This circuit with losses of 20 dB at 350 Hz was found in older documentation, but it applies to modern preamp and amplifier circuits.
Found in documentation from the 90s, this circuit can employ other comparators in the series such as...
This circuit was found in a PE Hobbyst Handbook from 1992. The second oscillator is a VFO. The...
This motor control using transistors was found in a recent English publication. The circuit is for...