Cordless telephone

• US 20040097275A1
• Filed: 01/09/2003
• Published: 05/20/2004
• Est. Priority Date: 11/20/2002
• Status: Abandoned Application

• Current Assignee: Uniden Corporation (Cornwall Capital Management LP)
• Original Assignee: Uniden Corporation (Cornwall Capital Management LP)
• Inventors: Hirayama, Fumiya, Ohno, Hiroki
• Application Number:
  US10/338,897
• Publication Number:
  US 20040097275A1
• Time in Patent Office: Days
• US Class Current: 455/572
• CPC Class Codes: H02J 2310/22 The load being a portable electronic device
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence

Abstract

The object of the present invention is to simplify the circuit configuration of a charge system in a cordless phone. For this object, a stationary device in the cordless telephone in accordance with the present invention is provided with a power source circuit for charging a secondary battery contained in a mobile device. The mobile device comprises a charge switch unit for continuously conducting ON/OFF of the charge current supplied from the power source circuit to the secondary battery and controlling a pulse-waveform charge current, and a switch control unit for adjusting the duty ratio of the pulse waveform and adjusting the average value of the charge current supplied to the secondary battery by controlling the ON/OFF time of the charge current in the charge switch unit.

Claims

1. A cordless telephone composed of a stationary device and a mobile device, wherein:

said stationary device comprises a power source circuit for charging a secondary battery contained in said mobile device; and

said mobile device comprises;

a charge switch unit for continuously conducting ON/OFF of the charge current supplied from said power source circuit to said secondary battery and controlling a pulse-waveform charge current; and

a switch control unit for adjusting the duty ratio of said pulse waveform and adjusting the average value of the charge current supplied to said secondary battery by controlling the ON/OFF time of the charge current in said charge switch unit.

2. The cordless telephone according to claim 1, wherein said switch control unit adjusts the duty ratio of said pulse waveform according to a charge mode.

3. The cordless telephone according to claim 1, wherein said switch control unit adjusts the duty ratio of said pulse waveform so that said charge current becomes a trickle current if said secondary battery is fully charged.

4. The cordless telephone according to claim 2, wherein said switch control unit adjusts the duty ratio of said pulse waveform so that said charge current becomes a trickle current if said secondary battery is fully charged.

5. The cordless telephone according to claim 1, wherein said charge switch unit comprises a three-terminal transistor in which a collector terminal and an emitter terminal are input/output terminals for said charge current and which is ON/OFF controlled by a base potential.

6. The cordless telephone according to claim 2, wherein said charge switch unit comprises a three-terminal transistor which has a collector terminal and an emitter terminal respectively serving as input/output terminals for said charge current and which is ON/OFF controlled by a base potential.

7. The cordless telephone according to claim 3, wherein said charge switch unit comprises a three-terminal transistor which has a collector terminal and an emitter terminal respectively serving as input/output terminals for said charge current and which is ON/OFF controlled by a base potential.

8. A cordless telephone composed of a stationary device and a mobile device, wherein:

said stationary device comprises;

a power source circuit for charging a secondary battery contained in said mobile device;

a modulation unit for continuously conducting ON/OFF of the charge current output from said power source circuit and outputting a pulse-modulated electric current; and

a modulation control unit for controlling said modulation unit so as to output said modulated current when power consumption in said stationary device exceeds the prescribed value determined in advance; and

said mobile device comprises;

charge limiting means for limiting charging of said secondary battery from said power source circuit when the modulated current output from said modulation unit has been detected.

9. A cordless telephone composed of a stationary device and a mobile device, wherein:

said stationary device comprises;

a power source circuit for charging a secondary battery contained in said mobile device; and

a charge control unit for outputting a control signal requiring charge limitation to said mobile device via a control system provided as a system separate from the charge system provided between said stationary device and mobile device, when power consumption of said stationary device exceeds the prescribed value determined in advance; and

said mobile device comprises;

charge limiting means for limiting charging of said secondary battery from said power source circuit when said control signal output from said charge control unit has been detected.

10. A cordless telephone composed of a stationary device and a mobile device, wherein:

said stationary device comprises;

a power source circuit for charging a secondary battery contained in said mobile device;

a wireless unit for conducting wireless communication with said mobile device; and

a charge control unit for outputting a control signal requiring charge limitation to said mobile device via said wireless unit when power consumption of said stationary device exceeds the prescribed value determined in advance; and

said mobile device comprises;

charge limiting means for limiting charging of said secondary battery from said power source circuit when said control signal output from said wireless unit has been detected.