PCB Connectors

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Hi all, looking for ideas on PCB connectors, for a PSU board. +/-40V all the way to +/-80V or higher.

Molex? IDC
Screw on PCB terminal block?
Faston PCB blade?

What are your preferences?

#12 AWG wire will be sufficient for something that might carry 10Amps? Or can I go smaller?
 
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Hi all, looking for ideas on PCB connectors, for a PSU board. +/-40V all the way to +/-80V or higher.

Molex? IDC
Screw on PCB terminal block?
Faston PCB blade?

What are your preferences?

#12 AWG wire will be sufficient for something that might carry 10 Amps? Or can I go smaller?

The #12 size is good. Keystone makes some nice tin plated brass pcb mount terminals up to 30A. Here's one example.

http://www.digikey.com/product-detail/en/7693/7693K-ND/151562
 
If you want the convenience of plug in/out connectors, .156 in (Molex/AMP) are just on the edge, that's what I use in my Musical Instrument amps but with the improved "trifurcon" female connector which strongly grabs the male square post .

Now if you want a better one, use flat blade ones for much higher contact surface, males on PCB, females on cable.

Practically the standard on high power rack mount PA amplifiers.

Of course, nothing beats soldering ;)

Not disagreeing but personally not a fan of screw terminals inside an amp, in less time than grabbing the proper screwdriver and tighten/untighten I solder/unsolder. :)

Understand their convenience on top of a telephone pole or when a homeowner wires his speakers ;)
 
Hey thanks for the responses. So many choices.

flat blade ones...Practically the standard on high power rack mount PA amplifiers.
Yeah, I fixed a Crown amp and they use these fastons blade connectors for speaker outputs. (but they soldered the PSU wires to the main board, but again it was an entry level pro amp).

You could look at Hirose DF22 (get the gold ones) if you want lots of current capability and wide wire gauge.
These looks nicer than the standard Molex. Thanks for the tip.
 
Samtec are worth a look as well, generally nicer then the entry level molex KK and such, but a bit spendy from the usual distributors (They are quite good about samples however).

If you are going to crimp, get the right tool, nothing worse then a badly made crimp for reliability.

Regards, Dan.
 
Flexibility somewhere else is good but at the actual connector point there must be absolute rigidity, same whether it's crimped or soldered.

The slightest movement there means very poor contact.

The "knee" is at least a couple mm away.

You must tie/clamp/glue/heatshrink your wires to reduce flexing .
 
Hardly use them these days for industrial/commercial, but did use them a couple of months ago on some PCBs for flight refuelling. I love them, had a nice sample that I was always playing with until someone nicked it, just the feel of them is sexy.....I probably need to get out more:)

Lucky you, when I was on my first placement from collage I got to learn how to wire up and solder BNC leads...
 
To bump up the old thread, I would like to ask your opinion on screw terminal blocks for PCB. Like this one.

I will need a good connection for 2A DC, or about 1.5A rectified DC (that means 6-7A peak pulses).

I was thinking about using this, or simple JST connectors, or faston blade types.

But I do have a question: I understand that the mechanical connection any one of these provides is good, resulting in a high contact area, low resistance joint.

What about the soldered joint to the pcb they need, though? Placing such a terminal block in a PCB (with say two 1.3mm holes and 3mm pads) and soldering it ensures a good enough joint? I feel there is little mechanical contact to the pcb pad before soldering, and the joint's resistance could be determined by the solder resistance (I might be mistaken, this is why I ask).
 

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... ... ...the joint's resistance could be determined by the solder resistance...

Effect of Solder Thickness and Joint Overlap on the Electrical Resistance of Soldered Copper Joints
http://files.aws.org/wj/supplement/WJ_1981_10_s199.pdf

That speaks of a lap-joint but I have re-drawn it as a connector.

For "neat" joints with solder-area at least 3 times the wire area, if the wire in the circuit is 100 times the solder thickness, the *wire* resistance dominates.

In general for "small" work (do not need a loan to finance the building), it is expedient to over-size wire, connector, and solder area so none of this really gets in our way.
 

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So this actually means that it doesn't even matter if the wire (or a terminal block's solder lug) does not make mechanical contact with the pad at all?

I realize that this is the case for single sided boards, where there is no chance of actually touching the pad together with the component's lug (unless you bend it, hardly the case with a terminal block).

EDIT: I did not understand what you mean by thickness vs solder area in your example. Solder area is the pad area + the area of the wire surrounded by solder, whereas solder thickness is the thickness of the "pyramid-shape"?
 
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