WSAL16681 – Fan-4020-PWM-5V/en

Documentation notice: This technical documentation was independently rewritten from an archived supplier source. Check technical details and commands against the product version and manufacturer documentation before use.

Summary

The Waveshare Fan-4020-PWM-5V is a dedicated cooling fan designed to cool the Jetson Nano. It connects to the developer kit's PWM interface and its speed can be adjusted via a system file.

Related products at JW Tech

WSAL16681 – Dedicated Cooling Fan for Jetson Nano, PWM Adjustment

Technical overview

The fan is designed for the Jetson Nano and supports PWM-based speed control.
Connection: plug the fan into the Fan connector on the Jetson Nano Developer Kit, paying attention to polarity.
The four wires have distinct roles: black = GND, red = Vcc, blue = tachometer signal, yellow = PWM.
Operating current is 0.27 A at 7500 rpm.
Wire colors for tach and PWM may vary between production batches; actual product wiring takes precedence.
Fan speed is set by writing a value from 0 to 255 into /sys/devices/pwm-fan/target_pwm.
/etc/rc.local can be used to start the fan automatically at boot.
nano can be installed as an alternative editor to vi for editing rc.local.

Commands and examples – verify before use:

sudo sh -c 'echo 255 > /sys/devices/pwm-fan/target_pwm'
sudo vi /etc/rc.local
sudo chmod u+x rc.local
sudo reboot
sudo apt-get install nano
sudo nano /etc/rc.local

Notes and version constraints

Tach and PWM wire colors can differ across batches; verify against the physical unit before connecting.
The path /sys/devices/pwm-fan/target_pwm assumes the kernel module for the PWM fan is loaded; otherwise the file will not exist.
rc.local must be made executable (chmod u+x) and exit cleanly (exit 0), or it may not run reliably.
The 0.27 A and 7500 rpm figures come from supplier material; consult the datasheet for other variants or revisions.
No warranty, certification, or safety-standard information was present in the source document.

Source and revision record

Fan-4020-PWM-5V - Waveshare Wiki
Source revision: 87154
Captured: 2026-08-31T03:47:12+00:00
SHA-256: 48a8df6e02381df057f47e5ad8ef1c7b4518589b1403668979d455c640e58014