The correct answer is: C. Synchro-resolver.
A synchro-resolver is a device that converts angular position or velocity to a three-phase electrical signal, or vice versa. It is used in a variety of applications, including position control, speed control, and navigation.
A synchro-resolver consists of two coils, a stator coil and a rotor coil. The stator coil is stationary, while the rotor coil is mounted on a shaft that can rotate. The stator coil is energized with a three-phase electrical signal, which creates a magnetic field. The rotor coil is then aligned with the magnetic field, and the voltage induced in the rotor coil is proportional to the angle between the rotor coil and the magnetic field.
The synchro-resolver can be used to convert angular position to a three-phase electrical signal by rotating the rotor coil until it is aligned with the magnetic field. The voltage induced in the rotor coil is then proportional to the angle between the rotor coil and the magnetic field.
The synchro-resolver can also be used to convert a three-phase electrical signal to an angular position by energizing the stator coil with a three-phase electrical signal. The rotor coil will then align with the magnetic field, and the angle between the rotor coil and the magnetic field is proportional to the voltage induced in the rotor coil.
Microsyns, selsyns, and synchro-transformers are all similar devices that are used for conversion of coordinates. However, they have different features and applications.
A microsyn is a small, lightweight synchro that is typically used in aircraft and other applications where space is limited. A selsyn is a larger, more powerful synchro that is typically used in industrial applications. A synchro-transformer is a type of synchro that is used to transmit power or signals over long distances.