This circuit for low frequency data transmission was found in the May 1977 issue of Radio Electronics magazine. The circuit modulates the signal at two frequencies for bits 0 and 1.
The project presented in a 2009 documentation is intended for radio amateurs operating in the...
This circuit consists of a rearrangement of the previous circuit also using 4 relays. We found this...
This circuit can be used to couple signal sources or low intensity transducers to microcontrollers (Shield)....