Abstract: An engine control unit and method of controlling the operation of a gas fuelled internal combustion engine of the kind having a gas injector for injecting gaseous fuel into each cylinder and an inlet manifold through which air flows into each cylinder of the engine, the inlet manifold having a manifold valve to control the flow of air into the inlet manifold. An improved control strategy employed by the engine control unit involves closed loop control of airflow through the inlet manifold of the engine. Manifold absolute pressure (MAP) (70) and manifold air temperature (MAT) (72) are employed to calculate air density (84) which is representative of the mass of air flowing through the inlet manifold (28). The detected air density (84) is compared to a desired air density (DAD) (86) and an air density correction (88) is calculated to adjust the manifold valve position (MVP) (90).

Abstract: A manifold valve controller (30, 32) designed to be embedded within the casing (24) of a throttle actuator in a manifold valve assembly for a gas fueled internal combustion engine. The controller (30, 32) senses the current position and current velocity of the valve (14) and calculates a rest position of the valve (14) if the valve commenced deceleration from its current position and velocity. The controller (30, 32) then compares the calculated rest position with a demanded position for the manifold valve (14) in order to determine whether the current position or the rest position exceeds the demanded position The controller (30, 32) then accelerates or decelerates the valve (14) to the demanded position as required, based on the comparison A feedback position sensor such as a potentiometer (22) provides the means for sensing the current position and velocity of the valve (14).

Abstract: An ink drying machine for T-shirts and other articles which employs an array of ceramic heating tiles having flat surfaces to provide a large area of uniform intensity and wavelength radiation to the surface of T-shirts and other articles moving below the heating tiles on a conveyor belt. The array of heating tiles may consist of adjacent rows or have gaps between the rows. By having a variable speed conveyor belt the amount of radiation each T-shirt receives can be adjusted. The surface temperature of the tiles may be adjusted to provide different wave lengths for different inks. In this manner the intensity, wavelength and time of irradiation can be controlled. Since different inks have different drying requirements the machine can be adjusted to maximize production rates by varying the time and wave length of radiation the ink is exposed to.