JP2000083326A - Noncontact charger for cordless telephone set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power loss in a telephone set by controlling the operation of the DC-to-AC converter in its base set. SOLUTION: When a hand set 2 is placed on a base set 1 with AC power supplied to a power circuit 13, a reed switch 6 is turned on, and a control switch 5 actuates a timer 8. When the output of the timer 8 is at a high level, the control switch 5 is on and supplies power to a DC-to-AC converter 14, and the DC-to-AC converter 14 applies alternating-current voltage to a primary coil 3. Alternating-current voltage is induced in a secondary coil 4 and is supplied to a power circuit 16 to charge a battery 15. The control switch 5 stops power supply to the DC-to-AC converter 14 at the falling edge of the timer 8, when the battery 15 is fully charged, and power supply to the DC-to-AC converter 14 at the falling edge of a magnetic switch 7 when the battery 15 is empty. When the battery 15 is fully charged, as a result, the DC-to-AC converter 14 is not operated and unnecessary power consumption is reduced, even if the hand set 2 is on the base set 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless charging device for a cordless telephone.

[0002]

2. Description of the Related Art One embodiment of a conventional wireless charging device for a cordless telephone will be described below. As shown in FIG. 4, the base set 21 has a D.C.
It comprises a C / AC converter 43, a primary coil 41 for transmitting the generated AC voltage to the handset 20, and a reed switch 40 for detecting on / off-hook of the handset 20. In addition, handset 20
Is configured to include a secondary coil 32 for generating an AC voltage from the primary coil 41 by electromagnetic induction, and a permanent magnet 33 for turning on / off the reed switch 40 of the base set 21.

Next, the operation of the above-described conventional contactless charging device for a cordless telephone will be described. Handset 2
0 is set on the base set 21, the permanent magnet 33 in the handset 20 causes the reed switch 4
0 turns on to supply power to the DC / AC converter 43 and apply an AC voltage to the primary coil 41. Since the primary coil 41 generates an AC voltage to the secondary coil 32 by electromagnetic induction, the AC voltage is rectified and stored in the battery.

[0004]

In the prior art described above, the start / stop of the DC / AC converter is controlled only by the on-hook information of the handset, so that the handset remains on the baseset even when the battery is fully charged. If so, the DC / AC converter circuit is operating. Therefore, there is a problem that the power loss in the DC / AC converter when the battery is fully charged is inefficient.

[0005] It is an object of the present invention to reduce the power loss of a contactless rechargeable cordless telephone by controlling the operation of a DC / AC converter in a base set.

[0006]

According to the present invention, a first communication circuit capable of cordless communication with a handset, a power supply circuit for supplying power to the entire cordless telephone, and a DC voltage supplied by the power supply circuit are connected to an AC power supply. DC / A to convert to voltage
A C converter, a primary coil for transmitting an AC voltage applied from the DC / AC converter by electromagnetic induction, a reed switch for detecting whether the handset is set, and a magnetic switch for detecting magnetism; A control switch for starting / stopping the DC / AC converter, a base set having a timer for turning on the control switch at regular intervals, a second communication circuit capable of cordless communication with the base set, and turning on the reed switch. /
A permanent magnet that is turned off, a power supply circuit that supplies power to the rectifier and the second communication circuit, a secondary coil that generates an AC voltage by electromagnetic coupling with the primary coil, a battery, and a DC that flows through the battery. A contactless charging device for a cordless telephone is provided which includes a handset having an electromagnet that detects a current to generate magnetism.

Further, according to the present invention, the control switch monitors the on / off-hook state of the base set, timer information, and the battery charge state of the handset, and starts and stops the DC / AC converter. And
The DC / A not only when the handset is off-hook, but also when the battery is fully charged.
A contactless charging device for a cordless telephone characterized by controlling to stop the C converter is obtained.

Further, according to the present invention, when the handset is placed on the base set while AC power is supplied to the power supply circuit, the reed switch is turned on by the permanent magnet, and a logic circuit inside the control switch is provided. Starts the timer by the output of the reed switch, and thereafter monitors the output of the timer. When the output of the timer is at a high level, the control switch turns on to supply power to the DC / AC converter. , The DC / AC
The converter applies an AC voltage to the primary coil, generates an AC voltage in the secondary coil by electromagnetic induction from the primary coil, supplies the AC voltage to the power supply circuit 16, and rectifies the output to produce the battery. When the battery is empty, current flows through the electromagnet to generate magnetism and turn on the magnetic switch, and when fully charged, the magnetic switch keeps off, and the control switch operates when the battery is fully charged. At the fall of the timer, when the battery is empty, the power supply to the DC / AC converter is stopped at the fall of the magnetic switch. When the battery is empty, the battery is charged after the timer rises. Is started, the magnetic switch is turned on, and charging is completed until the magnetic switch is turned off. When the DC / AC converter is supplied with power and the battery is in a fully charged state, after the timer rises, no charging current flows through the battery, and the magnetic switch does not change to an off state. The control switch is kept on while the output of the timer is at a high level. When the output of the timer is at a low level, the power supply to the DC / AC converter is stopped, and when the handset is separated from the base set and put on again, the handset is put on again. By repeating the above operation, the DC / AC converter does not operate even when the handset is on the base set when the battery is fully charged, thereby obtaining a wireless charging device for a cordless telephone.

Further, according to the present invention, the pulse of the timer is at least twice (including a charge start pulse) between the start of charging and the time when the battery completely discharges.
A contactless charging device for a cordless telephone characterized by the necessity is obtained.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In FIG. 1, a base set 1 is a cordless telephone base unit, and includes a communication circuit 12 that is a telephone circuit capable of performing cordless communication with the handset 2, a power supply circuit 13 that supplies power to the entire cordless telephone, and a power supply circuit 13. A DC / AC converter 14 for converting a DC voltage to an AC voltage;
A primary coil 3 for transmitting the AC voltage applied from the converter 14 to the secondary coil 4 of the handset 2 by electromagnetic induction, a reed switch 6 for detecting whether the handset 2 is set on the base set 1, and a handset A magnetic switch 7 for detecting the magnetism of the second electromagnet 10;
A timer 8 for turning on the control switch 1 at regular intervals, a control switch 5 for starting and stopping the DC / AC converter by the output of the reed switch 6, the magnetic switch 7, and the timer 8
It consists of.

The handset 2 is a cordless telephone handset, a telephone circuit 11 which is a telephone circuit capable of performing cordless telephone communication with the base set 1, a permanent magnet 9 for turning on / off the reed switch 6, a rectifier, and a power supply for the telephone circuit 11. It comprises a power supply circuit 16 to be supplied, a secondary coil 4 that generates an AC voltage by electromagnetic coupling with a primary coil, an electromagnet 10 that detects a DC current flowing through a battery to generate magnetism, and a battery 15.

Next, the operation of this embodiment will be described with reference to FIGS. When the handset 2 is placed on the base set 1 while AC power is supplied to the power supply circuit 13, the reed switch 6 is turned on (H) by the permanent magnet 9. The logic circuit inside the control switch 5 starts the timer 8 based on the output (H) of the reed switch 6 and thereafter monitors the output of the timer 8. The timer 8 outputs a pulse having a constant width at a constant interval. The control switch 5 is a timer 8
When the output of the DC / AC converter 1 is at a high level, it is turned on to supply power to the DC / AC converter 14,
4 applies an AC voltage to the primary coil 3.

An AC voltage is generated in the secondary coil 4 by electromagnetic induction from the primary coil and supplied to the power supply circuit 16. The output is rectified to charge the battery 15.
At this time, if the battery 15 is empty, a current flows through the electromagnet 10 to generate magnetism and turn on the magnetic switch 7 (H). If the battery is fully charged, no current flows through the electromagnet 10 so that no magnetism is generated and the magnetic switch 7 is kept off (L). The control switch 5 controls the timer 8 when the battery 15 is fully charged,
When the battery 15 is empty, D falls when the magnetic switch 7 falls.
The power supply to the C / AC converter 14 is stopped.

If the battery 15 is empty, the timer 8
After the rise, the battery 15 starts to be charged, so that the magnetic switch 7 is turned on (H), and the power supply to the DC / AC converter 14 is maintained until the charging is completed and the magnetic switch 7 is turned off (L). . When the battery 15 is in the fully charged state, after the timer 8 starts, no charging current flows through the battery 15, and the magnetic switch 7 remains off (L) and does not change. The control switch 5 keeps the on (H) state while the output of the timer 8 is at the high level.
Becomes low level, the DC / AC converter 14
Stop supplying power to

When the handset 2 is separated from the base set 1 and put on the base set again, the above operations 1 to 5 are repeated. By the above operation, when the battery 15 is fully charged, the DC / AC converter 14 does not operate even if the handset 2 is on the base set 1, and wasteful power consumption is reduced.

Next, the operation of the timer 8 will be described.
If the handset 2 is fully charged, the control switch 5 stops the DC / AC converter 14, and the handset 2 is not separated from the baseset 1 for a long time,
If charging is not restarted at regular intervals, the battery 15 will discharge spontaneously until it becomes empty. The output of the timer 8 at regular intervals is to prevent the spontaneous discharge of the battery 15, and it is necessary to restart charging before the battery 15 becomes empty.

Therefore, the pulse of the timer 8 needs to be at least twice (including the charge start pulse) from the start of charging to the time when the battery 15 completely discharges naturally. For example, if the battery 15 takes 4 hours for charging and 8 hours for spontaneous discharge, two or more pulses including a charging start pulse are required within a total of 12 hours.

[0018]

According to the present invention, even if the handset is on the base set, the operation of the DC / AC converter is stopped if the battery is fully charged, so that the power loss can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a control switch.

FIG. 3 is a diagram showing a time chart of an operation of a control switch.

FIG. 4 is a diagram showing an embodiment of the prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base set 2 Handset 3 Primary coil 4 Secondary coil 5 Control switch 6 Reed switch 7 Magnetic switch 8 Timer 10 Electromagnet 11, 12 Talk circuit 13, 16 Power circuit 14 DC / AC converter 15 Battery 17 Logic circuit 18 Power switch

Claims (4)

[Claims] 1. A first communication circuit capable of cordless communication with a handset, a power supply circuit for supplying power to the entire cordless telephone, a DC / AC converter for converting a DC voltage supplied by the power supply circuit to an AC voltage, A primary coil for transmitting an AC voltage applied from the DC / AC converter by electromagnetic induction, a reed switch for detecting whether the handset is set, a magnetic switch for detecting magnetism, A base switch having a control switch for starting / stopping the converter, a timer for turning on the control switch at regular intervals, a second communication circuit capable of cordless communication with the base set, and a permanent switch for turning on / off the reed switch A magnet, a rectifier, and a power supply circuit for supplying power to the second communication circuit, and electromagnetic coupling with the primary coil Contactless charging for a cordless telephone, comprising: a secondary coil that generates an AC voltage, a battery, and a handset having an electromagnet that generates magnetism by detecting a DC current flowing through the battery. apparatus. 2. The control switch monitors an on / off-hook state of the base set, timer information, and a battery charge state of the handset, and controls the DC / A.
The C / C converter is started and stopped, and the DC / AC converter is controlled to be stopped not only when the handset is off-hook but also when the battery is fully charged. Item 1. A contactless charging device for a cordless telephone according to Item 1. 3. When the handset is placed on the base set while AC power is supplied to the power supply circuit, the reed switch is turned on by the permanent magnet, and a logic circuit inside the control switch is configured to operate the reed switch of the reed switch. The timer is started by the output, and thereafter, the output of the timer is monitored. When the output of the timer is at a high level, the control switch is turned on to supply power to the DC / AC converter. Applies an AC voltage to the primary coil, generates an AC voltage in the secondary coil by electromagnetic induction from the primary coil, supplies the AC voltage to the power supply circuit 16, and rectifies the output to power the battery. When the battery is empty, current flows through the electromagnet when the battery is empty, generates magnetism and turns on the magnetic switch. The magnetic switch keeps off, the control switch stops power supply to the DC / AC converter at the fall of the timer when the battery is fully charged, and at the fall of the magnetic switch when the battery is empty, When the battery is empty, after the timer rises, the battery starts charging, so the magnetic switch is turned on,
Power is maintained in the DC / AC converter until charging is completed and the magnetic switch is turned off. If the battery is fully charged, no charging current flows through the battery after the timer starts. The magnetic switch remains in the off state and does not change, the control switch is kept on while the timer output is at the high level, and when the timer output goes to the low level, the DC /
When the power supply to the AC converter is stopped, the handset is separated from the baseset, and then put on again, the above operation is repeated. When the battery is fully charged, the DC / AC converter does not operate even if the handset is on the baseset. The wireless charging device for a cordless telephone according to claim 1 or 2, wherein: 4. The pulse of the timer is required at least two times (including a charge start pulse) between the start of charging and the time when the battery completely discharges spontaneously. A wireless charging device for a cordless telephone according to one aspect.