Factless

I believe I have linked to Shop Class as Soulcraft in The New Atlantis web-zine before, but I keep running across in various venues, and it is too good to miss.

Anyhow, what I really wanted to mention was a couple of very readable articles written by Jim WIlliams, a famous analog (electronics) designer at Linear Technologies, the first of which you don't need to be an electrical engineer or a geek to understand. Try fixing it yourself is as much philosophy as electronics, and I think anyone can appreciate the lesson Jim is trying to share. The second is "Tripping the light fantastic: a case study in circuit design" which although more technical is still an insightful essay on process (the good kind) and is a wonderful description of what engineering really is. You can browse more of Jim's writings at EDN, including Somthing from nothing.

Continue reading "classic articles by Jim Williams" »

Posted by mctaylor at 10:16 PM | Permalink | Comments (0)

I am not sure who coined the term Joule Thief, but I like it. It is used to describe a simple voltage boost circuit that "squeezes" otherwise wasted stored power (W) in a primary (non-rechargeable) battery, in the last lag of the battery's life where it suffer from voltage drop off.

As far as I know the majority of battery powered devices do not use a similar circuit to help extend the useful life of non-rechargeable batteries even in the excessively common low current demanding mass market device like TV remotes and such.

So here is one how to make a joule thief page by Alex Smith. Another make a Joule Thief from Big Clive, and you can watch a video podcast with Evil Mad Scientist Laboratories and Bre Pettis (if you don't just become obsessed with Bre's hair, it just creeps me out for some reason). Finally, there is another Joule Thief booster circuit that is available in kit form and uses two transistors, out of a total of 7 parts for ~70% efficiency. That could be almost invisible with SMT parts. Here is some more information from White LED Drive Circuit by Dick Cappels and Joule Thief wiki page from David Wagner.

Posted by mctaylor at 8:16 PM | Permalink | Comments (0)

Kaden Harris's website Eccentric Genius is the sort of thing I find inspiring, where raw creativity applied to available materials, typically scrap (I mean recycled). I discovered his site from mention in a Globe and Mail article Zen and the art of scrapyard archeology where it describes the small rise in Making in the sense used by O'Reilly's Make magazine.

Fun stuff.

Posted by mctaylor at 3:33 PM | Permalink | Comments (0)

It turns out that the 52 inch DLP projection TV I bought made by Toshiba has a flaw in regards to the lamp included with it.

References:
* Toshiba 52HMX85 bulb has blown! (Digital Home Canada)
* Toshiba Investigates DLP Lamp Problems (Audioholics Editorials)
* Information for Owners of 2005 DLP® Televisions (Toshiba Canada Support)

The good news is that Toshiba has owned up to the issue and has extended the warranty for the bulb to two (2) years automatically for TV models affected by the problem. This is great as my bulb blew last night. I wasn't sure about the "dimming" I had experienced before it blew was my mind playing tricks on me or not because I haven't been watching a lot of television lately (into summer reruns).

I also found out that bulbs certainly seem to vary in price, from about $230 to nearly $300 Canadian in a couple of Canadian stores to as little as equivalent to $200 Cdn on eBay (incl. shipping) for the same Toshiba brand replacement bulb (D95-LMP - part no. 23311153).

My replacement bulb from Toshiba should be sent tomorrow, so I won't be without high definition television for too long. I suppose I could hook up my 27" RCA CRT (tube) standard definition TV is I get desperate, but I've been watching so little television I doubt I will bother.

Posted by mctaylor at 5:16 PM | Permalink | Comments (1)

Lately I've been trying to design a 24V_dc @ up to 2 Amperes power supply. The power supply is for a surplus Datum (acquired by Symmetricom) LPRO Rubidium oscillator that I picked up off eBay.

I figured I should use a linear power supply with good voltage regulation, and able to meet the up to 1.45A needed during 15 minutes of initial warming up (literally, there is a heater for the Rubidium (vapor?) as I understand it). So I figured that I should use something better than just a 3-terminal 78xx or LM317 series voltage regulator with a pass transistor.

Continue reading "Designing a power supply using the LM723 regulator" »

Posted by mctaylor at 11:09 AM | Permalink | Comments (0)

No I wasn't playing tag with kids, they would probably beat me. I have my HP Z3801A GPS-based frequency and time standard working.

Continue reading "What time is it Mr. Wolf?" »

Posted by mctaylor at 10:24 AM | Permalink | Comments (0)

I want to build a "gadget box" like the one describe at the Pulse-per-second Signal Interface page that is part of the NTP documentation. The gadget box would allow me to decode the time signal in Bell 103 (300 baud) standard from CHU, the Canadian National Research Council's shortwave broadcast transmitter located near Ottawa, Ontario, Canada (Google Maps).

Continue reading "Using CHU broadcasts as a time source" »

Posted by mctaylor at 11:47 PM | Permalink | Comments (1)

Here is a laundry list of online learning resources about electronics.

Lessons In Electric Circuits (which All About Circuits is derived from)

MIT OpenCourseWare 6.002 Circuits and Electronics (Fall 2000)

Bob Pease Analog Engineer and thinker from National Semi

Op Amp Applications by Walter Jung is either available in print (2005 ed) or as a free download (2003 ed).

A Designer's Guide to Instrumentation Amplifiers from Analog Devices by Charles Kitchin and Lew Counts

Basic Analog for Digital Designers (Intersil AN 9510 PDF)

An audio circuit collection, Part 1 (TI)

Op Amps for Everyone Design Guide from TI

Understanding Basic Analog - Ideal Op Amps - Several examples of amp circuits are described.

Single-Supply Op Amp Design Techniques

Analog Electronic Design in a Day! free online course from TI

SwitcherCAD / LTspice III - a free full featured SPICE program from Linear Technology

Eric KE6US has a page about SPICE for Hams (radio amateurs).

Posted by mctaylor at 11:10 AM | Permalink | Comments (0)

Normally people complain about their experiences with warranty replacement, so I wanted to share this seemly unique painless experience of getting my DVD player replaced under warranty by Toshiba Canada.

I had purchased a Toshiba SD-5970 DVD player with HDMI Video Upconversion (better resolution for displaying on a HDTV display) and 3:2 Pulldown from Future Shop (why does it seem that every time I buy something from them, it turns out to be a bad idea?) in the fall of 2005.

Earlier this year the display panel on the DVD player died, at first I thought I had dimmed the display so I couldn't see it. But after a while I dug out the manual (ek gads) and tried to reset the unit, still no display. Since the remote was pretty sad from day one, and while I could use it to play back discs it was annoying for music CDs where I wanted to know which track was playing.

So called Toshiba, well I did after I found their current toll-free number, the one listed in the manual for warranty calls didn't work, but I quickly found the right phone number on the web site. Once I had the serial number and found my receipt, I scheduled a pickup and Purolator came and picked up the unit in its original box with the remote (I was reminded to include this). That was a Tuesday I believe, on Friday I received a replacement SD-4990 unit with all the same features, plus some trivial bonus features (DivX playback). So I was impressed with Toshiba who answered the phone quickly, with a person in Canada as far as I could tell, and got the replacement unit to me in a short period of time with no hassle.

Now back to enjoying my home theatre setup.

Posted by mctaylor at 6:27 PM | Permalink | Comments (0)

If you want to learn about microcontrollers, basically a single chip with a microprocessor (aka CPU), RAM, and program memory (ROM, EPROM, EEROM/EEPROM, or increasely common Flash memory) you can easily find many development kits to make it easy to get started. Some are even very cheap (~ $20-50 USD). The three most common microcontrollers for hobbists are the BASIC Stamp 2 modules from Parallax, the PIC series from Microchip, and the AVR series from Atmel.

Continue reading "Learning about microcontrollers" »

Posted by mctaylor at 7:20 PM | Permalink | Comments (0)

Lately I've been trying to beef up my electronics knowledge, I recently finished "Guide to Understanding Electricity and Electronics" by Randy Slone, and am currently reading Designing Embedded Hardware, 2nd ed. by John Catsoulis (errata) which is pretty much as close as I can expect for a good second book for trying to do something more advanced with electronics, i.e. making a "system" that interfaces with the real-world rather than a just a isolated "gadget."

Of course I've been reading Make magazine published by O'Reilly which I love and hate at the same time. I love the creativity of ideas and approaches, but the authors can annoy me with their "hip" writing style. If you're too cheap to shell out for the paper copy, check out Instructables.com which tends to have many of the projects on their site, in either a prequel or revised version.

Continue reading "Learning about electronics and antennas" »

Posted by mctaylor at 10:54 PM | Permalink | Comments (0)