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right-angle card-edge connector

M

Mochuelo

Jan 1, 1970
0
Hi,

I need a very cheap (ideally below 0.8 EUR (1 k units)) right-angle
card-edge connector with 8 or 10 positions. Rating: 24 V, 0.1 A per
pin. Contact spacing is not critical. Any recommendation?

Thanks in advance,
 
P

Pooh Bear

Jan 1, 1970
0
Mochuelo said:
Hi,

I need a very cheap (ideally below 0.8 EUR (1 k units)) right-angle
card-edge connector with 8 or 10 positions. Rating: 24 V, 0.1 A per
pin. Contact spacing is not critical. Any recommendation?

Yes. Never use a pcb as part of your connection. Use a 2 part connector.

Next question ?

Graham
 
M

Mochuelo

Jan 1, 1970
0
Yes. Never use a pcb as part of your connection. Use a 2 part connector.

Tell that to the manufacturers of DIMM, SIMM, RIMM, AGP, PCI, PCI
Express, ISA...
 
P

Pooh Bear

Jan 1, 1970
0
Mochuelo said:
Tell that to the manufacturers of DIMM, SIMM, RIMM, AGP, PCI, PCI
Express, ISA...

Which is precisely why 'reseating' a card is so popular. Edge connectors are
used because they're cheap not because they're reliable.

Is this an application where reliability doesn't matter ?

Graham
 
R

Ross Herbert

Jan 1, 1970
0
SNIP

Edge connectors are used because they're cheap not because they're reliable.

I would dispute that statement. In my experience use of card edge
connectors is much more expensive than using two part connectors,
mainly because they are more labour intensive to produce and require
plating (usually with gold). The reason they are used on DIMM etc is
because they require far less board space and they are very reliable.
 
P

Pooh Bear

Jan 1, 1970
0
Ross said:
I would dispute that statement. In my experience use of card edge
connectors is much more expensive than using two part connectors,

I'm sure this isn't true of PC motherboards etc.
mainly because they are more labour intensive to produce and require
plating (usually with gold). The reason they are used on DIMM etc is
because they require far less board space and they are very reliable.

The ones used for DIMM SIMM etc at least have a locking mechanism. There are
issues wrt whether the contacts are tin or gold plated though.

Graham
 
R

Ross Herbert

Jan 1, 1970
0
I'm sure this isn't true of PC motherboards etc.

What do you mean??

It is many years since any computer motherboard used edge connectors
so how does this apply to PC's which never used them?
The ones used for DIMM SIMM etc at least have a locking mechanism. There are
issues wrt whether the contacts are tin or gold plated though.

What makes edge connectors more expensive (whether tin or gold plated)
is the fact that the edge connector must be formed as part of the pcb
manufacturing process. Once etched, the edge connector part is then
electrolytically plated and the commoning strip used to connect the
pads (for electroplating) is then trimmed off during drilling and
routing and then chamfered. The board handling and processing is thus
made so much more expensive compared to using modern two part
connectors. That's the main reason this process isn't used today,
except in certain circumstances. It was not so much a question of
reliability because they were at least as reliable as two part
connectors.

I have found the variation in pin dimensions and receptacle tensioning
on some very reputable two part connectors to be quite variable such
that the reliability from batch to batch was quite poor. At least with
pcb card edge connectors the board and copper thickness was fairly
standard and only the socket manufacturing could be variable thus
reducing the probability of poor reliability of connection due to
manufacturing defects and errors by 50%.

Ross H
 
R

Ross Herbert

Jan 1, 1970
0
What do you mean??

It is many years since any computer motherboard used edge connectors
so how does this apply to PC's which never used them?


What makes edge connectors more expensive (whether tin or gold plated)
is the fact that the edge connector must be formed as part of the pcb
manufacturing process. Once etched, the edge connector part is then
electrolytically plated and the commoning strip used to connect the
pads (for electroplating) is then trimmed off during drilling and
routing and then chamfered. The board handling and processing is thus
made so much more expensive compared to using modern two part
connectors. That's the main reason this process isn't used today,
except in certain circumstances. It was not so much a question of
reliability because they were at least as reliable as two part
connectors.

I have found the variation in pin dimensions and receptacle tensioning
on some very reputable two part connectors to be quite variable such
that the reliability from batch to batch was quite poor. At least with
pcb card edge connectors the board and copper thickness was fairly
standard and only the socket manufacturing could be variable thus
reducing the probability of poor reliability of connection due to
manufacturing defects and errors by 50%.

Ross H

Duh - oh....
It seems that we are going off at a tangent anyway... On re-reading
the OP's initial request, it appears he is NOT referring to an etched
and plated card edge connector at all, so what we are saying is
irrelevant. It seems he may in fact have been asking for
recommendations for a two part RIGHT ANGLE CONNECTOR for mounting on
THE EDGE of the pcb.
 
M

Mochuelo

Jan 1, 1970
0
Duh - oh....
It seems that we are going off at a tangent anyway... On re-reading
the OP's initial request, it appears he is NOT referring to an etched
and plated card edge connector at all, so what we are saying is
irrelevant. It seems he may in fact have been asking for
recommendations for a two part RIGHT ANGLE CONNECTOR for mounting on
THE EDGE of the pcb.

No, I'm looking for a right-angle card-edge connector (so, one part).
I finally need 12 contacts, in dual row (6+6). Tin plating on the pcb
edge contacts is more than enough, since there will be no vibrations,
no mechanical stress, and 2 or 3 insertion cycles in total. These
things are pretty expensive, compared to some two-part pieces. I can't
find anything for less than 1.2 .. 1.5 EUR (in 1 k).

Thanks,
 
P

Pooh Bear

Jan 1, 1970
0
Mochuelo said:
No, I'm looking for a right-angle card-edge connector (so, one part).
I finally need 12 contacts, in dual row (6+6). Tin plating on the pcb
edge contacts is more than enough, since there will be no vibrations,
no mechanical stress, and 2 or 3 insertion cycles in total.

Vibration comes from lots of sources. Nothing is ever likely to be entirely
vibration free.
These
things are pretty expensive, compared to some two-part pieces. I can't
find anything for less than 1.2 .. 1.5 EUR (in 1 k).

Maybe because no-one in their right mind uses them any more.

I do hope you're not passing any analogue signals through this connection. I
also highly recomment reconsidering your connection method.

Graham
 
M

Mochuelo

Jan 1, 1970
0
Vibration comes from lots of sources. Nothing is ever likely to be entirely
vibration free.


Maybe because no-one in their right mind uses them any more.

In your previous post you said "edge connectors are used because
they're cheap," and now you try to justify why they are expensive.
This is good.

"No-one in their right mind uses them any more." You mean that the
manufacturers of DIMM, SIMM, RIMM, AGP, PCI and PCI Express are out of
their minds? This is even better. Who do you think you are, Graham?

Maybe you are just angry because I didn't take your recommendation.
Why should I have? You have provided no supporting data, and have
shown to have quite a mess in your mind. If you can't help, that's ok,
but don't bother.
 
P

Pooh Bear

Jan 1, 1970
0
Mochuelo said:
In your previous post you said "edge connectors are used because
they're cheap," and now you try to justify why they are expensive.

I've never said they were expensive. You have. I simply commented that there's
little demand for them aside from PCs, so as they aren't very popular as an
industrial connector you can expect to pay accordingly.

In large quantities for PC motherboards I bet they are dead cheap. Consider what
any alternative with that many contacts would cost at the small quantities you're
talking about. For comparison's sake some older Macs used DIN41612 dual row 64
pin connectors. Work out how much that would cost for a typical mobo.
This is good.

"No-one in their right mind uses them any more." You mean that the
manufacturers of DIMM, SIMM, RIMM, AGP, PCI and PCI Express are out of
their minds? This is even better. Who do you think you are, Graham?

They are used because PC mobos have always used edge connectors for the same
reasoning. They're cheap. The cost of gold plating the pcb contacts is minute
compared to the other half of a 2 part connector too.

Maybe you are just angry because I didn't take your recommendation.
Why should I have? You have provided no supporting data, and have
shown to have quite a mess in your mind. If you can't help, that's ok,
but don't bother.

If you want to screw up your project that's fine by me. I do have plenty of
experience of their failings though. I can't even remember now how many times a
fix has involved 'reseating the card' !

I also know what they do to analogue sigals as well. One reason that audio gear
dropped using edge connectors about 30 yrs ago ! You can hear the effect.

Graham
 
M

Mochuelo

Jan 1, 1970
0
Pooh Bear : "Edge connectors ARE USED because they're cheap."
Pooh Bear : "Maybe because NO-ONE in their right mind USES THEM any
more."

.... ARE USED...

.... NO-ONE USES THEM...

Can you see at least this contradiction?
If the answer differs from "yes," good luck.
 
P

Pooh Bear

Jan 1, 1970
0
Mochuelo said:
Pooh Bear : "Edge connectors ARE USED because they're cheap."
Pooh Bear : "Maybe because NO-ONE in their right mind USES THEM any
more."

... ARE USED...

... NO-ONE USES THEM...

Can you see at least this contradiction?
If the answer differs from "yes," good luck.

You'ver had it explained. I wouldn't use a connector that's known to be
troublesome in its best known application, the PC motherboard.

Please go ahead and use it but don't come back here bleating about your woes in
a few months time.

Graham
 
P

Pooh Bear

Jan 1, 1970
0
Mochuelo said:
Pooh Bear : "Edge connectors ARE USED because they're cheap."

In a PC motherboard application.
Pooh Bear : "Maybe because NO-ONE in their right mind USES THEM any
more."

They're expensive and difficult to find for anything other than a mobo
application precisely because they're not popular for *anything else* !

Maybe you should stop to give some consideration *why* they aren't popular any
more btw. And why PCs often need 'the boards reseated'.

If you can't see the logic in that then god help you.

Graham
 
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