Bending Light To Fit Technology

September 22, 2023 by 3 Comments

Solar power is an excellent way of generating electricity, whether that’s for an off-grid home or for the power grid. With no moving parts maintenance is relatively low, and the downsides of burning fuel are eliminated as well. But as much as it’s revolutionized power generation over the last few decades, there’s still some performance gains to be made when it comes to the solar cells themselves. A team at Stanford recently made strides in improving cell efficiency by bending the properties of sunlight itself.

In order to generate electricity directly from sunlight, a photon with a specific amount of energy needs to strike the semiconductor material. Any photons with higher energy will waste some of that energy as heat, and any with lower energy won’t generate electricity. Previous methods to solve this problem involve using something similar to a prism to separate the light out into colors (or energies) that correlate to specific types of cells calibrated specifically for those colors. This method does the opposite: it changes the light itself to an color that fits the semiconductor material. In short, a specialized material converts the energy from two lower-energy photons into a single higher-energy photon, which then strikes the solar panel to create energy.

By adding these color-changing materials as a layer to a photovoltaic solar panel, the panel can generate more energy with a given amount of light than a traditional panel. The major hurdle, as with any research, is whether or not this will be viable when produced at scale, and this shows promise in that regard as well. There are other applications for these materials beyond photovoltaics as well, and the researchers provide an excellent demonstration in 3D printing. By adding these color-change materials to resin, red lasers can be used instead of blue or ultraviolet lasers to cure resin in extremely specific locations, leading to stronger and more accurate prints.

You Can Use An Old Tape Deck As A Distortion Pedal

September 21, 2023 by 16 Comments

Distorted guitars were a big part of the rock revolution last century; we try to forget about the roll. As a youth, [David Hilowitz] couldn’t afford a loud aggressive amp, a distortion pedal, or even a proper electric guitar. This experience ended up teaching him that you can use random old audio hardware as a distortion effect.

[David’s] guitar journey started when he found a classical guitar on a dumpster. He learned to play, but longed for the sound of a proper electric guitar. Family friends gifted him a solitary pickup, intending he build a guitar, but he simply duct-taped it to his steel-strung classical instead. The only thing he lacked was an amp. He made do with an old stereo system and a record pre-amp. With his his faux-electric guitar plugged into the microphone input, he was blessed with a rudimentary but pleasant distortion that filled his heart with joy.

[David] goes on to explain the concepts behind distorted guitar sounds, and how his home hi-fi was able to serve as a passable starter amp when he was young and couldn’t afford better. He then goes on the hunt for more old gear at a local Goodwill store, finding a neat old tape deck that similarly produced some nice warm distorted tones. In [David’s] experience, old hi-fi gear with microphone inputs can generally do a decent job in this role, with electric guitar pickups typically overloading the preamps which expect a lower-level signal. It’s different to what you’d get from a Big Muff or Boss DS-1, but it’s a neat sound nonetheless.

We’ve looked at distortion effects before, including rolling your own and putting it into production. Video after the break.

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Ballistic BMW Blocks Both Bullets And Booms

September 21, 2023 by 47 Comments

Maybe you like to live dangerously. Like, James Bond dangerously. Well, we won’t judge, but we will pass this along — BMW has created the ultimate driving machine for shootouts and war zones.

Rather than having aftermarket anti-ballistic bits and bobs attached at a later date, this BMW 7 Series is born anti-ballistic and explosion-resistant, built from the ground up with armor steel. They call this the BMW Protection Core.

By building it this way, there are many advantages like more cabin space, lower curb weight, and better handling, which is exactly what you’d want if you were under these types of attacks.

For starters, the car has chunkier A-pillars and door/window frames meant to withstand the damage pictured here. The car has special armoring in the roof and undercarriage to withstand explosions. And the fuel tank is self-sealing, so you have a chance at getting out of there if the thing takes a bullet.

Can’t afford this ballistic-grade beast? You could always roll your own armored vehicle.

Latency Meter For Accurate Gaming

September 19, 2023 by 15 Comments

The gaming world experienced a bit of a resurgence in 2020 that is still seen in the present day. Even putting aside the effects from the pandemic, the affordability and accessibility has arguably never been better. Building a gaming PC can have its downsides, though, and a challenging issue to troubleshoot is input lag or input latency. This is something that’s best measured with standalone hardware, and if this is an issue on your setup you may want to take a look at this latency meter.

Unlike other measurement devices that use the time between a mouse button input and the monitor’s display of a bullet or shooting event, this one looks at mouse movement and the change in the scene instead. This makes it much more versatile than other methods since it’s independent of specific actions, and can be used in any game without any specific events needed to perform the measurement. A camera phototransistor is placed on the monitor’s top edge and the Arduino-based device sends mouse commands to the computer while measuring the time between those commands and the shift in the image on the monitor.

The project is open source, so with the right hardware it’s possible to build one to troubleshoot latency issues or just to learn more about a particular hardware configuration’s behavior. Arduinos and other microcontrollers have been doing all kinds of things by pretending to be human interface devices like this for a while now. One of our favorites of late was this effects pedal that replicates musical effects on mice and keyboards.

Printed Upgrades Improve Cheap Digital Microscope

September 19, 2023 by 7 Comments

Digital microscopes used to be something that only labs or universities might have, but as image sensor technology has progressed, the prices have fallen to the point that any classroom or hobbyist can easily obtain a usable device. The only problem is that a lot of features and quality have been lost to make some of these digital microscopes more affordable. In an effort to add some of these creature comforts back into more inexpensive devices, [Marb’s lab] has created a special carriage for one of these microscopes.

The first addition to the microscope is improved lighting. To accomplish this, three LEDs were built into custom housings and wired to a purpose-built LED driver board coupled with a voltage regulator. Two of the LED housings were attached to the end of adjustable arms, allowing them to be pointed in whichever direction is needed. The third is situated directly below the microscope underneath the stage. These are all mounted to a large, sturdy PVC base which also holds an adjustable carriage for the microscope itself. This allows much more fine-tuning of the distance between the sample and the microscope than it otherwise would have had.

For just a few dollars and a little bit of effort, the usability of a device like this is greatly improved. If you want to take the opposite approach and really go all-out for your microscope, though, take a look at these microscopes used for PCB circuit construction and troubleshooting or even this electron microscope for viewing things at a much higher magnification than any optical system would allow.

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Multi-Year Doorbell Project

September 17, 2023 by 5 Comments

Camera modules for the Raspberry Pi became available shortly after its release in the early ’10s. Since then there has been about a decade of projects eschewing traditional USB webcams in favor of this more affordable, versatile option. Despite the amount of time available there are still some hurdles to overcome, and [Esser50k] has some supporting software to drive a smart doorbell which helps to solve some of them.

One of the major obstacles to using the Pi camera module is that it can only be used by one process at a time. The PiChameleon software that [Esser50k] built is a clever workaround for this, which runs the camera as a service and allows for more flexibility in using the camera. He uses it in the latest iteration of a smart doorbell and intercom system, which uses a Pi Zero in the outdoor unit armed with motion detection to alert him to visitors, and another Raspberry Pi inside with a touch screen that serves as an interface for the whole system.

The entire build process over the past few years was rife with learning opportunities, including technical design problems as well as experiencing plenty of user errors that caused failures as well. Some extra features have been added to this that enhance the experience as well, such as automatically talking to strangers passing by. There are other unique ways of using machine learning on doorbells too, like this one that listens for a traditional doorbell sound and then alerts its user.

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A Die-Cast Car Subframe, Pushing The Limit Too Far?

September 16, 2023 by 81 Comments

A piece of manufacturing news from Tesla Motors caught our eye, that Elon Musk’s car company plans to die-cast major underbody structures — in effect the chassis — for its cars. All the ingredients beloved of the popular tech press are there, a crazy new manufacturing technology coupled with the Musk pixie dust. It’s undeniably a very cool process involving a set of huge presses and advanced 3D-printing for the sand components of the mould, but is it really the breakthrough it’s depicted as? Or has the California company simply scored another PR hit?

We produced an overview of die casting earlier in the year, and the custom sand moulding in the Tesla process sounds to us a sort of half-way house between traditional die casting and more conventional foundry moulding. I don’t doubt that the resulting large parts will be strong enough for the job as the Tesla engineers and metallurgists will have done their work to a high standard, but I’m curious as to how this process will give them the edge over a more traditional car manufacturer building a monocoque from pressed steel. The Reuters article gushes about a faster development time which is no doubt true, but since the days of Henry Ford the automakers have continuously perfected the process of making mass-market cars as cheaply as possible. Will these cast assemblies be able to compete with pressed steel when applied to much lower-margin small cars? I have my doubts.

Aside from the excessive road noise of the Tesla we had a ride in over the summer, if I had a wish list for their engineers it would include giving their cars some longevity.

Header: Steve Jurvetson, CC BY 2.0.