This circuit was presented in a January 1990 Radio Electronics magazine article as part of a home theater sound effects system. It consists of a 3 kHz high-pass filter.
In the figure we have the way to obtain an adjustable constant current source of 2 mA. The...
This complementary transistor stage was found in a 1968 publication. The transistors are germanium types and...
This circuit warms a light bulb slightly so that the wind through it alters the filament...