Quiet, reliable and fanless power from 200 to 350W with 150% peak, ideal for sealed enclosure applications.

These semi-potted AC-DC power converters are designed to operate without relying on fans for airflow to cool them but assisted by baseplate cooling for higher temperature performance.

The new range of fanless power supplies, which is to be extended later in the year with a 500W and a 750W version, currently offer power densities currently up to 15.28W/in3. Their semi-potted design rigidises the product and distributes heat across the PCB avoiding hot spots and provides the possibility of increasing thermal performance through baseplate cooling above 55°C ambient. This is particularly useful for audio noise sensitive applications, outdoor applications or perhaps ATEX sealed enclosures where there is no fresh airflow and waste heat in that enclosure must be kept to a minimum. With a normal power supply, its waste heat is dissipated either in natural convection or by forced convection (fan) to the surrounding air. With base plate cooling the heat is dissipated through the base and out of the enclosure efficiently helping keep the ambient temperature down in the sealed enclosure to promote better lifetime and more design flexibility of other components that share the enclosure. 

Quiet, reliable and fanless power from 200 to 350W with 150% peak, ideal for sealed enclosure applications.

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The 150% peak the units offer is ideal for printer applications, motorised applications such as pumps and conveyors. The large capacitive load capabilities of these products lend themselves well to motor driving applications where there is no pre-charge circuit to the servo driver / stepper driver. The motor driver is essentially a clever DC-DC converter and uses a bulk capacitor as its energy storage to energise phases from as the motor turns. When first powered up (not even driving the motor) there is a large inrush of current to charge the bulk capacitors in the motor controller. Some motor controllers have pre-charge circuits that switch in a resistor to slew the charge rate of the bulk capacitor to prevent this large current draw on the source. Once the voltage across the bulk capacitor rises the resistor is switched out of the circuit and the capacitor completes its charge at a more manageable rate. If you have multiple motor drivers in your design their power up can be staggered to ease the load on the power supply. With these new units it is likely that this mitigation won’t be necessary. The overload functionality supports these types of applications by adopting a short term constant current output protection as opposed to immediately tripping and re-starting (hiccupping) like most power supplies.  

The units offer common rail voltages from as low as 5V to 48V complete with output voltage adjustment, 5000M operation, and efficiencies up to 94%. A wide temperature of operation ideal for outdoor applications, especially the 350W units offering from -40°C up to 85°C (the smaller 200W operates up to 70°C). They offer true universal world-wide performance and only the 350W unit derates to 70% load without base plate cooling below 110VAC. The units are designed to meet the household appliance standard EN60335 with high flame retardant components and the higher isolation requirements (defined by EN61558-2-16) and of course presume conformity to the Low Voltage Directive and Safety of Electrical Equipment Statutory Instrument and bare the CE and UKCA mark respectively. 

If you are working on a project where these quiet punchy powerful units would be useful, please request a sample. Please get in touch with your FiDUS Account Manager or call us on 01183 420730 

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LMF350-23BxxUH product info

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