A Beginner's Guide to Barrel Connectors

[dliscomb]

I am trying to order a chassis for my AKSA-Lender pre-amplifier, and it looks like a Modushop 2U Pesante will have ample room. The pre-amplifier currently uses a 12V/1.5A wall wart, the business end is a 5.5mm x 2.5mm barrel connector. While I realize they can be polarizing (heh), since what I have is working well, I'd like to keep it.

We can find several different types of panel-mount barrel connectors. I understand the idea behind the threaded-body types (e.g. the PJ-064B); I've used them already for my MoFos. But I'm not that keen on the esthetics of them.

And so my question is about the other types, of which there seem to be at least two:

• Sockets with 'wings' that look like they are meant to accept small screws (e.g. the PJ-039BH) Sometimes the screw sockets are 'inside' and sometimes they are 'outside'
  
  
• Sockets with 'grooves' that look perhaps like they are meant to be slid into an opening cut from the edge of a panel (e.g. the PJ-009BH, or the PJ-008B)
  
  

Can anyone describe to me how these are attached to a panel? CUI has not deigned to answer my question from several days ago.

Kind regards,
Drew

 

[454Casull]

For the first, you use coarse-threaded self-tapping screws. The threads will cut into the bosses of the pre-formed holes. Screw (head) is on outside of sheet metal, connector is on the inside. Pick a screw size where the minor diameter matches the ID of the pre-formed holes, or is just a hair under.

For the second, you pretty much got it.

 

[rayma]

Switchcraft has some very nice pcb and wired connectors that just mount in a round hole. Much easier.
https://www.switchcraft.com/Categor...9TiDJYpcSXOPbLOB7OOJUeqDymMs0KOwaAkoqEALw_wcB

 

[tvrgeek]

Only use sheet metal screws if you can clear the shavings after install.
Yes, in a slot. A nibbler works great for that kind of thing.

And then there is always JB-Weld.

 

[dliscomb]

Only use sheet metal screws if you can clear the shavings after install.

I was thinking to drill holes in the panel to the diameter of the holes in the bosses, to minimize that. And then self-tapping screws aren't necessary.

Kind regards,
Drew

 

[dliscomb]

Thank you to everyone! This has been super helpful.

Kind regards,
Drew

 

[454Casull]

I was thinking to drill holes in the panel to the diameter of the holes in the bosses, to minimize that. And then self-tapping screws aren't necessary.

Kind regards,
Drew

You still need self-tapping screws to actually go into the plastic bosses. Or are you thinking about "self-drilling" screws? Self-tapping screws are any kind where you're not having pre-existing threads to spin into.

 

[dliscomb]

You still need self-tapping screws to actually go into the plastic bosses. Or are you thinking about "self-drilling" screws? Self-tapping screws are any kind where you're not having pre-existing threads to spin into.

Ah, I was not clear. I did not mean what I call "machine screws" that require a nut, and I was thinking "self-drilling" screws; the ones that have a small cut at the bottom that acts like a drill bit. I didn't think about how "sheet metal screws" are "self-tapping", although on reflection, it makes perfect sense as the screw is accomplishing what a tap does. TIL! Thanks for that!

I was thinking of #6-20 Thread Size, 3/8" sheet metal screws, or similar. Something where the screw body is "very close" to the size of the boss holes, but the threads will bite. The hole in the panel would accommodate the screws's threads.

I have seen this implemented in commercial amps (NAD, Carver) that I took apart.

Kind regards,
Drew

 

[454Casull]

Sounds like you're on the right track.