Looking for low-cost connectors - Page 1
Forum section: electronics / beginners

author: justanothercanuck
author_rank: Frequent Contributor
timestamp: February 08, 2013, 01:37:04 pm
content: Looking for some connectors to link a few boards together for a project I'm working on... The one set of connectors is a board-wire-board power connector, 2 wires, 5 volts and no more than an amp. The second set of connectors is board-board, but I need roughly 40 pins for signals (to connect to a backplane).I've looked at molex connectors and berg connectors for the power, but they're too expensive. For the signal connectors, I've considered PCI, DIN 41612, and even 40-pin IDE connectors, but they're also too expensive. Sure, they would be cheaper if I bought them by the thousand, but I only need 6 or 7 sets of each connector. Not to mention, I'd need to buy a crimper.Aside from just soldering the boards together, is there a cheaper way to make connections?Thanks

author: c4757p
author_rank: Super Contributor
timestamp: February 08, 2013, 01:53:53 pm
content: I'm confused. Is this meant to be direct board-to-board or via a cable? If it's via a cable, with that many signals, I'd probably go with the IDE connectors. Just two rows of twenty 100mil pins - you can even omit the shrouded connector - and pre-made IDE cables are dirt cheap. If it's direct I'd put some work into eliminating some of the signals (are you sure you can't encapsulate them in a serial protocol or something?) and use a card-edge connector. Mouser has PCIe x1 sockets for less than 50c each.

author: justanothercanuck
author_rank: Frequent Contributor
timestamp: February 08, 2013, 02:11:32 pm
content: Sorry for the confusion. Let's see if I can clear that up a little. The power connectors would be a wire with connectors on both ends. The signal connectors, I'm building a backplane for the boards to talk through, I just need connectors for them.40 pin IDE connectors cost like $5 a piece, which I don't understand because it's a common connector.

author: Marco
author_rank: Super Contributor
timestamp: February 08, 2013, 02:30:20 pm
content: What's wrong with cheap pin header/sockets like arduino uses? (Other than that they are not rated for a whole lot of insertion cycles.)

author: LEECH666
author_rank: Frequent Contributor
timestamp: February 08, 2013, 02:33:02 pm
content: Have you considered 37 to 50 pin D-SUB connnectors for the signals?http://www.newark.com/multicomp/5502-50pa-01-f1/plug-d-pcb-straight-50way/dp/93K4308?Ntt=1084691Sure they ain't high density and a bit clunky, but they're cheap and well proven, they might not meet your space/size requirements tho (you didn't specify).Cheers,Florian

author: justanothercanuck
author_rank: Frequent Contributor
timestamp: February 08, 2013, 02:46:24 pm
content: Quote from: LEECH666 on February 08, 2013, 02:33:02 pmAren't those meant for external connections? I'm not sure those would work that great for me.

author: madires
author_rank: Super Contributor
timestamp: February 08, 2013, 03:01:18 pm
content: Quote from: justanothercanuck on February 08, 2013, 02:11:32 pmThat seems to be a rip-off. Just checked a local online shop: 0.20 Euros.

author: mariush
author_rank: Super Contributor
timestamp: February 08, 2013, 06:12:41 pm
content: http://www.digikey.com/product-detail/en/SFH11-PBPC-D20-ST-BK/S9200-ND/1990093http://www.digikey.com/product-detail/en/SBH11-PBPC-D20-ST-BK/S9175-ND/19900681-2$ a piece depending if it's female or male connectors. You can probably find them cheaper.You can use the regular rows strips of pins that can be bought cheap on ebay, even at vertical angle ... or get something like thishttp://www.digikey.com/product-detail/en/SBH11-PBPC-D20-RA-BK/S9183-ND/1990076http://www.digikey.com/scripts/dksearch/dksus.dll?FV=fff40016%2Cfff802f3%2C114016f%2C1140215%2C1600017%2C8000010%2C8cc0003&vendor=0&mnonly=0&newproducts=0&ptm=0&fid=0&quantity=0&stock=1IDE cables are cheap but be careful because I think one pin is missing in the 40pin connector, so you'd actually have 39 signal wires.There's another option ... put the contacts at the edge of the board and use such connectors:http://www.digikey.com/product-detail/en/5530843-4/A31717-ND/770543But you'd have to be careful when making the board, to be thick enough so the contacts would be good.

author: Paul Moir
author_rank: Frequent Contributor
timestamp: February 08, 2013, 10:21:47 pm
content: D-SUBs are sometimes used internally. At least I'm sure I've seen them used for a backplane on *something*. You can get them in not-right-angle for a backplane. But pin headers have to be cheaper. (I do see a $2.29 37 pin d-sub at Digikey though).But what I really wanted to know is if there's a particular reason you want to keep your power on a separate connector? If if doesn't matter, just devote a few parallel pins for power and ground.

author: justanothercanuck
author_rank: Frequent Contributor
timestamp: February 09, 2013, 03:29:10 am
content: Quote from: mariush on February 08, 2013, 06:12:41 pmThose will fit the bill nicely, but is there a right-angle male connector to go with it? I didn't happen to see one. I saw one by another manufacturer, but it was like $4.70 a piece.Quote from: Paul Moir on February 08, 2013, 10:21:47 pmSignal noise I guess? It also saves me from running extra traces through the backplane and/or one of the boards.Thanks again

author: Psi
author_rank: Super Contributor
timestamp: February 09, 2013, 04:06:10 am
content: The cheapest connectors will be ones used for other purposes in mass market products like PC components etc..

author: mariush
author_rank: Super Contributor
timestamp: February 09, 2013, 04:10:51 am
content: Quote from: justanothercanuck on February 09, 2013, 03:29:10 amDigikey is full of connectors and pins, you can waste hours just searching.Look up the connectors sections, filter by pitch 1.27mm and 2.54 mm, number of rows and pins, even right angle or not..http://goo.gl/kz0jhThe plain unshrouded pins are very cheap, under 2$ for a 40 pin set... but you could be smart and play with volume prices even though you need just a few. Instead of getting 40 pin, get 20 pin or 10 pin and buy in volume, price may actually be better if you get 100 pieces of 10 pin compared to 25 x 40 pin connectors.http://goo.gl/euaaz(scroll down, 40 pin connectors start from around page 3... the link above filters to show only straight, surface and through hole, with 1.27 and 2.54 mm pitch/row spacing)And digikey isn't even the cheapest, but they're close to canada, much like mouser.com is or ca.newark.comthe ones that are male unshrouded you may be able to get from eBay really cheap (it's the same spacing as the breadboard holes so you can find them as breadboard accessories) but you don't have the guarantee that the pins have gold plating on them, or you have female + male from the same alloy... it's little things but it can matter.I think it would be cheaper to put a straight male pins on the base board and a female at vertical board, the regular straight pins are cheaper