Cooling a camera built to prove reality: The NF-A4x10 5V PWM in CAIM1

Two intensive workloads in one protective shell

Creating this proof directly in the camera poses a substantial engineering challenge. CAIM1 must capture and process high-bitrate 4K video at 60fps while simultaneously performing the complex cryptographic calculations required to generate verification proofs. Together, these workloads push both the processors and the image sensor to their thermal limits.

At the same time, the components are tightly packed inside a highly protective, mostly enclosed shell that is designed to withstand harsh environments and prolonged UV exposure. Passive heatsinks alone proved insufficient: without active airflow, the processors would thermally throttle and drop frames, preventing the camera from maintaining its intended video performance.

However, simply adding a fan was not enough. As a portable, battery-powered device, CAIM1 requires precise fan control so that cooling is only provided when necessary. Any unwanted fan noise could interfere with onboard audio capture, while micro-vibrations transmitted to the image sensor could cause motion blur or rolling-shutter artefacts. Cooling performance, power consumption, acoustics and running smoothness therefore all had to be considered at once.

Why the NF-A4x10 5V PWM was the right fit

Measuring just 40x40x10mm, the NF-A4x10 5V PWM provides a combination of compact dimensions, strong airflow and pressure performance, low-noise operation and precise PWM speed control. Its native 5V operating voltage was particularly important because CAIM1 runs entirely within a low-voltage battery domain.

Using a conventional 12V fan would have required an additional step-up converter. The CAIM1 team specifically wanted to avoid this, as voltage conversion would consume valuable circuit-board space, reduce battery efficiency and introduce electrical switching noise and ripple that could potentially affect image-sensor performance. The NF-A4x10 5V PWM can instead be powered directly from the camera’s main board, while PWM control allows its speed to be adjusted according to the current thermal load.

Finding the ideal balance between fan size, airflow and noise was so important that the CAIM1 team redesigned the entire main circuit board to accommodate the Noctua fan, relocating major components in order to make room for it. The NF-A4x10 5V PWM’s SSO2 bearing system and smooth motor drive are also particularly well suited to an application in which even minute vibrations and tonal noises must be kept to a minimum.

One fan, one airstream

Rather than using separate fans for the image sensor and the main processor, CAIM1 employs a unified single-airstream cooling design. The NF-A4x10 5V PWM is positioned directly behind the image sensor and decoupled from the main chassis using anti-vibration mounts.

Fresh air is first drawn across the sensor’s alloy heatsink backplate before passing through the fan. The same airstream then moves over the CPU heatsinks and is finally exhausted through the side of the camera. Cooling both major heat sources with a single fan helps to conserve internal space and battery power while reducing the number of potential sources of noise and vibration.

As Josh Cowell, creator of CAIM1, explains:

Cooling that is built to last

Reliability was another key consideration. Replacing the fan would require a complex teardown of the camera body, so long-term dependability was just as important as thermal and acoustic performance.

CAIM1 places an unusually broad set of demands on such a compact fan: efficient cooling within a tightly enclosed space, native 5V operation, precise PWM control, minimal power consumption, low noise, smooth running and long-term dependability. We are excited to see the NF-A4x10 5V PWM become part of a camera that is designed not only to capture important moments, but also to help prove where those recordings came from.

Prototyping with Prusament PETG 

The CAIM1 is currently in the prototype stage. To build the latest series of prototypes that will be presented at Ethereum Tokyo week and Pragma Tokyo 2026, Josh Cowell and his team utilised Prusament PETG Noctua Beige and Noctua Brown for the outer shell and fan mount. The current target is to have the first batch available in Q1 2027. However, watch their project closely for opportunities to get hands on with the device earlier. 

For more information, visit caimera.one