Give Your Twist Connections Some Strength

September 9, 2025 by Jenny List 44 Comments

We’ve all done it at some time — made an electrical connection by twisting together the bare ends of some wires. It’s quick, and easy, but because of how little force required to part it, not terribly reliable. This is why electrical connectors from terminal blocks to crimp connectors and everything else in between exist, to make a more robust join.

But what if there was a way to make your twist connections stronger? [Ibanis Sorenzo] may have the answer, in the form of an ingenious 3D printed clamp system to hold everything in place. It’s claimed to result in a join stronger than the wire itself.

The operation is simple enough, a spring clamp encloses the join, and a threaded outer piece screws over it to clamp it all together. There’s a pair of 3D printable tools to aid assembly, and a range of different sizes to fit different wires. It looks well-thought-out and practical, so perhaps it could be a useful tool in your armoury. We can see in particular that for those moments when you don’t have the right connectors to hand, a quick 3D print could save the say.

A few years ago we evaluated a set of different ways to make crimp connections. It would be interesting to subject this connection to a similar test. Meanwhile you can see a comprehensive description in the video below the break.

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Turning A $2 IKEA Lantern Into A Stylish Enclosure

September 9, 2025 by Fenix Guthrie 35 Comments

It’s fair to say that the average Hackaday reader enjoys putting together custom electronics. Some of those builds will be spaghetti on a breadboard, but at some point you’ll probably have a project that needs a permanent case. If you’re looking for a small case for your latest creation, check out [Julius Curt’s] modification of an IKEA Vårsyren lantern into a customizable enclosure!

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Faux Potentiometers Use Magnets, No Contacts

September 6, 2025 by Al Williams 22 Comments

Ever tear open a potentiometer? If you haven’t, you can still probably guess what’s inside. A streak of resistive material with some kind of contact that moves across it as you rotate the shaft, right? Usually, you’d be right, but [T. K. Hareedran] writes about a different kind of pot: ones that use magnetic sensing.

Why mess with something simple? Simplicity has its price. Traditional units may not be very accurate, can be prone to temperature and contamination effects, and the contact will eventually wear out the resistive strip inside. However, we were a little curious about how a magnetic potentiometer could offer a resistive output. The answer? It doesn’t.

Really, these would be better described as rotary encoders with a voltage output. They aren’t really potentiometers. The SK22B mentioned in the article, for example, requires a 5 V input and outputs somewhere between 10% and 90% of that voltage on the ersatz wiper pin.

That makes the devices much easier to puzzle out. The linearity of a device like that is better than a real pot, and, of course, the life expectancy is greatly increased. On the other hand, we’d rather get one with quadrature or I2C output and read it digitally, but if you need a voltage, these devices are certainly an option.

[T. K.] goes on to show how he fabricated his own non-contact sensor using photosensors and a gray-coded wheel with a single track. You do need to be careful about where you position the sensors, though.

Could you make a real non-contact resistive pot? Seems like you could get close with an FET output stage, but it wouldn’t be as generally applicable as a good old-fashioned smear of carbon. If you have a better idea, drop it in the comments or build it and give us a tip.

Want a 20A-capable device? Build it. Want to see how we like to read encoders?

Flyback Converter Revealed

August 13, 2025 by Al Williams 10 Comments

As [Sam Ben-Yaakov] points out in a recent video, you don’t often see flyback converters these days. That’s because there are smarter ways to get the same effect, which is to convert between two voltages. If you work on old gear, you’ll see plenty of these, and going through the analysis is educational, even if you’ll never actually work with the circuit. That’s what the video below shows: [Sam’s] analysis of why this circuit works.

The circuit in question uses a bridge rectifier to get a high-voltage DC voltage directly from the wall. Of course, you could just use a transformer to convert the AC to a lower AC voltage first, but then you probably need a regulator afterwards to get a stable voltage.

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Continuous-Path 3D Printed Case Is Clearly Superior

August 12, 2025 by Lewin Day 9 Comments

[porchlogic] had a problem. The desire was to print a crystal-like case for an ESP32 project, reminiscent of so many glorious game consoles and other transparent hardware of the 1990s. However, with 3D printing the only realistic option on offer, it seemed difficult to achieve a nice visual result. The solution? Custom G-code to produce as nice a print as possible, by having the hot end trace a single continuous path.

The first job was to pick a filament. Transparent PLA didn’t look great, and was easily dented—something [porchlogic] didn’t like given the device was intended to be pocketable. PETG promised better results, but stringing was common and tended to reduce the visual appeal. The solution to avoid stringing would be to stop the hot end lifting away from the print and moving to different areas of the part. Thus, [porchlogic] had to find a way to make the hot end move in a single continuous path—something that isn’t exactly a regular feature of common 3D printing slicer utilities.

The enclosure itself was designed from the ground up to enable this method of printing. Rhino and Grasshopper were used to create the enclosure and generate the custom G-code for an all-continuous print. Or, almost—there is a single hop across the USB port opening, which creates a small blob of plastic that is easy to remove once the print is done, along with strings coming off the start and end points of the print.

Designing an enclosure in this way isn’t easy, per se, but it did net [porchLogic] the results desired. We’ve seen some other neat hacks in this vein before, too, like using innovative non-planar infill techniques to improve the strength of prints.

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A pink sine wave is seen against the black background of an oscilloscope display.

Coping With Disappearing Capacitance In A Buck Converter

August 10, 2025 by Aaron Beckendorf 25 Comments

Designing a circuit is a lot easier on paper, where components have well-defined values, or lacking that, at least well-defined tolerances. Unfortunately, even keeping percentage tolerances in mind isn’t always enough to make sure that circuits work correctly in the real world, as [Tahmid] demonstrates by diagnosing a buck converter with an oddly strong voltage ripple in the output.

Some voltage ripple is an inherent feature of the buck converter design, but it’s inversely proportional to output capacitance, so most designs include a few smoothing capacitors on the output side. However, at 10 V and a 50% duty cycle, [Tahmit]’s converter had a ripple of 0.75 V, significantly above the predicted variation of 0.45 V. The discrepancy was even greater at 20 V.

The culprit was the effect of higher voltages on the ceramic smoothing capacitors: as the voltage increases, the dielectric barrier in the capacitors becomes less permittive, reducing their capacitance. Fortunately, unlike in the case of electrolytic capacitors, the degradation of ceramic capacitors performance with increasing voltage is usually described in specification sheets, and doesn’t have to be manually measured. After finding the reduced capacitance of his capacitors at 10 V, [Tahmid] calculated a new voltage ripple that was only 14.5% off from the true value.

Anyone who’s had much experience with electronics will have already learned that passive components – particularly capacitors – aren’t as simple as the diagrams make them seem. On the bright side, they are constantly improving.

Is It Time To Retire The TP4056?

August 8, 2025 by Tyler August 30 Comments

The TP4056 is the default charge-controller chip for any maker or hacker working with lithium batteries. And why not? You can get perfectly-functional knockoffs on handy breakout boards from the usual online sources for pennies. Betteridge’s Law aside, [Lefty Maker] thinks that it may well be time to move on from the TP4056 and spends his latest video telling us why, along with promoting an alternative.

His part of choice is another TI chip, the BQ25185. [Lefty] put together his own charge controller board to show off the capabilities of this chip — including variable under- and over-charge protection voltages. Much of his beef with the TP4056 has less to do with that chip than with the cheap charge modules it comes on: when he crows about the lack of mounting holes and proper USB-PD on the knock-off modules, it occurs to us he could have had those features on his board even if he’d used a TP4056.

On the other hand, the flexibility offered by the BQ25185 is great to future-proof projects in case the dominant battery chemistry changes, or you just change your mind about what sort of battery you want to use. Sure, you’d need to swap a few resistors to set new trigger voltages and charging current, but that beats starting from scratch.

[Lefty Maker] also points out some of the advantages to making your own boards rather than relying on cheap modules. Namely, you can make them however you want. From a longer USB port to indicator LEDs and a built-in battery compartment, this charging board is exactly what [Lefty Maker] wants. Given how cheap custom PCBs are these days, it’s not hard to justify rolling your own.

The same cannot be said of genuine TI silicon, however. While the BQ25185 has a few good features that [Lefty Maker] points out in the video, we’re not sure the added price is worth it. Sure, it’s only a couple bucks, but that’s more than a 300% increase!

We’ve seen other projects pushing alternative charge controllers, but for now the TP4056 reigns as the easy option.

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