Abstract: A system and component for generating a drive signal suitable to operate a fuel injector. The drive signal includes one or more injector pulses. Each injector pulse is characterized by a desired pulse profile. The system includes an injector driver and a controller. The injector driver is operable to apply a supply voltage to the fuel injector. The controller is configured to store a plurality of state definitions that determine an operation state of the injector driver when a selected definition of the plurality of state definitions is communicated to the injector driver. The controller is further configured to receive a sequence of state values that determine an order that the state definitions are communicated to the injector driver to generate piecewise an injector pulse exhibiting the pulse profile, and thereby generate the drive signal.

Abstract: A system and component for generating a drive signal suitable to operate a fuel injector. The drive signal includes one or more injector pulses. Each injector pulse is characterized by a desired pulse profile. The system includes an injector driver and a controller. The injector driver is operable to apply a supply voltage to the fuel injector. The controller is configured to store a plurality of state definitions that determine an operation state of the injector driver when a selected definition of the plurality of state definitions is communicated to the injector driver. The controller is further configured to receive a sequence of state values that determine an order that the state definitions are communicated to the injector driver to generate piecewise an injector pulse exhibiting the pulse profile, and thereby generate the drive signal.

Abstract: A direct fuel injection control for an internal combustion engine includes first and second controllers. The first controller has a microprocessor and generates injection timing and duration signals on injector select lines. The second controller is a state machine including injector controls that receive the injection timing and duration signals and control injector current according to sets of injector current profile defining parameters received from the first controller on a serial bus and stored in register sets in the second controller. The second controller includes switching apparatus that can quickly change the connection of each injector control between different register sets to select different injector current profiles in successive injection pulses. Several alternative ways of providing register select signals are disclosed, and these may be incorporated in the same second controller for selection by the first controller.

Abstract: A direct fuel injection control for an internal combustion engine includes first and second controllers. The first controller has a microprocessor and generates injection timing and duration signals on injector select lines. The second controller is a state machine including injector controls that receive the injection timing and duration signals and control injector current according to sets of injector current profile defining parameters received from the first controller on a serial bus and stored in register sets in the second controller. The second controller includes switching apparatus that can quickly change the connection of each injector control between different register sets to select different injector current profiles in successive injection pulses. Several alternative ways of providing register select signals are disclosed, and these may be incorporated in the same second controller for selection by the first controller.

Abstract: Prior to the operation of a solenoid type of fuel injector, a DC voltage is applied across the injector to create a current through the injector that is below the activation current of the injector. A capacitor is then placed in series with the injector and the flyback energy from the injector transfers a charge onto the capacitor. When the injector current drops to a predetermined level, the capacitor is removed from the circuit and isolated. This process is repeated until a minimum charge is on the capacitor. By placing the capacitor charge onto the injector at the time that the injector is to be activated, the opening response of the injector is improved. By applying the charge on the capacitor to the injector in a manner to neutralize the eddy currents when the voltage across the injector is removed, the closing response is improved.

Abstract: A drive circuit is provided in a full H-bridge and half H-bridge configuration for controlling one or more piezoelectric fuel injectors. The drive circuit includes a voltage input for receiving a voltage signal, an energy storage device coupled to the voltage input for storing an electrical charge, a bidirectional current path coupled to one or more piezoelectric injectors, an inductor coupled in series with the piezoelectric injector(s) in the bidirectional current path, and switching circuitry for controlling current flow through the piezoelectric injector(s) and the inductor to open and close the piezoelectric injector(s). The switching circuitry is controlled to provide a recirculation current to recover energy stored in the piezoelectric injector(s) for storage in the energy storage device.

Abstract: A control system for an electric heater, e.g., an electric catalyst heater (ECH), includes a current sensor, a voltage sensor, a switching element, and a control circuit. The control circuit is coupled to the current sensor, the voltage sensor and a control terminal of the switching element and varies a control signal on the control terminal to maintain the temperature of the heating element within a predetermined temperature range.

Abstract: A multi-processor AC motor control system having a timer processor which generates multiple synchronized PWM waveforms while minimizing software latency effects. The timer processor generates a 50% PWM duty cycle sync signal at the PWM frequency, creating a logic level transition (leading edge) in each PWM period. At each such transition, the timer processor interrupts the host processor for the purpose of updating a multi-byte timer data register with PWM on-time data stored in nonvolatile memory as a function of machine position and requested current. A separate timer channel is provided for each PWM waveform to be generated, and the timer processor sets off-to-on and on-to-off transitions of each waveform in accordance with the updated PWM on-time data such that respective off-to-on and on-to-off transitions in each waveform are centered about the leading edges of the sync signal.

Abstract: An improved digital PWM closed-loop current control for a multiple phase winding AC machine which requires only a single sensor for monitoring the current in one of the phase windings of the machine. The PWM on-time values for the various phase windings of the machine are stored in a single look-up table as a function of stator position and requested current amplitude, and the on-times used to schedule phase winding energization are periodically updated using a two-part look-up procedure. Initially, the stored on-time value for a single phase winding is retrieved from the table as a function of stator position and the requested current amplitude. The retrieved value is then compared with a measure of the actual current in the respective phase winding to form an error signal, which is used to adjust the requested current amplitude.