AC-DC Power System Delivers 8 kW in 1-U Rack Space

July 1, 2004
The Mini DC Power System from Valere Power (Richardson, Texas) produces up to 8 kW of 48-V output in a 1-U rack space, while achieving 93% efficiency.

The Mini DC Power System from Valere Power (Richardson, Texas) produces up to 8 kW of 48-V output in a 1-U rack space, while achieving 93% efficiency. The heart of this power system is the 14.2-in. × 4.0-in. × 1.6-in. H-Series ac-dc rectifier module that delivers as much as 2.3 kW of output. That translates to a power density of 25 W/in.3

Geared toward telecom and data center applications, the system offers several options for output voltage and current ratings, including models with a 12-V or 24-V main output, as well as 5-V and 12-V auxiliary outputs (see the table). Also included are various options for local and remote management, such as an Ethernet interface. In addition, the system features flexible options for distributing power to equipment, including bulk dc power, the ability to split into two voltage feeds or the ability to connect to separate distribution.

In developing the Mini DC Power System, the company has transferred the functionality of its Compact DC Power System, which was packaged in a 2-U format, into a 1-U package. In the process, Valere Power raised the 92% efficiency of the original product, a 1% improvement that equates to a 15% reduction in heat dissipation.

The higher efficiency of the Mini DC Power System has been attributed to improvements in the supply's zero-voltage switching circuitry, which allows the supply to recover energy losses on the rectifier's secondary. In the new rectifier, snubbers have been eliminated and reverse recovery currents are redirected so that their energy is stored in the primary-side of the supply.

Table. Output ac-dc rectifier output options.Voltage (V) Current (A) 48 5, 10, 15, 20, 25, 30 or 40 24 10, 25 or 50 12 60 or 100

The Mini DC Power System is configured for front-to-back airflow with two fans located in the front of the rectifier module. By monitoring and controlling fan speed, the supply can address the most common cause of power supply failure — a faulty fan. As fan speed drops, control circuitry in the supply drives the fans harder to maintain airflow, while also setting a flag to inform the system of fan failure. The rectifier modules are rated for 10 years of service.

The system also monitors five internal temperatures, output voltage and output current. Because the rectifier also incorporates a real-time clock, it's possible to perform data logging on power levels in the application and predict pending faults.

The system has built-in network intelligence, including a front-panel controller that gives system status information, and an optional SNMP-based network management console that can provide monitoring information, as well as the ability to change parameters and run battery tests remotely. Local and remote management can be performed either via a network interface card, the company's HC controller or through an I2C interface.

For telecommunications applications, the Mini DC Power System is NEBS Level 3 compliant and has backup battery interface capabilities, including options for breakers, fuses and low-voltage disconnects required in customer premise or remote terminal applications.

In addition to offering the Mini DC Power System as a stand-alone product, the company is in discussions with manufacturers of networking and computing systems to embed the system within the OEMs' equipment.

The Mini DC Power System is available now. Unit pricing for the H-Series rectifier starts at $500. For more information, visit

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