This circuit is from 1964 documentation but can be easily implemented based on current components. Input waveforms and detection are shown next to the diagram.
1 We found this circuit in GE's 1977 semiconductor manual. The optical isolator uses an opto-SCR, and the...
This circuit was found in a 2005 Linear Technology manual. The circuit monitors 12 V batteries in...
This simple receiver was found in a book on transistors from 1954. The coil determines the...