4 layers76.2 × 76.2 mm
Dodekaedri
e-xla/dodekaedri
dodekaedrin muotoinen radio ":D" / dodecahedron shaped radio ":D"
227 parts2
2 layers152.4 × 55.9 mm
SainSmartFanModKiCad
jurihock/SainSmartFanMod2SainSmart solder fume extractor modification
- Size
- 152.4 × 55.9 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 20
- Nets
- 16
- Pads
- 48
- Tracks, vias
- 78, 2
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 5 Apr 2026
- Updated
- 6 Apr 2026
Overview
SainSmartFanModKiCad is an open-source printed circuit board by jurihock, from the jurihock/SainSmartFanMod repository on GitHub, published under the GPL-3.0 licence. It is a 2-layer board of 152.4 × 55.9 mm with 20 parts on 16 nets, routed with 78 tracks and 2 vias.
It is built around the ATTINY85-15M and IRL510PBF. Its parts include 7 resistors, 5 connectors, 2 capacitors, 2 transistors and 1 IC. It belongs with the AVR (ATmega, ATtiny) boards of this library.
Main components
2
ATTINY85-15M
WQFN-20-EP(4x4)-40℃~+85℃ 16MHz 2.7V~5.5V 512Byte 512Byte 6 8 Bit 8KB AVR Built-in FLASH WQFN-20-EP(4x4) Microcontrollers (MCU/MPU/SOC) ROHSMicrochip TechnologyMicrocontroller Units (MCUs/MPUs/SOCs)
IRL510PBF
TO-220AB-55℃~+175℃ 1 N-channel 100V 2V 43W 5.6A 6.1nC@5V 760mΩ@4V N-Channel TO-220AB MOSFETs ROHSVishay IntertechnologyMOSFETs
README
README.mdSainSmart solder fume extractor modification
This project is about replacing the default AC fan in the SainSmart solder fume extractor with a DC fan like Noctua NF-A14.
Why?
- the built-in fan is way too loud
- it runs at constant speed only
- the power cable is way too stiff
Features
- toggle switch to power the device on or off integrated in the housing
- dual LED to indicate power on and standby
- MOSFET switch to turn the fan on or off using MCU
- pot with a large knob 🫠 to select the fan speed
Thoughts
Electrical
In fact, the Noctua fan draws around 2A during the initial turn. I decided to use a logic-level MOSFET to switch the fan on. Adding a cap between 10uF and 100uF increases the Miller effect, forcing the fan to start up slowly and reducing the initial current as well. But in this case, an NPN transistor is needed to ground the PWM signal against the N-MOSFET drain.
I'm unsure whether a DC fan requires a flyback diode. I decided to skip it for now.
Mechanical
The JST connectors are intentionally placed on the edges, which puts mechanical stress on the board. There is certainly a better solution for connector placement.
How it looks like
Parts
20| Qty | Value | Footprint | References |
|---|---|---|---|
| 4 | 10k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R1, R3, R6, R7 |
| 3 | 100k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R2, R4, R5 |
| 1 | 100n | Capacitor_THT:C_Disc_D3.0mm_W2.0mm_P2.50mm | C2 |
| 1 | 12V PSU | Connector_JST:JST_EH_B2B-EH-A_1x02_P2.50mm_Vertical | J1 |
| 1 | 2N3904 | Package_TO_SOT_THT:TO-92_Inline_Wide | Q2 |
| 1 | 47u | Capacitor_THT:CP_Radial_D6.3mm_P2.50mm | C1 |
| 1 | ATtiny85 | Package_DIP:DIP-8_W7.62mm | U1 |
| 1 | BUCK IN+ | Connector_PinHeader_1.00mm:PinHeader_1x01_P1.00mm_Vertical | J2 |
| 1 | BUCK IN- | Connector_PinHeader_1.00mm:PinHeader_1x01_P1.00mm_Vertical | J3 |
| 1 | BUCK OUT+ | Connector_PinHeader_1.00mm:PinHeader_1x01_P1.00mm_Vertical | J4 |
| 1 | BUCK OUT- | Connector_PinHeader_1.00mm:PinHeader_1x01_P1.00mm_Vertical | J5 |
| 1 | Fan_4pin | Connector_JST:JST_EH_B4B-EH-A_1x04_P2.50mm_Vertical | M1 |
| 1 | IRL510 | Package_TO_SOT_THT:TO-220-3_Vertical | Q1 |
| 1 | LED_Dual_AAK | Connector_JST:JST_EH_B3B-EH-A_1x03_P2.50mm_Vertical | D1 |
| 1 | R_Potentiometer | Connector_JST:JST_EH_B3B-EH-A_1x03_P2.50mm_Vertical | RV1 |
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Questions
How big is the SainSmartFanModKiCad PCB?
It measures 152.4 × 55.9 mm and has 2 copper layers, 1.6 mm thick.
What parts does the SainSmartFanModKiCad use?
20 parts, built around the ATTINY85-15M and IRL510PBF. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the SainSmartFanModKiCad KiCad files?
From the jurihock/SainSmartFanMod repository on GitHub, at the commit this page was made from: the board is SainSmartFanModKiCad/SainSmartFanModKiCad.kicad_pcb and its schematic SainSmartFanModKiCad/SainSmartFanModKiCad.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the SainSmartFanModKiCad design in my own project?
Its repository publishes it under the GPL-3.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).