Questions tagged [cooling]

Questions regarding Cooling electronics. Varies based on needs, can include Fans, Heatsinks, proper ventilation, Peltiers, or PCB design and mounting. Could also refer to Cooling applications, like freezers in industry. Repair questions for Cooling applications will most likely be closed if outside the Scope of the Site and FAQ. Try DIY.StackExchange.com for those.

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28
votes
6answers
11k views

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. ...
22
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3answers
702 views

How do you build a machine in a solid block?

I'm aware that a number of mass produced electronics are embedded in a solid thermal resin of some form. How reasonable is that for the home hacker? What materials are used? How do you do it? Are ...
21
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5answers
6k views

If the silicon wafers from which the processors are made are so sensitive that workers wear special suits how is delidding a processor possible?

I saw many videos on YouTube in which people delid processors and then apply better liquids for cooling the processor. Example: i5 & i7 Haswell & Ivy Bridge - FULL Delid Tutorial - (Vice ...
21
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8answers
64k views

Fans: suck or blow?

For a fan, should air be sucked in, or should it blow air out? I'm talking about an enclosure mounted fan.
14
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4answers
12k views

What's needed to put a PC fan into reverse?

I've got a PC fan here (I've peeled off a sticker). And although this one doesn't come with the usual 3 or 4 wire connectors, it has enough electronics in it to only operate when power + is on red, ...
14
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3answers
3k views

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 ...
12
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5answers
1k views

Enclosure best air flow profile

I'm in final step of a project an I need some advice about what heat evacuation profile should I use to place three fans for cooling, I have four alternatives as shown in the diagram but I don't know ...
11
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2answers
2k views

What is this spongy material?

Hi, while I am tring to repair electronic circuit. I'm encountering this sponge. I wonder what is this sponge? and can I find out what it is used for. I often see this in sensitive circuits like in ...
11
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3answers
5k views

How to cool down DIP devices?

I have AD811 in my application that works just fine but as it is working in +/-15 v supply at around 14.5 mA, it's power is around one third of watts. It is hot when touched. I checked if this is a ...
10
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4answers
2k views

Determine whether chassis is a suitable heatsink?

I picked up a sweet little aluminium box for a small USB powered DAC project... ...and while putting it together I noticed the side panels of the box were very cool to the touch, and made of thick ...
9
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4answers
8k views

How do I make an opamp comparator work in schmitt-trigger mode?

I want to control a small 12V case fan. I will set values of R1, R2 and R3 so that the fan will work above temperatures 40oC. I understand that in these kind of systems, there will be an indecisive ...
9
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4answers
3k views

How to cool electronics when the air is always hot

I'm in the process of planning an experiment that involves placing some electrical equipment in a mine for a year or more. Where the equipment will be placed in the mine (770m in depth,) the amient ...
9
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2answers
694 views

Pour-and-drain conformal coating as an alternative to potting

Is there a standard process to pour conformal coating, similar to potting, but then drain the excess? The benefit of draining the excess is to reduce weight and get better cooling. From my limited ...
8
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3answers
2k views

Should I cool off in water the desoldered components?

I use a REGULAR (for home-use, not for electronics) hot air gun to desolder non-SMD components from PCBs. The components are really hot (naturally) after desoldering and it takes a while until they ...
7
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4answers
7k views

Effective MOSFET cooling

We need to drive a motor with around 40 Amps. The mosfet has an Rdson of about 7 mohms at 90 degrees Celsius. That is a whopping 11.2Watts of heat generated on the poor mosfet. We are very space ...
7
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2answers
5k views

How does power dissipation for surface mount components work?

I know that with usual through hole components we can attach heatsinks etc. But how does it work with surface mount components? Is having a copper plate around the component the way to go? How do we ...
7
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3answers
483 views

How to cool ICs?

I've read this question and in its comments it is said: LDO and IC heatsinks will generally have a very different answer then computer motherboard heat sink. This question really doesn't ...
6
votes
2answers
7k views

How to find a fitting cooler/heatsink for a Mosfet?

How do I find a fitting passive cooler/heatsink for a TO-220 Mosfet? What parameters do I have to search for?
6
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3answers
809 views

How do electrons carry thermal energy in Peltier coolers?

I've read that when electrons enter from metal to semiconductor type N, they gain thermal energy and make that side cooler and the reverse happens when they leave semiconductor to the conductor. Why ...
6
votes
2answers
572 views

Is Non-Passive Cooling bad for Lithium Ion Cells?

I'm in the process of designing a device capable of charging, discharging and testing internal resistance of 18650 cells. My device will be capable of testing 100x 18650 at the same time, each will ...
5
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3answers
4k views

What properties vary with the number of blades on a BLDC fan?

In general, what properties vary with the number of blades on a axial BLDC fan when physical and electrical dimensions are the same (e.g.: rated at approximately 12V and 0.15A and 60mm Ø)? So far I'...
5
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2answers
1k views

Experience with thermal glues/adhesives?

I'm planning on using a thermal adhesive to bond an LED pcb to an aluminum enclosure. The enclosure is meant to serve as a heat sink and wick away any heat generated by the LED board. The aluminum ...
4
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3answers
3k views

Can a soapbox-sized device dissipate 10-15W of heat? If yes, how?

Some time ago, I built a soapbox-sized battery testing device. One of its functions was to discharge batteries at a specified current, and it handled most of the common battery sizes well, but its ...
4
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2answers
2k views

What are the efficiency limits of the Peltier effect?

I understand that thermoelectric coolers are perhaps a quarter as efficient as heat pumps. Why? What is the source of this efficiency limit? What would have to change for thermoelectric coolers to be ...
4
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3answers
1k views

Calculate the effects of cooling fans on a system?

If I have a home-audio receiver that draws a given amount of power (lets say 200W), and its passively cooled reaching a temperature differential of 50F over ambient, how can I calculate how much ...
4
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2answers
3k views

Heat Transfer of Aluminum Plate with LEDs

I'm building an LED grow light for an, um, indoor vegetable garden, and I'm trying to figure out what dimensions I can get away with for the aluminum sheeting I'm going to use for the mounting plate. ...
4
votes
1answer
877 views

Which side should I place a TO-220 transistor on a heat sink?

On TO-220 heat sinks, there are usually two sides, on which the transistor fits easily. One side is more narrow, surrounding the transistor. The other side is more open. Which of these sides is ...
4
votes
1answer
118 views

Circuits inside high-pressure oil

I am considering placing a typical PCB in a high-pressure oil environment. Right now it is just a "crazy idea", but I am wondering what would prevent this from theoretically working. Notionally, ...
4
votes
1answer
932 views

Does the Arduino have any specific cooling requirements?

If I were to encase my Arduino in a sealed case with no ventilation, would this be an issue? What about if I were to pot the Arduino in epoxy, would that pose a cooling issue?
3
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3answers
689 views

Regulator cooling in a confined space

I've designed a simple PWM RGB LED slow fader to be used as a garden lighting effect. My circuit works great, but I under-estimated the amount of heat that is generated by the 7805 linear regulator. ...
3
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3answers
2k views

Cooling an outdoor electronics enclosure

I built an outdoor enclosure which contains electronic devices (cable modem, router, battery backup, MCU, etc) for a long-distance internet connection. The enclosure is made of insulated metal panels ...
3
votes
2answers
788 views

Shunt resistor specifications do not contain thermal resistance data. How come?

I'm looking at the specifications of an ohmite shunt resistor: http://www.ohmite.com/catalog/pdf/10_series.pdf It is a 0.005 ohm resistor, rated at 2,3,5 and 7 Watts (4 different parts in the same ...
3
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1answer
1k views

Use single heatsink for muliple MOSFETS

I'm using 3 MOSFETS in a circuit due to the large currents flowing through these MOSFETS. I want to use one big single heatsink for all instead of 3 separate heat sinks. This is because at ...
3
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2answers
3k views

Small DC motor Heating up!

I am just trying to build a small fan to keep my Mac a little cooler from outside. So I have this little Box Design I made. Now, I'm a total noob at this thing so I need beginner level help here. I've ...
3
votes
2answers
1k views

Mosfets cooled with Heatsink and fan?

For my circuit, I have mounted heatsinks to my mosfets to dissipate heat. I have below a crude drawing of how the heatsink/mosfet is placed on the PCB I was thinking to integrate a LM35 to measure ...
3
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2answers
217 views

Temporary thermal adhesive for PCB measurement

I am making an examination on the effects of adding cooling to some existing electronics (making an comparison between having no cooling of the electronics and adding a heatsink or heatpipe + heatsink)...
3
votes
1answer
135 views

Regime of unsteady flow over heat sink

For my master thesis I'm simulating the cooling of an 2.5D microchip (2 dies next to each other on an interposer (slice of silicium with interconnections)). So I want to calculate the flow over the ...
3
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4answers
3k views

Two weaker peltiers vs one stronger peltier for cooling?

I'm planning on making a small water cooler for a project. I need to cool approximately 1.5L of water and have two TEC1-12706 (12v 6amp) peltier modules, and hoping to cool to as low as 6 degrees ...
2
votes
4answers
18k views

Peltier Unit Not Working

Recently I ordered a Peltier unit online and received it yesterday. Naturally, I was very excited to play with it. When I first turned it on, One side got hot, an another very cold. I had read that I ...
2
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2answers
2k views

Cooling an MCU to boost performance

As part of an ongoing project of computers ran by microcontrollers, one of my desktop models will overclock it's main MCU far past recommended operating frequency, since the first model isn't very ...
2
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3answers
3k views

How Long Will This Battery Keep My Fridge Powered For?

I have an interesting mathematical/electrical dilemma and I'm not sure where to start. I am considering buying this fridge (specs on page). I will be hopefully buying a battery pack with it to ...
2
votes
3answers
13k views

How efficient is a Peltier TEC1-12706 and TEC1-12715

I need to know some details about Peltier coolers before moving into making an air-conditioner. I have watched several videos on YouTube that demonstrate making air-conditioners with Peltier thermo-...
2
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2answers
2k views

What dielectric liquids can be used as coolants?

I've seen some interesting videos of people putting their computers in containers with sunflower oil, where they continue to work normal. Are there any other dielectric liquids that can be used to ...
2
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1answer
478 views

Thermal grease / adhesive: Higher Conductivity & Lower Impedance or vice-versa?

I have been reading a fair bit about Thermal grease & adhesive comparisons. There is a lot of information out there - even including tests made with tooth paste(!), which is mind blowing for me. ...
2
votes
1answer
167 views

Faulty temperature sensor on PCB - lights keep blinking, how to replace this?

I’ve been working on a broken continuous operating high power LED system - it starts blinking when powered. This was an indication of overheating and it was clear that the cooling fans have stopped ...
2
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1answer
1k views

is CFM additive?

I currently have a heatsink with 1 (loudish) 1000-1500 CFM fan. If I was to put 2 quieter 500-750 CFM fans on either side of the heat sink, would they effectively push the same amount of air? It is a ...
2
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2answers
2k views

How to calculate heatsink requirements? Explanation of the K/W unit

I'm planning to make a power supply with the LM2596 (adjustable voltage variant). In the datasheet I read that efficiency for VIN=12V, VOUT=3V, ILOAD=3A is 73%. That means, if I'm not mistaken, that 3 ...
2
votes
1answer
157 views

Heating and Chilling ICs instantly from 200C to 0C? Does it damage the silicon inside?

I soldered VCXO oscillator and suddenly tried to cool it down with a cooler spray. Do you think that sudden cooling and heating damages the chip. The heating and cooling were well within the spec ...
2
votes
2answers
2k views

Heatsink calculations for a TRIAC

It's very rare that I get to design applications in need of cooling so I haven't had the need to study in-depth about that, but now I face an occation where I need cooling for a TO220 and I'm unsure ...
2
votes
3answers
139 views

Cooling circuits in a hot loft with dusty air and bugs

I have a home-made home-automation system that includes a CCTV unit, circuit boards for controlling PIRs and outside lights, a UPS and power supplies. In the summer the loft gets hot (>40C) and the ...