JPH0739077A - Cordless power station - Google Patents

Abstract

PURPOSE:To control a power receiving apparatus satisfactorily without a waste power consumption. CONSTITUTION:A power receiving apparatus 6 has a voltage detecting means 14 and 15 which detects the voltages of the power receiving apparatus 6 and, further, has a transmitting means 16 and 17 which transmits the detection signals of the voltage detecting means 14 and 15. A power transmitting apparatus 1 has a receiving means 18 and 19 which receives the transmission signals from the transmitting means 16 and 17. A power which is transmitted from the power transmitting apparatus 1 to the power receiving apparatus 6 is controlled by the receiving signals from the receiving means 18 and 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cordless power station suitable for application to portable electric home appliances such as portable telephones and headphone stereos.

[0002]

2. Description of the Related Art Previously, a cordless power station has been proposed which transfers electric power in a non-contact manner to charge a secondary battery of a portable home electric appliance such as a portable telephone.

The principle of the cordless power station will be described with reference to FIG. 2. Reference numeral 1 denotes an electric power transmission device. In the electric power transmission device 1, a power plug 2 is provided.
The commercial power source obtained from the power transmission circuit 3 is supplied to the power transmission circuit 3, and the predetermined frequency obtained by the power transmission circuit 3, for example, 100 KH.
The power transmission signal of z is supplied to the power transmission coil 5 wound around the center leg of the E-type ferrite core 4 provided in contact with the inner surface of the upper surface 1a of the resin casing of the power transmission device 1.

On the other hand, in a power receiving device such as a portable telephone 6, a power receiving coil 8 is attached to the center foot of an E-type ferrite core 7 arranged in contact with the inside of a lower surface 6a of a resin casing of the portable telephone 6. As if to wind. The power transmission signal obtained by the power receiving coil 8 is supplied to the charging circuit provided in the housing of the mobile phone 6 so that the secondary battery for powering the mobile phone 6 is charged.

In this cordless power station, the E-type ferrite core 4 of the power transmitting device 1 and the E-type ferrite core 7 of the power receiving device 6 are arranged in correspondence with each other, and the power transmitting coil 5 and the power receiving coil 8 are separated by a gap. The electric power from the electric power transmission device 1 is transmitted to the electric power reception device 6 in a contactless manner by utilizing the electromagnetic induction effect generated between the electric power transmission coil 5 and the electric power reception coil 8.

FIG. 3 shows a conventional example of the charging circuit of the power receiving device 6. In FIG. 3, the power transmission signal obtained by the power receiving coil 8 is supplied to the rectifier circuit 10 via the connection switch 9 for rectification, and the rectified DC voltage obtained at the output side of the rectifier circuit 10 is supplied to the filter circuit 11. Through the current stabilization circuit 1
2, and the direct current obtained at the output side of the current stabilizing circuit 12 is supplied to the power receiving device, for example, the secondary battery 13 for power supply of the portable telephone 6, so that the secondary battery 13 is charged. .

The voltage obtained at the positive electrode of the secondary battery 13 is supplied to the battery voltage detection circuit 14. In the battery voltage detection circuit 14, a reference voltage at which charging of the secondary battery 13 is completed is determined in advance, and the secondary battery 13 is determined.
The connection switch 9 is turned off when the positive electrode voltage reaches the reference voltage. In FIG. 3, 5a,
5b is a power transmission signal input terminal to the power transmission coil 5 of the power transmission device 1.

According to the example of FIG. 3, the power transmission signal from the power transmission coil 5 of the power transmission device 1 is transmitted to the power reception coil 8 by the electromagnetic induction action, and the power transmission signal is used for the power source of the power reception device, for example, the portable telephone 6. The secondary battery 13 can be charged.

[0009]

In the conventional cordless power station as shown in FIG. 3, the connection switch 9 is turned off when the charging of the secondary battery 13 is completed. Had the inconvenience of operating and wasting power.

Further, since the power transmission device 1 and the power reception device 6 are electrically non-contact with each other, the voltage across the power reception coil 8 cannot be known, and it is determined whether the power reception device 6 is operating properly. There was an inconvenience that could not be determined.

In view of the above problems, an object of the present invention is to make it possible to favorably control the power receiving device without consuming unnecessary power.

[0012]

A cordless power station according to the present invention is, for example, as shown in FIGS. 1 and 2, a power transmission coil 5 of a power transmission device 1 and a power reception coil 8 of a power reception device 6.
In the cordless power station, the electric power is transmitted from the electric power transmitting apparatus to the electric power receiving apparatus in a contactless manner by electromagnetic induction generated between the electric power transmitting coil 5 and the electric power receiving coil 8. The power receiving device 6 is provided with voltage detecting means 14 and 15 for detecting the voltage of the power receiving device 6 and the voltage detecting means 1 is provided.
Transmitting means 16 and 17 for transmitting the detection signals of 4 and 15 are provided, and receiving means 18 and 19 for receiving the transmitting signals from the transmitting means 16 and 17 are provided in the power transmission device 1, and the receiving means 18 and The electric power transmitted from the electric power transmission device 1 to the electric power receiving device is controlled by a reception signal from the electric power transmission device 19.

Further, the cordless power station of the present invention, as shown in FIG. 1 and FIG.
The receiving coil voltage detecting circuit 15 for detecting the terminal voltage of the receiving coil 8 and the battery voltage detecting circuit 14 for detecting the terminal voltage of the secondary battery 13 are configured.

[0014]

According to the present invention, the power transmitted from the power transmitting device 1 to the power receiving device 6 is controlled by the output signal of the power receiving coil voltage detection circuit 15 which detects the terminal voltage of the power receiving coil 8. Good secondary battery 13
Can be charged.

Further, since the output signal of the battery voltage detection circuit 14 for detecting the terminal voltage of the secondary battery 13 is transmitted to the power transmission device 1, this power transmission device 1 uses the secondary battery 13
The end of charging of the battery can be known, and wasteful power consumption can be eliminated.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the cordless power station of the present invention will be described below with reference to FIGS. In FIG. 1, parts corresponding to those in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the example of FIG. 1, the power transmission signals obtained at the power transmission signal input terminals 5a and 5b of the power transmission device 1 are supplied to the voltage control circuit 21 via the connection switch 20.
The voltage control circuit 21 controls the voltage of the power transmission signal according to a command from the control circuit 22 described later.

A power transmission signal of, for example, 100 KHz controlled to a predetermined voltage obtained at the output side of the voltage control circuit 21 is supplied to the power transmission coil 5.

On the other hand, a power receiving device, for example, a power transmission signal obtained by a power receiving coil 8 of a charging circuit provided in a portable telephone 6 is supplied to a rectifier circuit 10 for rectification, and a rectified DC voltage obtained at an output side of the rectifier circuit 10. Is supplied to the current stabilizing circuit 12 via the filtering circuit 11, and the DC current obtained at the output side of the current stabilizing circuit 12 is supplied to the output power receiving device, for example, the secondary battery 13 for power supply of the portable telephone 6. Then, the secondary battery 13 is charged.

The voltage obtained at the positive electrode of the secondary battery 13 is supplied to the battery voltage detection circuit 14. In the battery voltage detection circuit 14, a reference voltage at which charging of the secondary battery 13 is completed is defined in advance, and the secondary battery 1
When the positive electrode voltage of 3 reaches the reference voltage, the charging end signal is supplied to the light emitting device 16 which constitutes the transmitting device.

The light emitting device 16 is composed of, for example, a light emitting diode, and the charge end signal of the secondary battery 13 is supplied as an optical modulation signal to the light receiving device 18 provided in the power transmission device 1 and composed of, for example, a phototransistor. To do.

Further, in the power receiving device 6, the voltage obtained in the power receiving coil 8 is used as the power receiving coil voltage detection circuit 15
The voltage value of the power receiving coil 8 obtained by the power receiving coil voltage detection circuit 15 is converted into a digital signal or the like and supplied to the light emitting device 17 which constitutes the transmitting device.

The light emitting device 17 is composed of, for example, a light emitting diode, and the voltage value signal of the power receiving coil 8 is supplied to the light receiving device 19 composed of, for example, a phototransistor provided in the power transmission device 1 as an optical modulation signal.

In this example, the light receiving devices 18 and 1
The respective output signals of 9 are supplied to the control circuit 22, respectively. In the control circuit 22, when the charging end signal is supplied from the light receiving device 18, the connection switch 20 provided in the power transmission device 1 is turned off, and the voltage is output according to the voltage value signal from the light receiving device 19. The control circuit 21 is controlled to control the output voltage value.

Further, in this example, when the power receiving device 6 is arranged on the power transmitting device 1, the power transmitting coil 5 and the power receiving coil 8 are made to approach each other as shown in FIG. 2, and the light emitting device 16 and the light receiving device 18 are arranged. And the light emitting device 17
And the light receiving device 19 face each other.

In this example, as described above, the voltage of the power transmission signal of the power receiving coil 8 of the power receiving device 6 is set to the power receiving coil voltage detection circuit 1.
5, the voltage value signal of the power receiving coil 8 detected by the power receiving coil voltage detection circuit 15 is transmitted to the power transmission device 1 side, and the power transmission coil 5 of the power transmission device 1 is transmitted according to this voltage.
Since the voltage supplied to the power receiving device 8 is controlled, the power transmitted from the power transmitting device 1 to the power receiving device 6 can be controlled by the voltage of the power receiving coil 8, and the secondary battery 13 can always be charged well in the power receiving device 6. Have a profit

Further, in this example, the terminal voltage of the secondary battery 13 is detected by the battery voltage detection circuit 14, and when the charging of the secondary battery 13 is completed, a charge end signal is transmitted to the power transmission device 1 side, Since the connection switch 20 is turned off by this charging end signal, the power transmission device 1 uses the secondary battery 1
3 has the benefit of not wasting power after the end of charging.

In the above embodiment, the light emitting devices 16 and 1
Although the example using 7 and the light receiving devices 18 and 19 has been described, it goes without saying that other wireless communication devices can be used instead of them. Further, the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various other configurations can be adopted without departing from the gist of the present invention.

[0029]

As described above, according to the present invention, there is an advantage that the charging circuit of the power receiving device can be favorably controlled and the power transmitting device does not consume unnecessary power.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a cordless power station of the present invention.

FIG. 2 is a sectional view for explaining a cordless power station.

FIG. 3 is a configuration diagram showing an example of a conventional cordless power station.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 power transmission device 5 power transmission coil 6 power receiving device 8 power receiving coil 13 secondary battery 14 battery voltage detection circuit 15 power receiving coil voltage detection circuit 16, 17 light emitting device 18, 19 light receiving device 20 connection switch 21 voltage control circuit 22 control circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H04B 7/26

Claims (2)

[Claims] 1. A power transmission coil of a power transmission device and a power reception coil of a power reception device are brought close to each other, and an electromagnetic induction action occurs between the power transmission coil and the power reception coil to electrically connect the power transmission device to the power reception device. In a cordless power station configured to wirelessly transmit power, the power receiving device is provided with voltage detecting means for detecting a voltage of the power receiving device and transmitting means for transmitting a detection signal of the voltage detecting means. The power transmission device is provided with a reception unit that receives a transmission signal from the transmission unit, and the power transmitted from the power transmission device to the power reception device is controlled by the reception signal from the reception unit. A cordless power station featuring. 2. The cordless power station according to claim 1, further comprising a power receiving coil voltage detection circuit that detects a terminal voltage of the power receiving coil and a battery voltage detection circuit that detects a terminal voltage of a secondary battery as the voltage detecting means. A cordless power station characterized by being configured.