(US4629905-A)      The turbine comprises a stator section formed with an axial core providing an annular passageway having an outlet end in close proximity to a rotor of a coaxial adjacent rotor section. The blades of the rotor have a length equal to the internal radius of the passageway. Flaps are arranged in an expandable circle betweenhe stator section and rotor. A float mechanism located in the intake basin follows the water level and controls the extended positions of the flaps reducing the water flow through the penstock in a predetermined relation to the water level.    The passageway has fixed vanes directing the stream of water in a helical swirling motion of predetermined pitch to impinge upon the blades which are disposed to receive the stream at an optimum angle of 90 degrees. The generator is lcoated remote from the turbine with a closed hydraulic system comprising a variable displacement pump located at and by the turbine and a hydraulic motor located at and driving the generator. The pump has a flow control driving the motor at a constant RPM at all acceptable load conditions placed on the generator.    USE -   For streams, in rural areas, which have at least 3 cubic feet per second flow and bed slipes is excess of 10% for providing power in 3 to 100 KW range.    (EP170916-B)      Circuit arrangement having two feed circuits (4,5) which can be connected to a load (1) with mutually opposite polarisation, and having a pair of connections (11,12) which are in each case connected to the feed circuits (4,5) via feed current paths, for a load resistance (1), and having a device for optionally feeding the load resistance (1) by means of one or the other feed circuit (4,5) characterised in that, at least at one of the feed circuits (4,5), switching means (31,32) provided for activation, are arranged outside its output circuit in that at least at one feed circuit (4,5) which can be activated by means of switching means (31,32) outside the output circuit, a transistor (61) is arranged in oen of the feed current paths one of the feed current paths between the feed circuit (4,5) and the pair of connections (11,12) for a load resistance (1), and in that the control electrode of the transistor is connected to such a control potential that the transistor is conducting with an activated associated feed circuit and is cut off with a deactivated associated feed circuit. (14pp)