Found in Motorola documentation from the 90's, this circuit has a high input impedance. The power supply must be symmetrical. The circuit can be implemented with modern operational amplifiers.
This circuit is a small FM transmitter, capable of carrying its signals over short distances...
This circuit is intended for underwater communications. Of course, the critical point is the...
Originally this circuit excites an incandescent lamp, but it also serves for LEDs, if they use a...