Power over two wire tether, still viable?


#1

Hello fellow makers,

I was reviewing the original two wire tether system and was wondering why the power isn’t sufficient to run the systems, line loss, etc.? Why batteries are needed if using a/c power with data over power line? Was the power transmission abandoned or is there power going through, but only enough for certain tasks?

I just purchased components from your store to recreate this system on a micro ROV, very small (3.5X2 inches), and wondered if there was power delivery issues on the OpenROV that may be sufficient for my needs on a super small ROV.

Any input would be helpful, and all props to OpenROV and your team.

Stackpole post: Two-Wire Tether


Hard wire for power instead of batteries on the 2.8
#2

The power transmission was abandoned. It’s too dangerous for an amateur to do correctly. An inexperienced person could easily die from a small mistake with AC power around water. The Ethernet over power adapters still work without AC Voltage present.

No AC power is being sent over the tether.

There is 5V DC from USB going through the tether. It’s to turn on an optocoupler that turns on the ROV, so the system can be reset at the surface by unplugging the USB to the topside adapter. But it’s not enough to power the ROV.

I can’t really comment on the power requirements for your ROV without knowing more about your design.
Sending AC power underwater is pretty dangerous unless you know what your doing.


#3

Thank you for the clarification Brendan! Much appreciated, and agreed, I do not want to cook myself or a family member while testing this system out. :smiley: