4 layers138.2 × 200.4 mm
2 layers9.5 × 11 mm
FanPacer
ixoo/FanPacerThis project provides a solution to regulate fan speed by sending a PWM signal, allowing you to throttle the fans down to a desired speed, reducing noise and improving usability.
- Size
- 9.5 × 11 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 8
- Nets
- 9
- Pads
- 17
- Tracks, vias
- 19, 7
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 8.0 (file 20240108)
- Created
- 9 Sep 2024
- Updated
- 9 Sep 2024
Overview
FanPacer is an open-source printed circuit board by ixoo, from the ixoo/FanPacer repository on GitHub. It is a 2-layer board of 9.5 × 11 mm with 8 parts on 9 nets, routed with 19 tracks and 7 vias.
It is built around the ATTINY85-20SU and BZT52C5V1. Its parts include 2 resistors, 1 IC and 1 diode. It belongs with the AVR (ATmega, ATtiny) boards of this library.
Main components
2
ATTINY85-20SU
SOIC-8-208mil-40℃~+85℃ 10bit 2.7V~5.5V 20MHz 512Byte 512Byte 6 8 Bit 8KB AVR Built-in FLASH SOIC-8-208mil Microcontrollers (MCU/MPU/SOC) ROHSMicrochip TechnologyMicrocontrollers (MCU/MPU/SOC)
BZT52C5V1
SOD-1231 Independent 130Ω 2uA 4.85V~5.36V 5.1V 500mW SOD-123 Zener Diodes ROHSMDDZener Diodes
README
README.mdFan Pacer
This project provides a solution to regulate fan speed by sending a PWM signal, allowing you to throttle the fans down to a desired speed, reducing noise and improving usability.
Overview
I own a Dell C410x GPU enclosure with a faulty fan board that incorrectly detects operational fans as non-operational. As a result, it triggers a fault that forces all eight fans to run at 100%, creating excessive noise. Since the enclosure otherwise works perfectly, I built this solution to throttle the fans down to 50% by using an interceptor board.
Temperature safety is maintained via GPU temperature monitoring, which handles throttling the GPU itself, so there's no risk of overheating.
Hardware
The hardware folder contains the KiCad schematics and PCB design for a compact board that connects to the fans' 12V power supply and generates a PWM signal to control the fan speed. The PCB is designed to be small enough to fit within the fan structure, without requiring modifications to the enclosure.
Software
In the software folder, you'll find the AVR C code designed to run on an ATtiny25/45/85 microcontroller. The code generates the necessary PWM signal. At startup, the system waits for 10 seconds before sending the signal, ensuring the fan reaches its full spin before reducing its speed.
Cost Breakdown
- 12 PCBs (delivered): $3.50 (via OSHPark)
- 12 ATtiny85: $10
- Zener diodes and pull-up resistors: ~$1
- Total cost for 12 completed boards: ~$15
Parts
8| Qty | Value | Footprint | References |
|---|---|---|---|
| 1 | 1.2K 1% 1/10W | Resistor_SMD:R_0603_1608Metric | R1 |
| 1 | 10K | Resistor_SMD:R_0603_1608Metric | R2 |
| 1 | 12V | TestPoint:TestPoint_Pad_1.0x1.0mm | TP2 |
| 1 | ATtiny85-20S | Package_SO:SOIC-8W_5.3x5.3mm_P1.27mm | U1 |
| 1 | BZT52C5V1 | Diode_SMD:D_SOD-123 | D1 |
| 1 | G*** | kibuzzard-66C9372B | kibuzzard-66C9372B |
| 1 | GND | TestPoint:TestPoint_Pad_1.0x1.0mm | TP1 |
| 1 | PWM | TestPoint:TestPoint_Pad_1.0x1.0mm | TP3 |
Questions
How big is the FanPacer PCB?
It measures 9.5 × 11 mm and has 2 copper layers, 1.6 mm thick.
What parts does the FanPacer use?
8 parts, built around the ATTINY85-20SU and BZT52C5V1. 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 FanPacer KiCad files?
From the ixoo/FanPacer repository on GitHub, at the commit this page was made from: the board is hardware/FanPacer.kicad_pcb and its schematic hardware/FanPacer.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the FanPacer design in my own project?
Its repository states no licence, so its author keeps all rights: ask ixoo before reusing the design.
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