Low leakage power supplies resuscitating medical technology

November 11, 2015 // By Paul Buckley
Powerbox has added to the company's medical Medline family. The OFM30 30W power supplies claim to be best in class EMC for medical systems in CF class while the OFM225 225W series is suitable for BF class with additional voltages.

The Powerbox OFM30 series is designed to meet and exceed safety standards for medical systems and equipment and  delivers 30 W in continuous operation (peak up to 45 W) features Class II double isolation and is UL/IEC60601-1 medically approved.

The OFM30 achieves low leakage current with low EMC.  The device is capable of reaching a leakage current below 10 µA and an EMC Class B average margin of 6dB.

Combining low power loss switching topology and selected components, the OFM30 series has an efficiency up to 88% whilst, fulfilling the Green Mode requirements of IEC60950-1, CEC Level V, EISA and ErP, at zero load. The OFM30 power consumption is below 0.3W thus assuring the family of its green credentials.

The OFM30 output power is rated at 30 W continuously, at 50ºC and free convection cooling; though it can respond to peak demands for extra power (e.g. pump systems), allowing up to 45 W during 10 seconds, with repetition every 100 seconds. In case of over temperature, the OFM30 integrates a protection system operating with linearity, reducing the output power down to 50%, securing the payload to proceed to all appropriated processes to avoid treatment disruption.

The OFM30 exploits the benefits of a switching topology based on a front edge fly-back, optimized to reduce components count down to 65. The lower number of components contributes to higher reliability, resulting in an MTBF over 500,000 hours and a minimum lifetime expectation of 80,000 hours.

The OFM30 series includes three models: OFM305025 delivering 12 V / 2.5 A (peak 3.75 A), the OFM305026 delivering 15 V / 2.0 A (3 A peak) and the OFM305028 delivering 24V / 1.25 A (peak 1.875 A). In case of a need for redundancy or extra power, all products can be connected in parallel without any additional external components. The product is available in an open frame format of 75.5 x 37.3 x 23 mm.

The OFM30 series is safety approved according to IEC 60601-1 ed.3, with CB’s by ETL Intertek Semco, and complies with other related IEC 61000 applicable standards and environmental norms RoHS, REACH and WEEE.