Ask Hackaday: Split Rail Op Amp Power Supply

April 20, 2023 by Al Williams 83 Comments

Water cooler talk at the office usually centers around movies, sports, or life events. Not at Hackaday. We have the oddest conversations and, this week, we are asking for your help. It is no secret that we have a special badge each year for Supercon. Have you ever wondered where those badges come from? Sometimes we do too. We can’t tell you what the badge is going to be for Supercon 2023, but here’s a chance for you to contribute to its design.

What I can tell you is that at least part of the badge is analog. Part, too, is digital. So we were discussing a seemingly simple question: How do we best generate a bipolar power source for the op amps on a badge? Like all design requests, this one is unreasonable. We want:

Ideally, we’d like a circuit to give us +/- 9 V to +/- 12 V at moderately low current, say in the tens of milliamps. Actual values TBD.
Low noise: analog circuitry, remember?
Lightweight: it is going on a badge
Battery operated: the badge thing again
Cheap: we only have a couple bucks in the budget for power
Available in quantity: we’ll need ~600 of these

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Ask Hackaday: Stripping Wires With Lasers

September 8, 2022 by Al Williams 22 Comments

Most of us strip the insulation off wires using some form of metal blade or blades. You can get many tools that do that, but you can also get by with skillfully using a pair of cutters, a razor blade or — in a pinch — a steak knife. However, modern assembly lines have another option: laser stripping. Now that many people have reasonable laser cutters, we wonder if anyone is using laser strippers either from the surplus market or of the do-it-yourself variety?

We are always surprised that thermal strippers are so uncommon since they are decidedly low-tech. Two hot blades and a spring make up the heart of them. Sure, they are usually expensive new, but you can usually pick them up used for a song. The technology for lasers doesn’t seem very difficult, although using the blue lasers most people use in cutters may not be optimal for the purpose. This commercial product, for example, uses infrared, but if you have a CO₂ laser, that might be a possibility.

The technique has found use in large-scale production for a while. Of course, if you don’t care about potential mechanical damage, you can get automated stripping equipment with a big motor for a few hundred bucks.

We did find an old video about using a CO₂ laser to strip ribbon cable, but nothing lately. Of course, zapping insulation creates fumes, but so does lasering everything, so we don’t think that’s what’s stopping people from this approach.

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Ask Hackaday: Are Extruders The Only Feasible Tools For Toolchanging?

December 13, 2021 by Donald Papp 34 Comments

Toolchanging in 3D printers is no longer something from the bleeding edge; it’s going mainstream. E3D has a high-quality kit for a toolchanger and motion system, our own Joshua Vasquez has shared details about the open-source toolchanging Jubilee design, and just recently Prusa3D formally announced the Prusa XL, which promises toolchanging with up to five different extruders.

It’s safe to say toolchanging on 3D printers has stepped to the front, but what comes next? What kind of tools other than extruders make sense on a 3D printer?

First, let’s explain what makes separate extruders such fantastic tools. Being able to change extruders on-demand during a print enables things like true multi-material printing. Printing in more than one color or material will no longer be done by pushing different filaments through a single nozzle, which limits a print to materials that extrude under similar conditions and temperatures. Toolchanging means truly being able to print in multiple materials, even if they have different requirements, because each material has its own extruder. That’s a clear benefit, but what about tools other than extruders?

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Ask Hackaday: Why Don’t Automakers Make Their Own EV Batteries?

December 1, 2021 by Lewin Day 88 Comments

Sales of electric vehicles continue to climb, topping three million cars worldwide last year. All these electric cars need batteries, of course, which means demand for rechargeable cells is through the roof.

All those cells have to come from somewhere, of course, and many are surprised to learn that automakers don’t manufacture EV batteries themselves. Instead, they’re typically sourced from outside suppliers. Today, you get to Ask Hackaday: why aren’t EV batteries manufactured by the automakers themselves? Continue reading “Ask Hackaday: Why Don’t Automakers Make Their Own EV Batteries?” →

In Search Of The First Comment

October 23, 2021 by Elliot Williams 105 Comments

Are you writing your code for humans or computers? I wasn’t there, but my guess is that at the dawn of computing, people thought that they were writing for the machines. After all, they were writing in machine language, and whatever bits they flipped into the electronic brain stayed in the electronic brain, unless punched out on paper tape. And the commands made the machine do things, not other people. Code was written strictly for computers.

Modern programming practice, on the other hand, is aimed firmly at people. Variable and function names are chosen to be long and to describe what they contain or do. “Readability” of code is a prized attribute. Indeed, sometimes the fact that it does the right thing at all almost seems to be an afterthought. (I kid!)

Somewhere along this path, there was an important evolutionary step, like the first fish using its flippers to walk on land. Comments were integrated into programming languages, formalizing the notes that coders of old surely wrote by hand in the margins of the paper first-drafts before keying it in. So I went looking for the missing link: the first computer language, and ideally the first program, with comments. I came up empty handed.

Or rather full handed. Every computer language that I could find had comments from the beginning. FORTRAN had comments, marked by a “C” as the first character in a line. APL had comments, marked by the bizarro rune ⍝. Even the custom language written for the Apollo 11 guidance computers had comments — the now-commonplace “#”. I couldn’t find an early programming language without comments.

My guess is that the first language with a comment must have been an assembly language, because I don’t know of any machines with a native comment instruction. (How cool and frivolous would that be?)

Assemblers simply translate mnemonic names to their machine instruction counterparts, but this gives them the important freedom to ignore anything starting with, traditionally, a semicolon. Even though you’re just transferring the contents of register X to the memory location pointed to in register Y, you can write that you’re “storing the height above ground (meters)” in the comments.

The crucial evolutionary step, though, is saving the comments along with the code. Simply ignoring everything that comes after the semicolon and throwing it away doesn’t count. Does anyone know? What was the first code to include comments as part of the code itself, and not simply as marginalia?

Ask Hackaday: What’s In Your Fastener Bin?

January 11, 2021 by Dan Maloney 143 Comments

A Saturday afternoon. The work week was done, the household chores were wrapped up, and with almost a week left until Christmas, there was just enough wiggle room to deny that there was still a ton of work left to prepare for that event. It seemed like the perfect time to escape into the shop and knock out a quick project, one that has been on the back burner since at least March. I’m nothing if not skilled in the ways of procrastination.

This was to be a simple project — adding an aluminum plate to a plastic enclosure that would serve as an antenna entry point into my shack. Easy as pie — cut out an rectangle of aluminum, cut and drill a few holes, call it a day. Almost all of my projects start out that way, and almost every time I forget that pretty much every one of those builds goes off the rails at exactly the same point: when I realize that I don’t have the fasteners needed. That’s what happened with this build, which had been going swimmingly up to that point — no major screw-ups, no blood drawn. And so it was off to the hardware store I trundled, looking for the right fasteners to finish the job.

Finding hardware has long been where my productivity goes to die. Even though I live a stone’s throw from at least half a dozen stores, each with a vast selection of hardware and most open weekends and nights, the loss of momentum that results from changing from build-mode to procure-mode has historically been deadly to my projects. I’m sure I’m not the only one who has run into this issue, so the question is: what can a hacker do to prevent having to run out for just the right fasteners?

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Ask Hackaday: Why Did GitHub Ship All Our Software Off To The Arctic?

July 29, 2020 by Ben James 95 Comments

If you’ve logged onto GitHub recently and you’re an active user, you might have noticed a new badge on your profile: “Arctic Code Vault Contributor”. Sounds pretty awesome right? But whose code got archived in this vault, how is it being stored, and what’s the point?

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