With the development of power electronics science and technology, electroplating rectifier is developing from single function to multi-function. Since the pulse power supply is mainly controlled by the embedded single-chip computer, it generally has a variety of control functions in addition to realizing the pulse output.
1, automatic stable current and pressure. The current or voltage of traditional silicon rectifiers cannot be stabilized automatically and fluctuates with the fluctuation of the grid voltage. The pulse power supply has a high-precision automatic adjustment function. If the three-phase voltage fluctuation of the power grid reaches hundreds of volts, the output voltage of the pulse power supply can be almost unchanged. The automatic regulation function of the pulse power supply generally has two modes:
(1) Constant current voltage limiting mode. When the electroplating process parameters, such as part area, temperature, concentration, pH and other process conditions change, the conventional rectifier current will fluctuate. In constant current mode, the output current is automatically constant and does not change at the set value. This is useful when the thickness of hard chromium needs to be calculated accurately. The purpose of the voltage limiting function in constant current mode is to protect the equipment from burning out.
(2) Constant voltage current limiting mode. When the electroplating process parameters are changed, the output voltage is automatically constant and does not change at the set value. This mode of hard chromium plating is not often used, but it is useful for aluminum oxidation coloring.
2. Multi-stage operation mode. When aluminum anodizing or hard chromium plating, it is often necessary to carry out reverse electrolysis, large current shock, step power transmission and other operations. Traditional power can only be achieved by hand. The pulse power supply with multi-stage operation mode only needs to be set in advance, and can be automatically adjusted in sequence during production. This feature is very useful for hard chromium plating. At present, the domestic pulse power supply has reached three-stage operation, and the setting can be adjusted within 0-255 seconds for each period of time.
3, bidirectional pulse function. Positive and negative pulse frequency, duty cycle, positive and negative output time can be adjusted independently, flexible and convenient to use. The coatings with different physical properties can be obtained by the hard chromium electroplating process.
4, DC superposition function. When the positive and negative pulse current is output, a pure DC component is output by the same power supply superposition, which broadens the application range and use of the pulse power supply.
