# Study on Relay Contact Bounce Based on the Adaptive Weight Rotation Template Matching Algorithm
## 4 Contact Bounce Analysis
### Analysis of Contact Bounce Causes  
To obtain a better understanding of the timing and status of contact bounce, the moving contact in the image is subjected to Hough circle detection. Subsequently, the detected moving contact is tracked using the KCF (Kernel Correlation Filter) algorithm for target tracking, resulting in the displacement curve of the moving contact along the y-axis. Next, the displacement curve of the moving contact along the y-axis is merged with the corresponding displacement curve of the contact bounce distance over time. The results, depicted in Figure 14, indicate that contact bounce occurs at the highest point of the first upward displacement during the joint vibration of the moving contact and the stationary contact following the relay's release.  
Considering the structure of the relay and the displacement curve of the moving contact, let us analyze the reasons for the observed phenomenon: In the relay studied in this paper, the need for the stationary contact has a certain elasticity. Therefore, the stationary contact does not remain fixed after coming into contact with the moving contact; instead, it undergoes some elastic deformation due to the continued movement of the moving contact. This results in the stationary contact moving in tandem with the moving contact, experiencing mutual vibration. Consequently, contact bounce does not immediately occur after the contact of the moving and stationary contacts, significantly reducing the likelihood of contact bounce in the relay.  
However, there are still instances of contact bounce in some relays. This is attributed to the fact that during the mutual vibration process after the contact between the moving contact and the stationary contact, the kinetic energy of the contacts is significant. Due to the presence of the brackets, the upward movement of the reed for the stationary contact is  
Figure 14: Curve of distance between contacts and displacement of moving contacts during contact bounce.  
restricted. As a result, when the stationary contact reaches the highest point of vibration, the kinetic energy of the moving contact is not zero. It continues to move upward for a certain distance, leading to the separation of the moving and stationary contacts and causing contact bounce. Furthermore, the occurrence of this phenomenon is closely related to the elasticity of the contact spring. The greater the elasticity of the spring, the higher the contact can bounce after contact, making it more likely to be restricted by the retainer and leading to contact separation.  
Based on the above research results, it is evident that relay contact bounce mainly occurs during the vibration process of the contact. In practical applications, this issue can be mitigated by altering the material or structure of the relay contact spring to reduce its elasticity, thereby reducing the amplitude of contact vibration and suppressing contact bounce. Alternatively, adjusting the position of the retainer appropriately can prevent it from restricting the maximum height of the stationary contact spring during its rebound, thus avoiding the separation of the moving contact from the stationary contact during vibration and preventing contact bounce.