This two-channel wired intercom was found in the April 1990 issue of Radio Electronics magazine. Maximum cable distance depends on cable thickness.
This simple window comparator based on the well-known LM339 was found in the June 1998 issue of...
This circuit makes use of a transconductance operational amplifier. It generates signals with TTL...
This circuit has a traditional configuration often found on this site. The transistor must be...