Flickering Pumpkin Lanterns

October 1, 2013 by James Hobson 19 Comments

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Halloween is coming and [Paulo] decided to make some flickering jack-o-lanterns by hijacking the flickering circuit of a cheap LED tea light to drive a much more powerful light!

He has tons of old 12V incandescent bulbs collecting dust, so he decided to make use of them for some holiday fun. He wondered if he could steal the circuit from the flickering LED tea lights and use them to drive the incandescents. Upon taking the LED tea candle apart, he discovered there was no circuit, as it was in fact embedded in the LED itself! Not to worry though, he simply integrated the flickering LED into his circuit! Coupling a capacitor with the LED, he used a transistor amplifier to take the signal, and then finally boosted it using a MOSFET to drive the light bulbs. He then powered the entire thing using an old laptop power brick. Nice one [Paulo]!

Do you have any cool Halloween hacks? Don’t forget to send them in to the tip line! For other pumpkin fun, check out last year’s Pumpkin Tetris!

Umbrella Turned Delta Kite

September 29, 2013 by James Hobson 13 Comments

How many broken umbrellas have you thrown out in your life? [BigApe] has come up with a novel way to reuse them, by turning them into kites.

The beauty of the build is in the MacGyver-style material list. Apart from a few store bought 8mm aluminum and plastic tubes, the majority of the build is out of other scraps that you can easily find around the house. Spokes from a broken bicycle wheel, plastic from a CD case, elastic bands, yarn, some washers, an empty hair gel tube, the list goes on… We really have to give him credit on the creative material choices!

Now before you get too excited, this project does involve quite a bit of sewing, so a sewing machine would be quite handy. Other than that, only basic tools such as pliers, scissors, punches, matches, drill bits, and a saw, are required.

The finished product ends up being a bit heavier than most similar sized consumer-grade delta kites, but [BigApe] achieved some kite-like flight out of it in low wind speeds. He promises to post a test video when it gets a bit windier to prove his design.

On the topic of kites, earlier this year we covered a remote-controlled, autonomous, power generating kite!

Project Thumper Walkthrough

September 29, 2013 by James Hobson 29 Comments

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The Geek Group is at it again! Many years ago they built Project Thumper, a 1,600V @80,000A electrical impulse … well … “thumper”.

For those of you that don’t know, The Geek Group is the world’s largest not-for-profit Hackerspace. Lately they have been working on developing better videos for their YouTube channel, and have just released a stunning CGI animation of the build, operation, and explanation of Project Thumper.

So what is Project Thumper? In the simplest terms, it’s a giant capacitor, or more specifically, an entire server rack filled with capacitors. The Hackerspace uses it for experiments and demonstrations — but from the looks of their videos, they mostly just use it to blow things up, as shown in their 2008 Project Promo video. I think we would too. They even used it to blow up an iPhone! (Skip to 3:00 for the explosion). We think someone with a high-speed camera really needs to film Thumper in action!

The awesome CGI animation explanation of it is after the break.

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Musical Pencil Synthesizer

September 29, 2013 by James Hobson 16 Comments

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Here’s another fun weekend project for the hacker younglings, a musical synthesizer that plays different musical tones based on the resistance of your conductive graphite drawing!

Like our recent post on a DIY Metal Detector, this project makes use of the ever relevant 555 timer. Except in this case they are using a more modern TLC555 timer which only requires 3V instead of the typical 4.5V. It’s a fairly simple project that you should be able to complete in just a few hours.

The circuit is quite basic. The 555 timer outputs in astable mode, which means there is a continuous stream of pulses from pin 3 which go right into the speaker circuit. The rest of the circuit monitors the resistance of whatever the pencil is touching, including you! Changes in resistance result in the variation of pulses outputted by the 555 timer.

As always, the video guide is after the break.

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Electronics Everything Reference Poster

September 28, 2013 by James Hobson 47 Comments

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[Ben] just sent us this great reference sheet. It’s a poster he compiled of datasheets and various electronic references. He made it after spending too much of his time sifting through datasheets while working on projects. It also helped that he realized his school, Georgia Tech, had a poster printing service!

It contains the basics from resistor color codes, typical pinouts of various chips, current capacity of wire gauges, Arduino pinout diagrams, schematic symbols, trace widths for current capacity, and even typical coding functions!

The full image is 9,000 x 6,000 pixels and will print nicely at 30 by 20 inches, just shy of the ANSI D paper size. It’s 6.1MB so only click here if you want it!

Maybe if we ask nicely he’ll share the original MS Publisher file so we can tailor it to our individual needs! Some of the text in the images is a bit blurry, but everything is basically still readable.

CD-ROM POV Clock

September 28, 2013 by James Hobson 12 Comments

[Kyle] wanted to try something new. A Persistence of Vision Clock using a CD-ROM drive.

We have covered lots of POV Clocks that make use of hard drives, but we think this is the first time we have seen a CD-ROM drive used instead. [Kyle] points out that CD-ROM drives are typically much quieter than hard drives, which is the main reason he chose the CD-ROM route.

At the heart of this project is a good old ATMEGA168 and an RGB LED strip for the lights. To measure and maintain the rotational speed of the clock [Kyle] used an IR photodiode that detects a reference mark on the disc. An elegant build of a classic POV Clock, with a new twist!

The cool thing about this project is he did not actually use the CD-ROM drive like you think he would — he chucked the spindle motor and instead is spinning the disk using the tray ejection motor! He did this so he could control the motor by PWM straight off the microcontroller, whereas the spindle motor would require an IC and a varying control signal with specific voltage amplitudes.

He also experimented with different backgrounds and background lighting, which you can see in the video after the break!

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DIY Metal Detector

September 28, 2013 by James Hobson 15 Comments

Looking for a light project to teach young hackers some very basic electronics? Here’s a quick and easy weekend project, a simple metal detector!

We all know 555 timers are very useful and pop up in a wide range of projects, but did you know a metal detector is one of them? [vonPongrac] stumbled upon this handy guide, a free eBook on 50 555 Circuits, which contains many cool project ideas, including a simple metal detector circuit. It’s a very basic concept that uses a coil of copper wire as a home-made choke — when metal or a magnet comes near the coil, it varies the output frequency, and the 555 timer in turn, varies the output sound, alerting you of the presence of something metal nearby.

After the break there’s a video of it during its testing phases. If you don’t have a 555 on hand (tisk tisk) but still want to have some treasure hunting fun you can also build one based on an Arduino.

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