Dave Plowman (News) wrote:

Just curious what use a constant current constant voltage bench supply
would be? Or does it mean *either* constant voltage or constant current?


For bench supplies, it's either, so I put a slash in my answer between
CC/CV.

It's a supply where you wind up the voltage to what you want and then
you set the current limiter to what you consider a safe maximum to the
load circuit you are fooling with.

If the load demands more current than your limit, the supply will reduce
the voltage to maintain the great law of Ohm. So essentially it will be
delivering constant current (CC) to the load and flashing warning lights
which will tell the user something is wrong with the circuit.

(Though in some circumstances ignoring the warning may be useful for
things like charging nicad cells which should be charged using the
constant regulated current.)

If you have no current limiter in force, then the supply works in
constant voltage (CV) up to the point of smoke (or blown internal fuse
or some other limiter) for excessive current delivered.

The following explains using a supply from HP for the point of view of
an EE student.

Basics of Power Supplies -
Use of the HP E3631A Programmable Power Supply
http://www.ese.upenn.edu/rca/instruments/HPpower/PS3631A.html

--
Adrian C