Abstract: A control methodology and apparatus for an engine suitable for use in capacitor discharge ignition systems for internal combustion engines or brushless DC motors is provided, which make use of a simple logic block to determine for instance an ignition timing advance angle or duty cycle signal based on actual engine speed versus engine control parameter data stored in a table, which is a read-only memory, preferably configurable. To minimize memory space, a small number of values of engine control parameter versus engine speed are stored in the table and the logic block determines the required engine control signal for a measured value of engine speed by an interpolation process, preferably linear interpolation.

Abstract: An ignition control device having an Electronic Fuel Injection mode and a Capacitive Discharge ignition mode is described. The ignition control device comprises: an output for providing an output voltage, connected or connectable to a load, the load being a fuel injection actuator of an EFI system or an ignition capacitor of a CDI system; and a driver unit connected to the output, for driving the output voltage from a low level to a high level and from the high level to the low level in dependence on an input signal, each transition of the output voltage from the low level to the high level having a low-to-high transition time which is longer for the CDI mode than for the EFI mode.

Abstract: A control methodology and apparatus for an engine suitable for use in capacitor discharge ignition systems for internal combustion engines or brushless DC motors is provided, which make use of a simple logic block to determine for instance an ignition timing advance angle or duty cycle signal based on actual engine speed versus engine control parameter data stored in a table, which is a read-only memory, preferably configurable. To minimise memory space, a small number of values of engine control parameter versus engine speed are stored in the table and the logic block determines the required engine control signal for a measured value of engine speed by an interpolation process, preferably linear interpolation.

Abstract: An ignition control device having an Electronic Fuel Injection mode and a Capacitive Discharge ignition mode is described. The ignition control device comprises: an output for providing an output voltage, connected or connectable to a load, the load being a fuel injection actuator of an EFI system or an ignition capacitor of a CDI system; and a driver unit connected to the output, for driving the output voltage from a low level a high level and from the high level to the low level in dependence on an input signal, each transition of the output voltage from the low level to the high level having a low-to-high transition time which is longer for the CDI mode than for the EFI mode.

Abstract: A gas turbine powerplant includes an attitude control nozzle comprising an aperture in a duct wall of the powerplant for discharging a propulsive stream from the powerplant. One or more flaps are each pivoted to the side edges of the aperture and pivotally movable into different positions relative to the duct. In one position the flaps co-operate to close the aperture and in further positions the free ends of the flap or flaps co-operate to define variously directed discharge orifices of variable area.

Abstract: A by-pass gas turbine engine capable of producing an unmixed exhaust stream which comprises a core of hot turbine exhaust gases surrounded by an annular layer of by-pass air, is combined with a target thrust reverser. The ratio of the total pressure of the by-pass air to the total pressure of the turbine exhaust gases is arranged to be greater than unity to a significant extent, and the buckets are made from lightweight materials such as titanium, light alloys or even fiber re-inforced composite materials.