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Effect of Ripple in DC Supply for Electroplating

We are using six pulse thyristorised rectifier for chrome plating. What is effect of ripple in the DC supply used for the electroplating?

Dilip Rane
Bajaj Auto Ltd. - Aurangabad, Maharashtra, INDIA
2001

If the thyristors are used for controlling current by changing firing angle, it is not good for chrome plating. As the angle increases, the ripple also increases.

Deval Yashawant
electroplating shop - Pune, Mah, India
2001

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Chrome can instantly passivate, causing laminar (mica-like) deposits, due to excess ripple. As Mr.Yashawant says, thyristor rectifiers are not ideal for chrome plating especially if not operated near capacity. At lower ratings the output will resemble shark fins, where the 'back of the fin' is no current, and consequent laminar plating.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2001

Thyristor rectifiers used in chrome applications typically have at least a choke filter output to keep ripple to nominal 5% above 50% load. Ripple below 1%, and/or at low loads is achieved by adding capacitor to choke filter to give LC output filter.

Tim Robbins, M.Sc.
- Melbourne, Victoria, Australia
2006