Found in the book 303 Circuits, this circuit compresses signals from 25 mV to 20 Vpp to intensities of 1.5 Vpp to 3.5 Vpp. The frequency range is from 7 Hz to 67 kHz.
This circuit triggers the LED when the monitored battery voltage drops below 9 V for 12 V...
We found this circuit in a Radio Electronics from January 1967. The SCR is already the C106, which...
This power source with silicon diodes at a time when valves were still used was found in Radio...