Electronics Now articles from July 1994

Electronics Now archives from July 1994

Micromachined magnetic actuators.
July 1, 1994... Photolithographic and micromachining techniques permitted researchers at the Georgia Institute of Technology to form the tiny electrical windings and nickel-iron cores in low-voltage magnetic microactuators that do things their electrostatic...

BDM40 benchtop digital multimeter. (Evaluation)
July 1, 1994... When performing benchtop troubleshooting or repair, it's best to use test equipment intended for benchtop use. Most readers of this magazine are familiar with bench testing; it's an essential part of working with electronics. For infrequent...

Build this amateur TV station. (part 1)
July 1, 1994... Build your own 2-way TV station that permits base and mobile operation. RADIO AMATEURS HAVE BEEN COMmunicating with two-way television for years, but their equipment was so expensive that it cost more than most amateurs could afford. However,...

The 'led-head.' (Electronic Face)
July 1, 1994... Build this amusing Electronic Face that appears to change mood when the LEDs that define its features are randomly switched. HUMANS RESPOND TO CHANGES IN the expressions on other human faces that reflect emotional state--happiness, anger,...

Relay output circuits.
July 1, 1994... THIS ARTICLE CONTINUES THE RElay switching circuit theme of last month by presenting a selection of practical control circuits for electromagnetic relays. Last month's article discussed the basic operating principles and application rules for...

Build this PC I/O breadboard. (personal computer; input/ouput)
July 1, 1994... Putting last month's PC breadboard hardware to work. SOME PEOPLE MASTER HARDWARE, others master software--but few master both. Those who do, however, can expect great rewards. Last month's project was building the hardware: a PC interface card...

Tunable shortwave antenna.
July 1, 1994... Improve your shortwave reception with this tunable antenna. FOR AS LONG AS SHORTWAVE LIStening has been popular, it has been difficult to match a random-length antenna to the typical 50- or 75-ohm input impedance of most radio receivers. The...

Build this computerized game.
July 1, 1994... Learn how electronic games work; then have fun playing one that you built. ALTHOUGH PLAYING COMPUTER games can be a lot of fun, operating them teaches you very little about how they work. A good way to learn how electronic games work is to...

Take back control of your telephone.
July 1, 1994... Upgrade the February 1994 Caller-ID project so it works with the calling-name delivery service. AN ARTICLE IN THE FEBRUARY 1994 issue of Electronics Now ("Take Back Control of Your Telephone") described the operation and construction of a...

Second law violations, soliton wave rectifiers, a fine new CD-ROM directory, a Santa Claus machine update, and some unusual hacker opportunities.
July 1, 1994... I just got a call from a graduate student who is certain that second law of thermodynamics has been proven wrong and he wanted to know what should be done about it. He said something about statistical thermal gradients nailing Maxwell's Demon in...

Sound pressure level: damage/sonic realism.
July 1, 1994... Regular readers of this column are probably aware of my strong interest in hearing preservation. Obviously, I'm swimming against the sonic tide, given the proliferation of killer car stereos, overdriven Walkmen, excessive concert-hall levels, and...

This month we build the PLL section of our tachometer. (phase-locked loop)
July 1, 1994... Before I get started this month, there's some unfinished automotive-related business to take care of. Some months ago I mentioned that while two stroke engines had just about disappeared, they were still used in chain saws. I wondered if anyone...

And then there were none. (computer industry advancements)(includes related article)
July 1, 1994... This year is shaping up as an eventful one for the computer industry. So far, several new technologies have been introduced, and several significant business events have occurred. Those events that happened in the first quarter of 1994 will have...