heat-variable fan controller with custom aluminum enclosure
If you, like me, hide your home entertainment system in a closed space, you may have a problem with heat, A practical way is needed to get the heat out of your Assembly and to breathe in some fresh air.
In addition, people like me tend to forget to manually open fans because of simple neglect and unknowingly barbecue their game stations.
So the solution is always
Option, but I want something that is not fully open (noisy)
Unless things get hotter and hotter.
The controller measures the heat in the cabinet and adjusts the fan speed (and noise)accordingly.
There are some very nice, very expensive cabinets with a built-in exhaust system, but if you already have a cabinet that you want to use, keep reading!
Adjust the temperature: seasonal changes, environmental temperature changes.
I chose to insert another \"constant\" variable in the whole thermometer calculation instead of having to connect the laptop to re-program the temperature values for minor changes.
The variable is set to one of the 10 locations to \"adjust\" the temperature value.
I use one of the interrupts to poll the button.
Each push adds a level to the adjustment value.
After 10 push it back to zero again.
The full purpose of the bar chart LED display is to display the current level of \"adjustment\" applied to the temperature.
My add anywhere from 0 to 20.
** WARNING ** This design uses 3-
This is a very common pin brush fan.
Some people will argue
In the circuit that drives the brushless DC motor, it may be subjected to the pressure of the pulsewidth-
Modulation power drive.
I\'m not sure if this is true, but in any case it\'s worth considering a fan failure in any design, which is why I have provided up to 6 fans on this controller.
I may modify version 2 one day. 0 and use 4-
Pin fan controlled by direct PWM.
In theory, 4-
The wired fan can also provide feedback on the tach line to provide an alarm for the fan failure, but you need some shift registers to release some pins.
Processor: Arduino Pro Mini 5 v (
You can also use Uno if you can stand the form factor)N-
Channel thermistors (any type)
LED display button (
I use LED backlight)
Power switching diode (not pictured)Resistors (
330 K, 1 K, 10 K, 47 K)
Resistance array Rod (2x 330K)Protoboards (x4)
2mm thick 1/2 \"aluminum corner channel screw (4 and 2), nuts (2)
The Rivets jumper wiresBanana plug and terminal is a schematic diagram of the small motherboard used by the processor.
This is quite simple.
The two rows in the middle are Arduino Pro.
I welded the male pin (extended a bit)
Then pass them through the back of the board and weld them to the board.
As you can see in the picture, I used a 90 degree male title on the programming side of the motherboard.
Make sure to install the 90 degree head on the board facing the top of the shell.
Then, if you need to modify the motherboard after installation, you can simply pop up the top and connect the programmer to it.
Keep in mind that the schematic diagram is not entirely drawn in scale, but the prototype plate is only about 2 \"square.
The \"Therm\" label is a thermal resistor.
G d s is the gain, source and drain of the MOSFET.
Digital pins 4-
I installed the LED bar chart on a separate board.
Arduino Pro is programmed with simple code to continuously monitor the temperature probe in the main loop.
The temperature adjustment button is set on the interrupt on the digital pin 2.
The \"analog\" output set on the digital pin 3 is actually a digital pulse width modulation on one of the Arduino\'s PWM pins, usually taking 0-254.
There are many ways to convert a temperature value to a PWM output level.
At first I tried to map the temp value to 0-254 range.
This produces a smooth transition of values, but I really don\'t want a smooth transition, so I gave up this approachtiered level.
Each level is activated when the temperature threshold is reached.
This is done by a simple comparative operation control structure.
I used a lit button so installed a 330 ohm resistor next to it.
There is only one male title for the positive and negative clues here.
The bar chart is a simple 10 LEDs clip together, so each one needs its own resistance.
I used two LED sticks with 5 resistors per stick.
The bar makes the line much simpler.
Just solder the resistor bars on the negative lead of the LEDs and weld a male head on each positive lead line of the LEDs, that\'s it.
The last board is just a row of 3-
Pin fan can be inserted directly. (Go Niners! )
First of all, I planned the size of the enclosure.
I don\'t want it to be too big, but it\'s always good to have extra wire space.
With the prototype board done, it\'s easier for you to see how much space you need.
The top and bottom decorations are then diagonally attached.
To do this, I used the chop saw with a black metal blade as it provided the cleanest and most accurate cut.
The top and bottom are removable.
The drill hole is large enough to hold the rivets on one side, the hole is in the right size, and 4 screws can pass through one side of the edge.
Next, cut the plate for the side, top and bottom.
The panel is small, no need to die-
I used a band saw and freedom because of the decorationPass me the wound.
Rivet the edges to the top and bottom panels.
I would suggest marking everything in it so you can keep it \"straight\", right?
I brushed each piece when I went to give it a better finish.
To connect the side panel as shown above, drill and tap the panel to accept 4 screws.
List the positions of the terminals and switches you want.
The buttons and bar charts on the front panel are clearly visible for easy viewing and access.
The rest are put where it is practical.
I drilled some holes in the case of the case in good condition and disassembled it for wiring and connection.
Some boards require gaskets to keep them away from the side of the shell.
Avoid any Short Circuit (
Aluminum is a great conductor! ).
In the picture of the motherboard, you can also see that I screwed a piece of residual aluminum that acts as a radiator on the MOSFET, although it doesn\'t get very hot.
Use punch holes to set where to drill smaller holes.
I used two screws and nuts.
Put a little line-
Lock to prevent them from exiting.
Cutting the square hole is a real pain, but it is necessary for some components.
It is necessary to make a good finished appearance on bar charts, fan terminals and power switches.
Drill a series of small holes and hammer them out.
When I knocked it out, it started to twist very thin aluminum, so I carved out the small hole with dremel, which made the hammering easier and faster.
The edges will be very jagged and must be smooth with manual files.
It was a good exercise, but it was worth it.
Next, trim the side edges.
Just assemble the box and cut each box as needed.
Mark each again so you don\'t confuse them.
There is no Mitter at the end, so it is easy to cut, but there are 4 holes to drill in each piece.
Then, punch, drill and tap the fit hole on the panel.
I used male titles for each board, so the final connection only needs a bunch of womenfemale jumpers.
Keep the four sides in the same direction as when screwed together.
I was a few behind because it was twisted and I had to rewire.
It is also possible to cut and make any custom connectors for fans and fans of any length.
Welding and shrink packaging of thermal resistors (mine are blue)
A pair of banana plugs can be used unless you choose to use different types of connectors.
This is my home.
I did some testing before installing all the fans.
As for the power supply, I am using the ATX PC power supply.
Good regulated power supply, I have installed it and used 5 v rails in another project.
I have a 12 v terminal waiting to be used.
This is the last location and a few fans near PS3/Blueray player.
I have added 5 fans and am glad I have provided up to 6 fans!