Electronics

Electromagnetic Pendulum – making it tell the time

May 31, 2011

A while ago I posted a video showing a pendulum driven by a pulse motor: It worked by using a single coil to detect the field from a magnet embedded in the pendulum base. An op-amp (wired as a comparator) detects when the pendulum reached the equilibrium point (vertical) a voltage (5-12v) is applied to […]

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Upgrading a Laser Cutter from China…

April 15, 2011
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I recently wrote about some of the problems I’d had with the Chinese Laser Cutter I bought over eBay. It became apparent that I was going to have to replace the X/Y controller board, as this was not functioning correctly. The Challenge – adding a new controller I just pulled my old CNC out of […]

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Microsoft to release Kinect SDK tomorrow?

April 13, 2011

Just got an email from my buddy Bob – he’s currently attending MIX11 in Vegas… The just handed out Kinect sensors and the new SDK to all attendees. The demo was neat. Looks like body tracking is part of the SDK. This is pretty awesome news. As some of you may remember I got myself […]

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Strange Wiimote camera…

March 29, 2011

Patrick van der Poel wrote to me with some pictures of what he found when he opened up a Wiimote recently. Instead of the normal Pixart sensor he found a strange daughter-board configuration. It looks very easy to remove, but it’s nothing like the regular sensor. Fortunately they labelled the board pinouts on the underside […]

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Creating a negative voltage from a positive one

March 28, 2011
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If you use opamps like the TL082/84 you’ll be in need of a “split” power supply. That is a power supply that has a positive voltage, ground, and the equivalent negative voltage (eg +5v, 0v, -5v). Since most audio signals are AC you need the opamp to operate in this range to be able to […]

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How to get 100% on your Senior Project…

March 26, 2011
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Build yourself a laser harp. At least that’s what Connor Thomas did – he’s been working on it for some time and he just sent me an email to let me know that the results came in and he scored 100%. Nice one. Here he is next to the tri-fold display.

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Inexpensive XY laser display using speakers

March 20, 2011
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[This project was featured on instructables.] Building an XY laser display “scanner” using a couple of 80W speakers. I looked into doing something like this way back when I was developing the laser harp – but I came to the conclusion that it would not be accurate enough – turns out as I wrong. This […]

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…getting one million views on YouTube

March 19, 2011
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Yay! After 3 years of ‘tubing I finally watched the view counter on my Youtube channel account click past 1,000,000 views. Here’s the 5 most popular videos by subject… 1. The Laser Harp – got the lion’s share at 389,367 views 2. How the TARDIS really works – 23,317 views 3. Building a robotic Dalek […]

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…the last darned MIDI interface I’ll ever build.

March 14, 2011
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I have a love/hate relationship with MIDI. More than half the projects I work on require some kind of MIDI interface, and I can *never* remember the hookup. All the diagrams on the web never indicate if the view is from the front, or the back of the connector. *And* I can never find a […]

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…still messing with forces I don’t understand – the formula.

March 2, 2011
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NEWSFLASH : Just when I thought this story was done with – I just tried adding a sprinkle of salt to the (already) potent mix of Hydrogen Peroxide and Muriatic Acid – Dang! It etched the whole board in under a minute… Wow! Definitely some kind of catalyst. Resulting solution is bright green (CuCl2?), not […]

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