You have it right.
A CC power supply will always provide better anodizing regardless of the scale. It also makes the job much easier.
The very small size of your work will require very accurate current measurements at low current levels, unusual for most anodizing applications. A real electronics laboratory CC/CV supply would be in order. You want accuracy down to 1 milliamp (0.001A). You might find one of these used on ebay, expect to spend several hundred dollars for a used one.
Alternately, you could use Caswell's 3A CC/CV rectifier with a minor addition. This will require a 1 Ohm 1% (at least) 3Watt (or larger) precision power resistor and a digital multimeter that is ACCURATE reading DC volts at 1 millivolt (0.001V). This won't work with a cheap $10 multimeter. Precision power resistors are available over the internet from Digikey or Mouser Electronics. You put the resistor in series with the positive output of the rectifier, and measure the current with the multimeter hooked across the resistor, it will read directly 1 millivolt = 1 milliamp. At your very low current levels, you will notice the inaccuracy of the meters on the rectifier, this is normal.
|