When the concept of electromagnetic waves was first proposed around 1864, it was met with great skepticism. As a result, the idea languished for a long time. It took several decades for a handful of dedicated persons — infatuated with the mysteries of electricity and magnetism — to finally put the theory on a solid footing.
In this article, we’ll take a look back at this period that launched the serious study of radio waves. We’ll examine the contribution of James Clerk Maxwell, the man most responsible for the concept. Next, we’ll look at the work of several notable scientists who came after Maxwell, and see how they confirmed the existence of radio waves.
Nixies were introduced when vacuum tube hardware automatically provided the high voltage they require. These days, circuitry typically runs on five volts or less, so finding the +170V or so for Nixie anodes can be a bit of a challenge. Here are three transformer based ways to obtain that high voltage in line-powered semiconductor-based devices.
Several months ago, an idea popped into my head for a fun project. I wondered if I could burn some characters into the yellow paint of a No. 2 pencil with one of those powerful diode lasers available on eBay. Perhaps it could be my name or my grandkid’s names, or even a happy birthday message to my lovely wife. Here’s how I did it.
All sorts of questions arise when choosing a new digital oscilloscope (DSO) — it can be somewhat daunting! Here are 16 tips that can make selecting the appropriate oscilloscope for your task at hand a lot easier.
Are you bored with conventional two-dimensional circuit layouts, or looking for a way to add an artistic flair to your next project? I’ve taken point-to-point construction style a step further by making it self-supporting, which opens up a wide range of physical circuit topologies. (Point-to-point construction usually uses supporting structures like terminal strips that are functional but not pleasing to the eye.) I call this construction style the copper cobweb. Here’s how to do it.
I’ll show you two examples of circuits that don't use a micro but are often built with one, and explain some of the logic and theory behind these circuits.
Signal generators are devices used to make the signals used in testing and troubleshooting of radio receivers and other circuits, so are of primary interest to almost everyone interested in electronics.
I love restoring old electronic equipment. A while ago, I was excited to find a vintage Heathkit EC-1 analog computer for a reasonable price on eBay. It definitely needed a little TLC. Here’s how I brought it back to life.
In the US, the DC volt is legally defined by the Josephson array — a super conducting quantum device with a highly repeatable output voltage. Banks of standard cells and temperature-stabilized zener diode references are used by the National Institute of Science and Technology (NIST) to calibrate DC meters for scientific and industrial customers. So how is the AC volt defined?
How many times each day do you pick up a probe to measure a DC voltage? The meter reads, say 4.65 volts, and we usually accept it without question. But just what is a volt and how is it maintained? Here's a fascinating look at the search for increasingly more accurate methods of building a “standard volt.”
It’s not all that often that a different piece of hardware comes along that immediately captures the attention of the builder community. The ESP8266 is an example of this. It’s only about the size of a nickel, yet contains a powerful 32-bit microcontroller and a Wi-Fi interface, plus you can buy it for under $10.
The Raspberry Pi represents a breakthrough in low cost computing power. Get a piece of this popular DIY action by learning how to cook up your own RPi to start experimenting with.
Perhaps one day soon we’ll have a battery that displays no “memory” effect; can be completely discharged or overcharged without harm; and require no complex computerized management system. Does such a battery sound like too much to hope for? Thomas Edison didn’t think so.
As an experimenter, I use wall warts all the time to power circuit boards, microcontroller boards, and even finished projects. However, during the checkout phase of a new circuit, wall warts present a problem. How do you measure their output when they’re plugged into a board or project box?
A fun take on an old favorite - Build this Entertaining and Educational Digital LED clock and learn “Charlieplexing” to control 180 LEDs.
Tired of broken wiring harnesses and bad connections on your trailer lights? Build a set of wireless taillights that you can use on anything you can tow.
Perfect for kids (or adults who act like kids!). When triggered by the motion sensor or via the push-button switch, this mini animatronic system moves servo motors, lights LEDs, and plays back the sounds you record!