DC Power Jack to Use on PCB

Harry Stoner

I am working on creating my first board layout with Eagle. I've never had a board made up. Yes, I've looked at ExpressPCB and use it for schematics, but their board costs are too high for me (actually the shipping to Canada).

I'm just trying to get familiar with the process. I understand a lot of what I'm doing but I'm stuck on the first thing I want to put on the board - a DC power jack for a wall wart (barrel connector).

If I look at the power jacks I have on hand and what I see in the Mouser catalog, they have 3 flat tabs with holes on them where you would put a wire through and solder it on. I'm not sure how you would put this on a PCB. Should I get a type that has different pins (e.g. round or whatever)? I didn't see that in the Mouser catalog. Can anyone point me to the correct part at Mouser (or another site)?

Also, the power jacks I have on hand have 2 round holes in the molded black plastic of the frame, presumably for use with screws to attach to a frame. Would I have holes drilled in the PCB for this - or should I be looking at other jacks that don't have the tabs/holes?

For a PCB I would expect a part with 3 round pins and no tabs for support screws, but no experience here. Thanks for any assistance.

Harry

Robert Schwartz

When you add a power connector into the schematic design, does it come out with round or straight tabs?

Paul Baker

Here's the library file for the dc jack I used, its a 2.1mm ID, 5.5mm OD jack made by CUI and is part number PJ-102A. I don't know if mouser sells them, but digikey does for around $1.25. The board is in fab right now, so I am not absolutely positive its correct, but I followed the spec to the tee and it looks just like the footprint for the one's parallax uses.

Post Edited (Paul Baker) : 2/14/2005 5:15:19 AM GMT

Harry Stoner

Robert said...
When you add a power connector into the schematic design, does it come out with round or straight tabs?

That would depend upon what I decided to use out of all the various and scattered Eagle libraries. And I don't have libraries for the physical jacks that I have in my possession.

Thanks.

Harry

Harry Stoner

Paul said...
Here's the library file for the dc jack I used, its a 2.1mm ID, 5.5mm OD jack made by CUI and is part number PJ-102A. I don't know if mouser sells them, but digikey does for around $1.25. The board is in fab right now, so I am not absolutely positive its correct, but I followed the spec to the tee and it looks just like the footprint for the one's parallax uses.

Thanks for that link Paul. The part you used looks more like what I would expect to be mounted on a PCB. I see from your library and the part data sheet that the hole diameter is 0.059 inches (1.5mm). I will look to buy a jack like you did. Did you create that Eagle package yourself or did you download it from somewhere? I've been downloading as many libraries as possible so I don't have to look at creating the devices/packages myself.

Thanks.

Harry

Paul Baker

I created it myself, many of the parts on my board don't have a library part (even on cadsoft's site). Whenever possible I tried to use an already defined package and just import it into the library (almost got burned a couple times since some package names have more than one definition, especially in the sot/ssop/soic arena, so its best to double check all spacing). But there were a few parts which had no availible package defined (smt spdt, smt·mom spst, smt oscillator, smt resonator and DC jack), So I created the packages for those (hardest one was the spdt which had 4 case connection pads, 3 signal pads·and two pilot holes a plastic plug fits into, it took me a while to figure·out how to place a guard ring around the holes·to prevent the ground plane from coming up to the holes).

As you see, the spec specifies the leads are rectangular, and I used round holes, I just plan of fileting the space with extra solder (low temp solder·to minimize the plastic melting).

BTW I guess you see that I was wrong on the price, the standard is $0.31 and the high current is $0.42.

I contemplated using a smt dc jack but decided against smt components for all off board connectors, the solder on the other side of the board is an extra mechanical fastener for a part helping to prevent lifting issues due to stress placed on the cable. I once bought an expensive walkman ($75 which was 4 months worth of chores for me, this was before there were portable CD players) and within a few months the headphone jack came loose. I carefully opened the case and found the jack was an smt type (first one I saw, this was back in the mid 80's) and the plug had seperated from the pcb and lifted the pad and part of the trace, snapping the trace in the process. Needless to say the unit was beyond repair. Moral is: smt is great but not for connectors.

Harry Stoner

Thanks again Paul. There was only one close DC jack in the standard CADSoft libraries that I saw - library con-shiua-chyuan.lbr. They specified elongated pads for that.

A surface mount jack doesn't sound too wise based on your experience ...

Harry