We recently started restoring a Teletype Model 19, a Navy communication system introduced in the 1940s.14 This Teletype was powered by a bulky DC power supply called the “REC-30 rectifier”. The power supply uses special mercury-vapor thyratron tubes, which give off an eerie blue glow in operation, as you can see below.
The power supply is interesting, since it is an early switching power supply. (I realize it’s controversial to call this a switching power supply, but I don’t see a good reason to exclude it.) While switching power supplies are ubiquitous now (due to cheap high-voltage transistors), they were unusual in the 1940s. The REC-30 is very large—over 100 pounds—compared to about 10 ounces for a MacBook power supply, demonstrating the amazing improvements in power supplies since the 1940s. In this blog post, I take a look inside the power supply, discuss how it works, and contrast it with a MacBook power supply.
What happens when you put 1,700 of the world’s smartest teens together and ask them to show their scientific stuff?
You may get more than you bargained for.
“Science Fair,” a new documentary, follows teenagers through the highs and lows of the Intel International Science and Engineering Fair, the world’s largest pre-college science competition.
The fair, at which young people compete for millions of dollars in prizes, is a hotbed of scientific research. It’s also a hothouse of competition and teenage angst, as the documentary shows.
The film follows nine teenagers seeking to change their lives through science. Among them: Kashfia, a young Muslim who feels out of place in her large South Dakota high school and dreams of escaping small-town life through science. Robbie, a West Virginia math whiz with terrible grades, who wants to meet other kids who share his niche interests. And Anjali from Louisville, who contends with helicopter parents as she navigates the weird world of competitive science.
Join Women of Color magazine’s Science Technology, Engineering, and Math (STEM) Conference Oct. 11 to 13.
The annual STEM Conference hosts award ceremonies for women who create innovation and puts you in a position to realize your STEM career dreams.
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Whether you’re a college graduate or a professional, you get countless networking opportunities. STEM mentors and role models help you find your footing in the industry. You connect with people who have been in your shoes.
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Save the Date:
OCTOBER 11-13, 2018
Detroit Marriott at the Renaissance Center Detroit, MI
Geeky-gadgets.com these days has a deal on the Force Flyers DIY Building Block Drone, so you can save 14% off the normal price. It could be an opportunity to start “playing” with drones, if you haven’t already. For $42.99 you can choose between different version of this drone: Space, Army, Fire Fighter and Police. Channel your inner […]
Pinball still has that bit of magic that makes it stand out from first person shooters or those screen mashers eating up your time on the bus. The secret sauce is that sense of movement and feedback, and the loss of control as the ball makes its way through the play field under the power of gravity. Of course the real problem is finding a pinball machine. Pinbox 3000 is swooping in to fix that in a creative way. It’s a cardboard pinball machine that you build and decorate yourself.
We ran into them at Maker Faire New York over the weekend and the booth was packed with kids and adults all mashing flippers to keep a marble in play. The kit comes as flat-pack cardboard already scored and printed with guides for assembly which takes about an hour.
The design is quite clever, with materials limited to just cardboard, rubber bands, and a few plastic rivets. Both the plunger that launches the pinball and the flippers are surprisingly robust. They stand up to a lot of force and from the models on display it seems the friction points of cardboard-on-cardboard are the issue, rather than mechanisms buckling under the force exerted by the player.
When first assembled the playfield is blank. That didn’t stop the fun for this set of kits stacked back to back for player vs. player action. There’s a hole at the top of playfields which makes this feel a bit like playing Pong in real life. However, where the kit really shines is in customizing your own game. In effect you’re setting up the most creative marble run you can imagine. This task was well demonstrated with cardboard, molded plastic packaging (which is normally landfill) cleverly placed, plus some noisemakers and lighting effects. The company has been working to gather up inspiration and examples for building out the machines. We love the multiple layers of engagement rolled into Pinbox, from building the stock kit, to fleshing out a playfield, and even to adding your own electronics for things like audio effects.
Check out the video below to see the fun being had at the Maker Faire booth.
Serpentine is a gesture sensor that’s the equivalent of a membrane potentiometer, flex and stretch sensor, and more. It’s self-powering and can be used in wearable hacks such as the necklace shown in the banner image though we’re thinking more along the lines of the lanyard for Hackaday conference badges, adding one more level of hackability. It’s a great way to send signals without anyone else knowing you’re doing it and it’s easy to make.
Serpentine is the core of a research project by a group of researchers including [fereshteh] of Georgia Tech, Atlanta. The sensor is a tube made of a silicone rubber and PDMS (a silicone elastomer) core with a copper coil wrapped around it, followed by more of the silicone mix, a coil of silver-coated nylon thread, and a final layer of the silicone mix. Full instructions for making it are on their Hackaday.io page.
There are three general interactions you can have with the tube-shaped sensor: radial, longitudinal, and tangential. Doing various combinations of these three results in a surprising variety of gestures such as tap, press, slide, twist, stretch, bend, and rotate. Those gestures result in signals across the copper and silver-coated nylon electrodes. The signals pass through an amplifier circuit which uses WiFi to send them on to a laptop where signal processing distinguishes between the gestures. It recognizes the different ones with around 90% accuracy. The video below demonstrates the training step followed by testing.