We found this circuit in the September 1992 issue of Radio Electronics magazine. It can be triggered by any signal above ½ Vcc, where Vcc is the supply voltage.
This reflex receiver for the mid-wave range employs germanium transistors of the time. We found it in...
These two circuits are of regulators for currents of the 500 mA order and can be assembled with modern...
This circuit causes an instrument needle to oscillate to signal an event. The circuit is powered by...