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 voltage level-triggered circuit was found in a 1969 Ferranti English documentation. Modern...
Using 555 integrated circuits, this alarm circuit was found in a 90s American documentation. The signal...
Unlike the CIR4620 circuit, the circuit shown in the figure operates by capacitance. This means...