This circuit was found in the July 1988 issue of Radio Electronics magazine. It makes use of an operational transconductance amplifier (OTA) still in use today.
This interesting shield circuit was obtained from a Poptronics of February 2001. The American...
This remote control receiver via the power grid appears elsewhere on this site from other sources....
This 555 IC circuit was found in the November 1994 issue of Radio Electronics magazine. The...