PULSE RECTIFIERS FOR ANODIZING
 

main unit
Main Unit

 

ADVANTAGES IN USING PULSE RECTIFIES IN ANODIZING
 

  • Even if the working is carried out with the same average value of current, the oxide quality is better than one obtained with a conventional rectifier; as proved by the tests on abrasion, efficiency (ISO 3110) and corrosion (Kesternich). 

  • It is possible (without disvantages) to work with a current density higher than with conventional rectifiers. thus the use of pulse rectifiers gives the benefits of 20-25% time saving compared with the conventional ones

Choice of current value (Ampere)

 

The pulse rectifiers are characterized by 3 values: 
 
  • Base current
  • Pulse current = base current x 1.5
  • Average current = 1.35 x base current
Example:
  • Base current = 2000 A
  • Pulse current = 2000 x 1.5 = 3000 A
  • Average current = 2000 x 1.35 = 2700 A
 

Therfore:
  • If the size of a pulse rectifier is chosen with the same average current of a conventional rectifier a better oxide quality is obtained, but without any time saving.
  • If the size is chosen with the same base current as a conventional rectifier, also a 20-25% time saving is obtained.
Max voltage
The pulse rectifiers are provided for a 22V max voltage (instead of 20V max as for conventional rectifiers) to have the possibility of pulse superposing.
 

TECHNICAL FEATURES
Control:
By means of SCR set on: primary or secondary side 

Rectifier circuit:
Six-phase provided with interphase transfomer. 

Main transformer: according to IEC 742 standard "Safety isolating transformers" 

General switch:
Magnetothermic or magnetic (automatic) type. 

Cooling:
Air cooling: by means of ventilator and air filters (max ambient temperasture: 45°C). Protection IP20
On request: closed loop air cooling by means of air/water exchanger (IP54). 

Protections:
- Max current: by means of electronic device and automatic general switch
- Max temperature: by means of thermostats inside the main transformer windings and on the diode cases. 

Voltage/current control:
Constant current and (or) constant voltage controol
Accurancy: ±1% against ±10% network variation and load variation from 10% to 100% 
 

STANDARD MODELS (22V)
In Imax Ieff Dimensions (mm.)
1000 A 1500 A 1350 A 1000x1000x2000 (h)
2000 A 3000 A 2700 A "
3000 A 4500 A 4050 A 1000x1500x2000 (h)
4000 A 6000 A 5400 A "
5000 A 7500 A 6750 A 1100x1700x2000 (h)
6000 A 9000 A 8100 A "
8000 A 12000 A 10800 A "
10000 A 15000 A 13500 A "
12000 A 18000 A 16200 A 1200x2200x2200 (h)
15000 A 22500 A 20250 A 1200x2800x2000 (h)
20000 A 30000 A 27000 A "
25000 A 37500 A 33750 A 1400x3800x2200 (h)
 

Caracteristic Current
 

OPTIONALS
  • Interfacing with external PLC (by means of opto-insulated cards)

  • Water Cooling
  • APC - Anodizing Process computer
Anodizing Process Computer
Clik on the image to enlarge
  • Automatic survey of the surface to be anodized
  • Presetting of anodizing current density
  • Presetting of the requested number of microns
  • Automatic printout of anodizing parameters
NOTE: Due to technical reasons existing rectifiers can't be equipped with APC device