750A AC to DC rectifier

750A AC to DC rectifier

AC to DC rectifier

AC to DC rectifier

 AC to DC rectifier features:

  • Our AC to DC rectifier uses famous brand components and international advanced full bridge inverter technology of precision machining, so that the performance of the whole AC to DC rectifier is stable,quality is more reliable.
  • Whole AC to DC rectifier has the function of over voltage, over current, over temperature, short circuit, equal and automatic protection alarm function and soft start function. And can be equipped with time control and computer interface.
  • DC output waveform is high frequency square waveform, ripple factor less than 1%, can increase plating, refuse passivation, enhance the gloss of the plating coating surface and the core of the dark corner of plating coating. And can reduce the loss of raw materials, to achieve a variety of special requirements of electroplating industry.

AC to DC rectifier cooling method:

  • High frequency switching power supply AC to DC rectifier adopts air cooling/water cooling design, easy to install. With remote control device, simple operation. Can switch off the machine when loading, reduce cumbersome procedures of adjustment.

AC to DC rectifier advantage of small size and energy saving:

  • Small size, light weight, the whole AC to DC rectifier machine use a full range of anti-corrosion technology, enhanced the product’s anti corrosion ability, extend the service life.
  • High efficiency, energy saving, work efficiency can reach more than 90%, any voltage current ratio is always linear matching. Eliminating the need for traditional rectifiers regulator and the main transformer loss, energy saving in more than 35%, greatly reducing the electro plating cost, which is the most sensible choice for surface treatment plating machine industry.

AC to DC rectifier Specification and parameter:

AC to DC rectifier Input voltage Single phase 220V AC, 3 phase 380V/415V/440V 50-60Hz, suggest to use 3 phase
Output voltage 6V/12V/15V/18V/24V/36V/48V optional or according to customers’ request
Output current 0-750A (Random optional)
Voltage stability ≤1%
Current stability ≤1%
Ripple factor 1%-2%
Efficiency ≥90%
 Stabilization mode Current stabilization/Voltage stabilization (Switchable easily)
Adjustment range Voltage/Current from 0-100% continuously adjustable within rated range
Cooling system Air cooling/Water cooling/Oil cooling
Control method Manual/PLC
Display contents Voltage meter/Current meter/Working/Over temp/Error, etc..
Protection method Input over voltage/Under voltage/Over current/Output short/Over heating self protection etc..
Operating temperature -20-50℃
Ambient temperature -30-65℃
Ambient humidity ≤90%
Working loading Full capacity operation, more than 1,000 meters above sea level, reduced load operation

AC to DC rectifier Packing details:

TypeLength (mm)Width (mm)Height (mm)Weight (kg)

Portable plating experimental power supply


Portable plating experimental power supplyPortable plating experimental power supply usage:

This product is based on actual production of plating and electroplating additive manufacturers to research and develop, which is especially for portable, used for production site Hull tank test plate and tank solution failure analysis.

Portable plating experimental power supply features:

Portable plating experimental power supply has features of small volume, portable, simple operation, digital display, etc.; therefore has been widely used to study the impact of solution main component and additives, to find out the cause of solution failure and so on. That is an essential laboratory test equipment for electroplating technician and plating additive manufacturers home coating solution maintenance, monitoring, modification and analysis.

Portable plating experimental power supply technical parameters:

Input voltage: 220V±10%(AC),50~60Hz;

Output DC voltage: 0-12V,0-15V(DC) (Two options);

Output DC current: 0-10A,0-20A(DC) (Two options);

Measurement timing range: 99 hours 99 minutes 99 seconds;

Input power: 30w~330w;

Dimensions: 250mm×210mm×120mm (including foot pad and terinmals);

Main functions: 1, stepless adjustment; 2, digital voltage and current; 3, digital timer; 4, constant voltage/constant current;

5, timing alarm function; 6, air agitation; 7, tank heating; 8, soft start; 9, protection for current limiting, over-current, short circuit.

Pulse rectifiers silver plating

Pulse rectifiers silver plating

Pulse rectifiers silver plating:

Normal silver electroplating machine can’t obtain bright plating coating directly, in order to get brightness need chemical dip or barrel rolling treatment, but will cause silver electroplating coating loss, and difficult to recover 50% of loss, resulting in a greater waste. Bright silver plating can obtain bright plating coating directly, which simplifies operation and reduces waste, but electro plating coating antitarnishing worse, and conductivity deteriorates. Because silver in the air due to the sulfur can easily change color, additives, mostly as sulfur compounds, attached to plating coating inevitably promote its easier to change color, thereby seriously affecting the electrical plating and welding properties. Furthermore, the plating agent attached (in this case the agent can be regarded as impurities) make the silver plating layer impure, electrical properties then decrease. To make an inappropriate analogy, cold medicine to cure a cold, but comes with side effects (such as dizziness, drowsiness, etc.). Bright silver palting solution additives like cold medicine, the use of which may obtain directly bright silver plating layer, but side effects (such as anti-tarnish coating capacity, electrical conductivity variation, additive decomposition products difficult to handle, etc.).

Silver plating pulse rectifiers

Silver plating pulse rectifiers

About brightness silver plating side effect problem, the connector industry has been pointed out, the inner and outer conductor of the RF connector using bright silver electroplating, have a greater impact to products environmental resistance and electrical conductivity. In silver plating process also found bright silver plating pieces changing coler fast thant chemical dipping bright or barrel tumbling process type.
Of course, can adopt passivation, immersion silver anti-discoloration agent, or both, and use other measures of bright silver plating coating for anti-color processing, but this is only remedial measures, can not change its attached staff that its nature of sulfur compounds that can cause discoloration or affect other property.
Therefore, if there is high requirements of silver plating coating, generally not advocate the use of bright silver method, some military products (such as aircraft engine bearings protection frame) electroplating silver even prohibited the use of additives. But without additives will not get brightness coating,, while military performance only need the performance not consider brightness, but other products (such as professional electroplating factory processing products) could not deal with like military. Other products even asked for both performance and also the brightness (not using dip or barrel rolling processing) requirements, this is probably some difficulty, it’s something like ask for cold medicine both cure and can not have the side effects.
Some people think of pulse rectifiers silver plating, by using of pulse current in the ordinary silver plating solution to get brightness silver plating coating. Be the case, the pulse current is really an agent both brightness sliver plating and no side effects (good performance) medicine. At first, use a single pulse. Fewer parameters, just turn on, shutdown and peak current, the test soon finished. The result failed, only a single pulse silver plating layer is more detailed than the DC power supply, white, but still dull.
Then consider double pulse. Experts said that if the parameters properly, using double pulse most possible to give a bright nickel plating layer, which in terms of looking for silver-plated medicine is undoubtedly a good news, because if dark nickel-plating use double pulse can be bright, dark silver should be more able to get (anti-cyanide silver plating peel effect is more obvious). But double pulse plating power supply has many parameters, there are positive & negative turn on/off, shutdown and peak current and the positive/reverse working time, and the positive and negative parameters may differ from each other, if all together will be a huge number, so look for a dark silver get bright plating coating were not as simple as a single pulse. At present, dual pulse plating dark silver no matter experiment or production, used commonly parameters, but did not explore deeper, the result certainly will not get bright silver plating. Nevertheless, the double pulse current dark silver-plating get some inspiring results.
It is believed more than one person has done such a test, or have such experience: compare with DC rectifier, single pulse, double pulse dark silver plating machine, DC’s silver no brightness, while single pulse rectifier delicate, white, but still no brightness, and double pulse power supply has clearly brightness (substantially semi-bright) especially in plating parts high area compare to single pulse, and observed other area of workpiece under the sun will be a reflection of light. But this is a result of the use of commonly parameters, commonly parameters may not be the optimal parameters, if the case of optimum parameters, what will happen?

Barrel plating machine tumbling action functions:
① Increase the brightness electroplating layer coating;
② Allows brightness and color more uniform, hanging plating machine type has been got semi-bright in high zone of electro plating parts, why not barrel plating line type can’t obtain whole bright plating layer coating?

Of course, the outcome need facts speak, but adopts double pulse can achieve both performance and brightness at least have the following meanings:
① The use of pulse rectifiers silver plating, double pulse rectifiers with only a small part of plating chemical solution can obtain bright sliver plating coating, which can greatly reduce the amount of additives, to improve plating coating performance (due to attached less additive and pulse plating dense) and as well as ensure brightness, but also saves expensive additives (amplitude usually 50% to 80%);
② If use a common silver plating line, dark silver double pulse rectifiers roll has been got half-bright electroplating coating, then a slight dip bright light treatment shall be bright, by this way, isn’t silver material waste can be reduced?

Pulse rectifers silver plating

Pulse rectifers silver plating

Ways of improving electrolyte solution dispersion and coverage capability

1, Cathodic polarization electroplating:

For the electrolytic solution which the cathode polarization is small, should strive to increase the cathodic polarization factors. Directly or indirectly contribute to increase cathodic polarization factors, such as selecting the appropriate complexing agent and additives, both can change coating film dispersion and coverage capability.

2, Electrolyte solution conductivity:

On large resistance electrolytic solution, a stronger conductivity electrolyte may be appropriate to add. When the electroplating solution has a larger cathodic polarization, to enhance conductivity can significantly improve dispersion and coverage capability. If the polarization dispersion is minimal, so the impact to dispersion capability is not big.

3, Cathode current efficiency:

Improving cathode current efficiency, can increase plating solution capacity of dispersion and coverage.

4, Organism surface condition:

To improve organism surface smoothness, to use a short shock waves, to increase hydrogen overpotential on organism, can eliminate organism side effects to dispersion and capacity.

5, Geometric factors:

Using auxiliary cathode and pictograph anode in actual production, and using methods: such as rationally regulate distance between the anode and cathode as far as possible to elimination geometric factors impact to electrolyte dispersion capability. But chrome electrolytic solution is special, which is a strong oxidizing acid electrolytic solution, and is a worst dispersion capability in using electrolytic solution. When in chromium plating, in order to improve the dispersion ability, often from the outside perspective of electrochemistry properties, make the using of protective cathode, auxiliary anode and nonmetal shield and reasonable to adjust distance between the electrodes and so on, to make it in the best current distribution.

Electrolyte soulution

Electrolyte solution

Factors impact electroplating solution dispersion and coverage capability

Factors impact electroplating solution dispersion and coverage capability:

The advantages and disadvantages of plating solution indicated by dispersion and coverage capability. Dispersion capacity refers solution has capability of uniform distribution in coating thickness, which only shows uniformity coefficient on the surface of plating workpiece. Coverage refers the electroplating solution has capacity of depositing coating film on parts deep hole, concavity surface, also called depth capability. Only stated plating surface concavity surface or deep hole whether has coating deposition or not.

1, Current distribution: When the current through the electrolyte solution, the amount of material deposited on the cathode in direct proportion to the electric quanlity through. Greater current density, the coating film is also the more thicker. Metal deposition on the cathode surface depends on the distribution of electricity in cathode. The electrolyte solution resistance and cathode electrochemical reaction resistance, are two important factors which impact the current distribution in cathode, and one of them play a dominant role.
2, Current efficiency: coating film metal distribution depends on the current distribution, but it does not mean equal to current distribution. Through primary current not only consumed metal ion deposition, but also consumed in hydrogen and other side effects. Current efficiency changes with current density changing.

Affect the distribution of the metal in different parts :
A. Cathode current efficiency with current density change almost no change . Different parts of the cathode plating metal depends directly on how much the size of the current.
B. Cathode current efficiency with the increasing of current density but decrease to improve the dispersion capacity. Where the current density high the low current efficiency, while the low current density the high current efficiency. To make the current density distribution uniform, have to change the dispersion capability of the electrolyte solution.
C. The surface state of organism:
Metal hardly deposited on the unclean cathode surface a uniform coating, or even can not deposite. Since hydrogn overpotential on rough surface less than on smooth surface, then on rough surface the hydrogen is easily to precipitate, so it is difficult to deposit coating film.
D. Cathode current efficiency with the increasing to increase will reduce dispersion capacity. Because of the electrical efficiency is high when the cathode current density high, but the current density low when current low, so the actual current density throughout more uneven, resulting in poor dispersibility .
E. Geometric factors:
Plating tank geometry shape, the shape of the anode and cathode, the two electrodes in the plating tank etc.. geometric arrangement factors can directly affect the distribution of coating .
Explain: All these related with the electrolyte solution dispersion and coverage capability, are not isolated from each other, but actual contacted each other.Factors impact electroplating solution dispersion and coverage capability

Factors of impacting plating crystal

Crystal nucleus generation speed is fast, while the crystal nucleus growth rate is slow, then resulting large number of crystal nucleus, and resulting the crystal nucleus small, conversely is bigger. If the generation rate of crystal nucleus is faster than growth rate, coating file crystallition will be more micromesh and tightening. Cathodic polarization of increasing electrocrystallization can accelerate the growth rate of growth speed of crystal nucleus, then easy to form smaller crystals.

1. The cathode polarization method improving metal electrical crystallization:

Enhancing the cathodic current density: generally, the cathode polarization will increase with cathode current density increasing, while the coating film become more delicate at the same time. Under the circumstance of polarization increase with cathode current density increasing, the appropriate way to improve the current density will increase cathodic polarization.

2. To lower electrolyte solution temperature properly :

Lowering the temperature can slow down the cathodic reaction speed or ion diffusion rate and improve the cathodic polarization. In actual operation, for the negative impact of increasing the temperature can get up by increasing current density. The specific production operation, in the according to the actual temperature to adjust the electrolyte solution.

3. Add complexing agent:

Complexing agent is a substance which can complex metal ions in electroplating process. Complex ion is relatively simple ion on the cathode which difficult to restore, thereby increasing cathodic polarization value.

4. Add additives:

Additives adsorped on the surface of the electrode preventing the precipitation of metal, increasing the cathodic polarization.Cathodic polarization effect is not alwarys the bigger the better, when polarization over a certain range, will lead to a large number of hydrogen precipitation, so that the plating film becomes porous and rough. In production process, the situation is more practical, to take specify measures to increase metal crystallization cathode polarization effect.

Factors of impacting plating crystal

Factors of impacting plating crystal

Factors of impacting platin crstal

Electroplating working principle

Plating is a technology which make the use of electrolytic to process the surface parts. When electroplating, the part in plating solution is negative, and metal ions under the action of DC power deposited the surface of parts to form a uniform, dense metal layer.

1,The necessary requirement for plating: external DC power supply, electroplating solution, electrolyzer constituted by plating workpiece and anode.

2, Electrolytic purpose: to change the parts’ surface appearance and physical and chemical properties, to acieve variety features of decorative, corrosion resistance, abrasion resistance, and other technical performance.

3, The crystallization of electrolytic process: the process of electrolyte metal ions or complex ions in the cathodic reduction to deposite metal coating called as electrolytic crystal.

Electroplating working principle

Electroplating working principle

Explain: Electrolytic crystal is an electrochemical reaction process, the metal ion is capable of reducing determined by cathode point . Only the cathode potential deviates from the equilibrium state, which produce certain overpotential will deposit metal crystal on cathode.

4. Metal electrodeposition is a complex process, which generally has several continuous stes or coincide interface reactions:
A. Metal ions in solution (such as Hydrated metal ions or complex of complexing ions) by mean of electromigration, convection, diffusion and other forms to arrive the near of of cathode surface .
B. Before reduction, the metal iron near by or on the cathode surface taking place of chemical conversion.
C. Metal ion gets electron from the cathode surface then reducts to metal atom.
D. Metal atom reach the growing point along the surface diffusion to reach growth point for crystal growth, or meet with other ions to form crystal nucleus and grow into crystals.
Explain: forming the metal crystals two steps: the formation and growth of crystal nucleus.

Electroplating machine important maintenance

The plating machine has two states, which are fully automatic production line and manual one. When the automatic state failure, will use the manual control, after the trouble removing, then resume automatic operation, that means will not because of a single failure to affect the whole production line, resulting in shut down. Production line in operation face with manual operation box, that enabling manual/automatic conversion, system start/stop, and the operation of translation, lifting; under the condition of crane running, there has a self-diagnostic function to prevent the failure occurrence of crane translation and lifting out of limit, and motor overheating. Automatic electroplating production line is based on the difference between size and capacity of the products to design different loading patterns and run beat, to formation corresponding run program, the crane will according to system requirements to move automatically, thus to realize the automation of the production process running. Complete electrical control system adopts PLC and IPC (optional) control, which has strong anti-jamming capability, to ensure long-term continuous and stable operation. The system has functions of good man-machine interface and database, interface with full English display, simple operation, achievable operation, tips and help functions etc.. Created real time and historical two databases in the computer. The historical database can achieved technical parameters history record and storage function, which will easy to trace product quality and production conditions for the management analysis. Real time database can realize to display entire production line running for dynamic process, to monitor the parameters. Through the database functions can complete variety statistical reports of records and generates.

Plating production line

Plating production line

Improving the automation control degree of plating equipment, not only can effectively improve production efficiency, reduce labor intensity, but also according to product characteristics to realize the pertinence structural design that is traditional manual production can not achieve, then to improve product electroplating quality. For example, barrel plating production line, automatic operation design of auto switch barrel doors and swing drum design. In the production process, when the barrel rotated to the door facing the anode, the barrel door will open, so that the liquor inside the barrel will be updated; further more, because there is no shield from barrel door, the power lines remain relatively smooth, under the constant pressure, the plating current density increases accordingly, which can speed up the coating deposition rate, and effectively avoid the workpiece appear problem of “bucket print”. Reduce energy consumption, reduce pollutant emissions and adapt to cleaner production requirements. The defination of cleaner production recognized from internationally recognized United Nations UNEP is: Cleaner production is a new kind of creative thinking, the thinking continue to apply overall preventive environmental strategy to production processes, products and services, in order to increase ecological efficiency and reduce human and environmental risks.

Regarding the production process, it is required to save raw materials and energy, to eliminate toxic raw materials, to reducte quatity and toxicity of all rubbish; refer to products, it is required to reduce adverse effect of full life circle which from raw material extraction to final products disposal; for service, it is required to bring environmental factors into design and provided services. The major contents of cleaner production including: cleaning energy; cleaning production processes; cleaning products. For the electroplating industry, water conservation technology and design, solution regeneration technology and so will be more and more popular. In the production line design process, using counter current rinsing, dripping delay, the receiving fluid design etc. all can reduce the waste of resource effectively in the production process. For renewable plating solution technology, due to solution effective recovery and regeneration, not only saves raw materials, but also reduce the amount of waste water treatment, and thus renewable plating solution technology also become one of the major trend for plating development. Improve the quality of electroplating workshop operating environment, strengthen the monitoring of harmful gases, is another important reflection of electroplating equipment user-friendly design. The acid mist, alkali mist, air containing cyanide and chrome anhydride generated in electroplating workshop will all bring serious harm to human body.

In addition to the exhaust system design, harmful gas real-time monitoring design will be an important measure to protect the operating worker’s health, when the operating environment contained harmful gas concentration exceeds the set value, the system will automatically alarm, causing the operator alert, thus protecting operator’s health. Electro plating waste water is an principle element causing environmental pollution. Ideally electroplating waste water treatment model is zero discharge of sewage systems, to achieve zero discharge of wastewater requires strict classification of harmful substances targeted for different treatment. But plating wastewater harmful substances contained species are very complex, in order to manage spilt-flow, the cost will be very high, which is electroplating enterprises unbearable. However, the zero-emission is the development direction of electroplating waste water treatment, along with increasingly stringent environmental requirements and water treatment technology, this technology must be developed and will eventually spread. Development of modern manufacturing needs, determine the electroplating industry must be present and will continue long-term development. However, compared with other professions, our electroplating manufacturing level and the international level there is still a significant gap. The electroplating industry, is inseparable from the improving of electroplating equipment manufacturing technology, so to meet the technical requirements of modern electroplating, more humane and intelligent technology development will become an inevitable trend in the development of electroplating equipment.

Plating equipment automation control system

chiller1, Plating equipment automation control system

With the electroplating machinery in plating production line, power device, heat exchange systems and other auxiliary facilities becoming better and approaching perfection day by day, the automation of automatic line will further towards to intelligent direction.

1.1 Temperature control features of Plating equipment automation control system

(1) When in the electroplating process, the process temperature control is very important, if the temperature fluctuation is too large, not only causing electrical energy waste, but also will have great impact to product quality. Using PID fuzzy control, will effectively reduce or even avoid these problems. In engineering practice, the most widely used regulator control law is a proportional, integral, differential calculus, referred to as PID control, also known as PID regulator. PID controller is based on the systematic errors,which make the use of proportional, integral and differential calculus to calculate the amount of control, its simple structure, good stability, reliable, easy to adjust and become one of the main technology of industrial control.

(2) Heating system matching liquid level control device, automatic water replenishment device, when the liquid level is below the set level, the system will conduct automatic level complement, then will protect the system reasonable, and to prevent heating pipe dry burning; meanwhile, each electric heating system equipped with a reliable ground protection measures to avoid accidents.

(3) Human machine interface set the pre-heating function, which set pre-heating time, if for the process which require higher temperature, will achieve the pre-heating system management, then greatly enhance the production efficiency of equipment.

Pulse rectifier

Pulse rectifier

Pulse rectifier Pulse rectifier plating principle:


Pulse rectifier plating is a powerful tool to control metal outer tank electrodeposition. It uses the time function to improve the physical and chemical properties of the plating coating film by changing the pulse parameters, to achieve savings in precious metals and obtain a functional electroplating coating film purposes. Pulse rectifier electro plating belongs modulation current plating, its current is a fluctuation or on/off DC rush current, therefore, is essentially on-off DC plating. There are a variety of pulsed current waveform, commonly as square wave, triangle wave, sawtooth, order staircase wave etc.. However, in application situation, typical pulse power generated square wave pulse current is widely used.

Pulse rectifier waveform

Modulated current plating:

Conventional electroplating is generally used in the form of direct current, referred to as DC. DC current is a current direction continuous steady and does not change with time changing. DC current waveform common as single-phase half-wave, single-phase full-wave, three-phase half-wave, three-phase full-wave, DC or steady current, etc.. While to generate these waveforms power supply are, silicon-controlled rectifier, high-frequency switching power supplies. DC current with features of continuity or continuity, without interruption to control plating coating film outside the bath. Such as DC current increase cathode current density, inhibit side reactions and reduce the content of impurities in the electroplating coating, to improve current distribution, etc. are useless.

DC current after pulsing signal or other modulating alternating signal is called as modulation current, as well as the plating process under condition of modulation current is carried as modulation current plating. Modulated current plating mainly generated and existed to play a role to control outside bath plating coating quality. It can get the effect that the DC current plating can not achieve. For example, the pulse plating increase several times or even ten times more than direct current plating cathodic density, and get more detailed crystalline coating. Modulation current normally has pulse plating, asymmetric exchange electroplating, DC overlay plating cycle for the several forms of direct plating and so on.

Current pulse plating is actually used by a DC on-off, but when on DC peak current equivalent more than ordinary DC current times or even tens times. it is this high instantaneous current density make the metal ions in the very high overpotential to reduce, so that the grains become fine deposit layer. Pulse rectifier plating is widely used in electronic circuits of the electronics industry, connectors, printed circuit, electroplating integrated framework, the stem, etc., these products can be greatly improved the performance of electronic devices, and significant saving precious metals. Pulse rectifier plating is currently the most widely used and one of the largest gains modulation current plating.