Rectifiers for aluminium treatments

Rectifiers for Anodizing

Aluminium anodizing is sensitive and reactive to DC voltage wave shape and other process parameters. Proper devices are indispensable to reduce costs and times and to increase quality. CAEV produces rectifiers and electronic devices specifically designed for aluminium anodizing.

Rectifiers for sulphuric anodizing – voltage up to 20Vdc and current up to 30000Adc
Rectifiers for chromic anodizing – voltage up to 60Vdc and current up to 30000Adc
Rectifiers for hard anodizing – voltage up to 100Vdc and current up to 10000Adc
Pulse current rectifiers – adjustable base current, pulse amplitude and duty cycle
Ramp Programmers
Oxide Thickness Programmers

Technical data

o Three phase input voltage according to customer requests
o Main breaker with handle and locking system
o Main transformer according to IEC standards
o Thyristor rectifying bridge: six phases with reactor, three phase bridge, twelve pulse bridge
o Output voltage and current stepless regulation from 0 to the nominal value
o Constant voltage and constant current regulation
o Output voltage and current rising ramp regulation
o Output voltage and current stabilization: 1%
o LC cell filter to reduce output ripple according to customer requests
o Manual controls on the front door or in remote control box
o Output voltage and current display
o Remote PLC control via opt insulated signals: 0-20mA, 4-20mA, 0-10V
o Remote PLC control via Modbus or Profibus serial net
o Forced air cooling
o Closed loop water cooling
o Cooling via air conditioner for IP55 enclosures
o Epoxydic painting
o Enclosure with lugs, feet or wheels. Easily removable.
o Enclosure protection degree: IP20…IP55
o Magnetic and thermal protection
o Over-temperature protection
o Extra-fast fuses for semiconductor devices protection
o RC snubbers for semiconductor devices protection
o Over-current electronic protection
o Input phase sequence monitoring circuit
o Auxiliary circuit protection by fuses and breakers
o Copper and aluminium busbars

Ramp programmer

The Ramp Programmer manages and supervises the rectifier working cycle, made up of programmable ramps and different voltage/current levels.
Cycles can be easily programmed and memorized.

Pulsing current programmer

The Programmer can modulate either current or voltage in order to obtain a pulsing DC wave.
Base value, pulse amplitude and duty cycle can be set.

Oxide thickness programmer

The Oxide Thickness Programmer is an instrument that, being based on the rectifier supplied voltage and current and bath temperature, calculates the oxide microns as they form.
Before starting it is possible to set the micron value and the current density.
When the process starts the Programmer calculates the total current needed and controls the rectifier output in order to stabilize the current density.
Besides, it calculates the micron value and when the oxide thickness has reached the set value an alarm is activated.

Suppliers for aluminium electrocolouring

For aluminum electrocoluring processes CAEV design and produces different lines of suppliers, including more traditional technologies as well as advanced and experimental solutions.

ACsyn model (0-20Vac, current on request)

This supplier is an AC/AC sinusoidal single-phase supplier. Voltage regulation is obtained by means of a motorized voltage regulator in order to guarantee a perfect sinusoidal voltage wave. By means of manual devices in remote control box the operator can set the full working cycle, including the soak time and current peak. “Hold voltage” facility for color check.

DC+ACsyn model (0-25Vdc, 0-25Vac, current on request)

A power supplier able to supply DC voltage and AC sinusoidal single-phase voltage (with both symmetric and asymmetric half-waves), that allows to obtain different colors (from steel color to black) over controlled time spans. The entire Six step cycle, from soak step to cycle end, is managed by a PLC on board. Different programs can be set and memorized. Asymmetric half-waves facility allows to lengthen and shorten color (light and dark) formation time in order to obtain easy color repetition.

DC+AC full solid-state control model (0-25Vdc, 0-25Vac, current on request)

Compared to the traditional supplier for electro colouring with single-phase autotransformer the full solidstate control supplier has the following advantages:
 Three phase balanced input
 No moving parts
 AC frequency regulation
 AC asymmetric half-wave regulation
 It’s wave shape can overcame busbars inductive reactance and reach high current efficiency at the starting peak.
It can supply: Direct voltage, Alternate voltage, Alternate voltage with asymmetric half-waves. By means of a PLC on the control panel different working modes and programs can be set. Asymmetric half-waves facility allows to lengthen and shorten color (light and dark) formation time in order to obtain easy colour repetition.