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Control of DC power for plating tanks

G'day,
For years we have used old fashioned resistance boards to control plating tank current where we supply more than one tank from a single rectifier. These old boards are reaching the end of their life and need to be replaced.
Is there a modern electronic equivalent? We do not want to have to purchase a new rectifier for each tank as they are sometimes not used every day so we cannot justify that capital cost.
Any suggestions appreciated.

Bob Lynch
plating company - Sydney, Australia
August 2, 2011

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Resistors dissipate lot of heat which is a waste of energy. Modern DC sources are inverter based. They are energy efficient, compact and light as they do not use heavy transformers. You can consult power electronics engineers who can add a PWM control unit to the existing rectifier. Alternately you can buy new power source ( similar to the ones used for TIG welding) which would perhaps be less expensive and more efficient.

H.R. Prabhakara - Consultant
Bangalore Plasmatek - Bangalore Karnataka India
August 14, 2011

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August 23, 2011

Hi Bob
Things seem to be a little slow down under!
I have not seen a resistance controlled rectifier in Europe or UK in at least the last 30 years.
Similarly I doubt if you could buy an inverter - you could try an antique shop.
Modern rectifiers are either variable transformer (variac) controlled or more advanced switched triac units.
Talk to your plant supplier. I would avoid sales talk on pulsed DC and the like. They can be effective but introduce many more variables (i.e things that can - and will - go wrong).

Geoff Smith
Hampshire, England