This circuit was found in documentation for radio amateurs of the 1980s. This is the so-called roger-beep, which is the beep that is transmitted when the talk-listen function is changed.
This circuit can be used to test zener diodes up to 25 V using a standard multimeter. The voltage...
This circuit without any capacitor operates based in the time the transistor need to turn on. The...
This circuit is suitable for recovering vinyl media, having been found in an old sound magazine from...