JPH11122809A - Power supply adapter, electronic apparatus and signal transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply adapter in which a code signal can be transmitted even if an AC adapter and an electronic apparatus set are connected at two terminals, i.e., + and - terminals. SOLUTION: A code signal is transmitted from the side of a set connected with an AC adapter outputting with low power. The code signal is detected by a signal receiving circuit 52 in the AC adapter and a decision is made that the set corresponds correctly to that AC adapter it the number, period, width of the pulse match each other. When a decision is made that the set corresponds correctly to that AC adapter, a transistor 42 is turned on through a stop circuit 53 and a high power is outputted from the AC adapter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply adapter capable of transmitting a code signal by connecting a power supply adapter and an electronic device through two terminals, a + terminal and a-terminal, and an electronic device. The present invention relates to a signal transmission system.

[0002]

2. Description of the Related Art Lithium ion batteries have attracted attention as secondary batteries for electronic equipment. Lithium-ion batteries are
Compared with the conventional secondary battery, there is an advantage that the duration can be extended and there is almost no memory effect. When charging the lithium-ion battery, signals are exchanged between a power supply adapter (hereinafter, referred to as an AC adapter) and a microcomputer (microcomputer) of the electronic device.
It is determined whether the AC adapter connected to the electronic device is an AC adapter having a correct correspondence with the electronic device. It is the rating of the secondary battery, for example, 4.2V /
This is because when a voltage and a current exceeding 0.5 A are supplied, for example, when the battery is charged at 6 V / 1 A, the secondary battery may be damaged.

[0003]

Therefore, in such a case, as shown in FIG. 34, the AC adapter 232 is provided with an outlet 231 that can be connected to a commercial power supply, and the AC adapter 232 and the electronic device set 233 are connected to each other by +. It was necessary to connect with three terminals, a terminal, a negative terminal and a signal terminal.

[0004] However, between the AC adapter 232 and the set 233, two terminals of the + terminal and the-terminal necessary for power supply are provided.
There is a problem in that the cost is increased by providing one signal terminal separately from the one terminal, and the size is increased by adding a protection circuit for preventing the charger from being heated and damaged. In addition, malfunction due to noise generated at the signal terminal is also a problem.

Accordingly, an object of the present invention is to provide a power supply adapter and an electronic device which can exchange a code signal even when an AC adapter and an electric device are connected by using two terminals of a + terminal and a-terminal. And a signal transmission system.

[0006]

According to a first aspect of the present invention, there is provided a code signal which is connected to an electronic device by two terminals, is capable of outputting high power and low power, and is transmitted from the electronic device. Signal detecting means for detecting whether or not the connected electronic device is in a correct correspondence relationship, based on the detected code signal, and as a result of the signal determining means, the electronic device has a correct correspondence. A power supply adapter comprising switching means for switching the output from low power to high power when it is determined that the power is related.

According to a fourth aspect of the present invention, a code signal for identifying a power supply adapter to be connected is generated based on power supplied from the power supply adapter and connected to the power supply adapter through two terminals. An electronic device having a signal generation unit that performs the operation.

According to a fifth aspect of the present invention, there is provided a power supply adapter connected to an AC power supply for generating a predetermined DC power supply voltage, and a signal transmission system for connecting the power supply adapter to an electronic device. And electronics 2
Connected by terminals, the power supply adapter is capable of outputting high power and low power, signal detection means for detecting a code signal from the electronic device side, and the electronic device connected to the power supply adapter Whether or not the electronic device has the correct correspondence is determined by the signal determination unit that determines the detected code signal based on the detected code signal. As a result of the signal determination unit, the power supply adapter and the electronic device are determined to have the correct correspondence. Switching means for switching the output of the power supply adapter from low power to high power, the electronic device identifies the power supply adapter to be connected based on the power supplied from the power supply adapter. A signal transmission system having code signal generation means for generating a code signal.

An electronic device is connected to an AC adapter, and the AC adapter operates with low power and supplies the output to the electronic device. On the electronic device side, the supplied small power is generated by the code signal generating means to generate a code signal (voltage) having a clock-like waveform, and the code signal is received by the AC adapter side. If it is determined that the electronic device is related, the AC adapter supplies a high-power output to the electronic device. If it is determined that the electronic device does not have a correct correspondence with the AC adapter, the AC adapter does not output large power. And
On the side of the AC adapter that outputs a large amount of power, it is determined whether the current is equal to or less than the reference value.
The output of the C adapter is switched to low power.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of an embodiment of the present invention. An AC adapter 2 coupled to an outlet 1 to which a commercial power supply can be connected and a set 3 of electronic devices are connected. The AC adapter 2 has a signal unit 2
a, a detection unit 2b, and an operation unit 2c.
A detection unit 3a and a signal unit 3b are included.

In this embodiment, the characteristics of the AC adapter are double characteristics. For example, as shown in FIG.
Adapter can output a small current low power output to a small power output from the no-load (I ₀ ~I _1), and a large current high power output of up to I ₁ '~I _3.

FIG. 2B shows an example of an AC adapter having a dual characteristic. DC power is supplied from input terminals IN-A and IN-B. The input terminal IN-A is connected to the anode of the diode 5, and the cathode of the diode 5 is connected to the input terminal I.
The capacitor 6 is inserted between NB. Further, the cathode of the diode 5 is connected to the small power supply 7 and the large power supply 8. The small power supply 7 includes a constant current circuit 7a and a constant voltage circuit 7b, and the large power supply 8 includes a constant current circuit 8a and a constant voltage circuit 8b. The constant current circuit 7a, the constant voltage circuit 7b, the constant current circuit 8a, and the constant voltage circuit 8b have an input terminal IN-B and an output terminal OUT, respectively.
-B. By controlling the on / off of the switch 9, the output of the high power circuit 8 is output from the output terminal OUT.
-A, OUT-B are controlled.

FIG. 3A shows a first example to which the present invention is applied in which a code signal is transmitted from a set of electronic devices to an AC adapter using the characteristics of I _{0 to} I ₁ . This FIG. 3A
Is a device in which a DC power supply 11 from an AC adapter charges a set of secondary batteries BT. The positive side of the low-power DC power supply 11 a is connected to the detection unit 13 via the switch 12.
And the negative electrode side is grounded. The high-power DC power supply 11b is connected to the detection unit 13 via the switch 12, and the negative side is grounded. The signal detected by the detection unit 13 is supplied to a switching unit 14 for switching the output characteristics from the AC adapter according to the signal. In the switching unit 14, a control signal for switching the switch 12 is supplied to the switch 12. In the switch 12, the DC power supply 11a or 11b is selected according to the supplied control signal. Selected DC power supply 11a or 11b
Supplies power to the set side.

The power supplied from the AC adapter is supplied to the collector of the transistor 15, the Zener diodes 16, 1
9, the signal transmission unit 17 and the switch circuit 20
Supplied to An anode of the Zener diode 16;
The base of the transistor 15 is connected via the switch 18. The emitter of transistor 15 is grounded. The signal transmission unit 17 controls the on / off operation of the switch 18. The anode of the Zener diode 19 is supplied to the switch circuit 20. Zener diode 19
Is turned on, the switch circuit 20 is turned on. The positive side of the secondary battery BT is connected to the switch circuit 20, and the negative side is grounded.

The operation of FIG. 3A will be described. When the set of electronic devices and the AC adapter are connected, first, in the AC adapter, the low-power DC power supply 11a is selected by the switch 12, and the small power is output to the set side. On the set side, small power is supplied from the AC adapter.
In order to output large power from the adapter and charge the secondary battery BT, a code signal for identifying a power supply adapter to be connected is transmitted. At this time, the signal transmission unit 1
7 turns on the switch 18. Therefore, when the Zener diode 16 of the signal generation reference voltage is turned on and the switch 18 is turned on, the transistor 1
5 is turned on, and one signal line voltage becomes a Zener voltage. When the switch 18 is off, the transistor 1
5 is turned off, and the signal line voltage increases.

That is, as shown in FIG. 3B, a code signal having a clock-like waveform is generated on one signal line. The detecting unit 13 detects a transmitted code signal. When the code signal is determined to be a code signal from a set having a correct correspondence relationship with the AC adapter, the switching unit 1
In 3, by switching the switch 12,
The characteristics output from the AC adapter are switched from the small current and small power output of the DC power supply 11a to the large current and large power output of the DC power supply 11b. When a large current and large power are supplied from the AC adapter, the Zener diode 19 for detecting large power, which has been in the off state, is turned on, and the switch circuit 20 is turned on. Then, the secondary battery BT is charged by the supplied large current and large power. At this time, as an example, AC
The output from the adapter is set to 4.7 V to 4.9 V / 0.5 A, and the set side generates 4.2 V / 0.5 A from the output to charge the secondary battery BT.

Here, the code signal detected on the AC adapter side is a set of electronic devices having a correct correspondence with the AC adapter when the number of pulses, cycle, frequency, pulse width or number of pulses match. Is determined.
If it is determined that the AC adapter and the set do not have a correct correspondence, the operation state of the small current and small power is maintained.

FIG. 4A shows a second example to which the present invention is applied in which a code signal is transmitted from an electronic device set to an AC adapter by utilizing the characteristics of I _{0 to} I ₁ . The AC adapter side has the same configuration as that of FIG. 3A described above, and a description thereof will be omitted. The power supplied from the AC adapter is supplied to the collector of the transistor 15, the Zener diodes 16, 19,
21 and is supplied to the switch circuit 20.
The anode of the Zener diode 16 and the transistor 1
5 is connected via a switch 18. The emitter of transistor 15 is grounded. The anode of Zener diode 21 is grounded via resistors 22 and 23. A midpoint potential extracted from a connection point between the resistors 22 and 23 is supplied to the time constant unit 24. Time constant part 2
In step 4, whether the switch 18 is connected to the Zener diode 16 or to the ground after a predetermined time constant is controlled. The anode of the Zener diode 19 is
It is supplied to the switch circuit 20. Zener diode 1
When the switch 9 is turned on, the switch circuit 20 is turned on. The positive side of the secondary battery BT is connected to the switch circuit 20, and the negative side is grounded.

In the second example shown in FIG. 4A, when the AC adapter and the set are connected, the Zener diode 21
Is turned on, and after a predetermined time constant, the switch 18 is connected to the Zener diode 16 side. The zener diode 16 of the signal generation reference voltage is turned on, and the transistor 15 is turned on. As a result, a code signal is generated from the set side and transmitted to the AC adapter side. On the AC adapter side receiving the code signal,
If it is determined that the connected set is a set of electronic devices having a correct correspondence with the AC adapter, the switch 1 is used to output a large current and a large power from the DC power supply 11b.
Switch 2. On the set side supplied with the large current and large power, the Zener diode 19 for detecting large power is turned on, the switch circuit 20 is turned on, and the secondary battery BT is charged. The switch 18 on the set side
Is switched to the ground side after a predetermined time constant.

FIG. 4B shows a third example to which the present invention is applied in which a code signal is transmitted from an electronic device set to an AC adapter using the characteristics of I _{0 to} I ₁ . The AC adapter side has the same configuration as that of FIG. 3A described above, and a description thereof will be omitted. The power supplied from the AC adapter is supplied to the collector of the transistor 15, the cathodes of the Zener diodes 16 and 19, the voltage detector 25, and the switch circuit 20. The anode of the Zener diode 16 and the base of the transistor 15 are connected via a switch 18. The emitter of transistor 15 is grounded. The voltage detection unit 25 detects a voltage to be supplied, and supplies a signal to the signal generation unit 26 to turn on the switch 18 when the voltage reaches a predetermined voltage. The signal generator 26 controls the on / off operation of the switch 18 according to the supplied signal. The anode of the Zener diode 19 is supplied to the switch circuit 20. When the Zener diode 19 is turned on, the switch circuit 20 is turned on. The positive electrode side of the secondary battery BT is connected to the switch circuit 2
0, and the negative electrode side is grounded.

In the third example shown in FIG. 4B, when the AC adapter and the set are connected, the voltage is detected by the voltage detecting unit 25, and when the voltage reaches a predetermined voltage, the signal generating unit 26 is turned off. The switch 18 is turned on via the switch. At this time, the Zener diode 16 of the signal generation reference voltage is turned on, and the transistor 15 is turned on. As a result, a code signal is generated from the set side and transmitted to the AC adapter side. On the AC adapter side receiving the code signal, if it is determined that the connected set is a set of electronic devices having a correct correspondence with the AC adapter, a large current and a large power from the DC power supply 11b are output. The switch 12 is switched. On the set side supplied with the large current and large power, the Zener diode 19 for detecting large power is turned on, the switch circuit 20 is turned on, and the secondary battery BT is charged. When the voltage detector 25 detects that a large current and a large power have been supplied, the switch 18 is turned off via the signal generator 26.

FIGS. 5 and 6 show examples of the switch circuit 20 shown in FIGS. FIG. 5 is an example in which the on / off operation of the switch circuit 20 is controlled by voltage detection. As shown in FIG. 5A, the cathode of the Zener diode 19 for detecting high power is connected to the source of the FET1, and a resistor R1 is inserted between the drain of the FET1 and the collector of the transistor Tr1. Transistor T
The base of r1 is connected to the anode of Zener diode 19, and the collector is connected to the gate of FET1. The emitter of the transistor Tr1 is grounded. F
A diode D1 is inserted between the source and the drain of ET1. In FIG. 5A, since the on / off operation of the switch circuit 20 is controlled by detecting the voltage, as shown in FIG.
<Detection is easier if the relationship of voltage V3 is established. At this time, the voltage V3 is
The Zener voltage becomes 9.

FIG. 6 illustrates the detection of voltage and current.
This is an example of controlling the on / off operation of the switch circuit 20. As shown in FIG. 6A, a resistor R2 is inserted between the cathode of the Zener diode 19 for detecting high power and the source of the FET1. Further, the resistor R2 is inserted between the emitter and the base of the transistor Tr2. The anode of the Zener diode 19 and the collector of the transistor Tr2 are connected to the base of the transistor Tr1. The collector of the transistor Tr1 is connected to the gate of the FET1, and the emitter is grounded. A diode D1 is inserted between the source and the drain of the FET1.
In FIG. 6A, the voltage is detected by the Zener diode 19, the current is detected by the resistor R2 and the transistor Tr2, and the respective results are expressed by the transistor T
r1 to control the on / off operation of the FET1.

In the circuit shown in FIG. 6A, when the on / off operation of the switch circuit 20 is to be controlled, the characteristic of the small power and the characteristic of the large power may be in the relationship shown in FIG. 5B or in FIG. 6B. The relationship shown may be good. That is,
FIG. 5A shows ON / OFF of the switch circuit 20 only when the voltage is detected.
To control the OFF operation, the voltage V2 is controlled as shown in FIG.
<If the relationship of the voltage V3 is not established, the switch circuit 20
It is difficult to control the on / off operation of the switch circuit 20. On the other hand, FIG. 6A shows the control of the on / off operation of the switch circuit 20 by detecting the voltage and the current. As shown, even if the relationship of voltage V2> voltage V3 is established, the ON / OFF operation of the switch circuit 20 can be easily controlled.

FIG. 6C shows another example of controlling the on / off operation of the switch circuit 20 by detecting the voltage and the current. As shown in FIG. 6C, a resistor R2 is inserted between the cathode of the Zener diode 19 for detecting high power and the source of the FET2. Further, the resistor R2 is inserted between the emitter and the base of the transistor Tr2.
The anode of the Zener diode 19 and the transistor T
The collector of r2 is connected to the base of transistor Tr1. The collector of the transistor Tr1 is FET2
Is connected to the gate of FET3, and the emitter is grounded. A diode D2 is inserted between the source and the drain of the FET2. A diode D3 is inserted between the source and the drain of the FET3. The drain of FET2 is connected to the drain of FET3, and a resistor R3 is inserted between the connection point and the collector of transistor Tr1. 6C, similarly to FIG. 6A, the voltage is detected by the Zener diode 19, the current is detected by the resistor R2 and the transistor Tr2, and the respective results are supplied to the transistor Tr1.
2 and the on / off operation of the FET 3 is controlled.

When transmitting a code signal with low power, FIG.
The configuration shown in FIG. A constant voltage,
It has a constant current power supply, and has a constant voltage and constant current load on the set side of the electronic device. The AC adapter includes a DC power supply 11 having a negative electrode grounded, and a constant current source 27 to which the positive electrode of the DC power supply 11 is connected. On the set side of the electronic device, a constant current source 28, a switch 29 connected between the constant current source 28 and the cathode side of the Zener diode 30, and a Zener diode 30 whose anode is grounded are configured. You. A code signal is generated by the on / off operation of the switch 29.

FIG. 8A is a block diagram of a more specific configuration corresponding to FIG. On the AC adapter side, the constant current circuit 31 supplies a constant current to the set side, and the constant voltage circuit 32 supplies a constant voltage to the set side. The supplied constant current and constant voltage are supplied to a constant current load circuit 36 and a constant voltage load circuit 37 via a switch 35.
At this time, by turning on / off the switch 35, the voltage becomes a code signal having a clock-like waveform as shown in FIG. 8C. This code signal is, as shown in FIG.
The transition of the voltage is detected by the detection circuit 33. If it is determined that the detected code signal is a set of electronic devices having a correct correspondence with the AC adapter, the switching circuit 3
4 switches the voltage output from the AC adapter. At this time, the low level of the code signal is a voltage at which the circuit of the present invention operates.

FIG. 9 is a block diagram showing a first embodiment of a signal transmission system including an AC adapter and a set of electronic devices according to the present invention. First, on the AC adapter side, the negative side of the DC power supply 41 is grounded, and the positive side is connected to the emitters of the transistors 42 and 49. The collector of the transistor 42 is connected to the voltage detection circuit 44 via the resistor 43, and the base is connected to the control circuit 45. In the resistor 43, a current is detected, and a voltage detection circuit 44
Then, the output voltage is detected. The detected current and output voltage are supplied to the control circuit 45. Control circuit 45
Is the current detected by the resistor 43 and the voltage detection circuit 4
On / off operation of the transistor 42 is controlled based on the output voltage from the control circuit 4 and the control signal from the stop circuit 51.

The output voltage from the voltage detection circuit 44 is supplied to a series circuit of resistors 46 and 47 inserted between the voltage detection circuit 44 and the ground. Resistors 46 and 47
The midpoint potential (−ΔV) is supplied to the control circuit 48 from the connection point. The resistors 46 and 47 give priority, and in this embodiment, the transistor 49 has a higher priority than the transistor 42. Control circuit 48 is connected to the base of transistor 49, and the collector of transistor 49 is connected to voltage detection circuit 44 via resistor 50. The current is detected by the resistor 50, and the detected current is supplied to the control circuit 48 and the stop circuit 51.
That is, in the control circuit 48, the on / off operation of the transistor 49 is controlled based on the current detected by the resistor 50 and the midpoint potential of the resistors 46 and 47.

In the stop circuit 51, a control signal for controlling the on / off operation of the transistor 42 is supplied to the control circuit 45 based on the current detected by the resistor 50 and the signal from the stop release circuit 53. . The signal receiving circuit 52 connected to the voltage detecting circuit 44 receives the code signal transmitted from the set side of the electronic device, and supplies the reception of the code signal to the stop release circuit 53. In the stop release circuit 53, a signal is supplied to the stop circuit 51 to release the stopped charging.

On the set side of the electronic device, the charging voltage supplied by the voltage detecting circuit 54 is detected, and the detected charging voltage is supplied to the stop circuit 55 and the switch control circuit 61. The stop circuit 55 turns on / off the switch of the switch circuit 57 in accordance with the supplied charging voltage.
A signal for performing the OFF operation is generated, and the switch circuit 5
7. The reference voltage detection circuit 56 detects a reference voltage for signal generation, and supplies the detected reference voltage to the switch circuit 57. In the switch circuit 57, on / off operation is controlled in accordance with a signal from the stop circuit 55, and the reference voltage from the reference voltage circuit 56 is applied to the control circuit 5
8.

The collector of transistor 60 is connected to voltage detection circuit 54, and the base is connected to control circuit 58. A resistor 5 is connected between the emitter of transistor 60 and ground.
9 is inserted. This resistor 59 detects a current,
The detected current is supplied to the control circuit 58. The control circuit 58 controls the transistor 60 based on the control signal from the switch circuit 57 and the current detected from the resistor 59.
On / off operation is controlled. By controlling the on / off operation of the transistor 60, a code signal is generated. The generated code signal is A
It is transmitted to the C adapter.

In the switch control circuit 61 to which the voltage detected by the voltage detection circuit 54 is supplied, the supplied voltage is
When it is determined that the power is low when the AC adapter and the set are connected, a control signal for turning off the switch circuit 62 is supplied to the switch circuit 62. When it is determined that the voltage supplied from the voltage detection circuit 54 is high power, a control signal for turning on the switch circuit 62 for charging a secondary battery (not shown) is supplied to the switch circuit 62. . Further, the switch circuit 57 is turned off via the stop circuit 55 to stop signal generation. In the switch circuit 62,
An on / off operation is performed according to the supplied control signal.

FIG. 10 shows a transition diagram of an example of the voltage / current at this time. As shown in FIG.
9 turns on, and the AC adapter operates as a low power output indicated by I ₁ and I ₂ . At this time, the switch circuit 6
2 is an off state. When the code signal is transmitted from the set side and the AC adapter side determines that the set has a correct correspondence with the AC adapter, the transistor 42 is turned on, and the output is switched to the high power output indicated by I ₁ and I _3. . The switch circuit 62 is turned on.

A first embodiment of the processing of the present invention is shown in FIG.
Is shown in the flowchart of FIG. In step S1, the AC adapter operates with low power. In step S2, the AC
The adapter is connected to the set of electronic devices. Step S
In 3, the code signal is generated by the constant voltage / current switch circuit on the set side and transmitted to the AC adapter side. In step S4, a voltage is detected by the reference voltage detection circuit 56. In step S5, it is determined whether or not the detected voltage is equal to or higher than a signal generation reference voltage for generating a signal to be transmitted from the set side. If it is determined that the voltage is equal to or higher than the reference voltage, the control proceeds to step S6. In step S6, the signal generator on the set side operates.

In step S7, a power supply capable of generating a signal is detected by the power supply detection circuit 54. In step 8, it is determined whether or not the power source cannot generate a signal from the set side. That is, in step S8, the set side determines whether or not the set connected to the AC adapter has a correct correspondence with the AC adapter. When it is determined that the signal cannot be generated, the control proceeds to step S9, and when it is determined that the signal can be generated, the control proceeds to step S10. In step S9, the switch circuit 62 is turned off, and the supplied power is turned off. Then, the control moves from step S9 to step S7. Also, as shown by the dotted line in FIG.
The control may shift from step 9 to step S4.

In step S10, the AC adapter detects a code signal from the set side. Step S11
Then, the AC adapter determines whether the detected code signal is a code signal from a set of a correct correspondence relationship with the AC adapter, and determines that the detected code signal is a code signal from a set of a correct correspondence relationship with the AC adapter. Then, the control shifts to step S12, and when it is determined that the code signal is not from a set having a correct correspondence with the AC adapter, the control shifts to step S10.

In step S12, the generation of the code signal from the set side is stopped. In step S13,
The output of the AC adapter is switched for high power. Then, in step S14, the current is detected. In step S15, it is determined whether or not the detected current is equal to or less than the reference value. If it is determined that the current is equal to or less than the reference value, the control proceeds to step S16. Move on. In step S16, the output of the AC adapter is switched to low power, and this flowchart ends.

As described above, according to the present invention, a code signal is first transmitted from a set of electronic devices, and when a set connected from the code signal is determined to be a set having a correct correspondence with the AC adapter. On the AC adapter side, the operation is switched from the low power operation to the high power operation.
For this reason, if the set and the AC adapter do not have a correct correspondence relationship, no large power is output from the AC adapter.

The algorithm for detecting the voltage in step S4 will be described with reference to the flowchart of FIG.
In step S21, the reference voltage detection circuit 56
Voltage is detected. In step S22, it is determined whether the detected voltage is equal to or higher than the voltage V1. When it is determined that the detected voltage is equal to or higher than the V1 voltage, the control proceeds to steps S23 and S29, and when it is determined that the detected voltage is lower than the V1 voltage, the control returns to step S21. This V1
The voltage is, for example, a reference voltage for signal generation. In step S29, the operation of the detection circuit is switched from the voltage V1 to the voltage V2.

In step S23, the constant current and constant voltage load circuit operates. In step S24, the voltage detection circuit 5
At 4, a voltage is detected. In step S25,
It is determined whether the detected voltage is equal to or higher than the V2 voltage. When it is determined that the detected voltage is equal to or higher than the voltage V2, the control proceeds to step S26, and when it is determined that the shot is less than the voltage V2, the control proceeds to step S30. Step S26
In, the switching operation from the voltage V1 to the voltage V2 is detected. In step S27, it is determined whether the detected voltage has been switched from the voltage V1 to the voltage V2. If it is determined that the switching has been performed, the control proceeds to step S28. If it is determined that the switching has not been performed, the control proceeds to step S30. In step S28, the switch circuit is turned on, and the constant current / constant voltage load circuit is stopped.

In step S30, after a predetermined time constant,
In step S31, the constant current / constant voltage load circuit is stopped. Then, the flowchart of this algorithm ends.

FIG. 13 is a block diagram showing a second embodiment of the signal transmission system of the present invention between an AC adapter and electronic equipment.
Shown in DC power is supplied from input terminals IN-A and IN-B. The input terminal IN-A, the emitter of the transistor 71, and the emitter of the transistor 79 are connected, and the input terminal IN-B is grounded. The base of the transistor 71 is connected to the control circuit 76, and the collector is connected to the resistor 72.
Are supplied to the voltage detection circuits 73 and 74 via The current is detected by the resistor 72, and the detected current is supplied to the control circuit 76 via the switch 73. Voltage detection circuits 74a and 74b detect a predetermined voltage value. The detected voltage value is supplied to a control circuit 76 and a voltage dividing (-ΔV) circuit 77 via a switch 75. The voltage dividing circuit 77 is a circuit for giving priority, and the voltage divided by the voltage dividing circuit 77 is supplied to the control circuit 78.

The collector of the transistor 79 is connected to a resistor 80
Is connected to the voltage detection circuit 74 via the. A current is detected by the resistor 80, and the detected current is transmitted to the control circuit 78.
And a stop circuit 81. Voltage detection circuit 7
The signal detection circuit 83 connected to 4a and 74b receives a code signal transmitted from the set side of the electronic device. When the code signal is received, the signal is supplied to the switching circuit 84 and the stop release circuit 82. Switching circuit 8
In 4, the switches 73 and 75 are switched to switch the detected current and voltage. The stop release circuit 82 supplies a control signal for controlling the stop circuit 81 to the stop circuit 81. The stop circuit 81 supplies a control signal for controlling the on / off operation of the transistor 71 to the control circuit 76 based on the current detected by the resistor 72 and the control signal from the stop release circuit 82.

The control circuit 76 controls the on / off operation of the transistor 71 based on the current detected by the resistor 72, the voltage from the voltage detection circuit 74, and the control signal from the stop circuit 81. Also, the control circuit 78
Then, the current detected by the resistor 72 and the voltage dividing circuit 7
7 based on the voltage from
Controls off operation.

In this example, the set side includes constant voltage circuits 85a and 85b, a switch 86 and a constant current circuit 87. The constant voltage circuits 85a and 85
b is connected to the voltage detection circuit 74. Constant voltage circuit 85
a and 85b each supply a different voltage value.
The constant voltage circuits 85a and 85b are connected to a constant current circuit 87 via a switch 86. The constant current circuit 87 is supplied with a predetermined current value. The voltage and current set by the constant voltage circuit 85 and the constant current circuit 87 are supplied from the set side to the AC adapter side as code signals.
That is, by switching the switch 86, a code signal to be supplied can be generated and supplied to the AC adapter side.

FIG. 14 shows a second embodiment of the processing according to the present invention.
Is shown in the flowchart of FIG. In step S41, the AC adapter is activated, and in step S42, the AC adapter operates in the low power mode. In step S43, the A
The C adapter is connected to the set (load) of the electronic device.
In step S44, a code signal (load signal) having a clock-like waveform is transmitted from the constant voltage circuit 85 and the constant current circuit 87 on the set side. In step S45, AC
A code signal (voltage) transmitted from the set side is detected by the signal detection circuit 73 on the adapter side. In step S46, it is determined whether the switches 73 and 75 are connected to the terminal on the a side or the terminal on the b side according to the detected voltage. If it is determined, control is transferred to step S47, and if it is determined that the terminal is connected to the b-side terminal, control is transferred to step S48.

In step S47, the switches 73 and 75 are switched to the terminals on the a side, and in step S48, the switches 73 and 75 are switched to the terminals on the b side. In step S49, the transistor 71 is turned on. In step S50, the code signal from the set side is stopped. In step S51, a current is detected. In step S52, it is determined whether or not the detected current is equal to or less than the reference value. If it is determined that the detected current is equal to or less than the reference value, the control proceeds to step S42,
If it is determined that the value is larger than the reference value, the control moves to step S51.

The aforementioned constant voltage circuits 85a and 85b
And the constant current circuit 87, the characteristics usually become as shown in FIG. 15A. However, when the voltage of the part a and the part b in FIG. 15B is detected by the signal detection circuit 83 on the AC adapter side, the switches 73 and 75 are switched, and the on / off operations of the transistors 71 and 79 are controlled. The characteristics are as shown in FIG. 15B.

FIG. 16 shows an example of voltage and current characteristics. First, the AC adapter side is output with low power as shown in FIG. 16A, receives the code signal from the set side,
Only when it is determined that the set has a correct correspondence with the AC adapter, as shown in FIG. 16B, the output from the AC adapter is switched to high power.

FIG. 17 shows a third embodiment of a signal transmission system between an AC adapter and electronic equipment to which the present invention is applied. On the AC adapter side, input terminals IN-A, IN
DC power is supplied from -B. The power is supplied to the small power supply circuit 91 and the large power supply circuit 92. When the switch 93 is turned on, the output of the large power supply circuit 92 is supplied to the set side. The output of the small power supply circuit 91 is connected to the cathodes of the Zener diodes 94 and 97, and the resistors 95 and 9 are connected between the anode of the Zener diode 94 and the input terminal IN-B.
6 are inserted in series. Similarly, Zener diode 9
7 and the input terminal IN-B, resistors 98 and 99 are inserted in series. A connection point between the resistors 95 and 96 and one terminal of the comparator 100 are connected.
And 99 are connected to the other terminal of the comparator 100. The output of the comparator 100 is supplied to the control circuit 101. The control circuit 101 controls the ON / OFF state of the switch 93 based on the supplied output result.

On the set side, one end of the resistor 102, one end of the switch 104, and one end of the switch 108 are connected to the output of the small power supply circuit 91. The collector of the transistor 103 is connected to the other end of the resistor 102, and the emitter is connected to the base via the resistor 107. The cathode of the Zener diode 105 is connected to the other end of the switch 104, and the anode is connected to the base of the transistor 103 via the resistor. A set load 109 is inserted between the switch 108 and the transistor 103. On the set side, a code signal is transmitted by the resistor 102 and the transistor 103, and the load power is reduced.

The operation of the set of the AC adapter and the electronic device shown in FIG. 17 will be described. First, when the AC adapter and the set are connected, the small power supply circuit 91 operates. When small power is supplied from the AC adapter side, the set side turns on / off the transistor 103 and transmits a code signal (voltage). The transmitted code signal is
It is detected by a Zener diode 94, resistors 95 and 96 and a Zener diode 97 and resistors 98 and 99.
As an example, a zener diode 94, resistors 95 and 96
Thus, a low-level voltage is detected, and a high-level voltage is detected by the Zener diode 97 and the resistors 98 and 99. If the control circuit 101 determines from the detection result from the comparator 100 that the set is a correct correspondence with the AC adapter, the control circuit 101 controls the switch 93 to an ON state and supplies the output of the high power supply circuit 92 to the set side. .

The control algorithm at this time will be described with reference to the flowchart of FIG. In step S61, input power is turned on. In step S62, the small power supply circuit 91 is operated. In step S63, the load signal on the set side operates, and the code signal is transmitted.
In step S64, the AC adapter detects a code signal, that is, a voltage having a clock-like waveform. In step S65, it is determined whether or not the detected code signal is a code signal from a set of electronic devices in a correct correspondence with the AC adapter, and is determined to be a code signal from a set in a correct correspondence with the AC adapter. Then, the control shifts to step S66, and if it is determined that the code signal is not from the set of the correct correspondence with the AC adapter, the control shifts to step S64.

In step S66, it is determined whether to operate the small power supply circuit 91 or the large power supply circuit 92 according to the code signal supplied from the set side, and the small power supply circuit 91 is operated. If so, step S
When the control is shifted to 70 and the large power supply circuit 92 is operated, the control is shifted to step S71. In step S67, the large power circuit 92 operates. In step S68,
The current is detected, and in step S69, it is determined whether the detected current is equal to or less than the reference value. When it is determined that the detected current is equal to or less than the reference value, the control proceeds to step S71, and when it is determined that the current is greater than the reference value, the control proceeds to step S68. In step S71, the low power supply circuit 91 operates, and in step S71, the low power supply circuit 91 is stopped. Then, control proceeds to step S62.

In this flowchart, step S69
In the above, when the detected current is equal to or smaller than the reference value, the control is shifted to step S71. However, when the detected current is equal to or smaller than the reference value, the control may be shifted to step S62. At this time, the control in step S71 is omitted.

FIG. 19 shows a basic block diagram of the embodiment of the present invention. DC power is supplied from input terminals IN-A and IN-B. The input terminal IN-A is connected to the small power supply circuit 111 and the large power supply circuit 113. The small power supply circuit 111 is a power supply for transmitting a code signal from a set side of an electronic device connected to the AC adapter. The high power supply circuit 113 is a power supply for charging the set side of the electronic device connected to the AC adapter. The switch 112 is inserted between the output of the small power supply circuit 111 and the output terminal OUT-A. This switch 112 has an input terminal IN-B and an output terminal OUT.
−B, the current detection circuit 115 inserted between
Controlled. Further, the current detection circuit 115 includes the control circuit 1
The detected current value is also supplied to 18.

Output of high power supply circuit 113 and output terminal O
The switch 114 is inserted between UT-B. The switch 117 and the signal detection circuit 116 are inserted in series between the output terminals OUT-A and OUT-B. The signal detection circuit 116 detects a code signal from the connected set side, and the detected code signal is supplied to the control circuit 118. The control circuit 118 controls the on / off state of the switch 114 based on the current value from the current detection circuit 115 and the signal from the signal detection circuit 116.

The small power supply circuit 111 and the large power supply circuit 1
FIG. 20 shows an example of the configuration with the X.13. As shown in FIG. 20A, the small power supply circuit 111 includes a small current constant current circuit 111.
a and a constant voltage circuit 111b. FIG. 2
As shown in FIG. 0B, the large power supply circuit 113 includes a large current constant current circuit 113a and a constant voltage circuit 113b. At this time, the current I ₁ outputted from the small current constant current circuit 111a and the current I ₂ outputted from the large current constant current circuit 113a satisfy a relationship of current I ₁ <current I ₂ . The voltage V ₁ output from the constant voltage circuit 111b and the voltage V ₂ output from the constant voltage circuit 113b are output according to the voltage-current characteristics as described above. It changes and does not have a fixed relationship.

The operation algorithm of the AC adapter at this time will be described with reference to the flowchart of FIG. In step S51, the AC adapter is operated. Step S
At 52, the operation of the large power supply circuit 113 is stopped.
Then, in step S53, the small power supply circuit 111 is operated, and the switches 112 and 117 are turned on. In step S54, the signal detection circuit 11
6 is operated to detect a code signal from the set side.
In step S55, the detected code signal is
It is determined whether or not the code signal is from a set having a correct correspondence with the adapter. If it is determined that the code signal is from a set having a correct correspondence with the AC adapter, the control proceeds to step S56, and the code from the set is transferred. If it is determined that the signal is not a signal, the control moves to step S54.

In step S56, it is determined whether the switches 112 and 117 are turned off or the switch 114 is turned on in accordance with the detected code signal. If it is determined that the switches 112 and 117 are turned off, step S
When the control is shifted to 61 and it is determined that the switch 114 is turned on, the control is shifted to step S57. In step S61, the small power supply circuit 111 and the signal detection circuit 1
16 is stopped, and the switches 112 and 117 are turned off. Then, from step S61 to step S
The control moves to 53.

In step S57, the high power supply circuit 11
3 is operated, and the switch 114 is turned on. In step S58, a current is detected. Step S59
In, it is determined whether the detected current is below the reference value,
When it is determined that the detected current is equal to or less than the reference value, the control proceeds to step S60, and when it is determined that the detected current is greater than the reference value, the control proceeds to step S58. In step S60, the high power supply circuit 113 is stopped. Step S6
In 2, the small power supply circuit 111 and the signal detection circuit 116 are operated, and the switches 112 and 117 are turned on. Then, the control moves to step S53.

In the flowchart of FIG. 21, after the control in step S60, the process is shifted to the control in step S53 via the control in step S62. However, the control is not performed in step S62 but to the control in step S53. The processing may be shifted. At this time, step S62
Is omitted. Further, in the control of step S59, when the current is equal to or smaller than the reference value, the process may shift to the control of step S62. At this time, the control in step S60 is omitted.

FIG. 22 shows a basic block diagram of an embodiment of the above-described AC adapter of FIG. 19 and a set of electronic devices in a correct correspondence. Output terminal OUT of AC adapter
-A and OUT-B are connected to the input terminal on the set side. The signal voltage detection circuit 121 includes an output terminal OUT-A,
OUT-B. The signal voltage detection circuit 191 detects a code signal transmitted to the AC adapter. Parallel constant voltage circuit 122, current detection circuit 1
23 and the switch 124 are connected in series to the output terminal OUT-.
A, and inserted between OUT-B. The result of the code signal detected by the signal voltage detection circuit 121 is supplied to the parallel constant voltage circuit 122. In the parallel type constant voltage circuit 122,
A constant voltage is supplied, and the current detection circuit 123 detects the current at that time. The detected current is supplied to the switching circuit 125.

The voltage detection circuit 126 has an output terminal O
It is inserted between UT-A and OUT-B. The voltage detection circuit 126 detects the terminal voltage of the set load. The detected voltage is supplied to the switching circuit 125. The switching circuit 125 controls switching of the switches 124 and 127 based on the current from the current detection circuit 123 and the voltage from the voltage detection circuit 126. The switch 127 and the set load 128 are connected to the output terminals OUT-A, O
Inserted between UT-B.

Here, the parallel type constant voltage circuit 122 is shown in FIG.
This will be described with reference to the circuit diagram shown in FIG. Input terminal IN-As, cathode of Zener diode 131 and transistor 1
34 collectors are connected. Zener diode 1
A resistor 13 is connected between the anode of the input terminal 31 and the input terminal IN-Bs.
3 is inserted. A resistor 132 is inserted between the anode of the Zener diode 131 and the base of the transistor 134. The emitter of the transistor 134 and the input terminal I
A resistor 136 is inserted between N-Bs. Comparator 13
One is connected to the emitter of the transistor 134, and the other is connected to the input terminal IN-Bs. A current is detected from the output of the comparator 137. The collector of transistor 135 is connected to the base of transistor 134, and the emitter of transistor 135 is connected to input terminal I
Connected to N-Bs.

The operation algorithm of the block diagram on the set side shown in FIG. 22 will be described with reference to the flowchart of FIG. In step S71, the signal voltage detection circuit 121 operates to detect a code signal transmitted from the set side. In step S72, the switch 124 is turned on, and the parallel constant voltage circuit 122 operates. Step S
At 73, the current is detected by the current detection circuit 123. In step S74, it is determined whether or not the detected current is equal to or greater than the reference value. If it is determined that the detected current is equal to or greater than the reference value, the control proceeds to step S75, and if it is determined that the detected current is smaller than the reference value, The control moves to step S73.

In step S75, the switching circuit 125
Operates to control the switches 124 and 127. In step S76, the switch 124 is turned off. In step S77, the switch 125 is turned on after a predetermined time constant after the switch 124 is turned off. In step S78, the voltage detection circuit 126
The voltage is detected at. In step S79, it is detected whether or not the detected voltage is equal to or lower than the reference value. If it is determined that the detected voltage is equal to or lower than the reference value, the control proceeds to step S80, and if it is determined that the detected voltage is higher than the reference value, The control moves to step S78.

In step S80, the switching circuit 125
Operates to control the switches 124 and 127. In step S81, the switch 124 is turned on. In step S82, the switch 125 is turned off after a predetermined time constant after the switch 124 is turned on. Then, the control moves from step S82 to step S72.

FIG. 25 is a block diagram showing an embodiment of the AC adapter according to the present invention. DC power is supplied from input terminals IN-A and IN-B. The input terminal IN-B and the output terminal OUT-B are connected. The supplied DC power is supplied to the current detection circuit 141 and the large current constant current circuit 144. The current detection circuit 141 detects an input current value, and outputs the detected current value to the switch control circuit 150.
Supplied to The small current constant current circuit 142 outputs a small constant current. The constant voltage circuit 143 outputs a constant voltage. The small current / constant current circuit 142 and the constant voltage circuit 143 constitute a small power supply circuit as described above. The large current constant current circuit 142 outputs a large constant current. The constant voltage circuit 143 outputs a constant voltage. The large current constant current circuit 142 and the constant voltage circuit 143 constitute a large current power supply circuit as described above. Switch 1 between constant voltage circuit 143 and input terminal IN-B
48 is inserted.

The voltage detection circuit 146 has an output terminal OUT-
A, which is inserted between OUT and B, is detected. The detected voltage is divided by a voltage dividing (-ΔV) circuit 14.
7 and the constant voltage circuit 145. Voltage dividing circuit 14
7 is a circuit for giving priority. The signal voltage detection circuit 149 includes output terminals OUT-A and OUT-A.
-B and detects a code signal (voltage) transmitted from the set side. The detected code signal is supplied to the switch control circuit 150. The switch control circuit 150 controls the on / off state of the switch 148 based on the current value from the current detection circuit 141 and the signal from the signal voltage detection circuit 149.

The operation algorithm of the block diagram of the AC adapter shown in FIG. 25 will be described with reference to the flowchart of FIG. In step S81, the power supply which is given priority by the voltage dividing circuit 147 operates. In the example of FIG. 25, the low power supply operates. In step S82, the signal voltage detection circuit 149 detects a code signal (voltage) transmitted from the set side. In step S83,
From the detected code signal, it is determined whether or not the set is a correct correspondence with the AC adapter. If it is determined that the set is a correct correspondence with the AC adapter, the control is shifted to step S84, If it is determined that the set is not a correct correspondence with the adapter, the control moves to step S82.

In step S84, the switch control circuit 1
50 is operated, and the switch 148 is turned on. In step S85, the large current constant current circuit 144 and the constant voltage circuit 145 are operated. In step S86, the current of the power supply to which the priority is given by the voltage dividing circuit 147 is detected. In step S87, it is determined whether or not the detected current value is equal to or smaller than the reference value. If it is determined that the detected current value is equal to or smaller than the reference value, the control proceeds to step S88, where it is determined that the current value is larger than the reference value. If so, step S
The control moves to 86. In step S88, the switch 14
8 is turned off. In step S89, the operations of the large current constant current circuit 214 and the constant voltage circuit 145 are stopped. Then, control is performed from step S89 to step S8.
Move to 1.

FIG. 2 is a circuit diagram of an example to which the present invention is applied.
FIG. DC power is supplied from input terminals IN-A and IN-B. The input terminal IN-B is connected to the output terminal OUT-B
Connected to Input terminal IN-A and transistor Tr1
The resistor R11 is inserted between the first emitter and the first emitter. Resistance R
1 is inserted between the respective inputs of the comparator CMP11. The detected current is output from the output terminal TM11 of the comparator CMP11.

A resistor R12 is inserted between the collector of the transistor Tr11 and the output terminal OUT-A. The base of the transistor Tr11 is connected to the collector of the transistor Tr13. A resistor R13 is inserted between the emitter of the transistor Tr13 and the input terminal IN-B, and a resistor R16 is inserted between the base of the transistor Tr13 and the output of the comparator CMP13. A resistor R12 is connected between the respective inputs of the comparators CMP12 and CMP13.
Is inserted. The detected current is output from the output terminal TM12 of the comparator CMP12.

The emitter of the transistor Tr12 is connected to the input terminal IN-A, and the base is connected to the collector of the transistor Tr14. Transistor Tr1
2 and the output terminal OUT-A.
Is inserted. A resistor R14 is inserted between the respective inputs of the comparator CMP14. The output of the comparator CMP14 is connected to the base of the transistor Tr14 via the resistor R17. A resistor R15 is inserted between the emitter of the transistor Tr14 and the input terminal IN-B.

Output terminal OUT-A and output terminal OUT-B
, Resistors R20 and R21 are inserted in series.
The connection point between the resistors R20 and R21 is connected to the comparator CMP15.
The other input of the comparator CMP15 is connected to the cathode of the Zener diode ZD11. The anode of the Zener diode ZD11 is connected to the output terminal OUT-B. The output of the comparator CMP15 is connected to the anode of the diode D11 and the anode of D12.

The cathode of the diode D12 is connected to the base of the transistor Tr13. Diode D11
Is connected to one terminal of the switch Sw11. The other terminal of the switch Sw11 and the transistor T
A resistor R18 is connected to the base of r14. A resistor R19 is inserted between the base of the transistor Tr14 and the output terminal OUT-B.

FIG. 28 shows a circuit diagram of another example to which the present invention is applied. DC power is supplied from input terminals IN-A and IN-B. The input terminal IN-B is connected to the output terminal OUT-
B is connected. The input terminal IN-A is connected to the transistor T
Connected to the collector of r11. Transistor Tr11
Is inserted between the output terminal OUT-A and the output terminal OUT-A. The base of the transistor Tr11 is connected to the collector of the transistor Tr13. A resistor R is connected between the emitter of the transistor Tr13 and the input terminal IN-B.
13 is inserted, and a resistor R22 is inserted between the base of the transistor Tr13 and the collector of the transistor Tr11.

A resistor R12 is inserted between the inputs of the comparators CMP12 and CMP13. The detected current is output from the output terminal TM12 of the comparator CMP12. The output of the comparator CMP13 and the transistor Tr
A resistor R16 is inserted between the base and the 15 base. The collector of the transistor Tr15 is connected to the base of the transistor Tr13, and a resistor R23 is inserted between the emitter of the transistor Tr15 and the input terminal IN-B.

The collector of the transistor Tr12 is connected to the input terminal IN-A, and the base is connected to the collector of the transistor Tr14. Transistor Tr1
Between the output terminal OUT-A and the output terminal OUT-A.
Is inserted. A resistor R15 is inserted between the emitter of the transistor Tr14 and the input terminal IN-B. A resistor R26 is inserted between the base of the transistor Tr14 and the collector of the transistor Tr12, and a switch Sw11 is inserted between the base and the input terminal IN-B.

The resistor R14 is inserted between the respective inputs of the comparator CMP14. The output of the comparator CMP14 is connected to the base of the transistor Tr16 via the resistor R17. The collector of the transistor Tr16 is connected to the base of the transistor Tr14. Transistor T
A resistor R2 is connected between the input terminal IN-B and the emitter of r16.
7 is inserted.

Output terminal OUT-A and output terminal OUT-B
, Resistors R20 and R21 are inserted in series.
The connection point between the resistors R20 and R21 is connected to the comparator CMP15.
The other input of the comparator CMP15 is connected to the cathode of the Zener diode ZD11. The anode of the Zener diode ZD11 is connected to the output terminal OUT-B. The output of the comparator CMP15 is connected to the anode of the diode D11 and the anode of D12.

The cathode of the diode D11 is connected to the base of the transistor Tr16. Diode D12
A resistor R24 is inserted between the cathode of the transistor Tr15 and the base of the transistor Tr15. A resistor R25 is inserted between the base of the transistor Tr15 and the input terminal IN-B.

The midpoint potential −ΔV generated by resistors R18 and R19 shown in FIG. 27 and R24 shown in FIG.
And the midpoint potential-[Delta] V generated by R25 may be reversed in the control phase. That is, −ΔV supplied to the transistors Tr11 and Tr12 is reversed.

FIG. 29 shows a first embodiment of an AC adapter capable of outputting small electric power and large electric power. A commercial power supply 161 is connected to the conversion transformer 162. One end of the secondary side 162 _2a of the conversion transformer is connected to the rectifying diode 16
3 of anode connected, the other end of the secondary side 162 _2a is connected to the cathode of the rectifier diode 163 via a capacitor 164. One end of the conversion transformer secondary 162 _2b, the anode of the rectifying diode 165 is connected,
The other end of the secondary side 162 _2b is connected to the cathode of the rectifying diode 165 via the capacitor 166. And the cathode of the secondary side 162 _2a of the other end and the diode 165 are connected.

The small power circuit 167 is inserted between the cathode of the diode 173 and one end of the switch 169.
The high power circuit 168 is inserted between the cathode of the diode 165 and the other end of the switch 169. Switch 16
One end of 9 is connected to the output terminal OUT-A, and the detection circuit 170 is inserted between the output terminals OUT-A and OUT-B. The AC adapter shown in FIG. 29 has a small power circuit and a large power circuit, and switches the circuits to switch the output.

FIG. 30 shows a second embodiment of the AC adapter. A commercial power supply 171 is connected to the diode bridge 172 and rectified. One end of the output of the diode bridge 172 is connected to one end of the capacitor 173 and the conversion transformer 17.
4 and the other end of the output of the diode bridge 172 is connected to the other end of the capacitor 173 and the conversion transformer 17.
The FET 175 is inserted between the other end of the FET 4. The other end of the conversion transformer 174 is connected to the cathode of the diode 176. The gate of the FET 175 is connected to a pulse width modulation (PWM) circuit 177. FET175
, Diode 176 and pulse width modulation circuit 177 constitute a switching regulator. The anode of the diode 178 is connected to one end on the secondary side of the conversion transformer 174, and a capacitor 179 is inserted between the other end on the secondary side of the conversion transformer 174 and the cathode of the diode 178.

The diode 178 has a cathode connected to the output terminal OUT-A.
Connected to output terminal OUT-B. High power detection circuit 18
0, the low power detection circuit 181 and the detection circuit 183 are inserted between the diode 178 and the conversion transformer 174. The detection result of the high power detection circuit 180 is the switch 1
82, the detection result of the small power detection circuit 181 is supplied to the other end of the switch 182. The switch 182 is controlled by the detection result of the detection circuit 183. The detection result of the large power detection circuit 180 or the detection result of the small power detection result 181 selected by the switch 182 is supplied to the pulse width modulation circuit 177. In the AC adapter shown in FIG. 30, the switching regulator is operated with small power or large power by switching the detection circuit.

FIG. 31 shows a third embodiment of the AC adapter. One end of the conversion transformer 191 is connected to one end of the FET 192, and a diode 193 is connected between the source and the drain of the FET 192. The gate of the FET 192 is
It is connected to a pulse width modulation (PWM) circuit 194. FE
T192, diode 193, and pulse width modulation circuit 194
Thus, a switching regulator is configured.
This switching regulator has a pulse width modulation circuit 1
Switching is performed according to the output from 94. An anode of a diode 195 is connected to one end on the secondary side of the conversion transformer 191, and a capacitor 19 is connected between the other end of the secondary side of the conversion transformer 191 and the cathode of the diode 195.
6 is inserted.

The cathode of the diode 196 is connected to the output terminal OUT-A, and a resistor 197 is inserted between the other end of the conversion transformer 191 and the output terminal OUT-B. A large current detection circuit 199 and a small current detection circuit 200 are connected to both ends of the resistor 197. The large current detection circuit 199 detects a large current, and the detected large current is supplied to the large power detection circuit 201. The small current detection circuit 20
At 0, a small current is detected, and the detected small current is supplied to the small power detection circuit 202. The voltage detection circuit 198 and the signal voltage detection 204 are inserted between the output terminals OUT-A and OUT-B.

The voltage detected by voltage detection circuit 198 is supplied to high power detection circuit 201 and low power detection circuit 202. The high power detection circuit 201 detects high power by multiplying the supplied voltage by the high current,
The detected large power is supplied to one end of the switch 203. The small power detection circuit 202 detects the small power by multiplying the supplied voltage by the small current, and supplies the detected small power to the other end of the switch 203.
The signal voltage detection circuit 204 detects a code signal from the set side of the electronic device, and supplies the detected signal to the switch control circuit 205. The switch control circuit 205 controls to switch the switch 203 according to the supplied code signal. The output from the high power detection circuit 201 or the output from the low power detection circuit 202 selected by the switch 203 is supplied to the pulse width modulation circuit 194 via the switch 203.

The AC adapter shown in FIG. 31 detects a voltage and a current, and switches the switching regulator according to the power obtained from the detected voltage and the current.

FIG. 32 shows a fourth embodiment of the AC adapter. One end of the conversion transformer 211 is connected to the cathode of the diode 213, and the diode 213 is connected to the FET2.
12 between the source and the drain. FET212
Is connected to a pulse width modulation (PWM) circuit 214. A switching regulator is configured by the FET 212, the diode 213, and the pulse width modulation circuit 214, and switching is performed according to an output from the pulse width modulation circuit 214. The anode of the diode 215 is connected to one end on the secondary side of the conversion transformer 211, and the capacitor 216 is inserted between the other end on the secondary side of the conversion transformer 211 and the cathode of the diode 215.

The cathode of the diode 215 and the output terminal O
A series low-power power supply circuit 217 is inserted between UT-A and UT-A, and a resistor 218 is inserted between the other end of conversion transformer 211 and output terminal OUT-B. A small current detection circuit 219 and a large current detection circuit 222 are connected to both ends of the resistor 218. The small current detection circuit 219 detects a small current, and supplies the detected small current to the switch control circuit 220. The large current detection circuit 222 detects a large current, and the detected large current is output to the large power detection circuit 223.
Supplied to A voltage detection circuit 223 and a signal voltage detection 225 are inserted between the output terminals OUT-A and OUT-B.

The voltage detected by voltage detection circuit 224 is supplied to high power detection circuit 223. High power detection circuit 22
In 3, large power is detected by multiplying the supplied voltage by the large current, and the detected large power is supplied to the pulse width modulation circuit 214. Signal voltage detection circuit 22
In 5, a code signal from the set side of the electronic device is detected, and the detected code signal is supplied to the switch control circuit 220. In the switch control circuit 220, ON / OFF control of the switch 221 is performed according to the supplied code signal. When the switch 221 is turned on, the output from the AC adapter is
7 and output.

In the AC adapter shown in FIG. 32, small power is produced by a circuit, and large power is produced by a switching regulator.

FIG. 33 shows a flowchart of the algorithm of the operation of the AC adapter shown in FIG. In step S91, first, the switch 211 is turned off.
In step S92, the series low power supply circuit 217 operates. In step S93, the signal voltage detection circuit 225
Operates, and a code signal transmitted from the set side of the connected electronic device is detected. In step S94, it is determined whether or not the set connected from the detected code signal is a set having a correct correspondence with the AC adapter. If it is determined that the set is a set having a correct correspondence with the AC adapter, The control moves to step S95, and if it is determined that the set is not a correct correspondence with the AC adapter, the control moves to step S93.

In step S95, the switch 221 is turned on. In step S96, the small current detection circuit 219 is operated. In step S97, it is determined whether or not the small current detected by the small current detection circuit 219 is equal to or smaller than the reference value. If the small current is equal to or smaller than the reference value, the control proceeds to step S98, and if the small current is larger than the reference value. Then, the control moves to step S97. In step S98, switch 2
21 is turned off, and control proceeds to step S91.

In this embodiment, as an example, an AC adapter is connected to an electronic device, a code signal is determined, and if the code signal has a correct correspondence, the power is changed from low power to large to charge the secondary battery. Although the output of the AC adapter is switched to the power, the code signal is determined, and if the correspondence is correct, the output of the AC adapter may be switched from the small power to the large power as the operating power supply of the electronic device. good.

[0101]

According to the present invention, a code signal can be transmitted even when an AC adapter and a set of electronic devices are connected to two terminals of a + terminal and a-terminal, and the code signal can be determined. By doing so, it is possible to determine whether or not the set is an electronic device having a correct correspondence with the AC adapter, so that an output suitable for the set can be obtained. can do. Therefore, a set of electronic devices that do not have a correct correspondence with the AC adapter is not broken.

[Brief description of the drawings]

FIG. 1 is a schematic diagram used for describing a set of an AC adapter and an electronic device according to the present invention.

FIG. 2 is a schematic diagram for explaining a basic process of the present invention.

FIG. 3 is a schematic diagram for explaining a basic process of the present invention.

FIG. 4 is a schematic diagram for explaining a basic process of the present invention.

FIG. 5 is a schematic diagram used for describing a switch circuit applied to the present invention.

FIG. 6 is a schematic diagram used for describing a switch circuit applied to the present invention.

FIG. 7 is a schematic diagram for explaining a basic process of the present invention.

FIG. 8 is a schematic diagram for explaining a schematic operation of the present invention.

FIG. 9 is a block diagram of a first embodiment of a signal transmission system between an AC adapter and an electronic device according to the present invention.

FIG. 10 is an example of voltage and current characteristics applied to the present invention.

FIG. 11 is a flowchart of a first embodiment of a power switching process according to the present invention.

FIG. 12 is a flowchart of an example of a voltage detection process applied to the present invention.

FIG. 13 is a block diagram of a second embodiment of a signal transmission system between an AC adapter and an electronic device according to the present invention.

FIG. 14 is a flowchart of a power switching process according to a second embodiment of the present invention.

FIG. 15 is an example of voltage and current characteristics applied to the present invention.

FIG. 16 is an example of voltage and current characteristics applied to the present invention.

FIG. 17 is a block diagram of a third embodiment of a signal transmission system between an AC adapter and an electronic device according to the present invention.

FIG. 18 is a flowchart of a power switching process according to a third embodiment of the present invention.

FIG. 19 is a basic block diagram of an embodiment of an AC adapter according to the present invention.

FIG. 20 is a block diagram of an example of a small power supply circuit and a large power supply circuit applied to the present invention.

FIG. 21 is a flowchart of a power switching process according to a fourth embodiment of the present invention.

FIG. 22 is a basic block diagram of an electronic apparatus set according to an embodiment of the present invention.

FIG. 23 is a block diagram of an example of a parallel type constant voltage circuit applied to the present invention.

FIG. 24 is a flowchart of a power switching process according to a fifth embodiment of the present invention.

FIG. 25 is a block diagram of a first embodiment of the AC adapter of the present invention.

FIG. 26 is a flowchart of a power switching process according to a sixth embodiment of the present invention.

FIG. 27 is a circuit diagram of an example used for describing a voltage dividing (-ΔV) circuit applied to the present invention.

FIG. 28 is a circuit diagram of another example used for describing a voltage dividing (-ΔV) circuit applied to the present invention.

FIG. 29 is a block diagram of a first embodiment of an input power supply and an AC adapter applied to the present invention.

FIG. 30 is a block diagram of a second embodiment of an input power supply and an AC adapter applied to the present invention.

FIG. 31 is a block diagram of a third embodiment of an input power supply and an AC adapter applied to the present invention.

FIG. 32 is a block diagram of a fourth embodiment of an input power supply and an AC adapter applied to the present invention.

FIG. 33 is a flowchart of a power switching process according to a seventh embodiment of the present invention.

FIG. 34 is a schematic diagram used to explain a conventional set of an AC adapter and an electronic device.

[Explanation of symbols]

41 ... DC power supply, 42, 49, 60 ... transistor, 43, 46, 47, 50, 59 ... resistor, 44
... voltage detection circuit, 45, 48, 58 ... control circuit, 51, 55 ... stop circuit, 52 ... signal reception circuit, 53 ... stop release circuit, 54 ... voltage detection circuit , 56... Reference voltage detection circuit, 57, 62.
..Switch circuits, 61 ... Switch control circuits

Claims (10)

[Claims] 1. An electronic device connected by two terminals, capable of outputting high power and low power, and a signal detecting means for detecting a code signal transmitted from the electronic device; Whether or not the electronic device has the correct correspondence is determined by the detected code signal. The signal determining unit determines that the electronic device is in the correct correspondence. A power supply adapter for switching the output from low power to high power. 2. The apparatus according to claim 1, wherein if the electronic device connected to the power supply adapter is determined not to have a correct correspondence as a result of the signal determination unit, the output is maintained in a low power state. A power supply adapter characterized in that: 3. The method according to claim 1, further comprising: a current detection unit configured to detect a current value, wherein the switching unit is configured to output a large power when the detected current value is equal to or less than a reference value. A power supply adapter characterized in that the output is switched from high power to low power. 4. A power supply adapter connected by two terminals, based on power supplied from the power supply adapter,
An electronic apparatus, comprising: signal generation means for generating a code signal for identifying a power supply adapter to be connected. 5. The signal generator according to claim 4, wherein the signal generator determines whether or not the power supplied from the power supply adapter is equal to or greater than a first reference value, and determines whether the power is equal to or greater than the first reference value. If it is determined that the power supply adapter to be connected generates a code signal for identifying the power supply adapter, after the power supply has reached the first reference value, a second reference greater than the first reference value The electronic device is characterized in that it is determined whether or not the power supply is equal to or greater than the second reference value, and when the power supply is determined to be equal to or greater than the second reference value, the code signal is stopped and a load is connected. 6. The electronic device according to claim 5, wherein when it is determined that the value is not larger than the second reference value, the code signal is stopped. 7. A power supply adapter connected to an AC power supply for generating a predetermined DC power supply voltage, and a signal transmission system connecting the power supply adapter to an electronic device, wherein the power supply adapter and the electronic device are The power supply adapter is capable of outputting high power and low power, and is connected to the power supply adapter, and a signal detecting means for detecting a code signal from the electronic device. A signal discriminating means for discriminating whether or not the electronic device is an electronic device having a correct correspondence, based on the detected code signal; and as a result of the signal discriminating device, the power supply adapter and the electronic device are correct. Switching means for switching the output of the power supply adapter from low power to high power when it is determined that the electronic device is in a correspondence relationship; Based on power supplied from the power supply adapter,
A signal transmission system comprising code signal generation means for generating a code signal for identifying a power supply adapter to be connected. 8. The signal transmission system according to claim 7, wherein the low level of the code signal is set to a value at which a circuit of the electronic device can operate. 9. The power supply adapter according to claim 7, wherein the output of the power supply adapter is maintained in a low power state when the signal determination means determines that the power supply adapter and the electronic device do not have a correct correspondence. A signal transmission system characterized in that: 10. The power supply adapter according to claim 7, wherein the power supply adapter has a current detecting means for detecting a current value, and the switching means outputs the detected current value when outputting a large power. A signal transmission system characterized in that the output is switched from high power to low power when the power is below a reference value.