USB interface between laptop and HV

Discussion in 'Analog & Mixed-Signal Design' started by coinmaster, Jul 7, 2016.

  1. coinmaster

    Thread Starter Active Member

    Dec 24, 2015
    I'm working on the specifics of floating a dedicated DAC I have to a high voltage and aside from the power supply I need to make sure that the connection between computer and dac is safe. The interface I use is USB communication between computer and dac for music playback.
    I am wondering since laptops are floating if I connect the usb cable on the computer to the x-hundred volt from earth referenced outlet on the dac if it would be safe. From my understanding the laptop should be okay but it would also be referenced to the earth referenced voltage of the DAC meaning the entire laptop circuitry would now be at the same reference?
  2. DickCappels


    Aug 21, 2008
    I would investigate how well your I/O port is protected from ESD. Switching the x-hundred volts on and off will cause displacement current (capacitance charging current) to flow in every conductor that can "see" (not shielded from) conductors are another voltage -such as ground.

    Then there is the chance that somebody will touch a liver part of the laptop and that could be had for both the laptop and the unlucky person.

    In other words, there must be a better way. Fiberoptics, optical isolators, bluetooth...?