Circuit and method for a wireless accessory of a moblie device

• US 7,936,226 B2
• Filed: 12/18/2008
• Issued: 05/03/2011
• Est. Priority Date: 12/20/2007
• Status: Active Grant

• Current Assignee: Suunto Oy (Anta International Group Holdings Ltd.)
• Original Assignee: Suunto Oy (Anta International Group Holdings Ltd.)
• Inventors: Akkila, Jari
• Primary Examiner(s): Chang; Joseph
• Application Number:
  US12/338,936
• Publication Number:
  US 20090160568A1
• Time in Patent Office: 866 Days
• Field of Search: 331/117.R, 331/107.A, 331/185, 455/336
• US Class Current: 331/107.00A
• CPC Class Codes: H03B 5/1203 the amplifier being a single transistor
• CPC Class Codes: H03B 5/1231 the amplifier comprising one or more bipolar transistors

Abstract

The invention relates to a circuit and method for a wireless accessory of a portable computer. The circuit comprises an oscillator circuit, a control circuit connected to the oscillator circuit, and a quenching circuit connected to the oscillator circuit. According to the invention, the oscillator circuit is formed of an LC resonator, the quality factor of which is at least 10, and the quenching circuit is formed in such a way that the energy of the oscillator circuit is discharged by a predefined current.

Claims

1. A circuit for a wireless accessory of a portable computer, which circuit comprises

an oscillator circuit,

a control circuit connected to the oscillator circuit, and

a quenching circuit connected to the oscillator circuit,

wherein

the oscillator circuit is formed of an LC resonator, the quality factor of which is at least 10, and that

the quenching circuit is formed in such a way that the energy of the oscillator circuit is discharged by a predefined current.

2. The circuit according to claim 1, wherein a transistor (Q10). one terminal of which is connected directly to the other end of the LC circuit, is used as a switching element.

3. The circuit according to claim 1 or 2, wherein an NPN transistor, the emitter of which is connected to the operating voltage (VCC) and the collector to the other terminal (D) of the oscillator circuit, is used as the switching transistor (Q10) of the quenching circuit.

4. The circuit according to claim 1, wherein the quenching circuit comprises means (Q10) for feeding the energy of the quenched oscillator circuit to the operating voltage (VCC).

5. The circuit according to claim 1, wherein the oscillator circuit generates a burst-like oscillation current.

6. The circuit according to claim 1, wherein circuit is implemented as part of a wireless accessory of a portable computer which uses the oscillator circuit to wirelessly transmit information to the portable computer.

7. The circuit according to claim 1, wherein the quenching circuit includes a resistor whose resistance value determines the predefined current magnitude.

8. A method for a wireless accessory of a portable computer, comprising:

forming an electrical oscillation, the oscillation being started by means of a control command, and

quenching the oscillation by means of a separate control command,

wherein

the oscillation is formed by means of an oscillator circuit that is formed of an LC resonator, the quality factor of which is at least 10, and that

the oscillation is quenched in such a way that the energy of the oscillator circuit is discharged by a predefined current.

9. The method according to claim 8, wherein a transistor (Q10), one terminal of which is connected directly to the other end of the LC circuit, is used as a switching element.

10. The method according to claim 8 or 9, wherein an NPN transistor, the emitter of which is connected to the operating voltage (VCC) and the collector to the other terminal (D) of the oscillator circuit, is used as the switching transistor (Q10) of the quenching circuit.

11. The method according to claim 8, wherein the energy of the quenched oscillator circuit is fed to the operating voltage (VCC).

12. The method according to claim 8, wherein the oscillation is formed by the oscillation circuit with a burst-like oscillation current.

13. The method according to claim 8, wherein the oscillation is used by the wireless accessory as part of a wireless transmission of information to the portable computer.