The relationship between electroplating process and electroplating power supply

Electroplating is an electrolytic machining process, and the power factor must directly affect the electroplating process. The electroplating power source occupies an important position in the electroplating process. The application of electrodeposition power supply and low-ripple rectifier power supply in the electroplating industry has enabled colleagues in the electroplating industry to choose a rectifier power supply, solve electroplating failures, and improve electroplating quality.

1. The basic type of rectifier.

Silicon rectifier: Silicon rectifier has a long history of use and mature technology, and it is currently a mainstream product. Different rectifier circuits can obtain pulsating direct current instead of pure direct current. In order to compare the number of pulsating components, it is generally expressed by the ripple coefficient. The smaller the value, the less the AC component and the closer to pure DC. Different rectifier circuits have different fluctuation coefficients. Its sequence is: three-phase half-wave rectification, three-phase full-wave bridge rectification, balanced reactor six-phase double reverse star rectification. SCR adopts an ordinary thyristor rectifier that changes the conduction angle of the thyristor to adjust the average output DC. The thyristor outputs an intermittent pulse wave, and its ripple coefficient is controlled by the conduction angle, and the output ripple coefficient is greater than that of an ordinary silicon rectifier circuit.

2. Switching power supply.

The switching power supply combines the smooth waveform of the silicon rectifier and the convenient voltage regulation of the silicon controlled rectifier. The current efficiency is high and the volume is small. The high-power switching power supply of thousands of amperes to tens of thousands of amperes has entered the practical stage of production. The frequency of the switching power supply has reached the audio level, and it is easier to achieve low-ripple output through filtering. Functions such as current stabilization and voltage stabilization are easier to implement. Therefore, switching power supply is the direction of future development.

3. Pulse power supply equipment.

The pulsating power supply is mainly controlled by the embedded single-chip microcomputer and other single-chip microcomputers. Therefore, in addition to realizing the pulse output, it generally has a variety of control functions.

(1) Automatic steady flow and stability. Conventional silicon rectifier current or voltage cannot be automatically stabilized, and fluctuates with the fluctuation of the grid voltage. In addition, the pulse power supply has a high-precision automatic adjustment function, and the output voltage of the pulse power supply can be almost constant. Generally, there are two ways to automatically adjust the pulse power supply: one is the constant current and voltage limiting method. The second is the constant pressure limit flow mode.

(2) Multi-stage operation mode. During aluminum anodizing or hard chromium plating, operations such as reverse electrolysis, high current impact, and stepped power transmission are often required. The pulse power supply of the multi-stage working mode only needs to be set in advance, and the sequence can be automatically adjusted during production. This function is very useful for hard chrome plating, and the setting time can be adjusted within 0~255 seconds.

3) Two-way pulse function. The positive and negative pulse frequency, duty cycle, and forward and reverse output time can be adjusted independently, which is flexible and convenient to use. Hard chromium electroplating process can be used to obtain coatings with different physical properties.

(4) DC superposition function. At the same time, a pure DC component is superimposed and output by the same power supply, thereby expanding the application range and application of the pulse power supply.