21. The rotor's magnetic field may be produced by permanent magnets, or by a field coil electromagnet. 22. START had six poloidal field coils within the vacuum tank and were encased in 3 millimeter stainless steel cases. 23. The area between the two field coils is filled with an analog of the original signal from the antennae. 24. Varying the amount of current through the stationary exciter field coils varies the 3-phase output from the exciter. 25. The field coils now moved into short, squat " internal " coils around the pole pieces themselves. 26. A "'magneto "'is an electrical generator that uses field coils rather than permanent magnets. 27. On larger machines the constant magnetic field is provided by one or more electromagnets, which are usually called field coils . 28. The 18 Toroidal Field coils at max field of 11.8 T will store 41 GJ ( total ? ). 29. In a rotating machine, the field coils are wound on an iron magnetic core which guides the magnetic field lines. 30. Above and below this chamber there were two series field coils surrounding and energizing the two poles of the magnetic circuit.
