Photo credit: Gizmodo
If you’re looking to destroy a computer in an unsuspecting manner, USB killer v2.0 by YouTube user “Dark Purple” should do the trick. This USb drive boasts a DC-to-DC converter that charges a set of capacitors concealed within its casing. Once plugged in to a functional port, the energy is then redirected back into the device as a 220-volt electric surge repeatedly, until the hardware completely fails. Continue reading for another video and more information.
The basic idea of the USB drive is quite simple. When we connect it up to the USB port, an inverting DC/DC converter runs and charges capacitors to -110V. When the voltage is reached, the DC/DC is switched off.
At the same time, the filed transistor opens. It is used to apply the -110V to signal lines of the USB interface. When the voltage on capacitors increases to -7V, the transistor closes and the DC/DC starts.
The loop runs till everything possible is broken down. Those familiar with the electronics have already guessed why we use negative voltage here.
I’ll explain to others that negative voltage is easier to commutate, as we need the N-channel field resistor, which, unlike the P-channel one, can have larger current for the same dimensions.