Back to Basics - DC Power Supply Terminology
(Our thanks to Agilent Technologies for supplying this article)
GPIB Programming
Programming a power supply remotely by means of a controller such as a PC. The controller must have a GPIB (General Purpose Interface Bus) card installed in it, and connects to the power supply by means of an GPIB cable.
Wattage Range
The output wattage range of the power supply.
Voltage Range
The output voltage range of the power supply.
Maximum Watts
The maximum output wattage rating of a power supply.
Maximum Volts
The maximum output voltage rating of a power supply.
Maximum Amperes
The maximum output current rating of a power supply.
Mainframe Modular
One of several power supply units that are installed in a mainframe.
Single/Multiple Output Ranges
Power supplies may have a single output, or multiple outputs that are individually controlled.
Number of Output Ranges
Some power supplies have more than one output range, only one of which may be active at a time. A dual output range usually has one range with high voltage and low current, and another range with low voltage and high current.
Number of Outputs
Power supplies that have more than one output. One example would be a mainframe consisting of a number of power supply units. Each unit is counted as one output.
High/Normal Precision
High precision power supplies have 14-bit programming and readback of voltage and current; normal precision power supplies have up to 12-bit programming and readback of voltage and current.
Autoranging
A power supply that can provide maximum rated power over a wide and continuous range of voltage and current settings.
Constant Voltage/Current
A power supply that operates as a constant-voltage power supply or a constant-current power supply, depending on load conditions. The supply acts as a constant-voltage source for comparatively large values of load resistance and as a constant-current source for comparatively small values of load resistance.
- A constant-voltage power supply stabilizes the output voltage with respect to changes in influence quantities. Thus, for a change in load resistance, the output voltage remains constant while the output current changes by whatever amount necessary to accomplish this.
- A constant-current power supply stabilizes the output current with respect to changes in load impedance. Thus, for a change in load resistance, the output current remains constant while the output voltage changes by whatever amount necessary to accomplish this.
Remote Sensing
Remote Sensing or remote error sensing, is a means by which a power supply or electronic load monitors the stabilized voltage directly at the load or source respectively, using extra sensing leads. The resulting circuit action compensates for voltage drops up to a specified limit in the load leads.
Laboratory Use
Laboratory Use describes power supplies that are designed to be used on a lab bench. All controls and connections are available at the front panel.