At the moment when the "Yutu" lunar rover safely landed on the moon, it was time for the "sine cosine rotary transformer" to show off its skills. Its function is to convert motion signals into electrical signals and send current signals to the system. The rotary transformer referred to here is an electromagnetic sensor used to measure the axial displacement and angular velocity of a rotating object.
Inside the lunar body, there is a high-end, atmospheric, and high-end rotary transformer。
With the separation of Chang'e-3 lander and rover, the Yutu rover successfully reached the surface of the moon. At around 11:40 on December 15th, the Chang'e-3 lander and the Yutu lunar rover completed their first mutual photo shoot. Subsequently, Ma Xingrui, the commander-in-chief of China's lunar exploration project, announced that the Chang'e-3 mission had achieved complete success.
Previously, when the lunar rover safely landed on the moon, it was the moment when the "sine cosine rotary transformer" showed off its skills. Its function is to convert motion signals into electrical signals. For example, the motor will record how many degrees the wheels have turned, how high the mast has been raised, and how hard the robotic arm is gripping, and send current signals to the system.
What is a rotary transformer?
The rotary transformer here is an electromagnetic sensor used to measure the axial displacement and angular velocity of a rotating object. It consists of a stator and a rotor. The stator winding serves as the primary side of the transformer and receives excitation voltage. The excitation frequency is usually 400, 3000, and 5000 Hz. The rotor winding, as the secondary side of the transformer, obtains induced voltage through electromagnetic coupling.
Working principle of rotary transformer
The working principle is basically similar to that of a regular transformer, with the difference being that the primary and secondary windings of a regular transformer are relatively fixed, while its winding changes relative position with the angular displacement of the rotor. The working principle of a rotary transformer is basically similar to that of a regular transformer, except that the primary and secondary windings of a regular transformer are relatively fixed, so the ratio of output voltage to input voltage is constant. On the other hand, the primary and secondary windings of a rotary transformer change their relative positions with the angular displacement of the rotor, so the magnitude of their output voltage changes with the angular displacement of the rotor. The voltage amplitude of the output winding is related to the rotor angle as a sine or cosine function, or maintains a certain proportional relationship, or is linearly related to the angle within a certain range of angles. Rotary transformers can be used to transmit angle or electrical signals in synchronous and digital servo systems; It can be used as a function solver in a computing device, so it is also called a solver.
Rotary transformers generally have two structural forms: two pole windings and four pole windings. The stator and rotor of a two pole winding rotary transformer each have a pair of magnetic poles, while the four pole winding has two pairs of magnetic poles each, mainly used for high-precision detection systems. In addition, there are also multipole rotary transformers used for high-precision absolute detection systems.
Types of Rotary Transformers
According to the functional relationship between output voltage and rotor angle, there are mainly three categories of rotational variables
1. Sine cosine rotary transformer - divided into sine or cosine functions based on the relationship between its output voltage and rotor angle.
2. Linear rotary transformer - divided according to the linear function relationship between its output voltage and rotor angle. Linear rotary transformers are divided into two types based on their rotor structure: hidden pole and salient pole.
3. Proportional rotary transformer - divided according to the proportional relationship between its output voltage and rotation angle.