Heatsink requirement
Posted by: powerfly
on
How do I determine if I power supply requires a heatsink.
I am using TOP246Y To220 package(closed frame design). The power output is 30W.
I think it will work fine for now. But how do I calculate the heatsink thermal resistance requirement, once the power output exceeds 40W.
(FYI: TOP246Y can be operated in closed frame at 40W without a heatsink)
I have seen some power supplies use a aluminum sheet as a heatsink(see attachment). Is this a part that's available widely or is it custom made.
Comments
How can I determine if I need a heatsink at the design stage?
How can I determine if I need a heatsink at the design stage?
A simple way to determine if your power supply requires a heatsink is to run thermal test - to run the unit at full load, low line voltage, at highest ambient temperature indicated in specifications for two hours and measure the temperatures for critical components (using thermal coupler), such as TopSwitch. If you don't see thermal shut-down (a protection feature of TopSwitch) and the temperatures are reasonable, you don't need to add or increase heatsink. The one as shown in the picture is just a piece of aluminum customized in "L" shape to fit in the space.