초록 ▼

A waveform-shaping apparatus for determining engine speed of an automotive vehicle is provided. The apparatus includes a waveform-shaping circuit including a comparator for comparing an input analog signal, alternating in synchronism with rotation of an engine, with a reference signal, so as to prod

A waveform-shaping apparatus for determining engine speed of an automotive vehicle is provided. The apparatus includes a waveform-shaping circuit including a comparator for comparing an input analog signal, alternating in synchronism with rotation of an engine, with a reference signal, so as to produce a binary-coded signal, provided with high and low levels, indicative of the engine speed. A hysteresis providing circuit provides first and second hysteresis components having first and second hysteresis levels to the input analog signal and the reference signal, respectively, to increase a difference in level between the input analog signal and the reference signal so as to mask the influence of noise from interfering with an operation of the waveform shaping circuit. A correcting circuit corrects at least either of the first and second hysteresis levels and time periods during which the first and second hysteresis components are applied, in a preselected relation to a given noise factor.

대표청구항 ▼

A waveform-shaping apparatus for a speed sensor which detects a speed of a rotatable member of a vehicle, said waveform-shaping apparatus comprising: waveform-shaping means for waveform-shaping an input analog signal from the speed sensor into a binary-coded signal, said binary-coded signal having a

A waveform-shaping apparatus for a speed sensor which detects a speed of a rotatable member of a vehicle, said waveform-shaping apparatus comprising: waveform-shaping means for waveform-shaping an input analog signal from the speed sensor into a binary-coded signal, said binary-coded signal having a high level when the input analog signal is greater than a reference signal and a low level when the input analog signal is smaller than the reference signal; hysteresis providing means for providing first and second hysteresis components having first and second hysteresis levels, respectively, said hysteresis providing means increasing a difference in level between the input analog signal and the reference signal so as to mask the influence of noise from interfering with an operation of said waveform shaping means, the first hysteresis component being applied to the input analog signal when the binary-coded signal has the high level, the second hysteresis component being applied to the reference signal when the binary-coded signal has the low level signal; and correcting means for correcting the first and second hysteresis components in a preselected relation to a given noise factor which interferes with the operation of said waveform shaping means so as to eliminate the influence of the given noise factor on the operation of said waveform shaping means.