Yesterday was one of the hottest days we’ve had so far this summer and my laptop was getting very hot running the PCB CAD.
I’ve tried a cooler pad before which was rubbish so I decided to solve the problem properly.
Where the laptop always sits I made two stepped holes using a couple of hole saws, a chisel and some sand paper. Some paint to seal the custom-wood and two small fans fit about flush into the bottom of the holes.
They are 40x40x10 mm 12V 110mA ceramic bearing fans that have a very long bearing life. I had to take a small amount off each corner to make them a tight fit. Some hot glue will stop them coming out but allow later replacement if required.
A general purpose power supply that’s already in place can also run the fans. There is a 34 ohm resistor (2 x 68R in parallel) in series with the two fans to slow them down; greatly reducing the noise and beat effect. I will have to build a small temperature controller that detects a rise in the temperature of the desk and runs the fans until it cools down.