jurasz.de

Jarek Jurasz

Ludzie gadają i marzą tyle
O przyszłych lepszych dniach.
Do szczęśliwego złotego celu
Wciąż biegną i nań polują
Świat się starzeje i rodzi na nowo
A człowiek ma nadzieję, że się poprawi

Continue reading...

Digital sampling of analog signals can produce surprising effects. It is tricky to explain and understand the frequency aliasing, which happens when undersampling. What is the aliased frequency? Why are there positive and negative frequencies in FFT, but only one Nyquist frequency?

Continue reading...

In electronics there is hardly anything simpler than a voltage divider circuit. Most people know that Vo = R2 / (R1 + R2) * Vi, where R2 / (R1 + R2) = f is the divider fraction. But it is not obvious how to choose the resistor values. You can start with one value, calculate the other one, get...

Continue reading...

My robotic lawnmower (Landroid M1000) stopped to work, complaining it is out of its work area. I knew the wire had some weak spots, but where? It is a few years old, several hundred meters long, hidden under grass... An interesting challenge.

Continue reading...

For a couple weeks now I have this Hantek 2D42 handheld oscilloscope, multimeter and generator and it is time to start a review.

Continue reading...