Recommendations for 4mm banana sockets - Page 1
Forum section: electronics / projects

author: OM222O
author_rank: Frequent Contributor
timestamp: January 05, 2019, 04:11:27 am
content: HelloI was looking for some cheap banana sockets (binding posts) that can be directly attached a PCB which also acts as the front panel.(i.e. it doesn't require to solder more wires to the end of it which then connect it to the actual PCB)The best ones I could find were these or very similar:https://uk.rs-online.com/web/p/4-mm-test-plugs-sockets/1222783/but it doesn't seem to be really intended for soldering. I'm not sure if the pressure from the nut is enough to make a good electrical connection (maybe I should get some spring washers too? idk).There are some plugs which have the "solder" termination style but seem too flimsy and unreliable for long term use like these:If you have recommendations on any cheap (less than 2$ a pop in 100+ quantity) please leave a link to them, thanks!

author: Andreas
author_rank: Super Contributor
timestamp: January 05, 2019, 05:52:36 am
content: Hello,not shure what you really want.- normally you do not want to have the forces from plugging on a solder joint.- you say "binding post" but show a 4 mm socket only (without possibility to connect a single wire).4 mm sockets that are soldered into the PCB have normally a right angle so are not intended for a front panel:https://www.conrad.de/de/cliff-fcr7350r-sicherheits-laborbuchse-buchse-gewinkelt-stift-o-4-mm-rot-1-st-419669.htmlhttps://www.reichelt.de/leiterplattenbuchse-4-mm-rot-pb-4-rt-p76865.html?&trstct=pos_0with best regardsAndreas

author: OM222O
author_rank: Frequent Contributor
timestamp: January 05, 2019, 06:05:45 am
content: I'm not quite sure what the difference is between a binding post and a socket sorry. They look very familiar tho ... the only difference I could spot was having a metal plate that contacts the PCB in case of a binding post, which the sockets don't seem to have (please correct me on that), but cost twice or 3 times as muchI can't use horizontal connectors as they make it so much more difficult to use the product, especially when you have to switch them (I know I can design around that but I'd rather not). I'm just not sure how reliable a simple nut is ... I probably use the socket I linked + a washer and some medium strength loctite

author: Nusa
author_rank: Super Contributor
timestamp: January 05, 2019, 06:15:16 am
content: What you see on most multimeters is a socket. The ONLY thing you can put in there is a banana plug.What you see on all the better power supplies is a binding post. You can put a banana plug in the end, or a wire around or through the screw-down post.Realize anything already soldered to a PCB can't be later attached to a solid panel with back-side nuts. It's physically impossible.Something like this (http://www.caltestelectronics.com/ctitem/161-safety/CT3150) will work, but the PCB needs to be well supported on both sides of the sockets, since it can't be secured to the front panel itself

author: OM222O
author_rank: Frequent Contributor
timestamp: January 05, 2019, 06:23:53 am
content: In that case a socket would be fine, it's just a simple diy device not a high end and fancy one. The socket *can* be soldered, you just have to place the nut and then solder it, but replacing it would become a nightmare in case it breaks ...I read about washers and nord lock washers seem to be a decent choice (practically impossible to loosen as the pitch of washer is steeper than the thread of the screw, so it needs sufficient force to deform the washer first which will never happen during normal use).Edit: I can actually buy self locking nuts for cheaper ... Just need to make sure they make good connection while tightening them.

author: Nusa
author_rank: Super Contributor
timestamp: January 05, 2019, 06:34:55 am
content: The PCB is the weak spot in this approach. I wouldn't worry about the sockets breaking first.

author: OM222O
author_rank: Frequent Contributor
timestamp: January 05, 2019, 06:49:41 am
content: so you recommend soldering the entire thing after tightening the nut?

author: JuanGg
author_rank: Regular Contributor
timestamp: January 05, 2019, 08:49:53 am
content: You may want to take a look at Dave's uCurrent. He has used both sockets and binding posts on a PCB front panel. I think they were just screwed on the PCB.Juan

author: Gyro
author_rank: Super Contributor
timestamp: January 05, 2019, 11:14:01 am
content: Don't underestimate the effects of stress on smd parts due to forcible board flex.

author: razvan784
author_rank: Regular Contributor
timestamp: January 05, 2019, 08:44:19 pm
content: I used XELA-4 (perpendicular to board, reinforced mounting)https://www.distrelec.biz/en/pcb-safety-socket-mm-black-cat-iii-staeubli-electrical-connectors-xela-black/p/11073263as well as the Cliff FCR7350 ones already suggested by Andreas (parallel to board).

author: mvs
author_rank: Frequent Contributor
timestamp: January 05, 2019, 10:32:05 pm
content: Quote from: OM222O on January 05, 2019, 06:23:53 amBanana sockets are not known to have problems with loose nuts... User just plugs banana plug in or out, no rotation forces envolved.Binding posts, that do not have any rotation locking mechanism (like notch or oval shaft), may go loose.

author: ajb
author_rank: Super Contributor
timestamp: January 05, 2019, 10:42:03 pm
content: Those threaded banana sockets are not meant to be soldered, so it's going to be quite a challenge to do so, especially without melting the plastic bit on the front. Just tightening the nut down is probably going to be perfectly fine. If you're really worried about the quality of the electrical connection between the nut and the PCB, there are little washers that have solder tabs that could be used (designed to provide electrical connections for screw heads on the top of single-sided PCBs), but I can't quite muster the right search terms to find an example right now. But I expect even a standard washer would be fine.

author: OM222O
author_rank: Frequent Contributor
timestamp: January 05, 2019, 10:47:47 pm
content: I'm just paranoid because I saw in one of dave's videos that one of the uCurrent units failed just because of a loose binding post, I'll use a washer

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: January 06, 2019, 03:59:22 am
content: Hi,You might want to look at Keystone 575. They come in various lengths.Link:https://www.digikey.ca/products/en/connectors-interconnects/banana-and-tip-connectors-jacks-plugs/302?k=keystone%20575I used these on my ESR meter adapter project:These solder to the PCB.Regards,Jay_Diddy_B

author: Gregg
author_rank: Super Contributor
timestamp: January 06, 2019, 04:27:27 am
content: The Schutzinger 4mm panel sockets you linked to has a data sheet link which shows a 2mm depression in the end beyond the threads. You could solder a wire into the hole and loop it to the board to ensure electrical contact. The threaded part could still be attached to the board and/or used to mount the board along with the soldered wire connection.