Abstract: The invention relates to an air-inlet system (10), and relates to an air-conditioning system (100, 101) and an internal combustion engine (200) comprising the air-inlet system. The air-inlet system comprises an air intake port (20), an air output port (30) and a turbine (40) for controlling air mass flow into a combustion chamber (202) of an internal combustion engine. The turbine is provided with a propeller hub (42) which comprises at least one blade (44). The propeller hub is arranged between the air intake port and the air output port for propelling the blade of the turbine. The turbine has an air-flow resistance for determining the air mass flow into the combustion chamber. The effect of the air-inlet system according to the invention is that the use of a turbine enables to use at least some of the pressure drop across the turbine to drive the blade of the turbine for generating rotational energy.

Abstract: This invention relates to automatic dual mode battery charging circuit which includes rectifying means and an adjustable voltage rectifier energized by the rectifying means and providing an output to a battery to be charged. The circuit includes a voltage controller connected to the voltage regulator means to set the level of voltage output from the voltage regulator and hence the charging current to the battery. The voltage regulating means provides two modes of operation, namely, a fast charge and a float mode of operation. A current detector connecting in series circuit with the voltage regulator and the battery provides a means for detecting current flow through the battery and controls the operation of the voltage controller, to change the output of the voltage regulating means between the two modes of operation.