A transmission configured to vary a rotational torque and a rotation speed output from an engine and to supply the varied rotational torque and rotation speed to a rotating mechanism, the transmission comprising: a generator (10, 20, 30) configured to output electric power according to rotational power transmitted from the engine, the generator (10, 20, 30) including a rotor (11, 21, 31), a stator (12, 22, 32), and a supply current adjustment unit (131, 231, 331), the rotor (11, 21, 31) including a permanent magnet, the rotor (11, 21, 31) rotated by the rotational power transmitted from the engine, the stator (12, 22, 32) arranged opposite to the rotor (11, 21, 31), the stator (12, 22, 32) including a winding (121, 221, 321) and a stator core (122, 222, 322), the winding (121, 221, 321) wound around the stator core (122, 222, 322), the supply current adjustment unit (131, 231, 331) configured to adjust a current to be output from the generator (10, 20, 30), the current adjustment being implemented by changing an inductance of the winding (121, 221, 321), the inductance change being implemented by changing a magnetic resistance of a magnetic circuit (F2, F22, F32) for the winding (121, 221, 321), which passes through the stator core (122, 222, 322); an electric load device being a motor configured to be driven by the electric power output from the generator (10, 20, 30), and configured to output rotational power to the rotating mechanism; and a control device configured to control the supply current adjustment unit (131, 231, 331) in accordance with a torque requirement of the transmission, to direct the supply current adjustment unit (131, 231, 331) to adjust the current to be output from the generator (10, 20, 30) by changing the inductance of the winding (121, 221, 321), the torque requirement requesting a torque to be output from the transmission to the rotating mechanism, wherein the supply current adjustment unit (13, 23, 33) is configured to change the state of the generator (10, 20, 30) from one of a high-resistance state and a low-resistance state to the other, wherein in the low-resistance state, the magnetic resistance of the magnetic circuit for the winding, which passes through the stator core, is lower than that in the high-resistance state, wherein at an equal rotation speed the generator (10, 20, 30) in the high-resistance state and the generator (10, 20, 30) in the low-resistance state outputs an equal magnitude of current, wherein, to further increase the drive source output while the electrical load device is rotating at a relatively high rotation speed, the supply current adjustment unit (13, 23, 33) is configured to change the state of the generator (10, 20, 30) from the low-resistance state to the high-resistance state, the generator (10, 20, 30) in the high-resistance state outputting a first current when rotating at a first rotation speed (M+) higher than the equal rotation speed, the first current being larger than a maximum current output by the generator (10, 20, 30) in the low-resistance state rotating at the first rotation speed (M+), and wherein at a relatively low rotation speed the supply current adjustment unit (13, 23, 33) is configured to change the state of the generator (10, 20, 30) from the high-resistance state to the low-resistance state, the generator (10, 20, 30) in the low-resistance state outputting a second current when rotating at a second rotation speed (M-) lower than the equal rotation speed, the second current being larger than a maximum current output by the generator (10, 20, 30) in the high-resistance state rotating at the second rotation speed (M-). a generator (10, 20, 30) configured to output electric power according to rotational power transmitted from the engine, the generator (10, 20, 30) including a rotor (11, 21, 31), a stator (12, 22, 32), and a supply current adjustment unit (131, 231, 331), the rotor (11, 21, 31) including a permanent magnet, the rotor (11, 21, 31) rotated by the rotational power transmitted from the engine, the stator (12, 22, 32) arranged opposite to the rotor (11, 21, 31), the stator (12, 22, 32) including a winding (121, 221, 321) and a stator core (122, 222, 322), the winding (121, 221, 321) wound around the stator core (122, 222, 322), the supply current adjustment unit (131, 231, 331) configured to adjust a current to be output from the generator (10, 20, 30), the current adjustment being implemented by changing an inductance of the winding (121, 221, 321), the inductance change being implemented by changing a magnetic resistance of a magnetic circuit (F2, F22, F32) for the winding (121, 221, 321), which passes through the stator core (122, 222, 322); an electric load device being a motor configured to be driven by the electric power output from the generator (10, 20, 30), and configured to output rotational power to the rotating mechanism; and a control device configured to control the supply current adjustment unit (131, 231, 331) in accordance with a torque requirement of the transmission, to direct the supply current adjustment unit (131, 231, 331) to adjust the current to be output from the generator (10, 20, 30) by changing the inductance of the winding (121, 221, 321), the torque requirement requesting a torque to be output from the transmission to the rotating mechanism,