Application Cooling for two TO-227 high power resistors.

Constraints: Minimum Airflow, Small device size constrained air flow. 

Solution: This solution required a large heatsink optimized towards a natural convection solution to be implemented since the available airflow was close to natural convection. The optimized solution was to embed a Nanospreader™ under each resistor.  This design allowed direct contact of the heat generating device with the Nanospreader™ allowing the heat to be efficiently conducted to the far ends of the heatsink.

Test Conditions: Power – 200 Watts Per Device; Air Flow- 0.5 m/s

Results: The Maximum Case temperature of the Resistors using the Nanospreader™ cooling was 78.4°C.  The existing 6mm, 2-heatpipe per resistor solution for each resistor, resulted with a Maximum T-case temperature of 87.2°C. The 9 degree temperature improvement from the NanoSpreaderTM solution allowed designers to choose between lower component temperatures or higher output from the devices