No information is given on the transformer in this circuit that we found in an American 1967 documentation. The power transistors are of the time and mounted on a plug-in module.
Found in American documentation from the 90s, this configuration detects the direction of rotation...
Circuits similar to this can be found in this section. This is from 1967 General Electric...
This circuit uses two transistors and can be powered by just two small batteries. The frequency is given...