This circuit was suggested by National Semiconductor in one of its manuals. The LM108 integrated circuit, uncommon nowadays, can be replaced by an equivalent. The power supply must be symmetrical.
We found this circuit in the Linear Applications Handbook of the National Semiconductor of 1994....
This tone-modulated transmitter was found in recent English documentation. The circuit operates in the 27...
This very low current circuit was found in the April 1995 issue of Electronics Now magazine. The...