Dippy birds are the toys that teeter-totter back and forth as the beak of bird-shaped body dips into a container of water. The felt covering the beak and head picks up water and, through evaporation, cools that end of the glass tubing. The temperature changes cause the dichloromethane to either boil off, or condense, shifting the weight of the liquid thereby pivoting the glass body.
The real question is, does the temperature of the water cause the toy to move differently, and can that be measured to calculate the temperature of the water? [Craig] put that query to the test, by designing an apparatus to measure the motion of a Dippy Bird. A photointerruptor was used to measure the motion of the body, causing an interrupt each time the tail of the bird passes in between the sensor and the emitter. For control data a DS1820 temperature sensor was positioned near the felt on the head of the bird, and a relative humidity sensor captured readings at the same time. Data from the three inputs was collected over a two-day period. Although not a precise measurement, the motion of the bird did trend in the same ways that were recorded by the temperature and relative humidity sensors.
Continuing on with our high-voltage theme, today we have a page describing Marx generators by [Grenadier]. Marx generators are devices that produce pulses of very high voltage with fast rise times. For most of us, that means that they can make neat sparks. For the more serious types out there, that also means that they are great for driving some high-powered lasers, simulating lightning strikes, and even igniting the conventional explosives surrounding the core of a nuclear weapon! His page includes a video of his Marx generator producing some pretty sparks for those of us who aren’t so serious.
We have featured several of [Grenadier’s] projects in the past. This one doesn’t deviate from his normal style of taking a subject and clearly describing it with lots of well-taken pictures.
Recently, he has been working on improving one of his projects that deviates from what he normally does. He is calling it “The Junkbox”. The Junkbox is something like a free online swap meet where you can sell your electronic parts.
This bar code tattoo was sent into us by [Lifespan]. Before going under the needle, [Lifespan] didn’t care much for tattoos. After seeing this video he realized that a tattoo could have dynamic content through domain redirection.
[Lifespan] spent a lot of time going over the different styles of 2D bar codes. QR codes were deemed ugly because of the three large squares in the corners. An EZ Code, like the one in his YouTube inspiration, are a proprietary format that must be read with a ScanLife app. He eventually settled on a Data Matrix bar code because of its open format and ubiquity in business and industry. To make the tattoo dynamic, [Lifespan] made the tattoo point to 5id5.com. With a little bit of smart phone wizardry, that domain can be redirected to any URL in a moments notice.
Like all well-planned tattoos, he found himself a very good artist to do the piece. [Connor Moore] managed to ink some skin at 15 dpi, which was a little risky, but the results came out great. While it’s not scarification via a laser cutter, barring fading this tattoo is technologically future proof.