Posted on 19 May 2008
This power supply module plugs straight into common bread boards, allowing you to cleanly and easily power your board with a wall wart plug or with wires into screw terminals. It features a variable voltage regulator that can be set to output 3.3 or 5V with a jumper, or any voltage if a potentiometer is added. The input has a rectifier that accepts AC or DC [more]
Posted on 08 May 2008
Using the term ‘music’ liberally here, it will play a squeaky, but recognizable stream of audio, generated from MIDI files.It’s a satisfying little project that is a nice change from the typical beginner embedded controller blinking LED project(s).You can’t get any simpler than this: a piezo buzzer, a power supply (3×1.5 AA), a breadboard, and an AVR (ATmega16, but almost any will do).To make new music files, you’ll also need Perl and a program such as MIDICSV to convert the files.[more]
Posted on 17 Apr 2008
Ralph W5JGV writes:This is an ongoing narrative of my attempt to construct a high-power switching power supply to replace the failed power supply in my Heath Warrior amplifier. Since I use the amplifier for experimental (non-Ham) work, it sometimes has to operate at full CW power for several hours at a time. The original plate transformer is unsuitable for that task, so I am attempting to build a really heavy-duty supply to replace the original power supply.My design concept started when I inherited a large quantity of well-built Dell computer power supplies. They were rated for 230 watts, and some testing showed that the switching transformers in the supplies could easily handle 250 watts. Hmm… If there was just a way that I could make these things put out HV instead of +5 Volts, I’d be all set. Well, to work! [more]
Posted on 18 Mar 2008
This rain detector will give you a heads-up the instant it starts to rain, hopefully giving you time to close windows and bring in possessions. The battery-powered circuit draws virtually no current when the sensor is dry and the current consumption is low when the buzzer is activated so a couple of AA cells will last a long time. Alternately, a molded power supply with a simple voltage regulator to drop the voltage to 3 volts could be used. The circuit is basically a handy flasher circuit that operates well on only 3 volts using ordinary silicon transistors. When the circuit is triggered, the buzzer is pulsed about once per second.[more]
Posted on 19 Feb 2008
AI-1 Remote is the All-in-one remote has been designed as a versatile, portable photographic accessory that you can tuck in your camera bag. It combines a number of useful features that you will provide capabilities that you’ll find both useful and fun during your field, home, or perhaps even studio photography.In one box, you’ll find a wired remote, a wireless remote, a power supply for your camera, a versatile intervalometer, and an interface to devices such as pressure-sensitive pads, trip wires, etc, that can take a picture when your subject trips the trigger device.[more]
