Power supplies not only need to be powerful and efficient, they also must meet performance and reliability requirements for rugged and demanding environments, such as military and medical applications. Two European companies, SL Power Electronics and Powersolve Electronics, are rising to the occasion.
SL Power Electronics has seen an increase in business because of its expertise in rugged high-reliability medical equipment. Yet this field isn’t immune to the world’s economic troubles. Companies that purchase medical equipment are coming under increasing finincial government constraints. Products like ventilators, though, are seeing an increase in interest.
“At SL Power, we have seen over the past six months, initially in the U.S. and now in Europe, destocking by both direct customers and distribution networks,” said Nigel Davies, SL Power’s European managing director. “This appears now to have levelled off and the market flat. Fortunately, SL Power took hard decisions early in the downturn, which have resulted in the company maintaining a healthy finincial outlooked despite reduced sales.”
SL Power is seeing a great deal of interest in its new generations of medical products released in the past six months. Manufacturers appear to be using the downturn to develop new equipment, demanding ever-lower prices, higher efficiencies and smaller sizes, and increasingly higher convection-cooled ratings.
“Major global manufacturers are looking for one-size-fits-all solutions to their equipment, so that they can minimize variety of parts held,” Davies said. “Ever more complex power systems are being requested, with as many as 24 outputs, battery charging, and computer-controlled operating and monitoring.”
However, medical legislation for power supplies hasn’t really changed during this period. New power-supply energy-consumption changes are affecting external commercial power supplies, such as the USA EISA laws, but all medical equipment is currently exempt from these requirements. SL Power is implementing the improved efficiencies required anyway as part of a general green initiative.
According to Davies, the types of product currently being supplied are varied but complex. On the one hand, the company is supplying a power system for a ship-borne communications system. The system uses multiple 5000-W distributed power systems, which include more than a hundred 300-W dc-dc converters. In contrast, a major American military equipment manufacturer is using three different systems in a mobile land-based vehicle. The high-power system is supplied with ac input, dc input, or dual ac-dc input.
SL Power recently won contracts to develop high-density platforms for secure broadband and radio data transmission in support of military and Homeland Security applications. The company expects increasing demand for this service as countries look to re-equip with ever-more complex military hardware. It also recently announced an addition to its Condor MINT Series of universal input power supplies designed for medical systems applications.
The single-output MINT1110 series units use a compact, open-frame design that measures 3 by 5 by 1.27 in. and offers a typical full-load efficiency of up to 87%. Available in four outputs ranging from 12 to 24 V, the supplies are intended for a range of medical applications, from diagnostic and respiratory care equipment to continuous positive airway pressure (CPAP) devices and monitors of all types.
The MINT 1110 units’ universal 100- to 240-V ac input provides flexibility for use anywhere in the world. They are protected against overvoltage, overcurrent, and short circuit with optional over temperature protection available. Also they carry a set of medical and safety approvals including EN/IEC/UL 60601-1 and CSA 22.2 No. 601.1-M90. The family complies with the European Union’s Restrictions on Hazardous Substances (RoHS) as well.
The PSL400BP baseplate-cooled ac-dc units from Powersolve Electronics offer single outputs of 5 V, 12 V, 24 V, or 48 V dc with output power up to 400 W. The input range is 85 to 264 V ac, 47 to 63 Hz. All models feature active power factor correction to conform with EN61000-3-2.
These ruggedized power supplies are housed in an extruded aluminium chassis designed for use in industrial or other types of equipment where cooling fans are undesirable and convection airflow is not available. Units can be mounted in a sealed box providing that the external heatsinking is adequate to maintain the baseplate at a temperature of 80ºC or below.
Standard features include overcurrent and short-circuit protection, overvoltage and overtemperature protection, output voltage adjust, remote on/off, output power good signal, +5-V, 1-A standby output, and LED indicator to show VOUT present. All units can operate in parallel for N+1 redundant operation and feature integral ORing diodes.
The printed-circuit board (PCB) is conformally coated for protection against the ingress of moisture and dirt. The operating temperature range is –20°C to 70°C, providing the baseplate temperature can be maintained at 80°C or below. All of the power supplies will carry full UL, cUL, and TUV EN60950 safety approvals and conform to EN55022 conducted electromagnetic-compatibility requirements.