Dimming AC lights the hard way

AC

It's that time of year again where the thermometer drops, the sun sets earlier, and we try to warm our hearts with the solstice festival that is common in our own respective cultures. Of course we all need a few strings of lights, but wouldn't it be great if we had PWM controlled dimmable lights? When he started out on his PWM-controlled, AC-powered light box, [Waterbury] immediately realized … [Read more...]

Follow up: Star Wars tree gets an upgrade

star-wars-tree-sound

We asked, and [Zach] listened. Earlier this week, we featured a circuit he built which allowed his tiny Star Wars Christmas tree to visually replicate the series’ theme song. Several of you, along with myself, thought it would be far cooler if the tree also played the music to accompany the light show, so [Zach] set off to add that functionality. Worried that the music would get annoying … [Read more...]

The force is strong with this Christmas tree light show

star-wars-christmas-tree

[Zach] is a huge Star Wars fan, and in addition to the array holiday decorations that adorn his house, he says that his wife is nice enough to let him put up a Christmas tree full of Star Wars ornaments. For the past few years, the tree sat in the corner of the room unlit, but his wife thought that it should have some lights this year. His wife came home with a small string of battery-operated … [Read more...]

Motor drivers: half h-bridge with brake and more

half-h-bridge-with-brake

Here's a nice little circuit that will drive a motor and allow you to stop its rotation, giving your robot a set of brakes. It's part of [JM's] post about the in's and out's of building microcontroller friendly motor controllers (translated). This particular setup is a half H-bridge. It allows you to drive the motor in one direction only. The MOSFET used on the ground-side of the motor doesn't … [Read more...]

Detailed tutorial shows how to unleash your inner [Michael Knight]

developing_a_larson_scanner

Our own [Mike Szczys] recently sat down and put together a great tutorial on building a Larson Scanner. The ubiquitous circuit is usually one of the first few projects on a budding hackers list of things to build, since they are just so darn fun. Simple versions of the scanner sweep back and forth lighting the LEDs without any sort of transition between them. The configuration most familiar to … [Read more...]

Converting PWM to DC signaling for more precise fan control

pwm_to_dc_fan_control

[hedgehoginventions] wrote in to share a little modification he made to his video card in order to keep it from overheating during strenuous 3D tasks. Having swapped out the stock cooler on his Nvidia 9600GT graphics card, he found that it did not need to utilize the fan while doing mundane things like checking email, but that it still required extra air flow while playing games. He figured he … [Read more...]

An introduction to DC boost converters

simple_boost_converter

If you are planning on creating some sort of Nixie tube display, you will undoubtedly need to find yourself a high voltage DC power supply. If you don’t want to add a transformer to your project, you can always opt to build a boost converter instead. [Andrew Moser] shows us just how easy it is to build one, discussing the theory behind simple boost converters along the way. Boost converters … [Read more...]