For those who experiment and build with vacuum tubes, an adjustable regulated benchtop high voltage power supply is essential. Many circuits for such units have been described that themselves use tubes. It’s nice to be consistent, but we can save some bench space and a few watts by using semiconductors in such a unit.
The NixieStar clock is the second timepiece kit I’ve developed. My aim was to have a kit that’s reasonably easy to build with intermediate soldering skills (i.e., minimal SMD components). I also wanted a clock kit that once it was built, any spouse (including my wife!) would accept it on their wall — even with a power cord hanging from it.
Work areas usually have multiple power strips ganged together and connected to the same outlet. Various devices are connected to these strips, including computers, lights, coffee pots, space heaters, etc. Environmentally conscious persons ask, “How much power does my work area consume?” Safety conscious persons ask, “Am I overloading my circuit?” Calculating the answers requires two basic measurements: the voltage supplied to the circuit, and the amperage consumed by the circuit. Measuring AC voltage and, particularly, amperage with a multimeter is a potentially dangerous diagnostic for laypersons.
Wouldn’t it be nice to have a self-contained volt/amp meter that displays the values on a webpage?
Magnetic loop antennas are becoming popular today because they can be very efficient for their size, do not need radials (even though most designs are vertically polarized), have useful takeoff angles, and can be easily rotated to peak or null a signal. Here’s how I designed a convenient setup for myself.
There are lots of circuits for generating high voltages out there, but what about the “gotchas?” Learn how to be safe and smart when working with these potentially dangerous types of projects.
For audiophiles, musicians, and ham radio operators, the soft glow of the vacuum tube filament is not only an indication of function, but a nostalgic trigger for memories of simpler times. Though they may have been outpaced by tiny transistors and integrated circuits, these workhorses still may have something to offer in many modern devices.
Small Geiger-Müller (G-M) tubes make ideal sensors for pocket-sized devices to detect radioactivity. However, even a small G-M tube needs an anode voltage in the 400 to 600 volt region. Here's how to generate that voltage from a 9 V battery.