New Electric Motor Tech Spins With No Magnets

When you think of electric motors, you usually think of magnets. But magnets are heavy, and good magnets can pose problems when you need lots of them. A technology called SESM (separately excited synchronous motors) requires no magnets, but now ZF — a German company — claims to have a different scheme using inductive excitation. Motors that employ SESM tend to be larger and require a direct current to turn the rotor. This DC is often supplied by slip rings or an AC induction with a rectifier. The innovation here is that the inductive excitation is built completely into the shaft, which the company claims makes the motor both compact and powerful.

This kind of motor is usually destined for electric vehicles. The company claims the motor reduces losses by about 15% over conventional techniques. To maximize efficiency, conventional SESM uses slip rings or brushes to transmit power to the shaft. However, ZF claims their inductive improvements are even more efficient and can reduce axial size by around 90 mm.

Another advantage of the technology is that there is no need to provide a dry space for slip rings. That means fewer seals and the ability to cool the rotor with oil as you would with a motor containing permanent magnets. The company plans to offer a 400 V version of the motor and an 800 V that uses silicon carbide electronics.

If you build your own motors, have you tried anything like this? Usually, we don’t see motors this big, of course. We have, however, seen builds of reluctance motors that don’t use magnets.

Grannophone Helps You Stay In Touch

Whether it’s distance, pandemics, or both that separate you from your elderly loved ones, what’s the best idea for communicating with them so they don’t suffer from loneliness on top of issues like dementia? We’d say it’s probably something like [Stefan Baur]’s Grannophone.

Back in late 2020, a Twitter user named [Nitek] asked the Internet what could be done in the way of a grandma-friendly video-conferencing solution, provided Grandma has a TV and a broadband internet connection. At first, [Stefan] was like, just get her an old iPad and FaceTime with her. But the question got him thinking. And prototyping.

Grannophones are essentially Linux machines with a video-capable SIP client connected over a VPN for privacy reasons. In simple mode, picking up the handset of one Grannophone will call the other, but more complicated configurations are possible. We particularly like that replacing the handset automatically obscures the camera. That’s a nice touch.

At this point, the Grannophone is a work in progress. The idea is that they be extremely easy to build at the kitchen table, like on the order of disposable Swedish furniture. If you can contribute to the project, please do. Be sure to check out the demonstration video after the break.

On the other hand, if Granny is 1337, you could always video-conference in terminal.

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Hackaday Links: September 10, 2023

Most of us probably have a vision of how “The Robots” will eventually rise up and deal humanity out of the game. We’ve all seen that movie, of course, and know exactly what will happen when SkyNet becomes self-aware. But for those of you thinking we’ll get off relatively easy with a quick nuclear armageddon, we’re sorry to bear the news that AI seems to have other plans for us, at least if this report of dodgy AI-generated mushroom foraging manuals is any indication. It seems that Amazon is filled with publications these days that do a pretty good job of looking like they’re written by human subject matter experts, but are actually written by ChatGPT or similar tools. That may not be such a big deal when the subject matter concerns stamp collecting or needlepoint, but when it concerns differentiating edible fungi from toxic ones, that’s a different matter. The classic example is the Death Cap mushroom (Amanita phalloides) which varies quite a bit in identifying characteristics like color and size, enough so that it’s often tough for expert mycologists to tell it apart from its edible cousins. Trouble is, when half a Death Cap contains enough toxin to kill an adult human, the margin for error is much narrower than what AI is likely to include in a foraging manual. So maybe that’s AI’s grand plan for humanity — just give us all really bad advice and let Darwin take care of the rest.

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An 8-bit ISA card with VGA, HDMI and composite video connectors

Upgraded Graphics Gremlin Adds HDMI Video To Vintage PCs

Although new VGA-equipped monitors can still be bought, the old standard is definitely on its way out by now, being replaced by high-speed digital interfaces like HDMI and DisplayPort. It therefore makes sense to prepare for a VGA-less future, as [Yeo Kheng Meng] is doing. He designed an 8-bit ISA display card with an HDMI output that enables even the very first generation of PCs to talk to a modern monitor.

The design is based on the Graphics Gremlin by [Tube Time], which is an 8-bit ISA display card that aims to be software compatible with the obsolete MDA and CGA display formats while outputting a clean VGA signal. [Yeo Kheng Meng] modified the board by adding a TFP410 HDMI bus driver and replacing the rarely-used 9-pin RGBI connector with an HDMI version. He also updated the HDL code for the Lattice FPGA, which forms the heart of the graphics card, to account for the new digital output. While he was at it, he also added a few features he was missing in the original product, such as the option to select the color displayed in MDA mode and the ability to output both HDMI and composite video at the same time.

The video below shows the updated card in action in an IBM 5155 Portable PC. The HDMI port connects to a modern monitor, while the composite video output is routed to the 5155’s internal CRT as well as a small color monitor on top. The IBM thereby joins a small list of retro computers that have received an HDMI upgrade — the Amiga 500 and PlayStation 2 being other examples. HDMI might be a lot more complex to work with than VGA, but luckily there are open-source implementations that do much of the work for you.

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Open Deck Is Your Window To Shortcuts

Once in a while, we see projects that could easily pass for commercial products. This is one of those projects: a (surprisingly) low-cost DIY macro pad from [Josh R] that was designed to be a cheaper alternative to the various stream decks out there. Between the carbon fiber top plate and the crystal-clear acrylic keycaps, this is quite the elegant solution.

This lovely little macro pad is built around the ESP8266, specifically the WEMOS D1 Mini V4. However, the most vital part to get right is the screen, which must be a 128 x 160 TFT display in order to line up with the 3D printed frame that divides it into fourths. Custom parts like the acrylic keycaps and the carbon fiber top plate are available on Tindie if you don’t have access to a CNC.

Operationally, Open Deck has a nice-looking GUI. Once programmed, each shortcut is capable of having three beneath it, with the fourth button reserved for Home. Be sure to check out the extremely satisfying build video after the break.

Want a stream deck, but don’t want to build it? Just dig up an old phone or tablet.

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Industrial Surge Protector Teardown

Surge protectors are a common item in the modern household, but the Meanwell unit that [Big Clive] tears apart was clearly intended for commercial use. In fact, he mentions it was made for outdoor signage. Removing the rear panel didn’t help much — the entire unit was potted in resin — but that didn’t stop [Clive]. Removing the resin revealed only a few components surrounded by a sand-like substance.

There’s no circuit board inside. Components are just wired together before potting. The significant player inside is a metal oxide varistor with a thermal fuse. [Clive] draws out a schematic, which is deceptively simple. The two LEDs are an older style of green LED, and he explains why the choice of LED is important in this application. In typical operation, the LEDs light. If a fuse blows, at least one of the LEDs will extinguish.

Not all useful circuits have to be complicated. This is an excellent example of how a simple but well-constructed design can succeed commercially.

Not all surge protectors are built this well. If you need a refresher on how varistors work, we can help with that.

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Zinc-Air, The Next Contender In Vehicle Batteries?

If you’ve got an interest in technology, it’s inevitable that your feed will feature a constant supply of stories with titles in the vein of “New battery breakthrough offers unlimited life and capacity!”. If we had a pound, dollar, or Euro for each one, we’d be millionaires by now. But while the real science behind the breathless headlines will undoubtedly have provided incremental battery improvements, we’re still waiting for the unlimited battery.

It’s not to say that they don’t conceal some interesting stories though, and there’s an announcement from Australia proving this point admirably. Scientists at ECU in Perth have created a new cathode compound for rechargeable zinc-air batteries, which it is hoped will make them much safer and cheaper competitors for lithium-ion cells.

Most of us think of zinc-air batteries as the tiny cells you’d put in a camera or a hearing aid, but these conceal a chemistry with significant potential that is held back by the difficulty of creating a reliable cathode. In these batteries the cathode is a porous support in which a reaction between zinc powder wet paste and oxygen in the air occurs, turning zinc into zinc oxide and releasing electrons which can be harvested as electricity. They have a very high power density, but previous cathode materials have quickly degraded performance when presented with significant load.

The new cathode support is a nano-composite material containing cobalt, nickel, and iron, and is claimed to offer much better performance without the degradation. Whether or not it can be mass-produced remains to be seen, but as a possible alternative to lithium-ion in portable and transport applications it’s of great interest.