This circuit was found in a 1970s General Electric documentation. This circuit already used an emitting LED. The circuit operates at frequencies from 50 Hz to 50 kHz with short pulses
This amplifier with gain control was obtained in a documentation from Signetics of the 80's....
This electronic flash circuit was found in the March 1961 Radio Electronics magazine. The circuit...
This voltage-controlled function generator circuit was found in ancient European documentation. The circuit...