Low voltage 3 way connector. 2.5mm stereo TRS? - Page 1
Forum section: electronics / projects

author: Buriedcode
author_rank: Super Contributor
timestamp: November 20, 2019, 10:26:51 pm
content: Hi,I've decided to mod a bluetooth transmitter, as I don't want it to be permanent I would like to add a socket to it to carry signals (power, ground, and a on/off signal). To make matters "interesting" (=annoying) I have a about 10x9mm panel space to work with. As there's already a 3.5mm socket for the audio I thought its smaller 2.5mm cousin would do, but I can't seem to find a stereo panel mount socket other than this one:https://www.rapidonline.com/lumberg-klb-13-jack-socket-2-5mm-chassis-mount-3-pole-stereo-54-4790I realize there isn't much market for 2.5mm stereo sockets - and there are plenty of PCB mount versions, but panel mount stereo? I can't find any apart from the above, which will do but has a rather large mounting hole which won't leave much surrounding plastic on the panel. I considered making a small PCB then finding a way of mounting this, but there just isn't room, unless I mount it to an adjacent enclosure wall (about 12mm to the left of this).My options are:1) use a 3.5mm and just remember not to get the two sockets confused - but the 3.5mm sockets are larger and dont' quite fit.2) Use the linked socket and hope the plastic enclosure can hold it, it shouldn't be under much mechanical strain.3) Find another 3-way connector that will fit in this space. All I can think of that will fit are Lemo ones, that are far too expensive.4) Use a PCB mount version, PCB, and find a small (<6mm) right-angle bracket to mount the board) like these:https://www.mouser.co.uk/ProductDetail/534-7790?R=7790virtualkey53400000virtualkey534-7790maybe these?https://www.sparkfun.com/products/102285) Keep searching for a 2.5mm socket like this:https://www.rapidonline.com/truconnect-2-5mm-mono-miniature-jack-socket-20-0131which will fit perfectly, but in stereo.I'm aware this is all pretty vague, but meh, thought I'd ask just incase.

author: magic
author_rank: Super Contributor
timestamp: November 20, 2019, 11:43:43 pm
content: Beware that TRS can produce all kinds of interesting shorts when you pull the plug under power.Maybe one of those barrel connectors with central pin used in laptops or mini-DIN/mini-XLR, though the latter are probably too large.

author: Yansi
author_rank: Super Contributor
timestamp: November 21, 2019, 12:00:58 am
content: Buy a small three pin "LEMO" from aliexpress. Almost the same space taken, 10 orders magnitude better that that stupid TRS.//EDIT: Or use a mini-XLR.//EDIT2: LEMO 00 (00B) connector is very small, just M7 screw. But very hard to get from China.LEMO 0B is a bit bigger, socket has M9 thread. Quite cheap for the decent construction. These are very impressive for their price. Link below:https://www.aliexpress.com/item/4000316842737.html?spm=a2g0o.productlist.0.0.f1156686KDfagw&algo_pvid=e55d02e4-2ed9-48aa-8386-958cf40e5590&algo_expid=e55d02e4-2ed9-48aa-8386-958cf40e5590-2&btsid=8387895b-ffc2-4022-8d12-bdcee8a80837&ws_ab_test=searchweb0_0,searchweb201602_3,searchweb201603_52//EDIT3: Found you the smaller sucker!https://www.aliexpress.com/item/4000320270797.html?spm=a2g0o.productlist.0.0.6ae11639x9q8G8&algo_pvid=338fffff-66b9-4d5f-a0ba-b727975c4b90&algo_expid=338fffff-66b9-4d5f-a0ba-b727975c4b90-0&btsid=538c6b66-ded8-4486-a92f-5f9a7e467db4&ws_ab_test=searchweb0_0,searchweb201602_3,searchweb201603_52

author: Buriedcode
author_rank: Super Contributor
timestamp: November 21, 2019, 01:18:13 pm
content: Quote from: magic on November 20, 2019, 11:43:43 pmAhh yes I thought about that when deciding the pinout - in all cases it would effectively short the supply as well as cause a brief spike on the "enable" line (the third line). But this would be a semi permenant thing - I won't be plugging/unplugging very often and not when its powered. I'll probably be the only one using it, so I could have probably just gone with a permanent cable coming out the enclosure, but I like neatness. If this was for a commercial product, or for others to use, I would have had to add some kind of protection. I tihnk mini-DIN might be too large, given the plug is 9.5mm in diameter - the whole socket area is 9x10mm max.Quote from: Yansi on November 21, 2019, 12:00:58 amThat is the cheapest I've seen a Lemo, and I only require one ( the other end can be TRS as that has no size requirements) I didn't think they could go for <$35 US. The last time I used them I had to make up 60+ cables 5 way, hand soldering everything including the tiny sockets. Beautiful connectors, but the price was silly.As I replied I realized, because I'm the only one using this, I could probably get away with 3.5mm. Cheap, cables are ubiquitous, and as I'm not going to be plugging/unplugging this regularly, I probably dont' have to worry about using the wrong socket. If I do, any damage would be my fault.Cheers folks