Homebuilt Rov Forum

Exploring the Hobby of Building your own ROV - Imagine, Create, Inspire.
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 Post subject: Re: Topside Battery
PostPosted: Jun 18th, 2013, 5:36 pm 
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Joined: Feb 28th, 2013, 6:01 pm
Posts: 383
Location: Australia
Thanks folks. Forward vs reverse: The 1m/S I quoted was with the "ROV" (RUV -more on that later) going astern. I deliberately put the props on with the cupped face pointing backwards to give more thrust to overcome the bulkiness of the motor housing inside the shroud. Had I put them on the other way around then I'm guessing astern speed would have been greater. Anyway, at the time I would say forward was maybe not as fast as reverse. Testing was fairly brief because after the motors started they could not be stopped until the ROV was lifted out of the water. Have some theories on this loss of control. Increase in current when loaded up causing interference, longish motor and logic wires not helping. Yet to be investigated. Dive thruster worked brilliantly, submerging straight down and fast. Quite a bit of force on the tether required to lift against motor! Will add some thin rope next time.
Current draw: No idea whatsoever. Have since gotten a plastic tub so will be able to do water tests at home in future
Run time: No idea but still had power after fooling around for 20 minutes
Battery pack size: 130mm long (had to Google it as ROV is still sealed up and notes not at hand) Similar to this http://www3.towerhobbies.com/cgi-bin/WT ... LXBSPL&P=8 Went for Ni-mh largely because I already had a suitable charger. Aft bottle (hull) was designed for D cells but the 3300 mAh pack was all I could get at the time

Ross


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 Post subject: Re: Topside Battery
PostPosted: Dec 26th, 2015, 4:03 am 
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Joined: Dec 15th, 2015, 6:41 am
Posts: 49
Location: Everett, WA
Saw this thread and wanted to get my $.02 in.

Do any of you think it would be feasible or even a good idea to run a 110VAC line in the tether and then rectify and condition it to yield a stable and usable DC voltage? You could even up the ante and use 220VAC. This would help greatly to eliminate line losses if a top side power source were used and could possibly eliminate the need for underwater batteries. Either AC voltage could be provided by a gen unit topside.

Randy


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 Post subject: Re: Topside Battery
PostPosted: Dec 26th, 2015, 5:22 pm 
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Joined: Feb 28th, 2013, 6:01 pm
Posts: 383
Location: Australia
Unless the hobbyist is an electrical or electronics engineer or technician possessing appropriate design expertise then mains power tethers are not practical. To be safe enough to use they would simply cost too much by the the time the safety mechanisms are designed, built, tested and implemented.

Do a forum search for "electrocution". The power supply tether subject has raised numerous times here. :)


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