| |
Electro-deposition for plating is undertaken by use of direct current (DC) which is energy converted after rectifying alternating current (AC). Generally, except hard anodizing and electro-polishing, all electro-chemical depositions use low voltage. Usually, three types of rectifiers are common
- Variac (Conventional)
- Thyristorised
- Solid State
General Characteristics :
- All electro-chemical deposits require low ripple content of not more than 5%, except for Chrome Plating, the latter necessitating not more than 3%. Measurement of ripple is best at 50% or lower load output.
- Power factor is 85%.
- Transformer windings and bus bars are out of electrolytic grade copper.
- AC output control panel houses contactor, switch fuse unit either analog or digital and indicating lamps.
- DC control panel houses ammeter, voltmeter and operating switches.
- Current control can also be achieved through PLC with additional facilities of control of current density, voltage, etc.
Typical rectifier outputs are as under :
|
8 V / 250 |
12 V / 250 A |
16 V / 250 A |
|
8 V / 500 A |
12 V / 500 A |
16 V / 500 A |
|
8 V / 750 A |
12 V / 750 A |
16 V / 750 A |
|
8 V / 1000 A |
12 V / 1000 A |
16 V/ 1000 A |
|
8 V / 1500 A |
12 V / 1500 A |
16 V /1500 A |
|
8 V / 2000 A |
12 V / 2000 A |
16 V / 2000 A |
|
8 V / 2500 A |
12 V / 2500 A |
16 V / 2500 A |
|
