Electronics Now articles from March 1997

Electronics Now archives from March 1997

Build the Guardian. (silent automobile alarm)
March 1, 1997... Worried that your car might not be there when you return? Let the Guardian alert you to a break-in without alerting the thief. You have invested a lot of your hard-earned money into your auto, van, or truck. Understandably, you'd like to...

Build the PCDrill. (computer-controlled drilling table)
March 1, 1997... Build a PC controlled drilling table that simplifies the task of making printed-circuit boards. Last month, we showed you the construction details for a stepper-controlled PC-board drilling system that can provide 0.001-inch accuracy in...

Phone line monitor. (telephone security system)
March 1, 1997... A cut telephone line can trigger your home security system into action. Many security systems can automatically call a central monitoring station to report a problem. But what do you do if the burglar, who is always trying to stay one step...

Designing active AC filters. (electronic frequency-selective alternating current filters)
March 1, 1997... Low-pass, high-pass, band-pass and notch - they're all here! Electronic frequency-selective AC filters (filters) are circuits that favor some frequencies and discriminate against other frequencies. Frequencies that pass through the filter with...

Build the animal sounds piano.
March 1, 1997... Here's a simple, easy, and educational project that's as fun to build as it is to use: a 10-key music synthesizer that "plays" barnyard-animal sounds! If you want to give your youngsters hours of fun and entertainment away from the television...

The idea-mortality curve, table lookups, and more. (development of new concepts and inventions)
March 1, 1997... I have recently been listed as a "commercial invention assistance provider" in the free directories you can get from R. L Conger at Batelle Pacific Northwest. Because of that, as you might guess, I get lots of calls. The majority of those callers...

Modulating a laser beam.
March 1, 1997... This month, let's turn our attention to a different type of laser application - using a laser to transmit sound. We will look at a couple of different approaches to doing that. Either approach could make a great beginning for a winner of a...

More on troubleshooting camcorder zoom lenses.
March 1, 1997... Last month, we began our look at troubleshooting camcorder zoom lenses by looking at how a modern zoom lens works. This month, we'll turn our attention to some real-life servicing problems and how to solve them. We'll start out with a look at the...

Can electronic commerce pass the ACID Test? (authenticity, confidentiality, integrity and delivery)
March 1, 1997... Many companies want to part you from your hard-earned cash via the internet. Some are even succeeding. For example, you can purchase audio cds on-line from cd-now. Most companies, however, are still waiting for a real market - paying customers -...