The circuit has been constructed to test and measure the voltage rating of zener diodes. To be able to test the voltage rating of a zener diode up to 50 VDC, a small transformer and a single 555 timer ...

[Hans] wanted to see the frequency response of a bandpass filter but didn’t have a lot of test equipment. Using an RTL-SDR dongle, some software and a quickly made noise generator, he still managed to ...