Battery-operated hand field-strength meter and method of null balancing same
US5877619A · kind A · utility
2Cited by
2References
3Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 2, 1996 |
| Grant date | Mar 2, 1999 |
| Priority date | — |
| Expiry date | Oct 2, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R29/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of null balancing a hand field-strength meter is described in which the effect of the measurement probe on the balancing is suppressed by short-circuiting the measurement probe by two MOS-FETs connected in series across the probe outputs so that the null balancing can be performed when the field-strength meter is located in the vicinity of a high strength field. In a preferred embodiment of the null balancing circuit for the meter another circuit branch consisting of two other complimentary MOS-FETs connected in series with each other is connected in parallel across the first two MOS-FETs via two resistors R1,R2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.