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Category : engineering   hardware

I bought a 300W continous / 600W peak 12V DC to 220V AC inverter for my car. It was pretty cheap, at around 25$. However it has one major drawback, a continuously on small noisy fan.

So I decided to cut open its top part and add a 120mm PC fan on top.

Note: be careful when working with the inverter’s insides as it has live 220V exposed pins and components

Parts list

  • Generic 12V DC to 220V AC inverter – 25$
  • 120 mm PC Fan (bonus: it has blue LED lights and a temperature sensor) – 0$ (had one laying around)
  • 120mm PC Fan grill and dust cover – 0$ (had some laying around)

Tools list

  • Angle grinder (I initially tried a small multitool but the aluminum body is pretty thick)
  • Hot glue gun

The build process

Idea: Add a fan on top of the inverter, cutting small section (or maybe a large section) of the top part of to allow cool air to get in. The fan will be covered by a dust filter, and blow air into the inverter. The air will exit through the lateral holes already present in the inverter.

Upon opening it I discovered its internal fan was powered by a 12V header, which is just perfect as 120mm PC fans are also powered by a 12V input, and are significantly quieter (mine was basically indistinguishable from background noise) whilst being able to move the same amount of air (in this case, size does matter).

As a bonus, the one I had also has blue LEDs that can be toggled and a temperature sensor, which I taped to a piece of metal in direct contact with some how ICs.

The result

A quiet 300W inverter, that you can easily sleep next to. It will be useful for charging my phone or laptop overnight in Rusty.

Since the inverter draws about 0.30A in standby, I decided to leave the fan’s LEDs always on as a power indicator (since it can’t be easily heard).