Waveform shaping apparatus
US5568141A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 24, 1994 |
| Grant date | Oct 22, 1996 |
| Priority date | — |
| Expiry date | Jun 24, 2014 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/0097
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.