Vicor VI-J00 Family DC-DC Converters and Configurable Power Supplies - Manual (Page 96)

Design Guide & Applications Manual
For VI-200 and VI-J00 Family DC-DC Converters and Configurable Power Supplies
VI-200 and VI-J00 Family Design Guide Rev 3.5 vicorpower.com
Page 95 of 98
Apps. Eng. 800 927.9474 800 735.6200
Product Grade. The environmental and acceptance tests
performed on Vicor products.
Pulse Width Modulation (PWM). A switching power
conversion technique where the on-time (or width) of a
duty cycle is modulated to control power transfer for
regulating power supply outputs.
Push-Pull Converter. A switch-mode power supply
topology that utilizes a center-tapped transformer and
two power switches. The two switches are alternately
driven on and off.
Q
Quasi-Regulated Output. The regulation of an auxiliary
output that is accomplished by regulation of the main
output. A transformer turns ratio, commensurate with the
desired auxiliary output voltage, is used in conjunction
with the output around which the main control loop is
closed. Quasi-regulated outputs are significantly affected
by second order effects in the converter.
R
Rated Output Current. The maximum load current that
a power supply can provide at a specified ambient
temperature.
Reflected Ripple Current. The rms or peak-to-peak AC
current present at the input of the power supply that is a
result of the switching frequency of the converter.
Regulation. The ability of a power supply to maintain an
output voltage within a specified tolerance as referenced
to changing conditions of input voltage and / or load.
Regulation Band. The total error band allowable for an
output voltage. This includes the effects of all of the types
of regulation: line, load, temperature and time.
Regulatory Agencies. CSA: Canadian Standards
Association; FCC: Federal Communications Commission;
FTZ: Fernmelde Technisches Zentralamt; TÜV: Technischer
Überwachungs Verein; U.L.: Underwriters Laboratory; VDE:
Verband Deutscher Electrotechniker.
Remote Inhibit. A power supply interface signal, usually
TTL compatible, that commands the power supply to shut
down one or all outputs.
Remote On/Off. Enables power supply to be remotely
turned on or off. Turn-on is typically performed by open
circuit or TTL logic “1”, and turn-off by switch closure or
TTL logic “0”.
Remote Sense. Wires connected in parallel with power
supply output cables such that the power supply can
sense the actual voltage at the load to compensate for
voltage drops in the output cables and / or isolation devices.
Return. The designation of the common terminal for
the power supply outputs. It carries the return current
for the outputs.
Reverse Voltage Protection. A protection circuit that
prevents the power supply from being damaged in the
event that a reverse voltage is applied at the input or
output terminals.
RFI. Radio Frequency Interference. Undesirable noise
produced by a power supply or other electrical or
electronic device during its operation. In power supply
technology, RFI is usually taken to mean the same
thing as EMC.
Ripple and Noise. The amplitude of the AC component
on the DC output of a power supply usually expressed
in millivolts peak-to-peak or rms. For a linear power
supply it is usually at the frequency of the AC mains.
For a switching power supply, it is usually at the
switching frequency of the converter stage.
S
Safety Ground. A conductive path to earth that is
designed to protect persons from electrical shock by
shunting away any dangerous currents that might occur
due to malfunction or accident.
Secondary. The output section of an isolated power
supply, it is isolated from the AC mains and specially
designed for safety of personnel who might be working
with power on the system.
SELV. An acronym for Safety Extra Low Voltage, a term
generally defined by the regulatory agencies as the
highest voltage that can be contacted by a person and
not cause injury. It is often specifically defined as 30 Vac
or 42.4 Vdc.
Setpoint Accuracy. Ratio of actual to specified output
voltage.
Sequencing. The technique of establishing a desired
order of activating the outputs of a multiple output
power supply.
Soft Start. A technique for gradually activating a power
supply circuit when the power supply is first turned on.
This technique is generally used to provide a gradual rise
in output voltages and inrush current limiting.
26. Glossary of Technical Terms