This approach alarm circuit was found in the September 1970 Radio Electronics issue. The 1 mH coil is wound on a ferrite rod. The relay is 12 V sensitive.
This old configuration of an audio amplifier has a push-pull two-transistor output stage. Output...
This bandpass filter has a simple feedback system. The component values can be calculated using the...
This hysteresis comparator was found in the 1994 National Semiconductor Linear Applications...