Unipower Intros MH Series Front-End Switching Power SuppliesAugust 15, 1999 by Jeff Shepard
Unipower Corp. (Coral Springs, FL) has introduced the new MH Series of front-end switching power supplies that produce 600W at three dc voltage levels: 24Vdc at 25.0A, 28Vdc at 21.4A, and 48Vdc at 12.5A. The low-profile supplies are housed in a case format measuring 2.5 x 5. The devices are available in three versions: open frame and covered, which are 9 long, and covered with an end-mounted fan, which is 10.5 long. Power density for the units is up to 5.3W per cubic inch. The power supplies are intended to drive a dc power bus for a distributed power system utilizing dc/dc converters. The MH Series features active power correction which meets EN61000-3-2 and a Class B input EMI filter. Efficiency is greater than 85 percent for all outputs. Total line and load regulation is better than 1 percent, and the output voltage adjustment range is +/-5 percent. Single-wire, active current sharing permits parallel operation for redundancy or to achieve higher power. The front ends also feature remote sensing, a dc power good output signal, an ac power fail output signal and input inhibit control. A 5Vdc, 100mA independent output is available. A 12Vdc, 0.5A fan output is available on models without the self-contained fan. Protective features include overload, overvoltage and thermal protection. There is no minimum load requirement. The MH Series power supplies are also available as standard hot-swap modules along with an easy-connect, 2U-system rack. The power supplies are priced as low as $285 each in OEM quantities.