You can even use the CPU_OPT header to power case fans, but keep in mind that some CPU_OPT have only three pins, meaning they lack PWM functionality. Dealing with the labyrinthine mess of wires ...

The system allows users to wirelessly control multiple AC appliances like lights and fans through an interactive web ...

Of course, the standard way of controlling CPU fans these days is with PWM, so he built a circuit which essentially converts the PWM signal from the motherboard into a phantom thermistor.