Power supplies and transformers; a learning experience

[Ladyada] is working on a tutorial series covering power supplies. If you’ve ever built an electronic project you’ve used some type of power supply but we think that most people have no idea how you get from mains power to the DC voltages that most small projects use. So if you want to learn, get started with the first … Read the rest

Bench supply with current limiting

This is a bench power supply with adjustable voltage and current limiting. [Sylvain's] creation can regulate 0-25 volts while sourcing 0-5 amps. Current limiting is a nice feature as it will allow you to test your prototypes to ensure the power regulator you choose will not be over or underpowered.

This supply is really a two-in-one. The case has … Read the rest

Replacement refrigerator controller

[Michael] got his hands on a refrigerator that he intended to store beer in but found that it ran constantly. Instead of buying a new thermostat he and his friend [Doug] set out to build an Arduino-based controller for the fridge.

The finished project will switch 240v so they’ve used a transformer to power the logic circuitry and a … Read the rest

Ionocraft aka Lifters

It’s hard to believe that in five years we haven’t covered lifters before. This realization was sparked when [Tyler] tipped us off about a lifter project demonstrated at the Kansas City hackerspace called CCCKC.

Lifters, the casual name for ionocraft, fly without combustion or moving parts. We’re not going to tackle the particulars of what makes flight possible, … Read the rest

A bright way to cycle

Want to be visible when cycling at night? [Neon Dean] came up with this possible solution, which he cruised on at Nuit Blanche. Its a bicycle with neon lights mounted on every surface possible. [Dean], who gave a similar treatment to his car, explained how it worked. All of the tubes take their power from a 12VDC battery he Read the rest

Pulse soldering iron


I’m always interested in new ways to solder. [SPman] sent in this diy pulse soldering iron. It heats up in 5 seconds on demand, then cools in about 15. The writeup is a bit terse (since it’s translated from Russian), but it would definitely be handy for larger wiring jobs. The transformer is hand wound, and an oscillation driver forms … Read the rest