What kind of connector is this? (Powering bread board) - Page 1
Forum section: electronics / beginners

author: JenniferG
author_rank: Frequent Contributor
timestamp: May 05, 2017, 09:37:19 pm
content: I'm interested in the connectors in the photo below. Just wondering if these are screw on or not. Seems like an easy way to get power to the breadboard. Are those connectors on the side banana plug jacks?

author: rs20
author_rank: Super Contributor
timestamp: May 05, 2017, 09:41:58 pm
content: Those are terminal blocks (like this, except cut up into individual little pieces.)You stick your screwdriver into the cylinder-shape protrusion on the side to undo/tighten up the screws holding onto the wires. They are not banana jacks, they are much smaller than banana jacks.

author: FlyingSquirrel
author_rank: Contributor
timestamp: May 05, 2017, 09:42:50 pm
content: im not sure about the exact name of the ones you illustrated (screw terminals?), but they do have screwsmaybe you might also want to take a look at these:http://www.ebay.com/sch/i.html?_odkw=Screw+Terminal+Solderless&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.XScrew+Terminal.TRS0&_nkw=Screw+Terminal&_sacat=0https://www.amazon.com/breadboard-screw-terminal/s?ie=UTF8&page=1&rh=i%3Aaps%2Ck%3Abreadboard%20screw%20terminal

author: Mickster
author_rank: Contributor
timestamp: May 05, 2017, 11:08:56 pm
content: They were/are also known as "Chocolate block connectors", or "Barrier strip connectors" and both search terms bring up the pictured item in the results.Regards.

author: Ian.M
author_rank: Super Contributor
timestamp: May 05, 2017, 11:35:59 pm
content: The smallest size that's commonly available has a nominal 3A current rating and is what you'd want for breadboarding.The better quality ones have a plated brass spring strip under the screw to stop the screw chewing up the wire (or in this case the pin of the breadboard jumper). Cheap ones tend to have a fairly sharp edge on the end of the screw and if you tighten it enough to hold a thin solid wire securely, it tends to bite into the wire enough to make it far too easy to break.

author: helius
author_rank: Super Contributor
timestamp: May 05, 2017, 11:37:55 pm
content: Also of note is that they accept bare solid copper wires, but are not really ideal for bare stranded wires, even if you tin them. In order to put stranded wires into terminal blocks, they are crimped with "bootlace ferrules", which come in a range of sizes and shapes.

author: Ian.M
author_rank: Super Contributor
timestamp: May 06, 2017, 12:00:42 am
content: Or at a pinch, take a single strand a bit thicker than the individual strands of the stranded wire, with plenty of extra length, and pinch the end of it against the insulation. Twist to lay it up smoothly with the stranded wire, then fold it sideways close to the tip of the stranded wire and tightly whip it round the stranded wire, in the direction that tightens the twist, back down towards the insulation. Take it under itself to make an overhand knot to secure it when you reach the insulation.Don't tin a stranded wire to be inserted in a screw terminal block. The solder creeps under pressure, which causes the connection to become loose and intermittent. It is permissible to lightly tin the very tip to stop strands untwisting, but the part the screw bites on must not be tinned and must be free from solder wicking.Don't try to put more than one solid wire (or two of the same diameter if there is a spring strip) under a single terminal's clamping screw. If you do, they will rock loose with the slightest movement.

author: Mickster
author_rank: Contributor
timestamp: May 06, 2017, 12:39:25 am
content: Quote from: Ian.M on May 06, 2017, 12:00:42 amI was also taught not to do this for any type of crimped terminal as well.Regards.