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 one is from an 80's EDN. Transistors can be general purpose types. The frequency is...
This power supply is not protected from shorts in the output. Output voltage is given by the...
This static switch or electronic contactor was found in a 1968 Motorola publication. The triac...