How to adjust the voltage of a USB
Many users are frustrated with the operation of the cooling fan on their laptops and are looking for a way to increase the voltage that goes into the system to increase the fan’s power. Users may wonder if the voltage coming from connected USB cables works. However, since the USB cables have a set voltage – and that two of the four wires in the cable are installed for data transmission, not the voltage – the alteration of this is not only practically impossible: it is not worth it. damage that you can cause to the device that connects with the USB cable.
Place a resistor on the USB cable. This is the only way to create voltage. However, there is a significant risk of damage if the voltage of your device and your computer are not at the same level. For example, if you use a USB cable from the printer to your laptop, to increase the voltage by adding a resistor, the imbalance can damage the device with less voltage – in this case, the printer – since you are adding a resistor, which sends more voltage to the laptop’s fan.
Avoid placing a resistor in the input port where you connect the device. The specifications of your USB cable maintain that fixed voltage.
Place a variable resistor on the red LED of the hard drive power cable. You will find this cable if you open the laptop: it is the cable that goes from the power supply (battery) to the hard disk. For those who are trying to adjust the fan speed through the USB voltage, this can accomplish the same goal without risking any damage to the peripherals. However, if you open your laptop, the manufacturer’s warranty will be voided and there is no certainty that the performance of your fan will improve by increasing the voltage in this way.