We can all use a little more green energy in our lives at home. So when [simpler than ever to build.
] — a fan of wind power — ran into durability troubles with his previous home-built turbine, he revised it to be
Outside of the DC generator motor, the rest of the turbine is made from recycled parts: a sponge mop sans sponge, a piece from an old CD drive case acting as a rudder, the blades from a scrapped fan, and a plastic bottle to protect the motor from the elements. Attach the fan to the motor and form the plastic bottle around the motor using — what else? — a soldering iron. Don’t forget a respirator for this step, folks.
Continue reading “The Most Straightforward Wind Turbine”
Everyone knows that if you spin the shaft of a DC motor, it will generate power. [Vapsvus] has found a novel way to do this with no direct mechanical connection to the shaft. He simply taped a loop of string around to the motor can. This effectively turns the motor into a whirligig. Flip the motor to give the string a few twists, then pull on the two loops. The string unwinds and then winds back up, just like the toy we all grew up with.
The interesting thing is that the motor generates usable power when being spun like this. [Vapsvus] connected two LEDs to the motor’s leads to show what’s happening. The white LED glows when current travels from positive to negative, and the red LED glows when current travels from negative to positive.
What’s going on under the hood is all about momentum. As the motor can starts to spin, the heavy iron rotor remains still. Power is generated. Eventually, friction and torque from back EMF cause the rotor to spin as well. By the time the rotor is spinning, the motor can is already reversing direction.This generates even more power with current traveling in reverse.
Sure, this isn’t exactly practical, but we’d love to see how far it could be taken. Add a super capacitor, and we bet it would be more efficient than the magnetic shake lights which were popular a few years back.
Whirligigs are usefully little devices. Not only do they keep children entertained, you can use them as centrifuges.
Continue reading “DC Motor Whirligig Generates Power”
Following the time-honored YouTube tradition of ordering cheap stuff online and playing with it while the camera runs, [Monta Elkins] bought a Stirling engine that drives a DC motor used as a generator. How much electrical juice can this thing provide, running on just denatured alcohol? (Will it blend?)
The answer is probably not really a spoiler: it generates enough to run “Blink.ino” on a stock Arduino, at least when powered directly through the 5 V rail. [Monta] recorded an open-circuit voltage of around 5 V, and a short-circuit current of around 100 mA at a measured few hundred millivolts. While he didn’t log enough of the points in-between to make a real power curve, we’re guessing the generator might be a better match for 3.3 V electronics. The real question is whether or not it can handle the peaky demands of an ESP8266. Serious questions, indeed!
The video is a tad long, but it’s more than made up for by the sight of an open flame vibro-botting itself across his desk while [Monta] is trying to cool the cold side down with a melting ice cube. Which got us thinking, naturally. If you just had two of the Stirling engines… Continue reading “Ethanol-Powered Arduinos”
Part of the problem with having an alarm system is its reliance on land line telephone service. Some of them are getting away from this practice, but there are still many legacy systems out there that require a check to be sent in to Ma Bell every month in addition to the alarm system fees. Like these antiquated systems, [jgyates] was having a similar problem with the generator at his home which could only be monitored with a link to a cell network. Now that there’s a Raspberry Pi in every house, however, [jgyates] has a generator monitor that isn’t beholden to the phone company.
The hardware setup is little more than connecting the communications lines from the generator’s controller (in this case, a Generac Evolution controller) to the serial communications pins on a Raspberry Pi 3. [jgyates] did most of the work in Python, and his code is able to monitor almost every aspect of this generator and report it over WiFi or Ethernet, as well as control the generator settings from anywhere that has an Internet connection.
Even if you don’t have a generator with this particular controller, it will be a good guide for converting a monitor of any type into one that doesn’t require a land line or cell network connection. To that end, there have been lots of projects that convert even simple, old, analog household devices to report data over the LAN.
When we see a new build by [Gord] from Gord’s Garage, we never know what to expect. He seems to be pretty skilled at whatever he puts his hand to, with a great design sense and impeccable craftsmanship. You might expect him to tone it down a little for a STEM-outreach wind turbine project then, but when you get a chance to impress 28 fifth and sixth graders, you might as well go for it.
Starting with an idea from his daughter’s teacher for wind turbines each kid could make, [Gord] applied a little lean methodology so the kids would be able to complete the build in the allotted time. The design is simple – a couple of old CDs holding vertical sections of PVC tubing to catch the breeze and spin neodymium magnets over four flat coils of magnet wire. It’s enough to light a single LED and perhaps a kid’s imagination.
As simple as the turbine is, the process of building it needed to be stripped of as much unnecessary work as possible, and [Gord] really shines here. He built jigs and fixtures galore, pre-built some assemblies, and set up well-organized workstations for each step of the build. Everything was clearly labeled, adult volunteers were trained using the video after the break, and a good time was had by all.
Sometimes the hack isn’t in the product but in the process, and [Gord] managed to hack a success out a potential disaster of disappointed kids. If getting a taste of [Gord]’s style makes you want to see more, check out his guitar fretting jig or his brake rotor mancave clock.
Continue reading “Lean Thinking Helps STEM Kids Build a Tiny Windfarm”
Pity the lowly lead-acid battery. A century of use as the go-to method for storing enough electrons to spin the starter motor of a car engine has endeared it to few. Will newer technology supplant that heavy, toxic, and corrosive black box under your hood? If this supercapacitor boost box is any indication, then we’d say lead-acid’s days are numbered.
To be fair, we’ll bet that number is still pretty big. It takes a lot to displace a tried and true technology, especially for something as optimized as the lead-acid battery. But [lasersaber]’s build shows just how far capacitive storage has come from the days when supercaps were relegated to keeping your PC’s clock running. With six commercial 400F caps and a custom-built balance board, the bank takes a charge from a cheap 24V hand generator. The output is either to a heavy-duty lighter socket or some automotive-style lugs, and the whole thing is housed in a simple box partially constructed using energy stored in the bank. Can the supercaps start a car? Stay tuned after the break for the answer.
Although we’ve seen supercaps replace a motorcycle battery before, we’re a little disappointed that the caps used here only have a 1500-hour life – lead-acid wins that fight hands down. But this one gives us lots of ideas for future builds, and we’re heartened by the fact that the supercaps for this build ring up to less than $70.
Continue reading “Hand Cranked Generator Charges Supercaps, Starts Car”
When you take a microcontroller class in university, one of the early labs they have you drudge through on your way to, promised, mastery over all things embedded, is a tiny music generator.
It’s a more challenging lab than one would expect. It takes understanding the clock of the microcontroller and its sometimes temperamental nature. It takes a clear mental picture of interrupts, and is likely one of the first experiences a burgeoning designer will have worrying about the execution time of one of their loops. Also tables, data structures, and more. It even requires them to go out of their comfort zone a learn about an unrelated field, a challenge often faced in practicing engineering.
Luckily [Łukasz Podkalicki] has done a great job of documenting the adventure. He’s got everything from the schematic and code to the PWM traces on the oscilloscope.
It’s also worth mentioning that he’s got a few other really nice tutorials for the ATtiny13 microcontroller on his blog. A tiny party light generator and a IR receiver among them.