Constant Voltage (Cv) And Constant Current (Cc) Mode - Tektronix Keithley 2281 Series Reference Manual

Section 2: General operation Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual

Constant voltage (CV) and constant current (CC) mode

The 2281S power supplies feature a constant voltage and constant current automatic crossover. This
feature permits continuous operation in the transition from constant-voltage mode to constant-current
mode as the load changes. Where the current setting (Iset) and the voltage setting (Vset) intersect is
known as the crossover point (see the following figure).
Figure 65: CC and CV mode
For example, if the resistive load is such that the power supply is operating in constant-voltage mode,
the power supply provides a regulated output voltage. As the load increases, the output voltage
remains constant until the preset current limit is reached. Then the crossover occurs.
Once the crossover occurs, the voltage drops in proportion to further load increases as the output
current becomes constant. The front panel will indicate the state of constant current or constant
voltage by indicating CC or CV. If CC is shown, the instrument is operating in constant-current mode.
If CV is shown, the instrument is operating in constant-voltage mode.
For this example, connect a 5 Ω resistor to the binding posts on the front panel, set the voltage to 5 V
and current limit to 2.5 A, and turn on the output. The power supply is operating in CV mode. For
details, refer to the following figure.
2-94 077114601 / March 2019