Electronic circuit
US6414318B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 6, 1998 |
| Grant date | Jul 2, 2002 |
| Priority date | — |
| Expiry date | Nov 6, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J1/44
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention relates to an electronic circuit for measuring small amounts of charge or small electrical currents. One embodiment of the present invention provides an electronic circuit for measuring current or charge that can be used with a variety of sensing media (including high impedance sensing media) that produce a signal by either charge or current production or induction in response to physical phenomena occurring within the sensing media. In another embodiment, the voltage level (bias) of either the sensing or reference electrode can be switched relative to the other upon receipt of a triggering pulse. This changes the polarity of the electric field to cause charge of the opposite polarity to be driven to the sensing electrode, thereby eliminating the need to electrically connect a discharge path to the sensing electrode to clear the charge accumulated at the sensing electrode. This can be supplemented by capacitively coupling a compensation signal to the sensing electrode to cause the amplifier output signal to lessen in magnitude below a threshold level that permits additional charge or current measurements of the same polarity before performing bias reversal. Al…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.