Self-excite

Using metal rollers to simulate the earth's cylindrical eddy currents, the team found some interesting results after beginning with a few viscosity problems. "...a more efficient geometry was found, so efficient that the dynamo would self-excite in a completely homogeneous state (i.e. with no insulation ) at a much lower rotor speed than was believed possible" [12] .

Source: wiktionary

The induction generator can self-excite using the external capacitor only if the rotor has an adequate remnant magnetic field.

Source: wiktionary

This so-called "field flashing" reestablishes the residual magnetism to allow the generator to self-excite.

Source: wiktionary

Thus warning systems can self-excite when they go on alert: When a decision maker thinks that an attack is likely, he will place more credence in reports indicating that a war is imminent than he would if the same information were received in a period of calm, and actions of the other side that usually would be missed or seen as innocent will be perceived as evincing hostile intentions.

Source: wiktionary