FC's Electronic Circuits

FC's Circuit Archive

Solar Power Circuits charge controllers, dark-on light, meters
LED Circuits LED illumination, 13 color LED rainbow
Amateur Radio and RF Circuits beacon keyer, smooth sidetone, antenna tuner, tube QRP
Music and Audio Circuits reverb, tube amps, tube fuzz, tube phaser, panner
Micro Power FM Broadcasting Circuits FM stereo, J-Pole antenna, FM10 mods, solar powered bug
Pulse Width Modulator (PWM) Circuits motor speed controls, DC light dimmers
Telephone Circuits phone tap
Computer Boot Management Circuits RS-232 reset, PC auto-start
Test Equipment Circuits logic probe, octopus tracer, frequency calibrator
Geiger Counter Circuits counter mods, numerical counter, probe rebuilding
Video Circuits remote camera motor, miniature camera and TV
Miscellaneous Circuitry:

Software

Some of my Free Software may be useful for working on electronics projects.

Also, see my list of Linux Cross Assemblers and related projects.

Electronic Stuff For Sale

Several of the solar power circuits featured here are available from my kit enterprise, CirKits.com. You can support this site by buying a kit.

My Electronics Garage Sale is an online virtual electronics swap-fest table. I currently have a lot of vintage PC cards and miscellaneous electronics goodies for sale there.

Overview

Here are some electronic circuits that I have designed and published. I have attempted to include a number of fairly unusual circuits, with an emphasis on useful applications over simple toy circuits. The majority of these projects can be built with readily available discrete components. Only a few of the circuits rely on microprocessors. Micros can greatly enhance the power of a small device, but the specialized development tools can put the project out of reach of many hobbyists. See the Arduino project for an easy to learn microprocessor platform with a free software development environment.

Most of the circuits on this site have been drawn with the open-source XCircuit circuit drawing program, it runs under both the Linux operating system and Windows.

I'm a big fan of the Linux operating system. If you have a spare Pentium PC lying around, I recommend giving the free Ubuntu Linux distribution a spin. A large selection of free electronic and ham radio applications are available for Linux. Linux also makes a great platform for dedicated systems: take an older computer, install Linux and the appropriate free software utilities and turn it into a specialized device. Possibilities include web servers, firewalls, security systems, multi-track audio recorders (Ardour, Audacity), weather stations, music jukeboxes, Tivo devices, electric train controllers (JMRI) and much more. The Android cell phone platform is quickly becoming the most wide-spread Linux-based system.

According to Rick Lehrbaum, creator of the Linux for Devices embedded Linux web site, Linux is the New DOS of the computer world. It's a natural platform for programmers, electronics hobbyists, and those who like to dig into the internals of the computer. The source code for the operating system is freely available and documentation is plentiful. Visit LWN.net for the latest Linux news.