Here's a relatively easy way to modify and improve your existing laptop cooling pad, or make one from scratch using the provided information.
I built it mainly to prevent the laptops graphics card from overheating, and I must say that it is very effective. I am using a Dell E6430 laptop with an overclocked Nvidia NVS5200M graphics card (GPU Clock has been raised from 672 to 857MHz and Memory clock from 785 to 929MHz), and with the ordinary cooling pad the temperature of the GPU would rise to 78-81°C when playing modern games like Farcry 4. With the improved pad it is around ten degrees lower, 66-68°C, which is much better.
If your laptop is overheating, you should definitely consider making one of these.
Step 1: What you need
List of parts:
1. Laptop cooling pad. I have used the Cooler Master Notepal CMC3, because I liked the design, it wasn't too big for my 14" laptop, and it was cheap. Feel free to use any cooling pad you like or make your own from scratch.
2. 12x12cm, 2000 R.P.M., 12V Fan. My choice was the Cooler Master SickleFlow 120 Blue. Again, you can use any other fan but make sure that the specifications are same.
3. 12V AC Power adapter. The one I used is from a broken HP printer with the following specifications: +16V, 500mA. Most (if not all) cooling pads are powered via USB port, but USB can only provide 5V of power, and that's simply not enough for what we're going to make here, so we need to use a separate power source.
4. Voltage regulator, like LM317. And a TO220 Heatsink. A heatsink with the RTH value of around 15°C/W should do just fine. Remember, the lower the RTH value, the better the heatsink is.
5. 2K5 Potentiometer, 220R resistor, Power switch.
6. Soldering iron
7. Super glue
8. Toilet paper. Yes, toilet paper.
Step 2: Removing the stock fan and attaching the new one
First you have to remove the built-in fan from the pad by unscrewing the four bolts that hold it in place.
After that, you should cut out the middle circle of the pad, because we want as much air as possible to reach the bottom side of the laptop.
Now you are ready to attach your new fan. I did it with four pieces of wire which I positioned on the leftovers of the central part of the pad, pushed them through the holes on the fan where the bolts usually go, and twisted them around with pliers. Nothing fancy, but I didn't care much about the looks since the fan is not gonna be visible when it's used anyway.
Step 3: Making the voltage regulator
Now it's time to make a voltage regulator. Just follow the diagram on the picture, it's a relatively simple circuit. The pictures should speak for themselves and you should be able to pull this one out without any help. You can use the protoboard to test the circuit before assembling. If you have any questions about this, just post them in the comments and I'll try to answer them asap.
When you assemble the circuit, connect it to the power adapter and use the voltmeter to measure the output voltage. You should get the values between 1.25V when the pot is set to 0, and around 16V when it's turned all the way. Now you can connect the fan to test it out. It should be speeding up and slowing down when you're turning the pot.
Step 4: Making the case for the voltage regulator
I struggled a little bit at this stage because I couldn't find a good case to use for this purpose. In the end, I managed to pull it off with an old audio cassette case and it turned out to be better then I expected. I only used the top part of the case, made a few a holes and then glued the components to it. I didn't glue the LM317 or the heatsink. Instead, I attached a little aluminum plate on the back of the heatsink and bolted it to the hole where the original fan was. In the end, I glued the whole case to the pad.
The gray part on the left is the power connector I removed from an old HP printer. As I mentioned earlier, I am using an adapter from this printer to power up the fan.
Step 5: Toilet paper? Seriously?
Why not? :)
Actually, you will only need the cardboard cones, and I'll explain you why in a minute.
We are using a very strong fan and it needs to be able to take in quite a lot of air. Since our pad sits quite low, it limits the amount of the airflow and in the end we see the fan spinning fast, but no air coming out on top. We can fix this simply by raising the pad a little bit. I chose to use the cardboard cones found in toilet paper for this purpose, but you can figure out a more elegant solution if you're a toilet paper lover and find this offensive.
Check the pictures to see how to create these. For the front two legs, you will need shorter cones. I've made mine to be 5cm long, and the two back legs are 6.5cm long. That will give the pad a nice leaned look and provide enough air for the fan. You can easily remove these legs when you need to pack your cooling pad.
Step 6: How do I use this pad when there is no available power source?
Let's head back to the original fan we removed at the beginning of this project. As you can see, it's built to be powered by a USB port, so we can cut that cable and use it to make another one that will allow us to power the new fan via USB port. It won't provide much air when it's powered like this, but it will still work and might be useful when you're on the go. However, I don't recommend overclocking your computer with just this on. :)
You will need a fan extension cable to connect it to the other part of the cutout cable. or you can desolder a 3pin fan connector from an old motherboard as I did. When you create this cable, you just need to unplug the fan from the voltage regulator, plug in the fan to the one side of this cable, plug in the other side of the cable to the USB port and you're good to go.
Step 7: Tips for better cooling
1. I highly recommend removing the back cover of the laptop, because exposing the inner components directly to the air that comes out of the fan will lower the temperature significantly.
2. You can also attach four rubber circles to the top of the pad. It will raise the laptop a little bit and make more room for the air to flow freely.
3. There is also a change you can make at the power plan options. Click on the battery icon at the low right corner, choose "More power options", than click on "Change plan settings" and after that on "Change advanced power settings". Now click on the "Processor power management", choose "Maximum processor state" and lower it from 100% to 99%. I found this to be effective, and I've used my computer with these settings for quite some time, until I discovered that there is a downside to it. When the maximum processor state is set to 99%, turbo boost is off. In my case, that means that instead od 3.7GHz (which is a maximum turbo boost frequency of my processor) processor was working on 2.7GHz maximum (which is a maximum processor rate without turbo boost). So, yes, the processor is colder, but there is a significant loss in the performance. That's why I recommend you to test out your computers performance and temperatures on 99% and see how much performance you'll lose and how cooler will your CPU be, and see for yourself if it's worth it.
Step 8: Final word
Job done! You have now successfully created a great cooling pad for your laptop!
This pad is almost silent when operating at about half speed, and it provides quite a lot of air. However, it can be a bit noisy when running at full speed, so I recommend using it at maximum power only when playing video games and using applications that are heavy on the GPU. Also, I wouldn't recommend running the fan down to stall - you should always provide enough voltage to keep the fan spinning, and when you want to turn it off you can do it simply by flipping a switch.
I hope you liked my first Instructable. If you have any questions about this project, you can post them in the comments or send me a private message. I'll be glad to answer them.