http://www.overunity.com/index.php/topic,1651.0.html

The problem we all encounter is how to remove or replace the water level.

Basically what it comes down to is water will fill the section of tube where the buoyant weight is released in to the water, and you must refill that section with air to drop the next weight.

You have a drop tube that is suspended under water that is connected to a valve that does two things, prevent water from filling the drop tube and allow the weight to exit the drop segment of the tube. The valve is connected to the jettison point which must have at least the volume of the dropped weight. There must be a vertical opening on the jettison point that does two things first it allows the buoyant weight to escape to the surface and also it prevents water from filling the drop tube when the first valve is opened. When the weight falls down the drop tube it reaches the valve, when the valve is opened the wight enters the air filled jettison chamber. The valve then closes to the drop tube and the vertical opening opens to eject the buoyant weight thus filling the jettison chamber with water. Now the work required to reset the rig is working the valves and most importantly now you must fill a chamber with air and the deeper the chamber is the more pressure required.

Sorry if I'm missing a important detail of your design, but this is the problem all buoyancy systems encounter... volumes and levels.

Hope this helped,
~Dingus

If both valves are open while the buoyant weight escapes the jettison chamber, the drop tube will fill with water. This happens because of presure balance. The open air offers no resistance to the waters presure due to the water level being higher. You could have a valve at the top of the drop tube to prevent air from escaping, but you would still lose the volume of air that the jettison chamber holds because the buoyant weight itself negates the air that should be there.

As for draining the chamber in to a mine... I'm not sure where you could feasibly do that, but there is a problem with that solution too. Try it on a microscale, if you have a cup of water and you take out a few drops per day and move it to a lower location to collect energy you'll find that it takes more energy then you collect to move the water to it starting level then you'll gain from its fall. Now if you're talking about a constant suply of water to drain then you're much better off looking in to hydro turbines and scrapping the weights.

Overunity wont be found in a new gimmick on an old trick, it requires collecting energy from open system of energy. Examples of open energy systems include: the sun, the currents of air and water that follow natrual cycles, the earths magnetic field, ZPE jitters, heat conversion, magnetic energy exchange, *exotic galvanic chemistry*. Anything that is naturally using energy already that you can latch on to and use that connection to collect power.