This space mark demodulator for FSK signals was found in an American telecommunication documentation from the 1980s. The circuit operates with 2025 Hz and 225 Hz mark space signals.
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...