第二种桶则是利用浮力驱动锥形水阀控制桶中的水流出。也是当水盆中的水升的一定高度时带锥形水阀的浮球就会在浮力的作用下关闭桶的出水口。另外水盆中的水位越高，侵入水中的浮球面积也越多，浮球受到的浮力也越大，浮力越大作用于锥形水阀的力越大（相当于阀门关的越死）。
The second kind of bucket uses buoyancy to drive the conical valve to control the flow of water in the bucket. It is also when the water in the basin rises to a certain height, the float ball with conical valve will close the outlet of the bucket under the action of buoyancy. In addition, the higher the water level in the basin, the more the area of floating balls invading the water, the greater the buoyancy of floating balls, and the greater the buoyancy, the greater the force acting on the conical valve (equivalent to the more dead the valve closes).
还有一种是一方有开口另一方封闭的圆柱体，在封闭方连上锥形水阀的控水装置。由于开口按装于下方，当水盆中的水位上升并挤压半封闭圆柱体内的空气，然后在被挤压空气的反作用力下推动半封闭圆柱体向上，并带动锥形水阀关闭出水口。
Another is a cylinder with an opening on one side and a closure on the other side, which is connected with a water control device of a conical water valve on the closure side. Because the opening is installed below, when the water level in the basin rises and the air in the semi-closed cylinder is squeezed, the semi-closed cylinder is pushed upward under the reaction force of the compressed air, and the conical water valve is driven to close the outlet.