constant current source in lab power supply

[Kurosen]

In EEVBlog #221 the first steps for building a power supply are shown. It consists of a constant current (CC) and a constant voltage (CV) part (two figures are included showing the PSU design and one showing the current source). I have two questions regarding the constant current source in the design:
How high is the voltage output of CC? I want to be able to determine the output range of the CV.
Second, what happens if the load connected to the CV draws less than the set current? Where does the excess current go?

Kurosen

[cellularmitosis]

If you have the CC set for 1 amp, but the load is drawing less than 1 amp, the CC regulator's voltage output goes as high as it can.  This is why the design works: the CC regulator doesn't get in the CV regulator's way until you hit the current set limit, at which point the CC regulator starts starving the CV regulator of voltage.

The excess current doesn't go anywhere, it is just never drawn from the rectifier in the first place.  Rather, it's the other way around.  It's the excess voltage which must be dealt with, not excess current.  If your are operating from a 18 volt supply, and your load draws 10 volts at 1 amp, the regulators must burn off the top 8 volts (at 1 amp) as heat.