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 circuit, from an American publication of 1974, provides a 0.005% regulation with a variation of...
This circuit was found in a 1958’s publication. It uses germanium transistor, availble that time....
In this circuit we have the voltage multiplied by 5, obtaining between 50 and 80 V output when the...