Wireless Charging On A Massive Scale

March 21, 2023 by Bryan Cockfield 26 Comments

Despite the increasing popularity of various electric vehicles, the limits of battery technology continue to be a bottleneck in their day-to-day use. They don’t behave well in extreme temperatures, they can wear out quickly, and, perhaps most obviously, charging them is often burdensome. Larger batteries take longer to charge, and this can take a lot of time and space, but this research team from Chalmers University are looking to make this process just a little bit easier.

The group has been developing an inductive wireless charging method for large vehicles including cars, trucks, busses, and ferries that can deliver 500 kW across a 15 cm (6 inch) air gap. The system relies on a silicon carbide semiconductor and extremely thin copper wire in order to make all this happen, and eliminates the need for any human involvement in the charging process. This might not be too much of a hassle for plugging in an electric car, but for larger vehicles like busses and ferries traditional charging methods often require a robot arm or human to attach the charging cables.

While this technology won’t decrease the amount of time it takes batteries to charge, it will improve the usability of devices like these. Even for cars, this could mean simply pulling into a parking space and getting the car’s battery topped off automatically. For all the talk about charging times of batteries, there is another problem looming which is that plenty of charging methods are proprietary as well. This charger attempts to develop an open-source standard instead.

Thanks to [Ben] for the tip!

Building The World’s Largest Nintendo 3DS

March 21, 2023 by Bryan Cockfield 2 Comments

While the Nintendo 3DS was capable of fairly impressive graphics (at least for a portable system) back in its heyday, there’s little challenge in emulating the now discontinued handheld on a modern computer or even smartphone. One thing that’s still difficult to replicate though is the stereoscopic 3D display the system was named for. But this didn’t stop [BigRig Creates] from creating this giant 3DS with almost all of the features of an original console present.

The main hurdle here is that the stereoscopic effect that Nintendo used to allow the 3DS to display 3D graphics without special glasses doesn’t work well at long distances, and doesn’t work at all if there is more than one player. To get around those limitations, this build uses a 3D TV with active glasses. This TV is mounted to a bar stool with the help of some counterweights, and a second touch-sensitive screen courtesy of McDonalds makes up the other display.

The computer driving this massive handheld console runs Citra, and also handles the scaled-up controls as well. To recreate the system’s analog touch pad, a custom joystick tipped with conductive filament is used to interact with a smartphone hidden inside the case. Opposing rubber bands are used to pull the stick back into the center when it’s not being pushed.

Plenty of 3DS games are faithfully replicated with this arcade-sized replica, and as Citra supports various 3D displays, upscaling of the graphics, and the touchscreen interface, almost everything from the original console is produced here. There are a few games that don’t work exactly right, but all in all it’s a remarkable build and, as far as we can tell, the largest 3DS in the world. Don’t forget that even though this console is out of production now, there’s still a healthy homebrew scene to take part in.

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Remote Water Quality Monitoring

March 20, 2023 by Bryan Cockfield 8 Comments

While it can be straightforward to distill water to high purity, this is rarely the best method for producing water for useful purposes. Even drinking water typically needs certain minerals in it, plants may need a certain pH, and wastewater systems have a whole host of other qualities that need to be measured. Measuring water quality is a surprisingly complex endeavor as a result and often involves a wide array of sensors, much like this water quality meter from [RowlesGroupResearch].

The water quality meters that they are putting to use are typically set up in remote locations, without power, and are targeting natural bodies of water and also wastewater treatment plants. Temperature and pH are simple enough to measure and grasp, but this device also includes sensors for total dissolved solids (TDS) and turbidity which are both methods for measuring various amounts and types of particles suspended in the water. The build is based around an Arduino so that it is easy for others to replicate, and is housed in a waterproof box with a large battery, and includes data logging to an SD card in order to make it easy to deploy in remote, outdoor settings and to gather the data at a later time.

The build log for this device also goes into detail about all of the steps needed to set this up from scratch, as well as a comprehensive bill of materials. This could be useful in plenty of professional settings such as community wastewater treatment facilities but also in situations where it’s believed that industrial activity may be impacting a natural body of water. For a water quality meter more focused on drinking water, though, we’d recommend this build that is trained on its own neural network.

Finessing A Soldering Iron To Remove Large Connectors

March 17, 2023 by Bryan Cockfield 32 Comments

One of the first tools that is added to a toolbox when working on electronics, perhaps besides a multimeter, is a soldering iron. From there, soldering tools can be added as needed such as a hot air gun, reflow oven, soldering gun, or desoldering pump. But often a soldering iron is all that’s needed even for some specialized tasks as [Mr SolderFix] demonstrates.

This specific technique involves removing a large connector from a PCB. Typically either a heat gun would be used, which might damage the PCB, or a tedious process involving a desoldering tool or braided wick might be tried. But with just a soldering iron, a few pieces of wire can be soldered around each of the pins to create a massive solder blob which connects all the pins of the connector to this wire. With everything connected to solder and wire, the soldering iron is simply pressed into this amalgamation and the connector will fall right out of the board, and the wire can simply be dropped away from the PCB along with most of the solder.

There is some cleanup work to do afterwards, especially removing excess solder in the holes in the PCB, but it’s nothing a little wick and effort can’t take care of. Compared to other methods which might require specialized tools or a lot more time, this is quite the technique to add to one’s soldering repertoire. For some more advanced desoldering techniques, take a look at this method for saving PCBs from some thermal stresses.

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Dobsonian Telescope Adds Plate Solver

March 16, 2023 by Bryan Cockfield 27 Comments

The amateur astronomy world got a tremendous boost during the 1960s when John Dobson invented what is now called the Dobsonian telescope. Made from commonly-sourced materials and mechanically much simpler than what was otherwise available at the time, the telescope dramatically reduced the barrier to entry for larger telescopes and also made them much more portable and inexpensive.

For all their perks, though, a major downside is increased complexity when building automatic tracking systems. [brickbots] went a different way when solving this problem, though: a plate solver.

Plate solving is a method by which the telescope’s field of view is compared to known star charts to determine what it’s currently looking at. Using a Raspberry Pi at the center of the build, the camera module pointed at the sky lets the small computer know exactly what it’s looking at, and the GPS system adds precise location data as well for a quick plate solving solution. A red-tinted screen finishes out the build and lets [brickbots] know exactly what the telescope is pointed towards at all times.

While this doesn’t fully automate or control the telescope like a tracking system would do, it’s much simpler to build a plate solver in this situation. That doesn’t mean it’s impossible to star hop with a telescope like this, though; alt-azimuth mounted telescopes like Dobsonians just need some extra equipment to get this job done. Here’s an example which controls a similar alt-azimuth telescope using an ESP32 and a few rotary encoders.

Spin Up To Speed With This Stroboscope

March 15, 2023 by Bryan Cockfield 3 Comments

A stroboscope is not the most common tool, and while they can be purchased fairly inexpensively from various online stores, they are straightforward enough tools that plenty of us could build our own mostly from parts laying around. The basic idea is to shine a flashing light on a spinning object, and when it appears stationary the stroboscope will indicate the rotational speed. There are a few specialty parts that might not be in everyone’s parts drawers, though, and [John] shows us the ins-and-outs of his own DIY stroboscope.

The effect relies on extremely precise timing, and as such the most important part of a build like this is making sure to get the LED circuitry correct so its duty cycle and frequency can be tightly controlled. [John] is using a PT4115E driver board for the LED, and is using it to power a 1W white LED which also includes its own heat sink and lens. The controls for the stroboscope are handled by an ATtiny1614 microcontroller which shows its pulse rate on a small screen. The user can control the rate the LED flashes with simple controls, and when the spinning object appears to come to a stop the only thing left to do is read this value off of the screen.

While it might seem like an overly niche tool, stroboscopes have plenty of day-to-day uses. Older cars that used a central distributor made use of a specialty stroboscope called a timing light in order to properly advance the ignition timing of the engine. They also retain some use in medical applications, and plenty of older readers may be familiar with their use adjusting the speed on record players. They can also be used to make sure the shutter speeds on cameras are calibrated correctly.

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Voice Without Sound

March 15, 2023 by Bryan Cockfield 14 Comments

Voice recognition is becoming more and more common, but anyone who’s ever used a smart device can attest that they aren’t exactly fool-proof. They can activate seemingly at random, don’t activate when called or, most annoyingly, completely fail to understand the voice commands. Thankfully, researchers from the University of Tokyo are looking to improve the performance of devices like these by attempting to use them without any spoken voice at all.

The project is called SottoVoce and uses an ultrasound imaging probe placed under the user’s jaw to detect internal movements in the speaker’s larynx. The imaging generated from the probe is fed into a series of neural networks, trained with hundreds of speech patterns from the researchers themselves. The neural networks then piece together the likely sounds being made and generate an audio waveform which is played to an unmodified Alexa device. Obviously a few improvements would need to be made to the ultrasonic imaging device to make this usable in real-world situations, but it is interesting from a research perspective nonetheless.

The research paper with all the details is also available (PDF warning). It’s an intriguing approach to improving the performance or quality of voice especially in situations where the voice may be muffled, non-existent, or overlaid with a lot of background noise. Machine learning like this seems to be one of the more powerful tools for improving speech recognition, as we saw with this robot that can walk across town and order food for you using voice commands only.

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