380 volt circuit continuity tester

There’s always a need for a multimeter when working with electronic circuits. Especially when it comes to semiconductors. Using the internal diode test, which is now a part of every good meter, we are able to double-check the proper function of every diode, bipolar transistor and the like, before using them in our projects. However, there are still certain parts, for which … [more]

Digital pulse counter

This here is a simple but versatile pulse counting/smoothing integrator circuit with an NE555 as the shaper, and a little LCD display as the output. I have originally done it for counting pulses from my Geiger counters, so I have included a piezo speaker combined with an LED for indication, but it can also have a variety of other applications, like revolution counters… [more]

Fully Regulated ATX Power Supply

Now, let me begin this article by stating that this *is not* a so-called “conversion” with an LM317 (or any other linear regulator in general) like you might have seen on thousands of other web pages, nor a so-called “lab” supply that was made just by shorting the PS-ON pin. This is a real ATX to regulated supply conversion, which might come in handy for you.… [more]

Geiger Müller counter

This is a “soap-box” device which I have constructed back in 2010, when I had no calibrated radiation metering devices such as the IT-65 at hand, and there was a need to distinguish between normal and abnormal intensity levels. The reason why I have chosen to do this from scratch was simple… [more]

Nixie tube tester

This very simple circuit can be used to verify the proper functionality of each cathodes in a Nixie tube, which was the predecessor of the solid-state LED 7-segment display, back in the 1960s and early 70s. The main anode voltage is obtained from a simple, battery-powered flyback inverter with just enough voltage to strike the glow discharge, and an adjustable resistor current limiter… [more]

Semiconductor free Geiger Counter

Tried searching the keyword “geiger counter” on Google, or even better, on YouTube? Now, how many of them contained a multitude of transistors, analog microchips or even digital microprocessors, and no shielding at all? Well, whatever the count is, a majority of them – if not all – are going to fail miserably, due to a huge electromagnetic pulse, when the… [more]