Vehicle detector with improved loop oscillator circuit
US9799217B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 11, 2016 |
| Grant date | Oct 24, 2017 |
| Priority date | — |
| Expiry date | Oct 11, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B2200/0062
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An oscillator unit for a vehicle detector includes an oscillator circuit for generating vehicle detector loop signals in response to enabling control signals from a vehicle detector control unit, a gain control circuit for maintaining the amplitude of the oscillator output signals within a limited range, and a clamping circuit for eliminating ringing of the oscillator output signals when operation of the oscillator circuit is disabled. The gain control circuit eliminates random amplitude changes in the vehicle detector loop signals generated by the oscillator circuit caused by changing environmental conditions experienced by the vehicle detector loop. The clamping circuit provides immediate clamping of the oscillator circuit operation to eliminate ringing when the control signal switches to the off state. The few additional circuit components which provide the gain control and clamping functions add very little to the overall cost of the oscillator circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.