tea

31 Articles

No Doorknobs Needed For This Nitrogen Laser Build

December 26, 2020 by 15 Comments

Sometimes the decision to tackle a project or not can boil down to sourcing parts. Not everything is as close as a Digi-Key or Mouser order, and relying on the availability of surplus parts from eBay or other such markets can be difficult. Knowing if and when a substitute will work for an exotic part can sometimes be a project all on its own.

Building lasers is a great example of this, and [Les Wright] recently looked at substitutes for hard-to-find “doorknob” capacitors for his transversely excited atmospheric lasers. We took at his homebrew TEA lasers recently, which rely on a high voltage supply and very rapid switching to get nitrogen gas to lase. His design uses surplus doorknob caps, big chunky parts rated for very high voltages but also with very low parasitic inductance, which makes them perfect for the triggering circuit.

[Les] tried to substitute cheaper and easier-to-find ceramic power caps with radial wire leads rather than threaded lugs. With a nominal 40-kV rating, one would expect these chunky blue caps to tolerate the 17-kV power supply, but as he suspected, the distance between the leads was short enough to result in flashover arcing. Turning down the pressure in the spark gap chamber helped reduce the flashover and prove that these caps won’t spoil the carefully engineered inductive properties of the trigger. Check out the video below for more details.

Thanks to [Les] for following up on this and making sure everyone can replicate his designs. That’s one of the things we love about this community — true hackers always try to find a way around problems, even when it’s just finding alternates for unobtanium parts.

Continue reading “No Doorknobs Needed For This Nitrogen Laser Build” →

How About A Nice Cuppa TEA Laser?

August 9, 2020 by 11 Comments

If lasers are your hobby, you face a conundrum. There are so many off-the-shelf lasers that use so many different ways of amplifying and stimulating light that the whole thing can be downright — unstimulating. Keeping things fresh therefore requires rolling your own lasers, and these DIY nitrogen TEA and dye lasers seem like a fun way to go.

These devices are the work of [Les Wright], who takes us on a somewhat lengthy but really informative tour of transversely excited atmospheric (TEA) lasers. The idea with TEA lasers is that a gas, often carbon dioxide in commercial lasers but either air or pure nitrogen in this case, is excited by a high-voltage discharge across long parallel electrodes. TEA lasers are dead easy to make — we’ve covered them a few times — but as [Les] points out, that ease of construction leads to designs that are more ad hoc than engineered.

In the video below, [Les] presents three designs that are far more robust than the typical TEA laser. His lasers use capacitors made from aluminum foil with polyethylene sheets for dielectric, sometimes with the addition of beautiful “doorknob” ceramic caps too. A spark gap serves as a very fast switch to discharge high voltage across the laser channel, formed by two closely spaced aluminum hex bars. Both the spark gap and the laser channel can be filled with low-pressure nitrogen. [Les] demonstrates the power and the speed of his lasers, which can even excite laser emissions in a plain cuvette of rhodamine dye — no mirrors needed! Although eye protection is, of course.

These TEA lasers honestly look like a ton of fun to build and play with. You might not be laser welding or levitating stuff with them, but that’s hardly the point.

Continue reading “How About A Nice Cuppa TEA Laser?” →

Minimalist Mate Maker Keeps You Caffeinated

December 24, 2019 by 3 Comments

Americans love their coffee. The Brits adore their tea. In South America, the number one way to get through the day is with yerba mate, a tea made from the yerba plant. It is typically shared in a social setting, with one person preparing the beverage for everyone to enjoy. Although caffeine certainly deserves a ceremony, it never needs one. Hit the streets and you’ll see people everywhere with a thermos under one arm, keeping water hot and ready to refill the cup of mate in their hand.

The Stanley vacuum thermos is quite a popular choice for drinkers on the go, but the Argentinian government recently placed new restrictions foreign imports. [Roni Bandini] decided to build a minimum viable mate machine so he always has perfectly hot water on tap.

An Arduino Nano heats the water and displays the rising temperature on an LCD screen. When the temperature is just right, the display asks for your cup. An ultrasonic sensor detects the cup and dispenses a certain amount of water determined in the sketch. Yerba leaves can be used a few times before losing their flavor, so the machine keeps track and lets him know when it’s time to replace them. You can sip on a brief demo after the break.

Let’s say you don’t have perfectly-prepared mate, and it always comes out too hot. That’s better than too cold, but still not ideal. Why not make a temperature-sensing coaster that alerts you when it has cooled to perfection?

Continue reading “Minimalist Mate Maker Keeps You Caffeinated” →

Tea Bot Solves Another First World Problem

July 24, 2019 by 19 Comments

In the movie Wall-E, future humans live in floating chairs and have everything done for them. Today, we grumble if we have to go to physically find a light switch or a remote control. How far away can floating chairs with screens be? T2, the Tea Bot, gets us one step closer to that. Using a laser-cut frame, an ESP8266, and a servo motor, the T2 brews your tea for exactly the right amount of time.

We were kind of hoping the robot would at least dunk the tea bag in and out, but it does provide a web interface that lets you select the brew. Of course, the code is available, so you could make modifications — maybe turn on a hotplate underneath the cup.

Continue reading “Tea Bot Solves Another First World Problem” →

A Modern Solution To Tea Bag Inventory Management

February 20, 2019 by 13 Comments

Britain is famously known as a land of manners and hospitality. Few situations could make an Englishman’s stiff upper lip quiver, short of running out of tea bags while entertaining house guests. Thankfully, [The Gentleman Maker] is here and living up to his name – with a helpful tea monitor to ensure you’re never caught out again.

The Intelli-T, as it has been dubbed, monitors tea inventory by weight. An Arduino Uno combined with a HX711 IC monitors a load cell mounted under a canister, with a reed switch on the lid. Upon the canister being open and closed, the Arduino takes a measurement, determining whether tea stocks have dipped below critical levels. If the situation is dire, a Raspberry Pi connected over the serial port will sound an urgent warning to the occupants of the home. If there is adequate tea, the Raspberry Pi will instead provide a helpful tea fact to further educate the users about the hallowed beverage.

It’s a fun project, and one that has scope for further features, given the power of the Raspberry Pi. A little more work could arrange automatic ordering of more tea online, or send alerts through a service like IFTTT. We’ve seen [The Gentleman Maker]’s uniquely British hacks before, such as the umbrella that tells you the weather. Video after the break.

Continue reading “A Modern Solution To Tea Bag Inventory Management” →

Internet Of Tea: Coaster Watches For Optimum Drinking Temperature

August 14, 2018 by 3 Comments

Ah, the age-old question: at what temperature does one’s tea need to be for maximum enjoyment? It’s subjective, of course, but subjective in a way that makes everyone else’s opinion demonstrably wrong. What’s worse, the window of opportunity for optimum tea temperature is extremely narrow. What’s a tea drinker to do?

Throw a little technology at the problem, of course, in the form of this Internet of Tea smart coaster. Through careful experimentation, [Benjojo] determined the temperature of his favorite mug when the tea within was just right for drinking and designed a coaster to alert him to that fact. The coaster is 3D-printed and contains an MLX90616 IR temperature sensor looking up at the bottom of the mug. An ESP8266 lives inside the coaster too and watches for the Optimum Tea Window to open, sending an alert via Discord when the time is right. Yes, he admits that a simple blinking LED on the coaster would keep his tea habit metadata from being slurped up by the international tea intelligence community, but he claims he has nothing to hide. Good luck with that.

What’s next for [Dane]’s tea preparation? Perhaps he can close the loop and automate the whole pre-consumption process.

The Best Part Of Waking Up Just Got Better

May 31, 2018 by 23 Comments

If you ask us, one of life’s greatest pleasures is sitting down with a nice, hot cup of something of coffee, tea or hot chocolate. Of course, the best part of this ritual is when the beverage has cooled enough to reach that short window of optimal drinking temperature.

Often times the unthinkable happens—we sip too early and get burned, or else become distracted by watching cat videos reading our colleagues’ Hackaday posts and miss the window altogether. What’s to be done? Something we wish we’d thought of: using the beverage’s heat to cool itself by way of thermal dynamics. For [Scott Clandinin]’s entry into the 2018 Hackaday Prize, he hopes to harness enough heat energy from the beverage to power a fan that will blow across the top of the mug.

[Scott] enlisted a friend to smith a thick copper slab in a right angle formation. The gentle curve of the vertical side pulls heat from the ceramic mug and transfers it to the heat sink of a CPU cooler. Then it’s just a matter of stepping up the voltage produced by the thermoelectric generator with a boost converter. Once he’s got this dialed in, he’d like to power it with supercaps and add a temp sensor and a microcontroller to alert him that his moment of zen is imminent. We’ll drink to that!

The HackadayPrize2018 is Sponsored by: