Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [heatsink]

A heatsink dissipates heat into the surrounding air and thus provides cooling.

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426 questions
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Fan and heatsink - suck or blow?

This question covered it for enclosures. However, from the point of view of the fan attached to a heatsink does it matter whether air is blown through the fins, or sucked through the fins. In other words, is the pattern of airflow different enough…
Dirk Bruere
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Optimize heat sink design - connect cooling pad on PCB backside by vias

In one of my current projects I'm using an MC7805 in a D2PAK package to generate my logic supply of 5 V from an available 24 VDC supply. The current required by the circuit is 250 mA. This results in a dissipated power of the MC7805 of: \$P=(24\…
KarlKarlsom
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How do I determine the area of copper needed on a PCB to provide adequate heatsinking for a power SMD MOSFET?

I am planning to use the IRFR5305PBF Power MOSFET (http://www.irf.com/product-info/datasheets/data/irfr5305pbf.pdf) to switch on a load. I have determined that I need an external heatsink with Rthsa < 29 C/W. How would I go about determining the…
dla59
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Why aren't CPUs cooled from below as well as above?

The transistory bits of an integrated circuit are approximately in the centre of the (plastic or ceramic) package. They sometimes get hot, and we cool them by affixing a heat sink to one side. Sometimes we just blow air over them with a fan. Some…
Paul Uszak
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Using CPU heat to generate electricity

I've been reading Tanenbaum's Structured Computer Organization and he says one of the major bottlenecks for increasing CPU clock speed is heat. So I started thinking: Is it possible to remove the heatsink altogether and use that heat to generate…
Enzo Ferber
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Dissipating 1W on a TO-220 without heatsink?

Can a TO-220 without a heatsink dissipate 1W in still air? Or, a different way of asking the question is: Assuming an ambient temperature of 25C, how can I go about calculating the maximum power I can dissipate on a TO-220 packaged MOSFET? The…
SomethingBetter
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Does the paint colour matter on a heat sink?

Heat leaves a heat sink via conduction, convection and radiation. I was taught that black surfaces are best at radiating heat and correspondingly a lot of heat sinks are black. But they also have fins for convection. And large heat sinks have…
Paul Uszak
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Copper or Aluminum Heatsink?

What would be a better heatsink to buy, copper or aluminum? What does copper do that aluminum doesn't? I know it is more expensive and is heavier, so what is the advantage of copper? EDIT: more detail about the application. I need a heatsink for a…
MH0517
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Why are electrically insulating heatsinks so rare? Is it just cost?

Edit: It seems my initial question (Why are there no insulating heatsinks?) was based on a false premise, and there are in fact insulating heatsinks--I just wasn't able to find them with a cursory search. So instead, I'm changing this to ask about…
Hearth
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Is a thermally conductive pad always useful between TO220 and heat-sink?

I have a doubt about heat-sinking that I could not solve by surfing the Web. My doubt arised when mounting a TO220 package on its heat-sink using these dirty cheap pads, but actually it has quite a general scope. There are a lot of articles out…
LorenzoDonati4Ukraine-OnStrike
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Would this component require a heat sink?

Would this LM7805 voltage regulator require a heat sink? It will regulate 12V to 5V and will be used for a 5V sensor which draws 4mA current.
GNZ
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Is it a good idea to use a single heatsink for two IC's?

I am using a 7805 IC along with a diode bridge Br805D (bridge rectifier) IC on a general purpose PCB, with a 220V / 50Hz AC input. Both the components tend to heat up really quick and I plan to set up a heat sink. My question is: Is it correct to…
Shakti Phartiyal
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Should I ground the heatsink?

I am using an npn transistor in TO-220 package, and its collector is electrically connected to the metal part on it. I have checked it via a multimeter. I use a heatsink for that transistor, with isolator. So after mounting it to heatsink with…
muyustan
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How tight can I mount a TO-220 to a bus bar?

I'm building a small switching circuit consisting of 8 MOSFETs (bi-directional blocking, 4 in each direction), which should switch 100-200A at about 1kHz. I've concluded that since PCB with a thick copper layer isn't readily available, a much…
user95482301
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When to use a heatsink for a voltage regulator?

Sometimes in small projects Im using voltage regulators with outputs 8V or 5V such as LM7805. Power is I*V but Im wondering when really a heatsink is needed. Sometimes the current flow from the regulator output is 1mA but in an other project 20mA or…
user16307
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