Electronics

Here you can find information and schematics for some of the projects I've done.  They are categorized, as follows:

• Automotive Electronics - calibrations and toys
• Electron Tube Audio - tunes via fire bottles
• Home Automation - make your house kinda smart

X10

Posted on August 05, 2003.

Since purchasing a home, I have been trying to make our living space more comfortable and convenient through home automation.  To implement this, I started with the X10 system.  The X10 technology has been around for a very long time.  It uses your house wiring to transmit low data rate signals to various modules plugged or wired into it.  Though slow and prone to noise, the system does work and is very easy to install and configure.  X10 also offers a wirless solution for control over the system.  A special tranceiver module receives the signal and transmits it to the modules through your wiring.  You then have many transmitters to choose from, such as keypads, keychain remotes, multifunction remote controls, motion sensors, etc.

X10 (the company) is only one vendor from which you can buy X10 (the technology) devices, though they are generally the cheapest.  There are other vendors, such as SmartHome, Leviton, PCS, and Home Pro that also offer X10 products, often of better quality and flexibility than those from X10 (the company).  Still, the quickest, most cost-effective way to get started is using one of X10's (the company) starter kits.

Beyond X10

Posted on August 05, 2003.

While X10 devices are completely self-sufficient (you can buy timer, etc to improve automation), in my mind the next level of home automation is to put it under intelligent computer control.  X10 (the company) offers several "ActiveHome" kits that are great to get started in this area.  The software that comes with ActiveHome leaves a few things to be desired, however (more on this later).  With a computer at the center, you can configure it to do intelligent things based on the time of day, whether it's light or raining outside, activity within the home, etc.  The possibilities are endless.

There are devices that you can connect only to a computer to improve flexibility and performance.  You can also extend the automation systems further with multi-I/O units that can interface with the world outside of X10, giving you control of doors, sprinklers, etc and allowing other types of sensor inputs (rain gauges, temperature, etc).

Why Tubes?

Posted on February 01, 2003.

Why thermionic electron emission devices (valves to our friends in the UK)? Well, I grew up listening to my LPs, cassettes, and the radio through a 6V6GT push-pull instrument amplifier and eventually found that I really missed its sound.  I actually didn't know what it was I didn't like about my audio system until I fired up that old amp again.  The brash, gritty sound was gone.  See my Thomas 6V6GT PP amp for more about that.  I don't consider myself to be an audiophile, however the difference to me is noticeable.  For an excellent article with a bit of empirical evidence, take a look at Tubes Vs. Transistors by Russell O. Hamm.

The other part of the answer to this question is that I enjoy the challenge as much as (if not more than) the results of my efforts.  In terms of components in the signal path, electron tube amplifiers are about as simple as it can get.  Perhaps some of the healthy fear involved in working with lethal voltages has something to do with it as well. :) Finally, tubes are just damn cool.  They operate on such a macro scale that you can actually "see" the process take place inside them that is providing you with service that you took the time to design/modify.  They're also pretty to look at....