Lawn Sprinkler the Introduction Part 1. Mike writes… [via]
The new craze for Home Automation is to use technology to Go Green. One aspect of Going Green is about managing resources in a more efficient way. I have seen a number of other hobbyists build projects that manage the amount of electricity or gas that they use within their home. In this project I am going to manage the amount of water I use for watering my lawn. In part 1 of this series I am going to cover the big picture of what I am attempting to do.
DIY sprinkler system with Netduino Plus - [Link]
Teravolt.org – DIY High Voltage Capacitors… [via]
Sure making a cap out of paper is fun and all, but making a high voltage one is even more fun!
You don’t need lots of money to make high voltage capacitors, in fact some pretty decent ones can be made with some cheap and readily available materials. This is because capacitors are very simple devices; consisting only of a dielectric and two plates. Most often a capacitor’s plates are just aluminum foil, and reynold’s wrap is easy enough to obtain, but what about the dielectric?
Enter the overhead projector sheet. Transparencies as they are commonly known as are nothing but acetate film, and while this is not the ideal dielectric for a capacitor it still does quite a good job. Typically a four mil OHP sheet can withstand 14kV before breaking down. As for obtaining them, the cheapest I have found these sheets is $10 for a box of 100, enough for about 16 capacitors.
How you make the capacitors is a rather trivial task, all that needs to be done is some cutting, flattening and rolling. Below I have an image that explains the process. Multiple sheets of OHP sheet are used to increase the capacitor’s voltage rating, and two sets of sheets are used so the capacitor can be rolled up.
DIY High Voltage Capacitors – [Link]
This project shows how to build a smartphone tripod adapter from easy to find materials. [via]
DIY smartphone tripod adaptor - [Link]
Jeri Ellsworth managed to build his own NMOS transistor at home using a kiln, Whink Rust and Stain remover, Emulsitone spin on dopant, ebay wafers and vinyl stickers. Entire proccess is demostrated step by step on the Youtube video above. Really awesome work! [via]
How-To Roll your own NMOS transistors - [Link]
Gio @ diyaudioprojects.com writes:
Like many of you, I love speakers and DIY Audio, but my woodworking skills are mediocre and I don’t have a suitable setup and proper tools for loudspeaker enclosure building. As a result I am often browsing the many DIY speaker kits that are available. When I came across the Tang Band D4-1 DIY Horn Speaker Kit, which is pre-cut (no cutting or drilling = no saw dust), pre-finished (no painting or staining) and looks like it goes together much like ready-to-assemble furniture, I figured it would be the perfect kit that can be built indoors as winter already had a firm grip on Winnipeg.
Tang Band D4-1 DIY Back Horn Speaker Kit - [Link]
DIY is cheaper and often better, as Justin Lee and Oliver Yeh found out when they decided to send a camera into space. The two students from MIT put together a low-budget rig to fly a camera high enough to photograph the curvature of the Earth. Instead of rockets, boosters and expensive control systems, they filled a weather balloon with helium and hung a styrofoam beer cooler underneath to carry a cheap Canon A470 compact camera. Instant hand warmers kept things from freezing up and made sure the batteries stayed warm enough to work. [via]
MIT Students took space photos on the cheap - [Link]
We live in the information age. Your phone knows where you like to eat, computer programs know what movies you like better than you do, and going to a party can mean going in this life, or a Second Life. So why is your message of love still stuck in the 16th century? These days it takes more than a sonnet to melt a girl’s heart. This video tutorial shows step-by-step how to make a Valentine’s Day card for the digital age. The NerdKits team shows how to make an LED Heart Valentine’s card powered by a microcontroller. The heart features an LCD screen for a personalized message, and 20 LEDs around the perimeter that can be programmed to show any pattern. The code provided contains a “twinkle” function that randomizes the process to provide a true star-like twinkle.
DIY LED Heart - [Link]
This tube amplifier is constructed uses point-to-point connections and the majority of the parts have been salvaged from old electronics. The amplifier uses 6T9 compactron vacuum tubes in a push-pull output stage. The preamp section uses 12AX7A tubes.
DIY 6T9 Push-Pull Tube Amplifier Project - [Link]