Help need DC connector/chassis part 40VDC 2Amps can't find any good one - Page 1
Forum section: electronics / projects

author: Kjelt
author_rank: Super Contributor
timestamp: July 31, 2015, 08:23:51 am
content: Hi all,I am searching for a DC power connector and chassis part for a next project that has the following specs:small but sturdy/reliableprice < $8 for connector + chassispart (@ 25 pieces)40VDC min.2 Amps min.2 poles for wires around 0,5 - 0,75mm2connector has pull relief for the cableconnector has some sort of physical connection with the chassis part so it won't accidently fall outavailable at Farnell/TME/Digikey/Conrad or the sorts not some exotic swiss handmade 2 year waiting time stuffSo what did I find already that has failed above criteria:- cheap DC jacks that easily fall out if you pull the wire.- The Phoenix Contact screw inserts (most used on DIN rail stuff: wires always open, no wire pull relief- expensive too large Hirschmann CA system connectors (nice though for mains outdoor) if there were small versions of that it would be a go- audio DIN connectors that have no DC power rating (so unknown if they can be used for 40VDC at 1,5 Amps)- Wieland BST14 can't find a decent source for those connectors.- AMP lok n mate stuff: open wires/connectors no chassis parts.So who has a golden tip for me?Thanks !

author: shebu18
author_rank: Frequent Contributor
timestamp: July 31, 2015, 08:30:28 am
content: What about this one:http://uk.farnell.com/fct-a-molex-company/f2w2sc-k121/d-sub-combo-receptacle-tht-de/dp/2433134

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: July 31, 2015, 08:40:51 am
content: Switchcraft do barrel jacks with screw-locking rings, Farnell stock themhttp://www.switchcraft.com/Category.aspx?Parent=943

author: daedalus
author_rank: Regular Contributor
timestamp: July 31, 2015, 09:29:22 am
content: molex mini-fit JR range is what I would use. They have panel mount versions, are locking, and aren't too expensive. For strain relief you can over-mould the plugs, also farnell has a range of dc-dc power bricks that come with molex connectors already attached and over-moulded for strain relief, which saves a lot of hassle.

author: Pjotr
author_rank: Frequent Contributor
timestamp: July 31, 2015, 09:43:06 am
content: Rean Tiny XLR (a Neutrik division) :http://www.rean-connectors.com/en/products/tiny-xlr/available from Farnell.Swichcraft makes these also, but more expensive and less reliable.

author: Kjelt
author_rank: Super Contributor
timestamp: July 31, 2015, 10:09:12 am
content: Quote from: shebu18 on July 31, 2015, 08:30:28 amWilll check it out, thanks.Quote from: mikeselectricstuff on July 31, 2015, 08:40:51 amDidn't know there were screw lock versions of this, that is a real good tip , thanks!Quote from: daedalus on July 31, 2015, 09:29:22 amThanks will check this out too.Quote from: Pjotr on July 31, 2015, 09:43:06 amI have been thinking about XLR connectors, the problem I have with these is that they are not specified for power usage (or are they?) and are made for audio applications. The issue is that this installation is going to be 24/7 on in my home and garage,so although I over fuse everything I really do not want in case of a fire that the insurance company can blame the connector for being incompliant for that power use. It will be a very expensive project then

author: Kjelt
author_rank: Super Contributor
timestamp: July 31, 2015, 10:24:09 am
content: Quote from: mikeselectricstuff on July 31, 2015, 08:40:51 amJust checked it out they are all spec'ed for max. 30V 5A.So how should I read/interpret this, see the specs below:They claim 5A upto 30VDC but I want 1,5A upto 40VDC , so should I simply use power (so upto 150W is allowed?) or what?It looks like the insulation is upto 500VAC, so that will not be the problem?So let me refrase would you Mike use this connector for 1,5A upto 40VDC for a client project?Thanks.

author: Pjotr
author_rank: Frequent Contributor
timestamp: July 31, 2015, 10:48:18 am
content: Quote from: Kjelt on July 31, 2015, 10:09:12 amLook at the spec sheet, they state a dielectric strength of 500V RMS. Standard 4-pole XLR's are quite often used for SELV power (< 60V DC) with professional AV equipment. The Rean mini XLR's are quite sturdy with a solid strain relief. If it is for mains power you are in another league anyway.

author: Kjelt
author_rank: Super Contributor
timestamp: July 31, 2015, 02:32:11 pm
content: Quote from: Pjotr on July 31, 2015, 10:48:18 amYes you are right, interesting would be a serious candidate. However now I see that:Quotewhich fails my 0,5-0,75mm² requirementBut indeed a standard XLR could be a well suited candidate.

author: rollatorwieltje
author_rank: Unknown
timestamp: July 31, 2015, 02:39:20 pm
content: Neutrik Powercon? The small blue ones are rated at 250V 20A if I remember correctly.

author: Kjelt
author_rank: Super Contributor
timestamp: July 31, 2015, 02:53:07 pm
content: Quote from: rollatorwieltje on July 31, 2015, 02:39:20 pmWill be tough with the price and it is very much overkill for only 40VDC 1,5A.I was thinking of the normal 230VAC connectors but that is not wise since someone (other than me) could put a real 230VAC connector on the device.It should be obvious that it is a DC socket.

author: Pjotr
author_rank: Frequent Contributor
timestamp: July 31, 2015, 03:08:33 pm
content: Then it is not wise to use a standard 3.5mm plug/socked either for 40V DC. Someone will plug de PSU into something intended for 9V - 12V some dayBut why 0.75mm2 for 1,5A? If it's for mechanical robustness then those 3,5mm plugs will not do.

author: rollatorwieltje
author_rank: Unknown
timestamp: July 31, 2015, 03:30:43 pm
content: Quote from: Kjelt on July 31, 2015, 02:53:07 pmThe audio store sells Powercon connectors at about €9 for a male+female pair. You could also look at Neutrik Speakon, those are cheaper at around €5 per pair, but not sure what the rating of those is.

author: Kjelt
author_rank: Super Contributor
timestamp: July 31, 2015, 03:42:35 pm
content: Quote from: Pjotr on July 31, 2015, 03:08:33 pmThe length of the wire to the device will give too much voltage drop at 0,25mm2at 1,5 Amps. My first design had 1,5mm2/sup] solid core

author: rx8pilot
author_rank: Super Contributor
timestamp: July 31, 2015, 04:19:46 pm
content: Quote from: Kjelt on July 31, 2015, 10:09:12 amXLR's have been used for power for decades in the pro video and film world. They are good to 60v I believe and have been used for 12-48v and up to 10A for the 4 pins and 12A for the 3 pins.

author: nali
author_rank: Frequent Contributor
timestamp: July 31, 2015, 04:22:15 pm
content: What about Neutrik Speakon? Although not designed for power connectors they seem to fit the criteria.

author: edavid
author_rank: Super Contributor
timestamp: July 31, 2015, 04:34:28 pm
content: Where did the Chinese GX16 connectors come from? Are they a clone of a name brand connector? Has anyone seen a datasheet?(They seem pretty good for this application.)

author: Pjotr
author_rank: Frequent Contributor
timestamp: July 31, 2015, 06:05:03 pm
content: Quote from: edavid on July 31, 2015, 04:34:28 pmThose are probably a copy of the Japanese connectors found on CB radio's long time ago:http://www.philmore-datak.com/mc/Page%2054.pdfThe original I think was the Amphenol 91-MC4M microphone connector.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: July 31, 2015, 06:51:23 pm
content: Quote from: Kjelt on July 31, 2015, 10:24:09 amdepends on the application. the voltage rating is mostly about issues with arcing if mated or unmated under load. If this wasn't expected to happen much then I wouldn't be too worried about voltage rating

author: Kjelt
author_rank: Super Contributor
timestamp: July 31, 2015, 08:00:29 pm
content: Ok thanks everyone for contributing, I am now first going to explore the XLR connector, I didn't know it was used as power connector in the pro setting.I could get it cheap and easy from a normal webshop (tomorrow will be delivered), a set of female connector and male chassis with silver contacts were total €7.- so close to the $8.-I like the sturdiness of the connector and have an extra spare pin left if I need it for another voltage or whatever. Thanks again everyone

author: nctnico
author_rank: Super Contributor
timestamp: August 01, 2015, 04:20:39 pm
content: Neutrik also makes Speakon connectors which are intended for connecting speakers to amplifiers. These are great for handling power and they are sturdy as well. Perhaps overkill for this application but they aren't expensive. I'm not a fan of using XLR in power application since there obviously is a lot of difference in quality between the various manufacturers.

author: Kjelt
author_rank: Super Contributor
timestamp: August 01, 2015, 05:49:20 pm
content: Quote from: nctnico on August 01, 2015, 04:20:39 pmTrue, that is why I bought the Neutrik NC3FXX-BAG and NC3MD-LX BAG, to my surprise Neutrik had a technical datasheet spec'ing the silver plated connector at 50VDC 16Amps more then enough for my application. So that is hard proof that it is a suitable connector for that purposeWhy I started this topic was that I hoped for a cheaper but equally good DC connector that could also suffice.However if I look at 95% of the consumer equipment they all use those worthless dc jacks or phoenix contact inserts that can fall out anytime or are open contacts, actually quite unbelievable.

author: Pjotr
author_rank: Frequent Contributor
timestamp: August 01, 2015, 05:50:50 pm
content: Select a decent one then. Some cheap Chinese makes are crap indeed, some others are not. But even the expensive Switchcraft ones are not my favourite, not that reliable on stage and even the original old Canons loose there strain relief screws after some time with heavy stage use. Neutrik is good reliable quality and not expensive.Posted at the same time, Kjelt already chooses the right one I see.

author: edavid
author_rank: Super Contributor
timestamp: August 01, 2015, 07:05:56 pm
content: Well, if you want a cheap connector, I think a GX16-2 would be fine. 1 zillion Chinese solder stations can't be wrong

author: Pjotr
author_rank: Frequent Contributor
timestamp: August 01, 2015, 07:18:13 pm
content: Quote from: edavid on August 01, 2015, 07:05:56 pmGood argumentI have some experience with some of those Chinese GX16 connectors. The isolation part was made of plain PVC or ABS or something alike. If you try to solder them the contacts simply melt away in the isolation. Same with some of the el cheapo Chinese XLRs.

author: Monkeh
author_rank: Super Contributor
timestamp: August 01, 2015, 07:37:53 pm
content: Quote from: Pjotr on August 01, 2015, 07:18:13 pmIf you keep both sides mated for more thermal mass it's a bit easier, and they'll move less. It also helps to use the lowest temperature you can get away with and a large tip.

author: Kjelt
author_rank: Super Contributor
timestamp: August 01, 2015, 11:01:04 pm
content: Quote from: edavid on August 01, 2015, 07:05:56 pmCould have used that tip before and safed €70.- on the other hand where can I find the datasheet, V and I specifications?Still a real cheap connector, always usefull for less critical applications.

author: tautech
author_rank: Super Contributor
timestamp: August 01, 2015, 11:10:43 pm
content: Quote from: Kjelt on August 01, 2015, 11:01:04 pmGoogle for "locking DIN connectors" there's many to choose from.

author: SL4P
author_rank: Super Contributor
timestamp: August 02, 2015, 10:50:27 am
content: if you decide on XLR, please choose a variant... e.g. 4 or more pins that won't accidentally find itself in the wrong hole.

author: Pjotr
author_rank: Frequent Contributor
timestamp: August 02, 2015, 11:32:35 am
content: Quote from: SL4P on August 02, 2015, 10:50:27 amTrue, but that only counts when 3-pole low level signal "holes" are around too, i.e. in music/film studios. And even then, 4-pole and 5-pole ones are also used for low level signals too. There is no general agreement about. Whatever the pin count, pin1 is always the "early" pin and intended for GND.

author: Kjelt
author_rank: Super Contributor
timestamp: August 02, 2015, 11:48:35 am
content: Quote from: SL4P on August 02, 2015, 10:50:27 amtoo late, order came in yesterday see picture. Nice those online shops, order before 22.00 delivered next dayBut I did look at this but the 3 pins are very easy to get for everywhere for cheap prices, the 4 and 5 pins are much more expensiveI will label the connector and chassis that it is for power to the lighting system, I am even going to use the third connector for 8VDC, saves me a DC-DC converter in each distribution box

author: SeanB
author_rank: Super Contributor
timestamp: August 02, 2015, 12:25:06 pm
content: Even with a label I would suggest putting protection against short circuits, reversed polarity and overvoltage on both supply side and load side.You never know in a lighting rig when somebody ( might even be you in a hurry in the dark) will either plug in a speaker into the power supply, or somebody might plug in a phantom powered microphone or patch cord, or trip over the cable and break the ground conductor, or plug in a MIC cable with shorted pins. At a minimum some TVS diodes, PTC fuses and reverse blocking diodes on them, so that you will only have a resettable failure in most cases.