AVT3172B - Smoke extract controller
Anyone who does soldering as a hobby at home knows how unpleasant and at the same time dangerous it is to directly inhale solder fumes. It is true that there are many ready-made factory solutions for smoke absorbers on the market, but their use is often cumbersome. The presented solution allows you to smoothly adjust the fan speed in accordance with the needs, thanks to which you can significantly reduce the noise emitted by the running fan.
Of course, such a concept will not replace a good exhaust hood, and the best and most effective solution is to combine a fan with a ventilation duct. However, implemented in parallel with the use of a carbon filter cartridge and mandatory regular ventilation of the room will significantly reduce the risk of direct inhalation of solder fumes. In addition, the presented system can be used more often - for example, on hot days it is perfect as a personal adjustable table fan.
Description of the layout
The schematic diagram of the circuit is shown in fig. 1. This is a classic application of the LM317 voltage regulator. The module must be powered by a standard 12V plug-in power supply connected to the IN connector. Diode D1 protects the system from reverse polarity of the input voltage, and capacitors C1-C4 filter this voltage. With the values of the elements shown in the diagram, the adjustment range allows you to set any voltage in the range from about 2 to about 11 V at the output, which provides smooth speed control of the fan connected to OUT. output.
Installation and adjustment
The assembly of the system is classic and should not cause any problems. Let's start by soldering the smallest elements into the board, and finish by mounting the heatsink with the U1 system and a potentiometer. Install the fan at the very end using short lengths of thicker silver-plated wire. A series of mounting holes with open copper field is used for this purpose. The fan assembly method is shown in the photographs. The plate is adapted for mounting 120mm fans and a maximum thickness of 38mm. The direction of installation of the fan is optional, depending on the needs and intended use of the device.
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