Device including battery-activated oscillator
US4725993A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 1987 |
| Grant date | Feb 16, 1988 |
| Priority date | — |
| Expiry date | Mar 20, 2007 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB06B2201/75
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A low duty cycle relaxation oscillator periodically gates an ultrasonic frequency relaxation oscillator into an on state. The ultrasonic frequency oscillations are supplied to an electric-compressional wave transducer by way of a push-pull driver. The duty cycle and repetition rate of the relaxation oscillator and the ultrasonic oscillation frequency are such that compressional waves derived by the transducer incident on fleas in the region where the transducer is located repels the fleas. All active elements in the oscillator and driver are CMOS devices which draw only leakage current while in quiescent bi-level states and through current from a battery during transitions between the bi-level states. The drain from the battery is reduced by connecting a high impedance between the battery and the CMOS devices during a relaxation oscillator transition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.