Couple questions about soldering/wiring/perfboards - Page 1
Forum section: electronics / beginners

author: Youkai
author_rank: Regular Contributor
timestamp: June 12, 2023, 05:19:10 am
content: I'm getting ready to solder together a project. There are two main things I'm thinking about doing and I want to figure out how bad of an idea they are. The project uses servo's and some DotStar LED's a Sparkfun Pro Micro and is going to have a couple buck converters supplying 5v.1) For the sake of testing and putting it together initially I'm thinking about having some of my wires be on the longer side. It's possible I'll be able to fit the wires comfortably in the space I'll have even with them long. But supposing I need them shorter at the end. How bad is it to take a 22 gauge wire that is 4 inches long and cut a chunk out of the middle it to be only 2 inches long? I'd solder it and cover it in shrink tubing. I assume the extra solder joint adds some minimal amount of resistance or whatever. Is the difference minimal enough that it's a non issue for my small hobby project?2) On the Perfboard I'm having a buck converter make a 5v rail. I was thinking I'd take a strip of wire and remove the sheathing. Then solder it at both ends with no slack so that it lies across the desired number of holes. Then I'd put the other wires in the holes and solder the wire through the hole to the rail wire lying across it (also to the board at that point so it isn't loose). Is this a decent idea? If not how do you connect multiple holes together? Bridge the gap with Solder?

author: ataradov
author_rank: Super Contributor
timestamp: June 12, 2023, 05:41:50 am
content: 1. Extra solder joint does not matter in most cases. But why not just shorten from one of the PCB sides? This seems like a much simpler approach. Soldering 2" long wires is fiddly and annoying. Soldering two 1"wires is even more annoying, especially if you need to use heat-shrink. It would shrink from the heat of the soldering iron before you have a chance to pull it over the joint.2. Yes, sure, this is pretty standard.

author: SmallCog
author_rank: Frequent Contributor
timestamp: June 12, 2023, 06:35:37 am
content: For prototyping consider soldering pin headers to your boardYou can use DuPont style female jumper wires between them whilst figuring things outLater on you can solder wires onto the pins and put a bit of heat shrink over them.

author: brucehoult
author_rank: Super Contributor
timestamp: June 12, 2023, 06:39:47 am
content: Extra solder joints aren't going to matter unless you're passing huge current.On perfboard I often use the unwanted tails of resistors to make other connections. I don't even bother insulating them unless they cross something else. They are rigid enough to stay where you put them.

author: EPAIII
author_rank: Super Contributor
timestamp: June 12, 2023, 08:22:53 am
content: Re: #1If you want to shorten the wire, why not just unsolder one end, cut it, and re-solder. That's a lot easier then messing around with a joint and heat shrink.Copper is a good conductor of heat as well as electricity. So you would need to keep the heat shrink tubing at least an inch or so away from the area of the soldered splice. Or work real fast.Been there!Done that!The heat shrink shrunk before I could pull it over the splice area. Had to force it on.

author: Ian.M
author_rank: Super Contributor
timestamp: June 12, 2023, 08:29:11 am
content: I agree that heatshrink sleeving spliced short wires with both ends tethered is a total PITA. Avoid!If your rail wire crosses a lot of holes, it will be much easier to do a neat job if it starts very straight.Hint: You can stretch bare solid copper wire to get it straight and make it more rigid. The easiest method is to clamp one end in a bench mounted vice and grip the other end with flat jaw pliers then pull till you feel it stretch (or it breaks).Consider using Veroboard (stripboard) or Tripad board rather than matrix board to reduce the number of pad solder bridges you have to add. The down side is a stripboard or tripad layout is usually less compact than a matrix board one, OTOH its much easier to rework/modify.Incidentally there is software available to help with protoboard layouts. I detest online/subscription stuff so my preferred tools for that are VeeCAD and its preferred schematic editor TinyCAD (though you can also use KiCAD or a wide range of commercial schematic editors). See:https://www.eevblog.com/forum/beginners/comparator-circuit-seems-to-be-oscillating-(well-pulsing-really)-solutions/msg4320124/#msg4320124

author: tggzzz
author_rank: Super Contributor
timestamp: June 12, 2023, 09:33:26 am
content: Quote from: Ian.M on June 12, 2023, 08:29:11 amConsider using manhattan, to reduce everything that matters: variableand varyingparasitic inductance, capacitance, resistance.The usual excuse for not using manhattan is that it requires soldering, and that is too offputting/difficult for beginners. Clearly that isnota "problem" for the OP.For examples of commercial products (near the bottom), seehttps://entertaininghacks.wordpress.com/2020/07/22/prototyping-circuits-easy-cheap-fast-reliable-techniques/Choose whichever combination of techniques is most convenient.

author: Youkai
author_rank: Regular Contributor
timestamp: June 12, 2023, 10:34:35 pm
content: Good stuff. Thanks for the help guys.