The ripple coefficient of the electrophoresis power supply directly affects the density, uniformity, and durability of the coating, and its mechanism of action is rooted in the stability of the electrochemical deposition process.

Excessive ripple can damage the four key stages of electrophoretic film formation: in the electrolysis stage, high ripple intensifies the electrolysis side reaction of water, producing a large amount of hydrogen and oxygen bubbles, which are wrapped in the deposited film layer, forming invisible pinholes and microbubbles, significantly reducing the anti-corrosion performance of the coating; During the electrodeposition stage, the periodic fluctuations of the electric field cause the migration path of charged resin particles to be disrupted, resulting in fluctuating deposition rates and causing local film thickness deviations, manifested as color differences, positive and negative surfaces, or patterns; During the electroosmotic stage, unstable electric fields hinder the uniform extraction of water from the pores of the coating, resulting in uneven stress distribution inside the film layer, which can easily lead to foaming and peeling under subsequent baking or mechanical impact.

Industry practice has formed a clear gradient for ripple control: ordinary industrial applications require ripple ≤ 5% RMS to meet basic anti-corrosion requirements; In high-end fields such as automotive body and aerospace, high-frequency switching power supplies with ripple ≤ 2% are commonly used. Some manufacturers (such as Koso) have achieved ultra-low ripple output of ≤ 1%, reducing the coating pinhole rate by more than 60% and extending the salt spray test life by more than 30%. This performance difference is not a theoretical speculation, but is verified by the stable performance of film thickness consistency (± 1 μ m), adhesion (scratch method level 0), and appearance glossiness in continuous production.

The domestic standard GB 46759-2025 is about to be implemented, which will standardize the electrical safety and output characteristics of electrophoresis power supplies for the first time. It explicitly requires ripple ≤ 5% and mandates the installation of seven protection functions, marking the industry's upgrade from "usable" to "optimal". Although there is currently no ISO or SAE standard for grading ripple, the technical parameters of international mainstream equipment manufacturers have become a de facto industry benchmark, driving the evolution of domestic supply chains towards high frequency, low ripple, and intelligence.