Abstract: A low-frequency PWM-modulated signal and a high-frequency, unmodulated signal for generating a high-frequency PWM-modulated signal is employed directly for driving an output stage of a device for noise suppression. The low-frequency signal and the high-frequency signal is advantageously provided by a microcontroller which already has an AD converter on the input side. The microcontroller furthermore already makes a PWM output signal with a high bit width available which has the high resolution necessary for driving the loudspeaker.

Abstract: An injector driver module includes a first converter and a second converter connected between a power supply and the load. The first converter generates a first voltage output and the second converter generates a second voltage output from the power supply. Switches control the level of the supply voltage so that the voltage applied to the load can be varied depending on an operational phase of the driver. Control over the current through the load can be therefore be conducted via pulse width modulation at lower voltage levels, thereby lengthening the switching time during modulation, reducing power losses, and reducing EMI emissions.

Abstract: A low-frequency PWM-modulated signal and a high-frequency, unmodulated signal for generating a high-frequency PWM-modulated signal is employed directly for driving an output stage of a device for noise suppression. The low-frequency signal and the high-frequency signal is advantageously provided by a microcontroller which already has an AD converter on the input side. The microcontroller furthermore already makes a PWM output signal with a high bit width available which has the high resolution necessary for driving the loudspeaker.

Abstract: A fuel injector system (10) calculates a first derivative filtered signal and a second derivative filtered signal from an unpowered spool valve coil signal. When the spool valve (16) reaches the end of travel, either open or closed position, a flat slope f is generated on the falling edge of the bell shaped signal. The second derivative provides a readily apparent determination of when the steep slope occurs. A comparator (62) thereby need only determine when the second derivative is zero to identify that the spool valve has reached the end of travel.

Abstract: A fuel injector system 10 calculates a first derivative filtered signal and a second derivative filtered signal from an unpowered spool valve coil signal. When the spool valve 16 reaches the end of travel, either open or closed position, a flat slope f is generated on the falling edge of the bell shaped signal. The second derivative provides a readily apparent determination of when the steep slope occurs. A comparator 62 thereby need only determine when the second derivative is zero to identify that the spool valve has reached the end of travel.