Communications Power

Unipower Introduces New RS Series Front-End Switchers

Unipower Corporation (Coral Springs, FL) recently announced that the new RS Series front ends have 2,500W output with active power-factor correction. The two models available are the 24Vdc at 104.2A and the 48Vdc at 52.1A. Power density is 11W per cubic inch in a fan-cooled, low-profile case 3.3in x 4.9in x 14in. There are two other models available with identical performance except that output isolation diodes are incorporated inside the case for parallel and/or redundant applications. These front ends are designed to drive a dc power bus for a distributed power system using dc/dc converters.

The RS Series features a Class B input EMI filter, single-wire active current sharing between units, no minimum load requirement, and 250,000 hours MTBF by the Bellcore method. There is also a 5V, 100mA independent supervisory output. Protective features include over-voltage protection, thermal protection, and overload and short-circuit protection. Control and monitoring functions are remote-enable and inhibit, dc power good, ac power fail, and thermal warning.

The input voltage range for these front ends is 170Vac to 264Vac. The output has remote sensing for regulation at the point of load. Efficiency at full load is 82 to 85 percent, and the switching frequency is 65kHz. The input has active inrush current limiting to 25A. The unit also incorporates a single connector located on the front panel that is claimed to simplify the connection to the customer's system in a fast and fool-proof way. These products are also available in "hot plug" versions for use in fault-tolerant systems with specialized connectors and isolation diodes included.

Pricing for the RS Series in OEM quantities start as low as $999 each.