Sensing device
US7690256B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 2007 |
| Grant date | Apr 6, 2010 |
| Priority date | — |
| Expiry date | Jun 13, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L5/00
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
To provide a Colpitts oscillation circuit formed with a quartz resonator and a transistor amplifier circuit, which can secure sufficient negative resistance, obtain stable oscillation, negate the need for an amplitude control circuit, and realize stabilization against temperature variations. In order to solve the problem, a structure in which the impedance of a tuning circuit provided in a collector of the transistor exhibits inductivity at the oscillation frequency is provided. The impedance ratio at the oscillation frequency of a capacitor C2 connected between a base and an emitter to a capacitor C3 connected between the emitter and a ground, of the transistor is set at 3 to 1 or more. Furthermore, the impedance of capacity C2 connected between the base and the emitter at the oscillation frequency is set at 300 Ω or more. A bias resistance R1 connected between the collector and the base of the transistor is set at 3 kΩ or less. A temperature compensation diode D1 is inserted in series between the base and the ground (GND) between the transistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.