This circuit has a gain of 6 dB for low frequencies from 85 Hz and can be used in a mini subwoofer. The circuit is from a Radio Electronics from March 1990.
This circuit from an old American publication uses a 12 V transformer and an incandescent lamp in an...
The integrated circuit used in this regulator is quite old. Its 1970s casing is still made of...
This crystal oscillator uses a common transistor and its frequency depends on the crystal used. We...