An inside look on how reed switches are manufactured

March 14, 2012 By Leave a Comment

reed-switch

[York] wrote in to share a video he stumbled across while researching reed switches and relays, which documents the tightly controlled process through which they are produced. Like many other electronic components out there, we usually don’t give a lot of thought to how they are made, especially when the final cost is relatively small.

For something often taken for granted, the process is an incredibly precise one, requiring a clean room environment the entire way through. The video follows the production line from beginning to end, including the soft annealing of the contacts to remove magnetic remanence, the sputtering process that applies sub-micron thick conductive coatings to the contacts, through the laser cutting and sealing of the glass tubes that make up the body of the switch.

At the end of the day, the video is little more than a manufacturer’s promotional video, but it’s worth the 8 minutes it takes to watch it, if only to satisfy your curiosity as to how they are made.

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Filed Under: misc hacks Tagged With: , ,

Easy workout logging with Ethernet-enabled exercise bike

March 3, 2012 By Leave a Comment

It will be easy to keep your exercise routine on track if you don’t have to do anything at all to log your workouts. [Reefab] developed this add-on hardware for his exercise bike that automatically logs his workout on the Internet.

He’s using RunKeeper to store and display the workout data. They offer a token-based API which [Reefab] implemented in his Arduino sketch. The hardware to grab data from the exercise bike is quite simple to set up. A rare-earth magnet was added to the fly-wheel with a reed switch positioned next it in order to measure the number and speed of rotations. This is exactly how a consumer bicycle computer works, needing just one accurate measurement corresponding to how far the bike travels with each revolution of that wheel.

In addition to the networked-logging feature [Reefab] included a character display so you can follow your speed and distance data during the workout.

Filed Under: home hacks Tagged With: , , , , , ,

Semaphore signal replica perfect for the train buff in your life

February 29, 2012 By Leave a Comment

semaphore-signal

[John Philip’s] brother has a sizable room set aside for his model railroad setup, and he was looking for something interesting to add to his brother’s collection. Rather than construct something for the railroad itself, he decided that an early 1900’s-style semaphore railroad signal would make a great novelty item for the room.

The project started with [John] scouring the Internet for colored signal lenses. Once he found a set that worked for him, he crunched some numbers to ensure that the rest of the semaphore box stayed true to original scale. Inside the signal’s case you will find a small regulator board for his light source, an Arduino, and a motor controller board to actuate the arm.

To ensure that the signal arm is always perfectly positioned, he installed a pair of reed switches on either side of the case, enabling the Arduino to auto-calibrate the signal’s position each time it is powered on. At first, this control scheme might strike you as a bit over the top, but we really like the fact that the signal can always configure itself to function perfectly, even if someone tinkers with/bumps into/moves the arm at any point.

Be sure to stick around to see a short video of the semaphore signal in action.

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Filed Under: arduino hacks, classic hacks Tagged With: , , ,