This cassette player motor speed control was found in the January 1991 issue of Radio Electronics magazine. The circuit is for voltages from 9 to 12 V.
This space mark demodulator for FSK signals was found in an American telecommunication...
Using the CA3018 released at the time, this circuit was found in the August 1970 Radio Electronics...
The circuit below simulates an inductance with value given by the components, which can be...