When the "Yutu" lunar rover made a safe soft landing on the lunar surface, it was the time for the "Sine and Cosine Rotational Transformer" to come into play. Its function is to convert the motion signals into electrical signals and send current signals to the system. The rotational transformer mentioned here is an electromagnetic sensor, used to measure the angular displacement and angular velocity of the rotating object's shaft.
Inside the lunar rover, there is a high-end, elegant and upscale rotary transformer.
After the landinger and the rover of Chang'e-3 separated, the "Yutu" rover successfully reached the lunar surface. At around 11:40 on December 15th, the landinger of Chang'e-3 and the "Yutu" lunar rover completed their first mutual photography. Subsequently, Ma Xingrui, the chief commander of the China Lunar Exploration Project, announced that the Chang'e-3 mission had achieved complete success.
Previously, at the moment when the lunar rover made a safe soft landing on the lunar surface, it was the time for the "sine and cosine rotary transformer" to come into play. Its function is to convert motion signals into electrical signals. For instance, when the wheels turned by a certain degree, how high the mast rose, and how much force the robotic arm gripped, all these would be recorded by the motor and sent as current signals to the system.
What is a rotary transformer?
The rotary transformer here is an electromagnetic sensor, used to measure the rotational angle displacement and angular velocity of rotating objects. It consists of a stator and a rotor. The stator winding serves as the primary winding of the transformer, receiving the excitation voltage. The excitation frequency is usually 400, 3000, and 5000 HZ, etc. The rotor winding acts as the secondary winding of the transformer, obtaining the induced voltage through electromagnetic coupling.
The working principle of the rotary transformer
The working principle of this transformer is basically similar to that of a conventional transformer. The difference lies in that the primary and secondary windings of a conventional transformer are fixed relative to each other, while the windings of this transformer change their relative positions according to the angular displacement of the rotor. The working principle of the rotary transformer is similar to that of a conventional transformer. The difference is that the primary and secondary windings of a conventional transformer are fixed, so the ratio of the output voltage to the input voltage is a constant. However, the primary and secondary windings of the rotary transformer change their relative positions according to the angular displacement of the rotor, so the magnitude of the output voltage changes with the angular displacement of the rotor. The voltage amplitude of the output winding is in a sine or cosine function relationship with the rotor angle, or maintains a certain proportional relationship, or has a linear relationship with the rotor angle within a certain angular range. The rotary transformer can be used to transmit angles or electrical signals in synchronous and digital servo systems; in calculation devices, it can be used as a function solver, so it is also called a calculator.
The rerotary transformer have two types of structures: two-pole winding and four-pole winding. The stator and rotor of the two-pole winding variable transformer each have one pair of magnetic poles, while the four-pole winding has two pairs of magnetic poles. They are mainly used in high-precision detection systems. Besides, there are also multi-pole type variable transformers, which are used in high-precision absolute detection systems.
The type of rotary transformer
According to the functional relationship between the output voltage and the rotor angle, there are mainly three types of rotary transformers.
1.Sine-cosine rotary transformers - classified according to the sine or cosine functional relationship between the output voltage and the rotor angle.
2.Linear rotator transformer - classified according to the linear functional relationship between the output voltage and the rotor angle. Linear rotator transformers are further divided into two types based on the rotor structure: the hidden-pole type and the exposed-pole type.
3.Proportional type rotary transformer - classified according to the proportional relationship between its output voltage and the rotation angle