JP2001275266A - Chargeable electric equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a power transmission from a primary side to a secondary side without contact as well as power transmission and reception of a signal through a power transmission transformer. SOLUTION: When power is transmitted from a primary side coil 20 to a secondary side coil 40, a power transmission control signal having a predetermined ratio of a power transmission state to a non-transmission state is formed within one period. Then, the power transmission control signals of different periods from each other are combined as prescribed to a signal to be transmitted from the primary side to the secondary side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rechargeable electric device for charging an electric device in a non-contact manner.

[0002]

2. Description of the Related Art Conventionally, non-contact rechargeable electric appliances as described in JP-A-8-88942 and JP-A-10-23676 have been known. The rechargeable electric devices described in these publications include a charger having a primary coil of a power transmission transformer, a secondary coil of the power transmission transformer and an electric double layer capacitor or a secondary battery. The electrical connection with the charger is made up of electrical equipment made by non-contact electromagnetic induction by the primary coil and the secondary coil of the power transmission transformer.

[0003] In the rechargeable electric device configured as described above, when the electric device is mounted on the charger, power is transmitted from the primary coil of the power transmission transformer to the secondary coil of the power transmission transformer by electromagnetic induction. The double layer capacitor or the secondary battery is charged.

[0004]

However, in the above-described conventional rechargeable electric device, only the power is transmitted from the charger to the electric device, and the primary coil and the secondary coil of the power transmission transformer are used. No signal transmission / reception is performed between them. Therefore, there is a problem that power cannot be efficiently transmitted from the primary side to the secondary side. On the other hand, there has been known a type in which a dedicated coil for signal transmission different from that for power transmission is provided to transmit and receive signals, but the structure is complicated.

[0005] The present invention has been made in view of such circumstances, and it is possible to perform power transmission from a primary side to a secondary side and signal transmission / reception without contact using only a power transmission transformer. It is an object of the present invention to provide a rechargeable electric device.

[0006]

In order to achieve the above object, the invention of claim 1 is directed to a transformer of a transformer provided on a side of an electric device having a load from a primary coil of a transformer provided on a charger side. A rechargeable electric device configured to perform power transmission to a secondary coil by electromagnetic coupling, wherein
It is characterized in that signals are transmitted and received between the secondary coil and the secondary coil.

According to this configuration, signals are transmitted and received between the primary side coil and the secondary side coil of the transformer for performing power transmission, so that the circuit configuration is not complicated.
It is possible to cause the secondary side to transmit power from the secondary side.

According to a second aspect of the present invention, in the first aspect, in order to transmit power from the primary coil to the secondary coil, a power transmission state and a non-transmission state within one cycle. And a power transmission control signal having a predetermined ratio, and a signal transmitted from the primary side to the secondary side by combining the power transmission control signals having different periods with each other in a predetermined combination. I have.

According to this configuration, by combining the power transmission control signals having different periods from each other in a predetermined combination, the signal can be transmitted from the primary side to the secondary side using the power transmission transformer.

According to a third aspect of the present invention, when power is transmitted from the primary side coil to the secondary side coil according to the first aspect, the power is transmitted from the primary side according to the state of charge of the load. By comparing a level signal corresponding to the level of the current flowing through the primary coil, which varies according to the load amount, with a preset threshold value, the comparison result is transmitted from the secondary side to the primary side. It is characterized by being a signal.

According to this configuration, the level signal corresponding to the level of the current flowing through the primary coil, which varies according to the load amount viewed from the primary side according to the state of charge of the load, and the preset threshold value Are compared, and the comparison result is 1 from the secondary side.
Since the signal is transmitted to the secondary side, it is possible to transmit the power from the primary side to the secondary side without complicating the circuit configuration.

According to a fourth aspect of the present invention, in accordance with the third aspect, the total transmitted power is controlled by changing the magnitude of the transmitted power from the primary coil to the secondary coil. When the level signal exceeds the threshold value, the total transmission power amount is reduced.

According to this configuration, when the level signal corresponding to the level of the current flowing through the primary coil that changes in accordance with the load amount viewed from the primary side according to the state of charge of the load exceeds the threshold value Therefore, since the total transmission power amount is reduced, it is possible to efficiently transmit power from the primary side to the secondary side.

According to a fifth aspect of the present invention, in accordance with the third aspect, a load resistance is connected in parallel to a load of the secondary coil so that the load resistance can be connected and disconnected, and the level of the load is changed by changing the load amount. Is changed.

According to this configuration, the load becomes large when the load resistance is connected to the load of the secondary coil, and becomes small when the load resistance is not connected to the load of the secondary coil. As a result, the level signal changes.

According to a sixth aspect of the present invention, in accordance with the fifth aspect, the level signal is waveform-shaped via a DC amplifier circuit and a differentiating circuit, and the waveform-shaped signal is used to change the magnitude of the load. It is characterized in that the presence or absence of is determined.

According to this configuration, the presence or absence of a change in the magnitude of the load is accurately determined by shaping the waveform of the level signal.

[0018]

FIG. 1 is a diagram showing a circuit configuration of a non-contact rechargeable electric device according to a first embodiment of the present invention. In this figure, a rechargeable electric device 10 includes a primary-side charger 12 and a secondary-side electric device 14.

The charger 12 includes a power transmission transformer 24
The primary coil 20, the oscillation circuit 22, the power supply circuit 26 that converts the commercial power to DC and supplies it to the power transmission transformer 24, controls the power transmission by the power transmission transformer 24, and It has a transmission control unit 28 for controlling transmission of a signal to the secondary side, a first comparator 30 and a second comparator 32, compares a signal received from the secondary side with a reference value, and compares the signal. A reception control unit 34 that outputs a result and a primary microcomputer (primary control unit) 36 that receives the comparison result from the reception control unit 34 and controls the operation of the transmission control unit 28 are provided.

The transmission control unit 28 includes the oscillation circuit 22
A switch circuit 281 including a first transistor for intermittent connection between the power supply circuits 26, and a control circuit 282 including a second transistor for receiving an output signal from the primary microcomputer 36 and controlling the operation of the switch circuit 281; The reception controller 34 has a first voltage generator 301 for supplying a reference voltage to the non-inverting input terminal (+) of the first comparator 30 and a non-inverting input terminal (+) of the second comparator 32. A second voltage generator 321 for supplying a reference voltage is provided.

The reception control unit 34 includes a detection resistor 341 for detecting the voltage of the primary coil 20 and a shaping circuit 342 for shaping the signal waveform detected by the detection resistor 341.
And The signal shaped by the shaping circuit 342 is input to the inverting input terminals (−) of the first and second comparators 30 and 32. The battery 12 is provided in the charger 12.
4 is provided with an LED (light emitting diode) 38 which is turned on by an output signal of the primary microcomputer 36 when the battery 4 is fully charged.

The electric device 14 includes a secondary coil 40 of the power transmission transformer 24, a secondary power supply circuit 42 that converts transmission power into DC and outputs the DC power, and a DC power output from the secondary power supply circuit 42. Storage battery 44, a reception control unit 46 that performs envelope detection of an oscillation signal induced in the secondary coil 40 and outputs the envelope signal, and receives an output signal from the reception control unit 46 to control power and signal reception. Secondary side microcomputer (2
And a device main body 50 driven by the storage battery 44.

The rechargeable electric device 10 configured as described above
When the signal output to the OUT terminal of the primary microcomputer 36 becomes L level, a DC current from the power supply circuit 26 is supplied to the primary coil 20 by the transmission control unit 28 and
When the signal output to the OUT terminal of the secondary microcomputer 36 becomes H level, the supply of the DC current from the power supply circuit 26 to the primary coil 20 is stopped. The oscillation circuit 22 is driven by being supplied to the oscillation circuit 22 by a current flowing from the power supply circuit 26 into the primary coil 20, and an alternating magnetic flux is generated in the primary coil 20. An AC voltage is induced in the secondary coil 40 by the alternating magnetic flux, and the AC voltage is converted into DC power by the power supply circuit 42 to charge the storage battery 44.

In this case, the primary microcomputer 36 controls the transmission control unit 28 as described below so that power transmission from the primary side to the secondary side and signal transmission from the primary side to the secondary side can be performed. It can be performed. That is, as shown in FIG.
From the primary side microcomputer 36, a short cycle “0” signal (for example, one cycle is L level for 40 msec, 10 msec
A signal of 50 msec consisting of an H level during c) or a long-cycle "1" signal (for example, one cycle is 60 msec)
80m consisting of L level for c and H level for 20msec
sec) is output to the transmission control unit 28.

When the L level signal is output from the primary microcomputer 36, the transmission control unit 28 enables the supply of the DC current from the power supply circuit 26 to the power transmission transformer 24 while the primary microcomputer 36 Output an H level signal from the power supply circuit 26,
4 supply is forbidden. When a DC current is supplied to the power transmission transformer 24 and the oscillating circuit 24 oscillates, a magnetic flux is generated in the primary coil 20, whereby the secondary coil 40
Output an oscillation waveform of 6.0 Vo-p.

This oscillation output is envelope-detected by the reception control section 46 and shaped into a waveform of 3.6 V. The waveform-shaped signal is input to the secondary microcomputer 48 as an H level signal. Also, a power supply circuit 26
During a period in which no DC current is supplied, the oscillation circuit 24 does not oscillate, so that no voltage is induced in the secondary coil 40. Therefore, the output from the reception control unit 46 is 0
V, and an L level signal is input to the secondary microcomputer 48.

For this reason, the secondary microcomputer 48 is configured as shown in FIG.
As shown in (b), the time of the input H level signal and the time of the subsequent L level signal are measured, and "0"
If the signal period (in this case, 50 msec), it is determined that the “0” signal has been transmitted from the primary side, and “
If the signal period is 1 '' (80 msec in this case),
It is determined that the “1” signal has been transmitted from the primary side.

According to the rechargeable electric device 10 operating as described above, a signal (power transmission control signal) of one cycle is formed by combining the power transmission state and the non-transmission state, and the power within this one cycle is generated. By controlling the transmission time, it is possible to control the total transmission power. On the other hand, by using different transmission periods, two types of signals, a "0" signal and a "1" signal, can be transmitted from the primary side to the secondary side. Can be sent to the next side.

That is, when power is transmitted from the primary side to the secondary side, the magnitude of the transmission power intensity is periodically changed, and the periods different from each other are arbitrarily combined to change the primary side to the secondary side. The signal can be transmitted to This makes it possible to transmit power efficiently from the primary side to the secondary side.

The transmission control unit 28 and the primary microcomputer 3
6 constitutes a signal generating means for generating a "0" signal and a "1" signal having different periods to be transmitted from the primary side to the secondary side, and the reception control unit 46 and the secondary side The microcomputer 48 constitutes a signal discriminating means for discriminating whether the signal transmitted from the primary side to the secondary side is a "0" signal or a "1" signal.

Next, an operation related to the reception control unit 34 of the rechargeable electric device 10 shown in FIG. 1 will be described. In the reception control unit 34, the detection resistor 341 in a state where the DC current from the power supply circuit 26 is being supplied to the power transmission transformer 24.
The signal obtained by shaping the signal waveform detected at the first comparator 3
While being input to the inverting input terminal (−) of 0, a preset input reference value (threshold) is input to the non-inverting input terminal (+) of the first comparator 30, and the two input values The magnitude determination result is input to the primary microcomputer 36 as an output signal. When the type of the output signal (L level signal or H level signal) of the reception control unit 34 is determined by the primary microcomputer 36, signal transmission is performed from the secondary side to the primary side.

That is, "0" is changed from the primary side to the secondary side.
A case where a signal is transmitted will be described with reference to FIG. The signal output from the primary microcomputer 36 is 40 m
L level for 10 sec, H level for 10 msec (at this time, the signal input to the secondary microcomputer 48 is 40 ms
The signal is a “0” signal with a signal period of 50 msec, which is H level for ec and L level for 10 msec. Now, when the charge capacity of the storage battery 44 is empty (FIG. 3A), the load on the secondary side as viewed from the primary side is heavy, so the current flowing through the primary side coil 20 increases.

Therefore, the detection resistor 34 of the reception control unit 34
The voltage of the input signal to the first comparator 30 after the voltage at both ends becomes high and the waveform is shaped is, for example, 2.8 V (FIG. 3).
(D)). On the other hand, since the input reference value input to the first comparator 30 is set to, for example, 2.7 V, the output signal of the first comparator 30 in this case becomes L level (FIG. 3).
(E)). The primary microcomputer 36 is connected to the first comparator 3
The output signal of 0 is determined during the L level of the transmission signal from the primary side to the secondary side, which is controlled by itself, and when the transmission signal is at the L level, the capacity of the storage battery is not empty or not in the full capacity (full charge) state. It is determined (FIG. 3 (f)).

Thereafter, when the charge amount of the storage battery 44 increases, the load on the secondary side decreases, so that the transmission power on the primary side gradually decreases (FIG. 3B), while the voltage across the detection resistor 341 decreases. As a result, the voltage of the input signal to the first comparator 30 also gradually decreases (FIG. 3D). When the voltage becomes lower than the input reference value of 2.7 V (for example, 2.0 V).
V), the output of the first comparator 30 becomes H level (FIG. 3)
(E)).

The primary microcomputer 36 determines the output signal of the first comparator 30, and determines that the capacity of the storage battery has reached the full capacity (full charge) state when the output signal is at the H level. As a result, the change in the charging capacity of the storage battery 44 is reduced by 1 from the secondary side.
It can be transmitted as a signal to the next side. Further, when the battery is fully charged, the primary microcomputer 36 outputs an H level signal to an LED (light emitting diode) 38 for performing a charge completion display to light the LED 38. Although FIG. 3 illustrates the case where the “0” signal is transmitted from the primary side to the secondary side, the same operation is performed when the “1” signal is transmitted. Thus, signal transmission from the secondary side to the primary side can be performed.

According to the rechargeable electric device 10 operating as described above, the charge amount of the storage battery 44 is detected, and when the charge amount exceeds a predetermined reference charge amount, the total transmission power amount transmitted from the primary side is reduced. A change in the amount of transmission power on the primary side is detected as a signal for controlling to be small. This gives 2
Signal transmission from the primary side to the primary side can be performed, and unnecessary transmission of power can be prevented, so that safe transmission power control can be performed.

That is, this rechargeable electric device 10
The power is transmitted from the secondary coil 20 to the secondary coil 40, and the level of the current flowing through the primary coil 20 changes according to the load amount viewed from the primary side according to the charge state of the load. The level signal (for example, the voltage value of a signal obtained by shaping the voltage between both ends of the detection resistor 341) and a preset input reference value (threshold value) are compared with one another from the secondary side.
The signal is transmitted to the next side. The first comparator 30 and the primary-side microcomputer 36 constitute a signal detecting section for detecting a signal transmitted from the secondary side, while the storage battery 4 based on the signal transmitted from the secondary side.
A charge state determination unit that determines the charge state (whether the battery is in a full capacity state) of No. 4 is formed.

Next, another operation related to the reception control section 34 of the rechargeable electric device 10 shown in FIG. 1 will be described. In the reception control unit 34, the detection resistor 3 in a state where the DC current from the power supply circuit 26 is being supplied to the power transmission transformer 24.
A signal obtained by shaping the signal waveform detected at 41 is input to the inverting input terminal (−) of the second comparator 32, while the input reference value (threshold) set in advance is the non-inverting value of the second comparator 32. The signal is input to an input terminal (+), and the magnitude determination result of the two input values is input to the primary microcomputer 36 as an output signal. When the primary microcomputer 36 determines the type (L level signal or H level signal) of the output signal of the reception control unit 34, signal transmission has been performed from the secondary side to the primary side. Thus, the total transmission power can be controlled.

Here, a case where a "0" signal is transmitted from the primary side to the secondary side will be described with reference to FIGS. That is, as shown in FIG. 4, the power transmission is not a continuous steady transmission but a transmission power small state and a transmission power large state, and the transmission power time length within one cycle is changed. The total transmission power is controlled by the time length (FIGS. 4A and 4B). In the small total electric energy state (FIG. 4A), the signal from the primary microcomputer 36 is, for example, 40 msec at L level for 10 msec.
At this time, the H level is set to c (the signal input to the secondary microcomputer 48 is the H level for 10 msec, and the L level is set to 40 msec).
For example, the signal from the primary microcomputer 36 is 40 msec.
L level for 10 msec and H level for 10 msec (at this time, the signal input to the secondary microcomputer 48 is H level for 40 msec.
Level (L level for 10 msec).

Now, if the storage capacity of the storage battery 44 is empty, the primary side transmission power increases, so that the primary microcomputer 36
10m at L level for 40msec
H level for sec (at this time, the signal input to the secondary microcomputer 48 is H level for 40 msec, 10 msec
(L level in FIG. 5C) (FIG. 5C), and the total power amount is large.
Since the storage capacity of the storage battery 44 is empty, the load on the secondary side as viewed from the primary side increases, and the current flowing through the primary side coil 20 increases.

For this reason, the detection resistor 34 of the reception control unit 34
1 becomes high, and the input signal to the second comparator 32 becomes, for example, 2.8 V (FIG. 5E). On the other hand, the second
The input reference value input to the comparator 32 is, for example, 2.5 V
, The output signal of the second comparator 32 becomes L level (FIG. 5 (f)). Primary microcomputer 36
Determines the output signal of the second comparator 32 after 5 msec from the timing of the change of the transmission signal from the primary side to the secondary side, which is controlled by the second comparator 32, from the H level to the L level. Not performed. If the result of the determination is at the L level, it is determined that the capacity of the storage battery 44 is empty, and control is performed such that the power transmission time within one cycle is a time when the total transmission power is large.

Thereafter, when the charge amount of the storage battery 44 increases, the load on the secondary side decreases, so that the transmission power on the primary side gradually decreases (FIG. 5B), while the voltage across the detection resistor 341 decreases. As a result, the input signal to the second comparator 32 gradually decreases (FIG. 5E). Then, for example, when the input reference value becomes lower than 2.5 V (for example, 2.0 V), the output signal of the second comparator 32 becomes H level (FIG. 5).
(F)). The primary microcomputer 36 is connected to the second comparator 3
In response to the output signal of No. 2, control is performed such that the power transmission time within one cycle is a time of a small total transmission power while the “0” signal cycle is maintained.

When the "1" signal is transmitted from the primary side to the secondary side, the same operation as described above is performed. That is, when the charge capacity of the storage battery is empty, the output signal of the primary microcomputer 36 is at the L level for 70 msec and at the H level for 10 msec (at this time, the signal input to the secondary microcomputer 48 is at the H level for 70 msec. (L level for 10 msec), and the power transmission time is lengthened by the 80 msec “1” signal period to increase the total transmission power. Thereafter, when the charge amount of the storage battery increases and the primary microcomputer 36 determines that the output signal of the second comparator 32 is at the H level, the output signal of the primary microcomputer 36 remains at the L level for 10 msec.
H level for 0 msec (at this time, the signal input to the secondary microcomputer 48 is H level for 10 msec, 70 ms
(L level between ec), and the power transmission time is shortened by the 80 msec “1” signal period to reduce the total transmission power.

According to the rechargeable electric device 10 operating as described above, the charge amount of the storage battery 44 is detected, and when the charge amount exceeds a preset reference charge amount, the total transmission power amount transmitted from the primary side is reduced. A change in the amount of transmission power on the primary side is detected as a signal for controlling to be small. This gives 2
A signal can be transmitted from the secondary side to the primary side, and unnecessary transmission of power can be prevented, so that safe transmission power control can be performed.

In other words, the total transmission power is controlled by changing the magnitude of the transmission power from the primary coil 20 to the secondary coil 40, and the transmission power is controlled according to the charging state of the load.
Primary coil 2 that changes according to the load seen from the secondary side
A level signal corresponding to the level of the current flowing to 0 (for example, a voltage value of a signal obtained by shaping the voltage between both ends of the detection resistor 341) is compared with a preset input reference value (threshold value). In such a case, the total transmission power is reduced. The second comparator 32 and the primary microcomputer 36 determine the state of charge of the storage battery 44 (whether or not it is in the full capacity state) based on the signal transmitted from the secondary side.
And a charge state determination unit that determines the state of the battery.

FIG. 6 is a diagram showing a circuit configuration of a non-contact rechargeable electric device according to a second embodiment of the present invention. Since the rechargeable electric device 100 has basically the same configuration as the rechargeable electric device 10 shown in FIG. 1, the following description will focus on the differences, and the same components will be the same. The description will be omitted by attaching the reference numerals. That is, the rechargeable electric device 100 includes a transmission control unit 52 that controls signal transmission by the secondary microcomputer 48 in the secondary electric device main body 14.

The transmission control unit 52 connects the load resistor 54 to the storage battery 44 in a connectable and disconnectable manner.
A switch circuit 521 including a first transistor for connecting a load resistor 54 in parallel with the storage battery 44 and the secondary microcomputer 4
And a control circuit 522 including a second transistor for controlling the operation of the switch circuit 521 in response to an output signal from the control circuit 8. Also, the reception control unit 3 of the primary charger 12
4 has only the first comparator 30. Other configurations are the same as those shown in FIG.

Next, the operation of transmitting a signal from the secondary side to the primary side of the rechargeable electric device 100 and controlling the reception on the primary side is performed by transmitting a “0” signal from the primary side to the secondary side. The case of transmission will be described with reference to FIG. Now, when the output signal of the secondary microcomputer 48 is at L level and the load resistance 54
Is connected to the storage battery 44 in parallel by the transmission control unit 52 (FIG. 7).
(A)).

At this time, although a voltage corresponding to the charged amount is applied to the storage battery 44 by the power transmission from the primary side,
Since the load resistor 54 is connected in parallel with the storage battery 44, the load on the secondary side viewed from the primary side is increased. As a result, the load on the secondary side as viewed from the primary side increases, and the current flowing through the primary coil 20 increases. As a result, the voltage across the detection resistor 341 of the reception control unit 34 increases.
The input signal to the first comparator 30 is, for example, 2.8 V (FIG. 7C).

On the other hand, since the input reference value input to the first comparator 30 is set to, for example, 2.6 V, the output signal of the first comparator 30 becomes L level (FIG. 7).
(D)). Therefore, the primary microcomputer 36 controls the output signal of the first comparator 30 from the H level to the L level of the transmission signal from the primary side to the secondary side, which is controlled by itself, as in the case shown in FIG. 5 msec after the timing of
It is determined to be the L level which is the 0 ″ signal.

The output signal of the secondary microcomputer 48 is H
When the level is at the level, the load resistor 54 is not connected in parallel with the storage battery 44, so that the load resistor is disconnected (FIG. 7A). Therefore, the transmission power from the primary side has a low value corresponding to the charge amount of only the storage battery 44, the voltage across the detection resistor 341 decreases, and the input signal to the first comparator 30 also has a low voltage. Then, for example, 2.V lower than the input reference value of 2.6V.
When the voltage becomes 1 V (FIG. 7C), the output of the first comparator 30 becomes H level (FIG. 7D).

Therefore, the primary side microcomputer 36 controls the output signal of the first comparator 30 by 5 msec from the timing when the transmission signal from the primary side to the secondary side, which is controlled by itself, changes from H level to L level. Later, it is determined that the signal is at the H level, which is a “0” signal. The same operation is performed when the “1” signal is transmitted from the primary side to the secondary side.

The rechargeable electric device 100 operating as described above
According to the above, by providing the load resistor 54 so as to be connectable and disconnectable in parallel with the storage battery 44, any information other than the charging information and the contact information between the primary side and the secondary side can be used as a signal from the secondary side to the primary side. Can be sent. The first comparator 30 and the primary microcomputer 36 constitute a signal detecting section for detecting a signal transmitted from the secondary side, and the storage battery 44 based on the signal transmitted from the secondary side. A charge state determination unit that determines the charge state (whether or not the battery is in a full capacity state) is configured.

FIG. 8 is a diagram showing a circuit configuration of a non-contact rechargeable electric device according to a third embodiment of the present invention. Since the rechargeable electric device 200 has basically the same configuration as the rechargeable electric device 100 shown in FIG. 6, the following description focuses on the differences, and the same components are the same. The description will be omitted by attaching the reference numerals.
That is, the rechargeable electric device 200 includes a DC amplification circuit 58 and a differentiation circuit 60 in place of the comparator in the reception control unit 34 of the primary-side charger 12, and other configurations are the same as those in FIG. Same as shown.

Next, the operation of transmitting a signal from the secondary side to the primary side of the rechargeable electric device 200 and controlling the reception on the primary side is performed by transmitting a “0” signal from the primary side to the secondary side. The case of transmission will be described with reference to FIG. Now, when the output signal of the secondary microcomputer 48 is at the L level, the load resistance 54 enters the load resistance connection state in which the transmission control unit 52 is connected to the storage battery 44 in parallel.

At this time, although a voltage corresponding to the charged amount is applied to the storage battery 44 by the power transmission from the primary side,
Since the load resistor 54 is connected in parallel with the storage battery 44, the load on the secondary side viewed from the primary side is increased. For this reason, the load on the secondary side viewed from the primary side increases, and the current flowing through the primary side coil 20 increases. As a result, the voltage between both ends of the detection resistor 341 of the reception control unit 34 increases, and the input signal to the DC amplification circuit 58 becomes 2.2 V, for example.
Becomes

On the other hand, the output signal of the secondary microcomputer 48 is H
When the level is at the level, the load resistor 54 is not connected in parallel with the storage battery 44, so that the load resistor is disconnected. Therefore, the transmission power from the primary side has a low value according to the charge amount of only the storage battery 44, the voltage across the detection resistor 341 decreases, and the input signal to the DC amplification circuit 58 becomes, for example, 2.0V. When the amount of change in the input signal is small as described above, a malfunction may occur in the determination by the comparator in the previous embodiment. Therefore, the determination is performed after shaping the waveform of the input signal as follows. .

That is, "1" from the secondary side to the primary side
The case of transmitting a signal will be described with reference to FIG.
Now, it is assumed that the output of the primary microcomputer 36 is at the L level for 20 msec and the H level for 30 msec (the transmission power is transmitted for 20 msec and stopped for 30 msec) (FIG. 9).
(A), (b)). Now, when the output signal of the secondary microcomputer 48 is at the H level, the transmission power is reduced (FIG. 9).
(A), (c)).

For this reason, the secondary microcomputer 48 operates for 10 msec from the rise of the transmission power from the primary side to the secondary side.
At a later timing, the output signal is switched from the H level to the L level, and is further changed to the H level after 20 msec (FIG. 9).
(C)). As a result, the input waveform to the DC amplification circuit 58 has a value of 2.0 V when the secondary load is small,
The waveform has a step from the value 2.2 V which is a value when the secondary load is large (FIG. 9D).

Then, this waveform is amplified by the DC amplification circuit 58 to emphasize the waveform step (FIG. 9E), and thereafter, a differential waveform is obtained by the differentiating circuit 60 (FIG. 9F). Then, the minus side of this differentiated waveform is cut (FIG. 9).
(G)), the waveform is input to the primary microcomputer 36.
The primary-side microcomputer 36 determines the input waveform 10 msec after the timing of the signal transmission from the primary side to the secondary side, which is controlled by itself, changing from the H level to the L level.
At this determination timing, if there is an H level signal that is equal to or greater than the microcomputer determination reference value, “1” changes from the secondary side to the primary side.
'' Judge that the signal has been transmitted.

On the other hand, when transmitting a "0" signal from the secondary side to the primary side, the secondary side microcomputer 48 sets the output level to H level.
Keep at the level. Therefore, no step occurs in the input waveform to the DC amplification circuit 58, and the primary microcomputer 36 does not have an H level signal higher than the microcomputer determination reference value at the determination timing. Therefore, in this case, it is determined that the “0” signal has been transmitted from the secondary side to the primary side.

The rechargeable electric device 200 that operates as described above
According to this, by shaping the input waveform by the DC amplification circuit and the differentiation circuit, it becomes possible to reliably receive the transmission of the signal by the transmission control unit on the secondary side on the primary side.

In each of the rechargeable electric apparatuses according to the above-described embodiments of the present invention, power transmission and signal transmission and reception are simultaneously performed. In the case where the storage device 14 is used, signals are transmitted and received between the primary side and the secondary side even if the capacities of the storage batteries built in the electric device 14 are significantly different, and the states are mutually recognized. Thus, appropriate and safe charge control can be performed.

[0064]

As described above, according to the first to third aspects of the present invention, signals are transmitted and received between the primary side coil and the secondary side coil. Power transmission from the secondary side to the secondary side and transmission and reception of signals can be performed only by the power transmission transformer.

According to the fourth aspect of the present invention, the total transmission power is controlled by changing the magnitude of the transmission power from the primary coil to the secondary coil, and the level signal exceeds the threshold value. Since the total transmission power is sometimes reduced, the power can be efficiently transmitted from the primary side to the secondary side.

According to the fifth aspect of the present invention, since the load resistance is connected in parallel to the load of the secondary coil so that the load resistance can be disconnected, the level signal can be changed.

According to the sixth aspect of the present invention, the level signal is waveform-shaped through the DC amplifier circuit and the differentiating circuit, and the presence or absence of a change in the load is determined based on the waveform-shaped signal. Therefore, the presence or absence of a change in the load amount can be accurately determined.

[Brief description of the drawings]

FIG. 1 is a diagram showing a circuit configuration of a rechargeable electric device according to a first embodiment of the present invention.

FIGS. 2A and 2B are diagrams for explaining a power transmission cycle of the rechargeable electric device shown in FIG. 1, wherein FIG. 2A shows a case of a short cycle and FIG.

FIG. 3 is a timing chart for explaining the operation of the rechargeable electric device shown in FIG.

FIG. 4 is a timing chart for explaining the operation of the rechargeable electric device shown in FIG.

FIG. 5 is a timing chart for explaining the operation of the rechargeable electric device shown in FIG.

FIG. 6 is a diagram showing a circuit configuration of a rechargeable electric device according to a second embodiment of the present invention.

FIG. 7 is a timing chart for explaining the operation of the rechargeable electric device shown in FIG.

FIG. 8 is a diagram showing a circuit configuration of a rechargeable electric device according to a third embodiment of the present invention.

FIG. 9 is a timing chart for explaining the operation of the rechargeable electric device shown in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 rechargeable electric device 12 charger 14 electric device 20 primary coil 24 power transmission transformer 28 transmission control unit 34 reception control unit 36 primary microcomputer 40 secondary coil 44 storage battery 46 reception control unit 48 secondary microcomputer 50 Device main body 52 Transmission control unit 58 DC amplifier circuit 60 Differentiator circuit

Claims (6)

[Claims] 1. A rechargeable electric power source, wherein power is transmitted from a primary coil of a transformer provided on a charger side to a secondary coil of the transformer provided on an electric device having a load by electromagnetic coupling. A rechargeable electric device, wherein the device transmits and receives signals between the primary coil and the secondary coil. 2. The rechargeable electric device according to claim 1, wherein a power transmission state and a non-transmission state are determined within a single cycle in order to transmit power from the primary coil to the secondary coil. A power transmission control signal having a ratio is formed, and the power transmission control signals having different periods are combined in a predetermined combination to be a signal transmitted from the primary side to the secondary side. machine. 3. The rechargeable electric device according to claim 1, wherein when power is transmitted from the primary coil to the secondary coil, a load amount viewed from the primary side according to a state of charge of the load. By comparing a level signal corresponding to the level of the current flowing through the primary side coil that changes in response to a predetermined threshold value, the comparison result is used as a signal transmitted from the secondary side to the primary side. A rechargeable electric device characterized by the following. 4. The rechargeable electric device according to claim 3, wherein the total transmission power is controlled by changing the magnitude of the transmission power from the primary coil to the secondary coil.
The rechargeable electric device, wherein the total transmission power amount is reduced when the level signal exceeds the threshold value. 5. The rechargeable electric device according to claim 3, wherein a load resistance is connected in parallel to a load of the secondary coil so that the load resistance can be connected and disconnected, and the level signal is changed by changing the load amount. A rechargeable electric device characterized in that: 6. The rechargeable electric device according to claim 5, wherein the level signal is waveform-shaped via a DC amplification circuit and a differentiation circuit, and the presence or absence of a change in the load amount is determined based on the waveform-shaped signal. A rechargeable electric device characterized in that: