This 80's circuit uses an audio amplifier to obtain a symmetrical source from a single source. The maximum current is on the order of 1.3 A and the input voltage must not exceed 20 V.
Also suitable for use as a noisy alarm, this Morse Code or telegraph practice oscillator was found...
We find this circuit in American documentation from the 1980s. It consists of a frequency folder...
The frequency of this oscillator can be set in a range from 5000 to 1. We found it in an old...