Quietly cool 15 ℃ mute version of exhaust radiator to create the full introduction

As we all know, notebook computer The most effective external cooling equipment is exhaust radiator, but efficient, it also has a hair dryer in general roar, in many cases we have to reluctantly discard. However, I can tell you solemnly, I have a way to let the exhaust type radiator quiet down, however, this requires you to work with me to do it!

Three main sources of noise: exhaust, bearings, resonance

Fan is the most important unit of the exhaust fan, but also the source of the noise, want to both efficient cooling and mute, you can only use the wind machine. The current mainstream fan is divided into three types: mixed-flow fan, centrifugal fan, axial-flow fan. The notebook exhaust type radiator adopts the centrifugal type fan. So where does the noise come from? Mainly consists of these parts: fan impeller rotation generated by the periodic exhaust noise, bearing mechanical noise and resonant noise.

Knowing the source of the noise, all we have to do is solve them.

For exhaust noise, we can add turbulence at the inlet and outlet, simply to increase the mesh structure at the entrance and exit.

For bearing noise, most exhaust ventilation radiator uses ball bearing fan, not magnetic bearing fan or hydraulic bearing fan, to know the latter both relative to the roller bearing fan noise is much less, which is why most exhaust type radiator noise is the main reason, therefore, Our homemade exhaust type radiator should choose the rear two fans.

Because of the noise caused by resonance, we can use hot melt adhesive as the fan and the shell of the thermal exhaust fan to improve, not only can be fixed fans, but also as shock absorbers.

Double fan and high power conjecture

Guess one: The air noise and fan size, power is proportional to, and the amount of air is not. The noise of the stack is not two 20dB fan work together there are 40dB, the actual noise is far from the value, that is, is not the use of two small fan to replace a large size fan, can reduce noise while ensuring the same high efficiency heat dissipation?

Guess two: The efficiency of the exhaust radiator is proportional to the power? The greater the power, the greater the noise will bring the better effect?

In order to verify my thinking, I decided to make 3 different exhaust fan fans, the first is the use of two small magnetic bearings centrifugal fan as the fan, which I think the ideal mute fan. The second one is a small current ball bearing fan with moderate size. The third is a single large current ball bearing fan with larger size. Through the comparison of the first and the other two to prove conjecture one, by the size of the current version of the comparison to prove conjecture two.

Double fan exhaust type radiator production article

The structure of the ventilation radiator is very simple, it divides into three parts, the circuit part, the shell and the fan. Part of the circuit by the series of voltage regulator, power supply, switch made, we just need to put them in a simple series.

Circuit diagram: Here I choose the lm317t chip to make the voltage regulator circuit, theoretically it can be in the input 37V from 37V to 0V voltage regulation, nature can easily meet our needs

Material Preparation: We need 1K size potentiometer, toggle switch, power plug, lm317t chip, 0.1uf electrodeless capacitor, 1uf has pole capacitor, 240ω and 680ω resistor, wire several, hole plate one, potentiometer knob one. These can be easily bought in the electronic market. Fan side I chose two AVC brand, the use of magnetic bearings fan, model 5010, which means that the length is about 50mm, and the height of 10mm. His current is also the largest fan of the same model, nominal 0.25A, measured 0.14A.

Step One: Insert the original into the hole plate, and then use the iron on the back with tin to the original pin according to the circuit diagram to weld. The module is finished, I measured it with a multimeter, it can adjust the 12V voltage output between 4.86V and 12V.

Step two: Then we'll measure the size of our laptop's heat sink, and then pick the right fan and plastic casing. First with the hand electric drill in the box corresponding position, according to the fan outlet size to open the hole, and then use the knife to outlet to do a repair, make it flat and clean. The power sockets, switches, etc. to be used in the upper cover are also drilled in the corresponding

Step three: The various electronic components fixed to the open hole, with hot melt adhesive to fix the fan, seal the fan and the gap between the shell (figure in the circle), let it play the role of shock absorption. Then the switch and the power outlet are connected in series, then the voltage input of the lm317t chip is connected, and the fan receives the voltage output. Note that each connector should be wrapped with a heat shrinkable tube and then ironed with a blow or iron to keep it stable.

Step four: The upper cover is also the same way to open the same size as the fan outlet, and then use hot melt adhesive to the fan to the upper lid. After making the upper and lower cover fans, wire them in parallel, then connect the lm317t module voltage output. Apply a bit of all-purpose glue to the contact place of the lid under the cover, and treat it slightly dry to merge the upper cover and the lower cover.

Step five: The next is to install the screen to reduce the noise of exhaust air. On the PVC foam plastic cut and the corresponding size of the notebook radiator openings, and then cut the same size of the mesh with adhesive tape glued to the back of the foam, with superglue foam adhesive to the exhaust radiator in the outlet

Since then, the double fan ventilation radiator is done!

Single fan ventilation radiator production article

The production of a single fan heatsink is the same as the approximate process of a double fan, or even simpler. The small current fan is 0.35A current, adopts ball bearing, the size is about 60mmx60mmx18mm, the noise of full speed operation is approximately equal to the sound of the desktop fan.

The big current fan is 0.7A current, adopt double wheel bead type bearing, the size is 75mmx75mmx30mm, the noise of full speed operation can be compared with the hair dryer of 1000W or so. However, because the volume is too large, can not be placed in the plastic box, can only be covered in the plastic box with the fan into the tuyere shape corresponding to the round mouth, and then fixed the fan to the place

Three fan production complete, to a photo bar!

Test Summary: Double fan effective, large current significance is not big

From top to bottom is the double fan exhaust type radiator, small current version of the exhaust radiator, large current version of the test results of the exhaust radiator, test methods are to be the notebook machine temperature stability, add exhaust fan.

Test result Description

Since there is no noise test tool, here I can only through the subjective experience to say, the use of magnetic bearings fan, even if the double fan, in the mute effect is far better than the use of ball bearing single fan, in this voice or can be happy to play and enjoy the film, but also basically to meet the needs of night use, I also recorded the related video, can hear the obvious difference of noise, please pay attention to Sina Weibo "computer newspaper Li Kun".

In the heat dissipation efficiency, the double fan mute version of the exhaust radiator cooling curve gradient small, that is, the mute version of the cooling rate is slightly lower than the other two, but the final can reach the approximate temperature, which proves that in the notebook exhaust radiator, the use of two small volume of fans to replace a large volume of the fan is completely feasible. And the large current version of the ventilation radiator cooling curve than the other two of the obvious inclination of cooling, that is, large current version of the biggest cooling rate, but note that it eventually reached the ultimate temperature is not significantly beyond the other two. This proves the correctness of the second guess, is not the greater the power of the exhaust radiator can bring better cooling effect, the so-called high-power fan, is only a means of marketing for businesses.

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