Medical power supply delivers safety to healthcare facilities

The OBR04 is available in 12 different voltages from 12-58V with an efficiency rating up to 91%. With a strong focus on ‘no interference and radio coexistence’, the product meets conducted and radiated EN55011 class B without requiring any additional components. Built to ensure patient and operator safety, the OBR04 has an input-to-output isolation of 4,000VAC (2xMOPP), an input to ground of 1,500VAC (1xMOPP) and a 1,500VAC output-to-ground, when many conventional products offer only 500VDC isolation. In order to guarantee full operation up to an altitude of 5,000m, the OBR04 has been designed in respect of required creepage distances and additional isolation barriers.

Many countries such as China or those in South America are bringing healthcare to mountainous region based populations, and it is very common in those countries for healthcare centres and hospitals to be located at altitudes higher than 3,000m. Medical equipment must be designed to guarantee the highest level of safety up to 5,000m. The base design altitude for power supplies is 2,000m but as the altitude increases, the insulating qualities of the thin air diminish and the clearance distances have to be increased from 8mm at 2,000m, up to 11.84mm at 5,000m, thus requiring power supplies to be designed in accordance with the needs of such physical requirements and in some cases to comply with local approvals such as the CCC (China Compulsory Certification). The Chinese Safety Standard GB 4943.1-2011 mandates strict rules for clearance distances and since 1st December 2012 - the primary-to-secondary clearance has increased by a factor of 1.48 to qualify the power supply for operation up to 5,000m.

Designed with high altitude applications in mind, Powerbox’s PRBX OBR04 withstands an isolation voltage of 4,000VAC (2MOPP) from the input to the output, 1,500VAC (1MOPP) from the input to ground and 1,500VAC from the output to ground, when most products currently available are offering only 500VAC. The OBR04 leakage current is 300µA maximum, and the touch current is 100µA maximum at 264VAC and 63Hz.

Powerbox’s OBR04 is available as standard in twelve output voltages; 12, 15, 18, 24, 28, 30, 32, 34, 36, 48, 57 and 58VDC, covering a large range of applications from 12VDC intermediate bus voltages through to point-of-loads up to 58VDC to power the latest generation of power amplifiers. Depending on the output voltage the maximum output power starts at 600W and rises to 650W with a peak power level of up to 720W. An auxiliary 12V output is provided for an additional fan, as well as a standby 5VDC supply at 200mA.

“Designed for medical and high altitude applications, the OBR04 is also suitable for other types of applications such as radio-transmitters and also observatory stations equipment installed at the top of mountains and requiring similar performance levels in term of clearance distances” said Martin Fredmark, Powerbox’s Vice President Product Management. “Also, we see a growing demand for industrial applications requiring higher isolation voltages and for equipment that is designed equally as good as those for altitude applications in order to make their final equipment none sea-level depending.”

The output voltage of the OBR04 is protected against overvoltage exceeding 115-140% of the nominal output voltage and is over-current protected. The power supply also includes thermal shutdown and a TTL interface that provides a power fail detect signal.

The OBR04 input voltage spans from 90-264VAC and includes an active PFC, typically 0.98. Exhibiting versatility, the power supply is designed for global operation with an input frequency range of 47-63Hz. The input current at 115VAC and 60Hz is 8.4A (RMS), and 4.2A (RMS) at 230VAC 50Hz. The power supply can be safely operated within a temperature range of -10 to 70°C and stored at -40 up to 85°C.

Housed in an aluminum chassis, the OBR04’s dimensions are 165.8x101.6x62.5mm (6.53x4.0x1.95") and it is available in a ‘U’ shape chassis or an enclosed box with built-in fan. Based on a calculated MTBF per MIL-HDBK-217F, at full load and at 25°C, the OBR04 has a MTBF of 190,000 hours.

Targeting demanding application and low EMI, the OBR04 series meets EN55011, FCC and VCCI Class B conducted and emitted standards. It also complies with safety standards TÜV EN60601-1, UL ES 60601-1, CSA C22.2 No.60601-1 and is RoHS compliant.