2026-02-06 14:00:28
The Commodore Amiga was famous for its characteristic Say voice, with its robotic enunciation being somewhat emblematic of the 16-bit era. The Commodore VIC-20 had no such capability out of the box, but [Mike] was able to get one talking with a little bit of work.
The project centers around the Adventureland cartridge, created by Scott Adams (but not the one you’re thinking of). It was a simple game that was able to deliver speech with the aid of the Votrax Type and Talk speech synthesizer box. Those aren’t exactly easy to come by, so [Mike] set about creating a modern equivalent. The concept was simple enough. An Arduino would be used to act as a go between the VIC-20’s slow serial port operating at 300 bps and the Speakjet and TTS256 chips which both preferred to talk at 9600 bps. The audio output of the Speakjet is then passed to an LM386 op-amp, set up as an amplifier to drive a small speaker. The lashed-together TTS system basically just reads out the text from the Adventureland game in an incredibly robotic voice. It’s relatively hard to understand and has poor cadence, but it does work – in much the same way as the original Type and Talk setup would have back in the day!
Text to speech tools have come a long way since the 1980s, particularly when it comes to sounding more natural. Video after the break.
[Thanks to Stephen Walters for the tip!]
2026-02-06 11:00:44
[Prof MAD] runs us through The Hidden Power of Inductors — Why Coils Resist Change.
The less often used of the passive components, the humble and mysterious inductor is the subject of this video. The essence of inductance is a conductor’s tendency to resist changes in current. When the current is steady it is invisible, but when current changes an inductor pushes back. The good old waterwheel analogy is given to explain what an inductor’s effect is like.
There are three things to notice about the effect of an inductor: increases in current are delayed, decreases in current are delayed, and when there is no change in current there is no noticeable effect. The inductor doesn’t resist current flow, but it does resist changes in current flow. This resistive effect only occurs when current is changing, and it is known as “inductive reactance”.
After explaining an inductor’s behavior the video digs into how a typical inductor coil actually achieves this. The basic idea is that the inductor stores energy in a magnetic field, and it takes some time to charge up or discharge this field, accounting for the delay in current that is seen.
There’s a warning about high voltages which can be seen when power to an inductor is suddenly cut off. Typically a circuit will include snubber circuits or flyback diodes to help manage such effects which can otherwise damage components or lead to electric shock.
[Prof MAD] spends the rest of the video with some math that explains how voltage across an inductor is proportional to the rate of change of current over time (the first derivative of current against time). The inductance can then be defined as a constant of proportionality (L). This is the voltage that appears across a coil when current changes by 1 ampere per second, opposing the change. The unit is the volt-second-per-ampere (VsA-1) which is known as the Henry, named in honor of the American physicist Joseph Henry.
Inductance can sometimes be put to good use in circuits, but just as often it is unwanted parasitic induction whose effects need to be mitigated, for more info see: Inductance In PCB Layout: The Good, The Bad, And The Fugly.
2026-02-06 08:00:37
[GizmoThrill] shows off a design for an absolutely gorgeous, high-fidelity replica of the main character’s helmet from the video game Satisfactory. But the best part is the technique used to create the visor: just design around a cheap set of full-face “sunglasses” to completely avoid having to mold your own custom faceplate.
One of the most challenging parts of any custom helmet build is how to make a high-quality visor or faceplate. Most folks heat up a sheet of plastic and form it carefully around a mold, but [GizmoThrill] approached the problem from the other direction. After spotting a full-face sun visor online, they decided to design the helmet around the readily-accessible visor instead of the other way around.
The first thing to do with the visor is cover it with painter’s tape and 3D scan it. Once that’s done, the 3D model of the visor allows the rest of the helmet to be designed around it. In the case of the Satisfactory helmet, the design of the visor is a perfect match for the game’s helmet, but one could easily be designing their own custom headgear with this technique.
With the helmet 3D printed, [GizmoThrill] heads to the bandsaw to cut away any excess from the visor, and secure it in place. That’s all there is to it! Sure, you don’t have full control over the visor’s actual shape, but it sure beats the tons and tons of sanding involved otherwise.
There’s a video tour of the whole process that shows off a number of other design features we really like. For example, metal mesh in the cheek areas and in front of the mouth means a fan can circulate air easily, so the one doesn’t fog up the inside of the visor with one’s very first breath. The mesh itself is concealed with some greebles mounted on top. You can see all those details up close in the video, embedded just below.
The helmet design is thanks to [Punished Props] and we’ve seen their work before. This trick for turning affordable and somewhat gimmicky sunglasses into something truly time-saving is definitely worth keeping in mind.
2026-02-06 05:00:28
When you think of a toy tractor, what probably comes to mind is something with fairly simple lines, maybe the iconic yellow and green, big rear tires, small front ones. Well, that’s exactly what [James] built, with simple, clean lines and a sturdy build that will hold up to driving around off-road in the garden. This Tractor is a great build, combining CAD, metal and wood work, some 3D printing, and electronics.
Starting at the power plant for the build, [James] went with a 350W DC motor powered by a 36V Li-ion battery from an e-bike. The motor turns a solid rear axle he made on a mini-lathe, connected to a set of riding lawn mower wheels. The mini-lathe spindle bore was too small to accommodate the shaft, and the lathe was not long enough to use the tailstock, so [James] had to get creative, using a vice and a piece of wood to make a stand–in tailstock, allowing him to turn this custom rear axle. The signature smoothly curved bonnet was made possible with plywood and body filler, rather than the sheet metal found on full-sized tractors. In fact, most of the build’s frame used plywood, giving it plenty of strength and, once painted, helping give it the appearance of a toy pulled out of a toybox.
This build had a bit of many domains in it, and all combined into a fantastic final result that no doubt will bring a smile to any face that gets to take the Tractor for a ride. Thanks [James] for documenting your build process, the hacks needed to pull off the tough bits along the way in making this fun toy. If you found this fun, be sure to check out another tractor related project.
2026-02-06 03:30:23
Macropads can be as simple as a few buttons hooked up to a microcontroller to do the USB HID dance and talk to a PC. However, you can go a lot further, too. [CNCDan] demonstrates this well with his sleek macropad build, which throws haptic feedback into the mix.
The build features six programmable macro buttons, which are situated either on side of a 128×64 OLED display. This setup allows the OLED screen to show icons that explain the functionality of each button. There’s also a nice large rotary knob, surrounded by 20 addressable WS2811 LEDs for visual feedback. Underneath the knob lives an an encoder, as well as a brushless motor typically used in gimbal builds, which is driven by a TMC6300 motor driver board. Everything is laced up to a Waveshare RP2040 Plus devboard which runs the show. It’s responsible for controlling the motors, reading the knob and switches, and speaking USB to the PC that it’s plugged into.
It’s a compact device that nonetheless should prove to be a good productivity booster on the bench. We’ve featured [CNCDan’s] work before, too, such as this nifty DIY VR headset.
2026-02-06 02:00:02
The heat pump has become a common fixture in many parts of modern life. We now have reverse-cycle air conditioning, heat pump hot water systems, and even heat pump dryers. These home appliances have all been marketed as upgrades over simpler technologies from the past, and offer improved efficiency and performance for a somewhat-higher purchase price.
Heat pumps aren’t just for the home, though. They’re becoming an increasingly important part of major public works projects, as utility providers try to do ever more with ever less energy in an attempt to save the planet. These days, heat pumps are getting bigger, and will be doing ever grander things in years to come.
The heat pump is a particularly attractive tool because it has a near-mystical property that virtually no other machine does. It is capable of delivering more heat energy than the amount of electricity fed into it, appearing to effectively have an efficiency greater than unity. We’re told that thermodynamic laws mean that we can never get more energy out than we put in. If you put 1 kW of electrical energy into a resistive heating element, which is near 100% efficient, you should get almost 1 kW of heat out of it, but never a hair more than that. But with a heat pump, you could get 1.5 kW, or even 2 kW for your humble 1 kW input. The trick is that the heat pump is not actually a magical device that can multiply energy out of nothing. Instead, the heat pump’s trick is that it’s not turning your 1 kW input into heat energy. It’s using 1 kW of energy to move heat from one place to another. If you’re running a heat pump-based HVAC system to cool your home, for example, it might use 2 kW of electricity to pump 3 to 4 kW of heat from your lounge room and dissipate it outdoors. Since the outdoors doesn’t change much in temperature when you pump out the heat from your home, you can keep doing this pretty much all day. You can even reverse the flow if your heat pump system allows it, instead pumping heat from the outdoors into your home. This works well until temperatures get so low that there isn’t enough heat left in the outdoors to appreciably warm your house up.
The heat pump achieves the feat of making heat go where we want it to go via the use of refrigerant. Specifically, refrigerant enters the compressor as a low pressure and low temperature vapor. It exits as a gas at high temperature and high pressure, and is then passed through a series of condenser coils. As it passes through, it releases heat to the surrounding environment and reduces in temperature, condensing into a liquid. From there, the liquid, still under high pressure, passes through an expansion valve, which rapidly lowers the pressure and drops the temperature further. The liquid is now cold, and passes through an evaporator coil where it picks up heat from the surroundings and turns back into a low-pressure, low-temperature vapor to start the cycle again as it heads back to the compressor. This system runs your fridge, your car’s air conditioner, and is used in so many other applications where it’s desirable to make something colder or hotter as efficiently as possible. You just choose which direction you want to pump the heat and design the system accordingly. Air conditioners and fridges pump heat out of a confined space, heaters and dryers pump it in, and so on. It’s heat pumps all the way down!
Thus far, you’ve probably used many a heat pump in your daily life, whether it be for heating, cooling, or drying clothes. However, there is a new push to build ever-larger heat pumps to work on the municipal scale, rather than simply serving individual households. The hope is to make utilities more energy efficient, and thus cheaper and greener in turn, by taking advantage of the efficiency gains offered by the magic of the heat pump.
One such project is taking place just off the River Rhine in Germany. A pair of massive heat pump units are being constructed by MVV Energie, each with a capacity of 82.5 megawatts. They will deliver heat to a total of 40,000 homes via a district heating system, and will be constructed on the site of a former coal power plant. Each pump will effectively draw energy out of the massive watery heat battery that is the River Rhine, and use it to warm homes in the local area. Thankfully, the river’s capacity is large enough that drawing all that heat out of the river should only affect temperatures of the water by around 0.1 C.
The Rhine project builds upon a previous effort to install a large heat-pump heating system in Mannheim, in partnership with Siemens Energy. That installation draws 7 megawatts of electricity to supply 20 megawatts of heating to the local district heating grid. Installed in 2023, it supplies the heating needs of 3,500 local households.
A similar project is underway in Denmark, which will supply 177 megawatts of heat to homes in Aalborg. The installation of four 44 megawatt MAN Technology heat pumps will be hooked up to the existing district heating system, which is also supported by other sources including waste heat from a local cement factory. The benefit of using smaller individual units is that it allows some of the pumps to be shut down when heating demand is lower, as winter passes through autumn into summer.
What makes these projects special is their sheer scale. Rather than being measured in the kilowatt scale like home appliances, they’re measured in the many tens of megawatts, delivering heating to entire neighborhoods instead of single homes. As it turns out, heat pumps work just fine at large scales—you just need to build them out of bigger components. Bigger compressors, bigger expansion valves, and bigger condensors and evaporators—all of these combine to let you pump enormous amounts of heat from one place to another. As utilities around the world seek ever greater efficiency in new projects, heat pumps will likely grow larger and be deployed ever more widely, seeking to take advantage of the free heat on offer in the earth, water, and air around us. After all, there’s no point dumping energy into making heat when you can just move some that’s already there!
