Power to Varying Resistance

Do these parts have varying surface areas? Any blind holes?

It's surely doable. Is it necessary is the question?

What are you trying to plate?

What is the base material?

What is the plating material?

Current feedback loop to a variable DC voltage controller? Commonly made products.

Put the parts in series.

Ah, you beat me to it. The most elegant solution (pun not originally intended). But of course, this would require sixteen separate plating baths.

Yes. It's called a current mirror. Google it.

That would be fine if all of the parts are of the same size and shape. If they are different, then they will require different current rates to achieve similar plating thickness in the same time frame.

Hanging the items off a non conducting rack and providing each with a constant current regulator would allow you to tailor individual currents to suit each item whether similar or different in size.

This appears to me to be a simple Ohm's Law question.

The plating current needs to be correct for the "area" of plating, I would guess that this is the reason for the variable current requirements.

It is quite easy with modern chips to control either the current, or the voltage quite accurately. Not a big deal.

The good point is that as already mentioned, if individual current control is organised, only one "bath" need be available.

I do believe (from a position of never having anything to do with metal plating!!) that something like a relatively simple PWM control, would be able to average out the current, seen over time, so that the end result is what is required.

Even a simple 555 circuit, controlled say by a potentiometer, with a MOSFET output may do it!! A current meter (even a simple one using leds and a control chip) , may be required for accuracy.

A lot here is simple guessing only, as the OP's information is not very extensive.....but I do feel that it should be quite easy to organise well.

And the application is what?

All good answers here. I think all here would agree, that how one approaches the problem depends on the results desired. We don't know enough about the problem. But, if this challenge belonged to those who answered here, they would have this problem solved, and moving on to finding better quality/efficiency in the process.

More Info

The 16 parts are identical within the tolerances of the print. The contact is not permanently attached to each part. The part sits in and on the contact thus the variation in resistance due to variation in the part tolerance and contact fit. The DC power must be adjusted for each part to ensure the amperage is identical in each part thus resulting in consistent plating thickness. Voltage of individual power sources will range from 3.5 to 6 Volts.

Let me complicate this further.

Having equal current applied at some point to the part may not insure even current density over the entire surface, so you may still see inconsistencies. Most, but not all, plating specs have a minimum thickness requirement. It would be difficult to control plating thickness to microns over an entire part, depending on the size.

It would be interesting to know your end requirements for thickness, and the motivation for such control.

Different metals plate at different rates and require different current densities, as well.

Refer to #2.

Like you said Lyn, the part geometry will affect the plating too.

We're just spitting in the dark without more info!

If all the target devices are connected in series the current through all of them MUST be the same, then it is only a case of boosting the dc voltage to the level required to achieve whatever current you require.

www.linear.com/docs/1059

One per circuit and adjust each to the desired plating current.