General Information
13
Front Panel Programming
The front panel has both rotary (RPG) and keypad controls for setting the output voltage and current. The panel display
provides digital readouts of the output voltage and current. Other front panel controls permit:
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Enabling or disabling the output.
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Setting the overvoltage protection (OVP) trip voltage.
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Enabling or disabling the overcurrent protection (OCP) feature.
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Saving and recalling operating states.
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Calibrating the power supply.
Analog Programming
The power supply has an analog port for remote programming. The output voltage and/or current of the power supply may
be controlled by d-c programming voltages applied to this port. The port also provides a monitor output that supplies a d-c
voltage proportional to the output current.
Output Characteristic
General
The power supply can operate in either CV (constant voltage) or CC (constant current) over its voltage and current ratings
(see “Performance Specifications”). The operating locus is shown by the output Characteristic Curve in “Supplemental
Characteristics”. The operating point is determined by the voltage setting (Vs), the current setting (Is), and the load
impedance. Two operating points are shown. Point 1 is defined by the load line cutting the operating locus in the
constant-voltage region. This region defines the CV mode. Point 2 is defined by the load line cutting the operating locus in
the constant-current region. This region defines the CC mode.
Downprogramming
The power supply can sink current for more rapid down programming in the CV mode. For Series 654xA and 655xA
supplies, this capability is defined by the second quadrant area (-Is) of the Output Characteristic Curve. These supplies can
sink about 20% of their maximum rated positive output current. For Series 657xA power supplies, this is an uncharacterized
current-sinking area that provides a limited downprogramming capability.
Specifications and Supplemental Characteristics
Table 1-1 lists the specifications and supplemental characteristics of the Series 654xA and 655xA power supplies. Table 1-2
lists the specifications and supplemental characteristics for the Series 657xA power supplies. Specifications are warranted
over the specified temperature range. Supplemental characteristics are not warranted but are descriptions of performance
determined either by design or type testing.