Evaulation_Engineering_March_2020 - 14

POWER SUPPLIES/LOADS

Sponsored by
Elektro-Automatik

output channels that can either be set as
open or switched to any of the three voltage rails. Each of the three voltage rails can
be programmed to output -10 VDC to +32
VDC or -20 VDC to +20 VDC with 14-bit
resolution."
Semancik added that MTS also offers a
PXI power interface card that provides the
user with access to the PXI +3.3 V, +5 V and
±12 V outputs. "These outputs are fused and
software controlled," he said. "This card is
a good economical fit for applications requiring a limited number of low power fixed
voltages for unit under test (UUT) or interface test adapter (ITA) circuitry."
According to Tom Goodman, product
manager at TDK-Lambda, customers face
challenges requiring better technical specs
(for constant-voltage and constant current
modes), higher power density (to reduce
unit height and depth), and lighter weight
(to increase portability, ease integration,
and reduce shipping cost). Customers also
want integrated advanced front-panel and
remote features, multiple built-in interfaces
(including Modbus-TCP and EtherCAT for
industrial automation) with isolation, and
easy software interfaces (with respect to
both GUI and drivers), and easy paralleling
(to support higher power levels as application power consumption increases). They
also want an effective calibration strategy
that minimizes measurement uncertainty
and reduces costs associated with manufacturing defects.
TDK-Lambda has recently introduced
several products in rackmount configurations that help meet these challenges,
including the GENESYS+ 1U half-rack 1.5kW platform (which Goodman described
as offering the highest power in half-rack
configuration); the GENESYS+ 1U full-rack
1.7-kW, 2.7-kW, and 3.4-kW platforms; and
the FLEX-HV 2U full-rack high-voltage programmable power supplies, which will be
on display at APEC.
Goodman noted that the GENESYS+
products offer a variety of features: multifunctional front-panel display with embedded user menus, an arbitrary waveform
generator with auto-trigger capability, a
constant-power limit mode (autoranging),
internal resistance simulation, programmable slew-rate control (up/down for voltage/current), wide-range 400 VAC/480 VAC

14

EVALUATION ENGINEERING MARCH 2020

inputs, built-in communication interfaces
(LAN, USB, RS-232/RS-485, and isolated
analog), protection functions (including CV
or CC foldback and OCL), an enable/disable
function with polarity selection, an internal pre-load ON/OFF control, a blank front
panel option, and an air-filter kit accessory.

From modules to systems
Acopian offers power supplies including
modules and rack-mount systems. The
products find use in a variety of applications, including electronics test, manufacturing, R&D, battery simulation, automotive test, military/aerospace test, electric
drivetrain test, renewable-energy test, and
grid simulation as well as in medical, audio,
and telecom industries, according to Alex
Karapetian, VP of sales. Specific products
the company offers include touch-safe linear
encapsulated power modules, 1U rack and
benchtop power supplies up to 720 W (to
be on display at APEC), and 2U rack and
benchtop power supplies up to 1,400 W.
Karapetian commented, "A few features
that stand out include 2-quadrant power
supplies, digital communication interfaces,
as well as the ability to design drop-in replacement for legacy products to help our
customers."
Karapetian added, "A challenge we see is
the ever-changing specifications of our customers and their requirements. Oftentimes,
a standard product doesn't meet their specifications. We address their challenges by
designing a custom unit or modifying
standard units to meet their needs for
application-specific power supplies."

Chips, IP, and software
Analog Devices' Power by Linear family of
Silent Switchers and uModules includes
products that operate with very low conducted and radiated EMI. This, in conjunction with their high efficiencies make
them well suited to test and measurement
applications, the company said.
Several new parts from the company
are targeted at bidirectional high-power
supplies. One example where these parts
can be used is in battery formation and
test. For example, the LT8228, which operates as a buck converter in one direction,
and a boost in the reverse direction.
Intellectual property is the focus of

CogniPower, an IP licensing firm that
holds more than two dozen patents relating to more efficient and more capable
power converters. "We actually do some
things differently from standard practice,
and we put an effort into teaching what
and why," said Thomas Lawson, founder
and president.
This year, the company will be attending its 12th consecutive APEC exhibition.
"We are presenting techniques for building
ultralow standby-power flyback and buck
converters," Lawson said. "By ultralow
standby power we mean under 1 mW."
He added that minimizing vampire
power requires simplifying the circuitry.
"Simpler designs are more cost effective
and can have excellent efficiency, even at
low loads," he said.
"We will be running a live demo at
APEC of Predictive Energy Balancing
(PEB). PEB is a superior method for controlling almost any switched-mode power
converter."
Finally, software has a key role to play
in power applications-from simulation to instrument control. With respect to the former, said Tony Lennon,
market manager for power electronics
control design, "For designing the software for programmable power supplies,
MathWorks provides Simulink software
that lets engineers model digital control
algorithms and analog circuits together,
before beginning detailed circuit design
with a SPICE circuit simulator."
Lennon continued, "One area that has
grown popular in the last year is the advances in hardware-in-the-loop (HIL)
testing. HIL testing helps engineers validate the control software they program
on a microcontroller or FPGA."
He said that MathWorks will join its
partner Speedgoat at APEC and demonstrate HIL systems for testing power
electronics.
A subsequent article will have more
on software for power-supply and load
applications.

REFERENCE

1.	 "Boost your efficiency with our new generation
of power supplies," Rohde & Schwarz. https://
www.rohde-schwarz.com/products/test-andmeasurement/boost-your-efficiency_252163.
html
http://www.rohde-schwarz.com/products/test-and-measurement/boost-your-efficiency_252163.html
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