Acoustic range-finding system
US5267219A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 17, 1992 |
| Grant date | Nov 30, 1993 |
| Priority date | — |
| Expiry date | Jul 17, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S367/903
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In an acoustic pulse-echo ranging system, a high impedance piezoelectric transducer element is connected via a transformer to a transmitter, and also directly to a high impedance input of a receiver through a network, in parallel with the transducer element which includes a limiting resistor having a value which is low compared with the impedance of the transducer and a pair of oppositely connected diodes connected across the receiver input, the diodes being in series with the resistor and conducting to complete a damping circuit for large amplitude signals during transmission, and to limit the amplitude of signals applied to the receiver. When the signals are not of sufficient amplitude to cause the diodes to conduct, the damping circuit is normally rendered ineffective, but a further circuit is provided in parallel with the diodes to selectively switch into the network a further smaller resistance which acts both to form an attenuator at the receiver input in conjunction with the damping resistor, and to restore the damping effect. By this means, the dynamic range required by the receiver is much reduced, and effective damping can be applied selectively during reception to reduce…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.