electroplater question

[krautschmidt]

I have an electroplater with a constant 3 amp current. I need to be able to reduce the current to as low as 1/10 amp under certain circumstances. What can I add to anode line to control as well as meter current?

[terri]

The immediate and inane answer is to shunt 2.9 amps around the cell.<p>But:<p>What are you using it for? (Application?)<p>Do you have a circuit of the power supply? Or even a brand name?<p>Details, please.

[Chris Smith]

krautschmidt <p>
We don’t know what power source you have so we cant really advise you on the best way to go. <p>What power supply do you have? <p>AC in and rectified with chokes, caps, and batteries, DC battery, generator, or AC SCR type and chokes, ??? <p>Depending on what system you have depends on how you can cut the current. <p>Ripple is your only main enemy.

[terri]

(Actually, a little ripple is usually a good thing in a plating tank. Most of the time, it smooths out the deposition. In fact, some plating operations work best with reverse current for a short part of the cycle. However, we don't know for sure that s/he's even plating, from the information supplied.)<p>I was also wondering if the 1/10 amp really referred to current density rather than total current to the suppposed plating cell --that is, 1 /10 amp per given area, like a square cm. ...If s/he was actually plating something.<p>I'm also wondering what s/he was taking off the anode, if that's the area of interest. In most plating operations, the concern is in what's being plated out on the cathode.<p>For all we know at this point, s/he may actually be electropolishing, not really plating. Or, s/he may be just using the plating power supply for something else altogether.<p>Wisdom dictates we wait for more details.<p>I repeat: Wisdom dictates we wait for more details.<p>[ September 23, 2005: Message edited by: terri ]</p>

[Chris Smith]

Terri<p>Which plating plant did you work for? <p>Ripple is good?<p>Now your just down right getting it wrong.
Ripple is the biggest enemy of plating, period.<p>Ripple Filters were the biggest component on our plating tanks. They could be as big as a house, while electric driven generators were the preferred method for producing as pure as it gets DC current with no ripple.<p>The SCR bank power supplies had huge chokes, coils, caps and diodes to keep out the ripple and for one tank alone this filter was the size of a industrial 10,000 amp panel. <p>The slightest amount of ripple makes the metal attract, then reject, back and forth and produces a shitty finish or a flawed one all together. <p>Even the charge in the water had to be de-ionized for rejection purposes.<p>Don’t confuse “pulse plating” with ripple.<p>[ September 23, 2005: Message edited by: Chris Smith ]</p>

[terri]

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