

 

Forget running the wire to the door and use instead
a magnetic reed switch on the door frame. The only
thing you need connect to the door is a small magnet.

 

Great, but I need power inside the door that originates from inside
the chassis. It would be fine if the power to the door was always on,
but the way I envisioned the contacts, this would not be the case.

 

I heard there was an application for car audio that had similiar
components, but have been unable to locate. Perhaps I'm not using the
correct keys in my search.....

 

A good example of the concept is the PENN ENGINEERING Waveguard
grounding system (PN:
DPRS-375-ZI)http://www.pennfast.com/design_info/partdescription.html.
Unfortunately, it is too large and is not isolated.

 

I have seen a spring loaded contact mounted in a nylon housing that
snaps into the door post on vans, and a mating contact that mounted in
the door for the license plate light. Another method was a small close
wound spring for the ground contact, and a wire run inside the spring.
This method was more reliable, but the spring could get in the way. it
would depend on your design. If this is a low current application, you
might consider the "Pogo Pins" used in bed of nail test fixtures. Not
cheap, but fairly reliable.

 

Thanks for your help. I knew something like it had to exist. The pem
product would work, but it's just too big. This is for a computer, so
I can't use the chassis or door to carry current or ground. Guess I'll
be using a grommet and feeding wire through. Not very elegant, but it
will function. My fear is that the opening and closing of the door
will wear on the wire and result in a break or short.

 

Just choose the right wire type. Talk to a wire manufacturer.
For example: http://www.alphawire.com/pages/flex.cfm

 

Use a spring (A smaller version of a screen door spring.) to keep the
wire from bending sharply. I have seen this done in industrial
equipment, and large computer systems to protect the wiring on swing out
assemblies.

If you do this, you will extend the life of the wires. You can also
make it a plug in assembly that is easy to replace, just in case.

 

For those of us in cold, relatively bug-free places for whom screen
doors are a bit alien - what does a screen door spring look like?


Tim

 

About a foot long, and formed so that it retracts to the point the
turns of the spring touch each other. They look like a threaded rod when
they are not stretched out by a door.

 

pass 12V current from a chassis to a door

You're making this much harder than it needs to be.
It's done all the time by burglar alarm companies.

To put lead foil on a door,
there is a cable which bridges the gap at the hindge side.
For more extreme cases, the cable is a coily-cord.

To sense closure,
a reed switch and magnet on the other edge of the door
(usually on the top side where the fewest people will monkey with it)
is the most foolproof.