DC level transition detecting circuit for sensor devices
US5949257A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 8, 1997 |
| Grant date | Sep 7, 1999 |
| Priority date | — |
| Expiry date | Oct 8, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K5/082
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The DC sensor signal S, on which a low frequency waviness component S1 and a high frequency noise component S2, is obtained by amplitude detecting for a sinusoidal output signal from a touch signal probe. For generating a touch trigger signal TG at an sbrupt DC level transition of the DC sensor signal S, the signal S is input to a LPF 21 to output a signal (S0+S1), where S0 is a DC offset component, and S1 is a low frequency waviness component. The amplitude transforming circuit 22 multiplies the signal (S0+S1) by a coefficient k to generate a reference signal k(S0+S1). The comparator 23 compares the DC sensor signal S with the reference signal to output the touch trigger signal TG at the abrupt DC transition point of the DC sensor signal S.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.