Nuts and Volts

A previous article about vacuum tubes and tube-based equipment included a sidebar about safety with tube-level voltages — it seemed to me an article on some of the issues associated with those voltages would be interesting. There are lots of circuits for generating high voltages out there, but what about the “gotchas?” How High is High? Let’s talk a bit about what the “high” in “high voltage” means.

Even when a circuit functions as it’s supposed to, it’s not always easy to tell what it’s doing. Plus, waiting for an output (especially if there’s a long delay involved) is not always practical. Conversely, if a circuit does not function, the only means to find out what’s wrong is to troubleshoot it with either a multimeter or oscilloscope. Wouldn’t it be great if the circuit itself could tell us more directly what’s wrong? This is solved, in part, by a light that turns on with an on-off switch.

There’s a deep sense of satisfaction that results from developing, building, testing, and ultimately using a circuit of your own design. It’s the creative process, after all, that attracts most electronics enthusiasts. Given the expense of components and tools relative to the price of finished electronics products, it’s difficult to rationalize the investment in time and energy simply to have a working device.

A Lost Technology of the 1950s Anyone can build it! Most folks believe that first came the vacuum tube and right on its heels came its successor, the transistor — an historical fact, correct? Not really. Another competitive control technology developed by US and Nazi engineers came in between. It was the magnetic amplifier.

It should be pointed out that if you intentionally try to fool the chessboard by doing something far outside the rules of chess — like picking up multiple pieces and switching them — it's not too hard to confuse the program or even lock it up. The software will do a good bit of checking to look for reasonable errors, but it cannot identify every trick you try. This should not present a problem if you simply stick to the rules of chess.

Posted in: Developing Perspectives (December 2008) By Bryan Bergeron To my dismay, the ‘audiophile’ cable came with gold-plated twist-on connectors. I was taken aback. Twist-on, not even crimp-on. The instructions said to just peel back a quarter inch of insulation and twist the wire into a connector. My first response was disbelief. After all, how would a twist-on connector hold up to the constant vibration of a subwoofer? Would the friction fit result in noise?

Hopefully, you remember the game: Four buttons, four different color lights, four different sounds, and you must repeat the “challenge” pattern as it gets longer and longer. If you fail, you get to hear the “raspberry” sound! Using a Flea-Scope™ board running StickOS® BASIC, it’s possible to quickly build a Simple Simon game in minutes at home using nothing but a soldering iron and a web browser! Take a look at Figure 1. FIGURE 1. Flea-Scope wired for Simple Simon.

When my wife and I moved into our current home a few years back, it didn’t have a doorbell. We live on a quiet cul-de-sac, so it really wasn’t a problem as we had few callers. After a while, I installed a wireless doorbell that lasted about three years. Recently, after writing the series of articles on “A Digital Analog — When a PIC Can Replace a 555,” I decided to make one using a PIC.

These days, recording music on a PC is a surprisingly straightforward affair. Once you master a program like Cakewalk’s Sonar or Steinberg’s Cubase, it’s a matter of if you can dream it up, you can record it. With programs like Sony’s Acid, you don’t even need to be much of a musician: just layer various loops to taste and you can start making music. Back in the 1980s, it was a different story.

An Invention that Changed the World It started with a Bell Telephone Laboratories program of basic research on solid-state physics in 1936 that produced a replacement for the vacuum tube in the 1950s and eventually gave us integrated circuits and the microprocessor. It spawned a huge semiconductor industry generating hundreds of billions of dollars in sales. However, behind this story of invention is one of collaborative genius, serendipitous mishaps, clashing egos, and secret research.