This circuit was obtained from a 1965 Radio Electronics. The semiconductors used admit modern equivalents. The high voltage coil is an automobile ignition coil.
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...