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    How does grounding work if I cut the 5V pads or connect schottsky diodes while keeping the USB plugged in?

    Idk if people care, but leaving this here in case anyone wants to do something similar in the future. I used the following product which isolates the tx and rx side of the usb and allows me to use an external power supply, send data to my computer, and extend the cable up to allegedly 165 feet...
  2. L

    How does grounding work if I cut the 5V pads or connect schottsky diodes while keeping the USB plugged in?

    I wanted to have data send to my computer but also power the teensy externally. I already solved it by following @nominals first reply and getting an isolator + soldering on two schottky diodes. But I still did not fully understand when a solution like this is necessary and when it is not. Now...
  3. L

    How does grounding work if I cut the 5V pads or connect schottsky diodes while keeping the USB plugged in?

    Thank you. I guess one last question. When you say USB wall wars are isolated AC-DC supplies, are they also floating? What about a laptop charger? Is the center prong of the plug purely for safety and does not actually set the ground potential? Lets say I have two laptop chargers, can I connect...
  4. L

    How does grounding work if I cut the 5V pads or connect schottsky diodes while keeping the USB plugged in?

    Okay revisiting this because I am once again confused. Why do I need an isolator if other people were able to accomplish what I wanted without the isolator as shown in the following? and also in the following threads...
  5. L

    How does grounding work if I cut the 5V pads or connect schottsky diodes while keeping the USB plugged in?

    I am a little confused. Correct me if i am wrong. As I understand it, the ground coming out of the DC-DC supply is floating and I need a bleed resistor to make it the same potential as my external power supply? So on the side of the isolator, I need to connect the 5V line to the ground line with...
  6. L

    How does grounding work if I cut the 5V pads or connect schottsky diodes while keeping the USB plugged in?

    I'll test out the EVC9103S since it is coming in the mail tomorrow but I will also mod a cable and try out the DSD TECH. By the way, the EVC9120S does support different speeds and devices. I think the comment that it does not like external power supply only applies if the 5V USB internal power...
  7. L

    How does grounding work if I cut the 5V pads or connect schottsky diodes while keeping the USB plugged in?

    How would this solve the problem still that the 5V PSU and the USB ground are not common?
  8. L

    How does grounding work if I cut the 5V pads or connect schottsky diodes while keeping the USB plugged in?

    So there would be no way to have a teensy that can be powered by both USB and VIN independently and at the same time if the two are two isolated. So I would need a removable jumper in this case rather than soldering a schottsky
  9. L

    How does grounding work if I cut the 5V pads or connect schottsky diodes while keeping the USB plugged in?

    If they are all connected and lets say the ground from the usb connection is 1 volt higher than the ground from the external, how big of a problem would this be?
  10. L

    How does grounding work if I cut the 5V pads or connect schottsky diodes while keeping the USB plugged in?

    I saw on both the teensy site (https://www.pjrc.com/teensy/external_power.html) and the following post (https://forum.pjrc.com/index.php?threads/external-power-and-usb.55400/) solutions to using an external power supply while keeping the USB plugged in. I am using a teensy 4.1 if that makes a...
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