Control Board Ground Patterns for Noise Reduction

The control board is divided into separate low-voltage circuit patterns and high-voltage circuit patterns with isolated ground patterns. This segmentation prevents electromagnetic interference between the two systems while maintaining both functionalities, resolving the contradiction between versatility and noise generation.

Capacitors are introduced as intermediary elements to connect the ground patterns of the low-voltage and high-voltage circuits. These capacitors act as mediators that provide electrical connection while blocking high-frequency noise, enabling the control apparatus to operate in both voltage systems without generating significant noise.

Capacitors serve as intermediary elements between the ground patterns of the two circuits. This intermediary connection maintains electrical connectivity while filtering out noise, achieving a balance between connection simplicity and noise prevention.

The capacitors change the electrical parameters of the ground connection by providing frequency-dependent impedance. At low frequencies, the capacitors allow signal passage; at high frequencies, they block noise, thus modifying the connection characteristics to prevent noise while maintaining functionality.

Multiple capacitors are connected in parallel at the ground-connection land, merging their noise-filtering effects while maintaining a compact structure. This approach achieves effective noise reduction across multiple frequency bands without proportionally increasing device complexity.

Capacitors are strategically placed only at the ground-connection land where noise filtering is most needed, rather than throughout the entire circuit board. This localized approach provides effective noise reduction while minimizing the increase in overall device complexity.