New Industry Products

TDK Expands Power Rating for DIN-Mounted Supplies by 50%

March 17, 2024 by Mike Falter

TDK has added three-phase input, DIN-mounted AC-DC supplies that increase the DRB series' output power rating to nearly 1 kW for industrial and other loads.

TDK Corporation has expanded its DRB series of DIN rail-mounted AC-DC power supplies by adding two models that extend the power rating for continuous operation by up to 50%. They are rated to 480 W and 960 W, respectively.

The DRB480 and DRB960 models accommodate a wide three-phase AC input range (350 to 575 VAC, 60 Hz) and provide regulated (and adjustable) DC outputs of 24 V, 48 V, or 72 V, with power conversion efficiencies above 96%.


DRB Series, DIN mountable AC-DC supplies

DRB Series, DIN mountable AC-DC supplies. Image used courtesy of TDK


The supplies are packaged in compact aluminum enclosures to save space and provide robustness for industrial environments. Input and output connections to the supplies can be made through screw terminals or push-in connectors.

Applications for the DRB series models include stand-alone machinery and industrial and information technology systems.


Power Supply Architecture

The DRB series of power supplies uses active PFC (power factor correction) at the input to convert three-phase AC to DC. The internal DC voltage is then conditioned through a transformer-isolated DC-DC conversion stage that provides more than 3,500 VAC of input-to-output isolation. 

The power stage controller receives feedback on output voltage levels across the isolation boundary through optical isolators, maintaining a regulated DC output through adjustments to the power stage’s switching parameters. Synchronous rectification on the transformer’s secondary side employs active switching to convert AC power at the transformer's output-to-output DC with minimal power loss.


DRB series functional block diagram

DRB series functional block diagram. Image used courtesy of TDK


DIN Mounting of Power Supplies

DIN mounting refers to the ability to mount electrical components on the DIN rails found within a system enclosure, mounted to the wall or equipment rack. The metal rails simplify mounting electrical components like power supplies, circuit breakers, and PLCs. DIN stands for Deutsches Institut für Normung, which roughly translates to German Institute for Standards, a German organization that sets industrial and electrical equipment standards.

The DRB series offers a broad range of models and supply configurations with relatively compact enclosures (100 mm x 129 mm x 171.9 mm for the DRB960). Combined with the flexibility of DIN rail mounting, architecting a complex industrial or other power distribution system with broad and diverse power requirements can be simplified.


Parallel Operation of Supplies

For higher power loads or supply redundancy, multiple DRB models with the same output voltage and current rating can be operated in parallel using droop mode current sharing. With droop mode current sharing, the output voltage is designed to “droop” with load to ensure loading is well balanced between the multiple supplies.


Parallel operation of DRB series supplies

Parallel operation of DRB series supplies. Image used courtesy of TDK


A dip-switch on the unit’s front panel allows for easy configuration to single or parallel operation. If more than three supplies are operated in parallel, each output must be protected by a decoupling module or other appropriate device.

The DC outputs have a wide adjustable range (22.5 to 29 VDC for a nominal 24 VDC output), which allows for cable drops, ORing FETs, or non-standard output voltage generation.


Output voltage “drooping” with Parallel Mode

Output voltage “drooping” with Parallel Mode. Image used courtesy of TDK


Meeting Global Safety Standards

The DRB series is designed for global applications and meets all seven major electrical standards, including:

  • IEC/EN/UL/CSA 62368-1, 61010-1, 61010-2-201
  • CE/UKCA marking per low voltage, EMC, and RoHS directives
  • EN 55011-B and CISPR11-B for radiated and conducted emissions
  • EN 61000-3-2 (Class A) harmonic current and IEC/EN 61000-6-2 immunity standards