This circuit was found in 1980's Radio Electronics. The circuit produces a 1500 Hz modulate 35 kHz. The components used are still common.
This circuit was originally suggested in a 1968 publication to generate a white mark (frame) on a...
This CMOS circuit was found in the July 1990 Radio Electronics magazine. Power is for a 12V...
This is the traditional configuration of an AND gate using an operational amplifier. Operational...