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 … [read more]

Arcs from mains voltage 230 V

You might have seen them all. Flyback transformers, microwave oven transformers, ignition coils, oil burner transformers, potential transformers, pole pigs, x-ray transformers, high voltage switched mode supplies, Tesla coils and the list goes on. However, have you ever thought of a possibility of drawing arcs directly from mains current?… [read 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, track/lap counters… [read 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.… [read more]

Geiger Müller counter

This is a 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: back then, I had quite a few GM tubes lying around doing nothing and I’d been unhappy with a conversion… [read 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… [read more]

Triac phase regulator

This circuit, also informally known as the poor man’s variac, is used in many applications in both consumer and industrial electronics, where a perfectly sinusoidal waveform is not required and a real variac (variable autotransformer) would be too heavy and bulky. This is the case of light dimmers, vacuum cleaners, motor speed control, heater elements and similar. It was… [read more]

Two watt blue laser driver 445nm

Now here’s a novelty, besides high voltage! A two watt 445nm “M140” diode in heatsinked, focusable housing, all with a regulated constant current driver. So, here’s the result of jumping on the bandwagon of lasers… [read more]

Uncategorized experiments

A handful of photos and comments regarding some of my unfinished, abandoned, failed or likewise hilariously stupid experiments, for which I have gathered up the courage to put them on-line 🙂… [read more]