JPH06319235A - Electric power device - Google Patents

Abstract

PURPOSE:To miniaturize an electric power device by extracting first DC voltage from a first capacitor and extracting second DC voltage higher than the first DC voltage from the series circuit of first and second capacitors. CONSTITUTION:First DC voltage V13L is formed by one half cycle of AC voltage output to a secondary coil NS, and another DC voltage is formed by the other half cycle while another DC voltage is added to the first DC voltage V13L and second DC voltage V13H is formed. The first DC voltage V13L is extracted from a first capacitor C1, and the second DC voltage V13H higher than the first DC voltage V13L is extracted from the series circuit of the first capacitor C1 and a second capacitor C2. Accordingly, a tertiary coil need not be mounted to a converter transformer T1, thus miniaturizing an electric power device 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device having a charging function and an AC adapter function.

[0002]

2. Description of the Related Art Generally, a mobile phone has a built-in secondary battery as its operating power source. When the secondary battery becomes empty, it is replaced with a charged secondary battery or the telephone is set in a charger to charge the built-in secondary battery. As the secondary battery, a nickel-cadmium battery or a nickel-hydrogen battery having good discharge characteristics is generally used, and its capacity is such that the current flowing during a call is about 1C. Often.

By the way, when a portable telephone is connected to a charger, the charger can not only charge a secondary battery but also act as an AC adapter for the telephone, that is, an external power supply device acts as a charger. If it doubles as an AC adapter, the phone can be used during charging or after charging is completed. Moreover, since the charge of the secondary battery does not decrease even if the phone is used, I thought that I could use it for a long time because I charged it when I removed the phone from the power supply next time. , It does not cause trouble such as the battery running out immediately.

Further, if the power supply device is composed of a flyback type switching power supply circuit, the size and weight can be reduced and heat generation can be suppressed.

[0005]

However, when the power supply device is constituted by a flyback type switching power supply circuit, a current output for charging and a voltage output for powering the telephone are provided on the secondary side of the converter transformer. In order to obtain, a very special transformer is required as a converter transformer, and its realization is extremely difficult.

When two secondary coils are provided in the converter transformer, one secondary coil provides a current output for charging, and the other secondary coil provides a voltage output as a power supply for the telephone, the current output It is possible to stabilize only one of the voltage output and the voltage output, but not both at the same time.

Further, as will be described in detail later, if a circuit that forms a voltage to be a power source of the telephone requires a starting voltage, a tertiary coil is provided in the converter transformer to obtain the starting voltage. Larger transformer,
It is extremely disadvantageous in terms of standardization and cost.

The present invention is intended to solve the above problems.

[0009]

Therefore, in the present invention, when the reference numerals of the respective parts correspond to the embodiments described later, in the power supply device 10 having the switching power supply circuit 12, the secondary coil NS of the converter transformer T1. Is connected to a series circuit of the first diode D1 and the first capacitor C1. The secondary coil NS is connected to the second diode D2.
And a second capacitor C2 in a series circuit, the first diode D1 and the second diode D2 are connected to the secondary coil NS in opposite polarities, and the first capacitor C1 and The second capacitor C2 is connected in series with each other, the first DC voltage V13L is extracted from the first capacitor C1, and the first DC voltage V13L is output from the series circuit of the first capacitor C1 and the second capacitor C2. The second DC voltage V13H higher than the above is taken out.

[0010]

The first DC voltage V13L is formed by one half cycle of the AC voltage output to the secondary coil NS, and the other DC voltage is formed by the other half cycle of the AC voltage. , And is added to the DC voltage V13L to form a second DC voltage V13H.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, 10 is a power supply device for a mobile phone, 1A is an output terminal of an external power supply, 1B is a charge output terminal, 1C is a charge detection terminal, and 1G is a common terminal.

Further, 11 is a power supply plug to which a commercial AC voltage of, for example, 100 V is supplied, and 12 is a switching power supply circuit (AC-AC converter) of a flyback type. Although details of the power supply circuit 12 will be described later, the power supply circuit 12 has a converter transformer T1, and the converter transformer T1 includes a primary coil NP, a secondary coil NS, and a feedback coil NB. Have. Then, from the secondary coil NS, for example, as shown in FIG.
As shown in, the AC voltage V12 having a positive peak value of about 9 to 10 V and a negative peak value of about -20 to -30 V is taken out.

Reference numeral 13 represents a rectifying circuit. The rectifier circuit 13 rectifies the voltage V12 and outputs a first DC voltage V13L having a low voltage but a large current capacity and a second DC voltage V13H having a high voltage but a small current capacity. . Therefore, the rectifying circuit 13 has rectifying diodes D1 and D2, charging capacitors C1 and C2, a smoothing choke coil L1 and a capacitor C3. In addition to having a resistor R1 to limit the current,
The values of the capacitors C2 and C4 are reduced. As an example, C2 = 1 μF C4 = 1 μF R1 = 33 kΩ. In this example, V13L = 1 when no load is applied.
About 0V and V13H = about 30V.

Further, 14 is a voltage / current control circuit, R2
Is a resistor for current detection, the magnitude of the load current of the rectifier circuit 13 is detected by the resistor R2, and the detection output and the voltage V13L are supplied to the control circuit 14 to form a predetermined feedback signal. This signal is supplied to the power supply circuit 12 through the insulation separation photocoupler 15.
The output voltage V12 is stabilized.

Reference numeral 16 denotes a constant voltage circuit. The constant voltage circuit 16 serves as an external power source of the mobile phone, for example, 6V.
The stabilized DC voltage V16 is output to the terminal 1A. Therefore, the constant voltage circuit 16 includes an output transistor Q1 and a control circuit 1 that drives the transistor Q1 with a PWM signal to make the output voltage V16 constant.
61 and. The control circuit 161 is a commercially available IC.
Therefore, the power supply voltage and current required for steady operation is about 9 to 10 V x 9 mA, but a voltage and current of 16 V or more x 400 μA is required at startup. It is a thing.

Since the control circuit 161 requires such a voltage and current, the diode D3 is provided between the voltage V13H line and the voltage V13L line and the power supply line of the control circuit 161.

Further, 17 indicates a charge control circuit composed of a microcomputer. And the rectifier circuit 1
The voltage V13L from 3 is supplied to the constant voltage circuit 18 and stabilized to a DC voltage V18 of 5V, for example, and this voltage V18 is supplied to the control circuit 17 as its operating voltage. In addition,
When the control circuit 161 is controlled by the control circuit 17 and the quick charge is performed, the transistor Q1 is turned off and the voltage V18 is not output. When the quick charge is not performed, the voltage V18 is output. Has been done.

Further, Q2 represents a transistor for quick charging, and this transistor Q2 is on / off controlled by the control circuit 17. During rapid charging, a constant current (charging voltage) for rapid charging is taken out from the transistor Q2, and the charging current is output to the terminal 1B through the backflow prevention diode D4. Further, R4 and R5 are resistors for measuring the charging voltage, R6 is a resistor for detecting the state of charge, and C5 is a capacitor for removing ripples. The output voltage V18 of the constant voltage circuit 18 is supplied to the terminal 1C through the resistor R6, and the voltage V6 of the terminal 1C is supplied to the control circuit 17 as a charge detection voltage.

FIG. 2 shows an example of a power supply system of a mobile phone, and 20 is the mobile phone. In the telephone 20, 2A is an input terminal for an external power source, 2B is a charge input terminal, 2C is a charge detection terminal, 2G is a common terminal, and 21
Is the main circuit of the telephone (mobile phone section), 22 is the power source 2
Indicates the next battery. The secondary battery 22 is built in the telephone 20, but is detachable from the telephone 20 so that it can be replaced with a charged one when it becomes empty. Further, the battery 22 is a nickel-hydrogen battery, and has a thermistor R22 integrally as an element for detecting the temperature thereof, for example. As an example, the output voltage of the battery 22 is 6V and the capacity is 65V.
It is set to 0 mAh so that the telephone 20 can be used for about 1 hour. The resistance value of the thermistor R22 is made equal to the value of the resistor R6, and is 10 kΩ at 25 ° C., for example.

Further, the telephone 20 has a switch circuit 2
3 and a voltage detection circuit 24 are provided. In this case, the switch circuit 23 can be configured by a transistor or a contact of a relay. In addition, the detection circuit 24
Detects the presence / absence of a voltage at the terminal 2A and controls the switch circuit 23 by the detection output thereof. If the voltage is not supplied to the terminal 2A, the switch circuit 23 is connected to the state shown in the figure.

FIG. 3 shows an example of the power supply circuit 12, in which the AC voltage from the plug 11 is supplied to the double-wave rectification circuit 121 to be a DC voltage, and this DC voltage is supplied to the primary coil NP of the converter transformer T1. It is supplied to the series circuit between the collector and the emitter of the switching transistor Q12. The output of the feedback coil NB of the transformer T1 is supplied between the base and the emitter of the transistor Q12, and the collector and the emitter of the transistor Q13 are connected between the base and the emitter. Then, the signal from the photocoupler 15 is supplied to the control circuit 122 and the PW
The M signal is generated, and this PWM signal is supplied to the transistor Q13. In this way, the output voltage V12 is stabilized.

According to such a configuration, when the AC voltage is supplied to the plug 11, the power supply circuit 12 starts up and the AC coil V12 is output to the secondary coil NS of the transformer T1. Then, the negative half cycle of this AC voltage V12
Since the capacitor C1 is charged through the diode D1,
A charging voltage is obtained in the capacitor C1 and this charging voltage is smoothed by the coil L1 and the capacitor C3 to obtain the DC voltage V.
It is taken out as 13L. Therefore, the charge control circuit 1
7 starts operation.

At this time, since the positive half cycle of the AC voltage V12 charges the capacitor C2 through the diode D2, the charging voltage is obtained at the capacitor C2. Since the capacitor C2 and the capacitor C1 are connected in series, the charging voltage of the capacitor C2 and the charging voltage of the capacitor C1 are added, and the added voltage is supplied to the capacitor C4 through the resistor R1, A DC voltage V13H is obtained at the capacitor C4.

This voltage V13H is supplied to the control circuit 16
1 is supplied as a start-up voltage to the control circuit 161. Then, when the control circuit 161 starts up,
After that, the voltage V13L is supplied to the control circuit 16 through the diode D3.
1 is supplied as the operating voltage in the steady state, the control circuit 161 continues the operation after rising, that is,
It becomes a steady state.

In this case, the resistor R of the rectifying circuit 13
Since the value of 1 is large and the values of the capacitors C2 and C4 are small, the regulation when the rectifying circuit 13 outputs the voltage V13H is poor, and the voltage V13H is lowered after the startup. That is, the control circuit 161 is supplied with a high voltage V13H at the time of start-up, and after the start-up, the normal operation voltage V13L is supplied to maintain a steady operation. Also,
At startup, V13H> V13L, so the diode D3 is off, and therefore the voltage V13H is not supplied to circuits other than the control circuit 161.

In this way, when the power is turned on, the necessary (starting voltage and) operating voltage is supplied to each part, and the power supply device 2
When 0 is set, the charging current or the operating voltage can be supplied to the telephone 10.

When the telephone set 20 is not set in the power supply unit 10, the terminal 1C has no load, so that V6 = V18. However, when the telephone set 20 is set in the power supply device 10, the terminal 2C is connected to the terminal 1C, so that the voltage V18 is divided by the resistor R6 and the thermistor R22, and V6 = V18 / 2 (temperature is 25 °). (When C). Therefore, the control circuit 17 can know from the magnitude of the voltage V2 whether the telephone 20 is set in the power supply device 10 or not.

Then, when the telephone set 20 is set in the power supply device 10, the control circuit 17 knows that the telephone set 20 is set in the power supply device 10 from the change in the voltage V2, and controls the transistor Q2 to perform quick charging. to approve. Therefore, the DC voltage V13L of the rectifier circuit 13 becomes
Transistor Q2 → diode D4 → terminal 1B → terminal 2B
The battery 22 is supplied to the battery 22 through the current line, and the battery 22 is rapidly charged with a constant current of 1C.

During this rapid charging, the control circuit 17 prohibits the operation of the control circuit 161 and the voltage V16 is not output. Therefore, although the voltage V16 is not supplied to the terminal 2A, the detection circuit 24 detects that the voltage V16 is not supplied to the terminal 2A, and the detection output thereof connects the switch circuit 23 to the state shown in the figure.

Thus, during the rapid charging, the terminal 2B and the battery 22 are connected to the power source line of the main body circuit 21 through the switch circuit 23. Therefore, the telephone 20 can be used during quick charging.

When the charge approaches 100%, the energy for charging is not used for charging but becomes heat. Therefore, as shown by the broken line in FIG. As the temperature of 22 rapidly increases, this temperature change is detected by the thermistor R22, and as shown in FIG. 5, the voltage V2 of the terminal 1C rapidly decreases from V2 = V18 / 2. Therefore, the control circuit 17 detects this sudden drop in the voltage V2, turns off the transistor Q2, and terminates the rapid charging. For example, during rapid charging, the magnitude of the voltage V2 is read every minute to detect a change in the voltage V2 every minute, and this change amount is, for example, 60 mV.
When it becomes larger than / minute or more, the quick charge is terminated.

When the rapid charging is completed, the control circuit 17 permits the operation of the control circuit 161, and the transistor Q1 outputs the voltage V16 to the terminal 2A through the terminal 1A. Then, the voltage V16 at the terminal 2A is detected by the detection circuit 24, and the detection output thereof connects the switch circuit 23 to the state opposite to that shown in the drawing, and the voltage V16 is supplied to the power supply line of the main circuit 21 through the switch circuit 23. It Therefore, even after charging is completed, the telephone 2
0 can be used, and its use is performed by using the voltage V16 from the power supply device 10 as a power source.

When the telephone set 20 is not equipped with the battery 22, V2 = V18 even when the telephone set 20 is set in the power supply unit 10, the quick charge by the transistor Q2 is not permitted, and the control circuit 161 is not permitted. Is permitted, the voltage V18 is supplied to the terminal 2A. Therefore, as in the case after the end of the charging described above, the voltage V
Since 18 is supplied to the main body circuit 21 through the switch circuit 23, even if the battery 22 is not attached, the telephone 20
Can be used.

When the battery 22 is a nickel-cadmium battery, the thermistor R22 is not provided, but the rapid charging and its termination can be controlled as follows. That is, when the telephone set 20 is not set in the power supply device 10, the transistor Q1 is in an unloaded state and the output voltage of the transistor Q1 is about 10 V. When the telephone set 20 is set in the power supply device 10, the battery 22 is discharged. As a load, the output voltage of the transistor Q1 becomes about 6V. Then, this change in the output voltage is supplied to the control circuit 17 through the resistors R4 and R5, so that the transistor Q
The control circuit 17 can also know that the telephone set 20 is set in the power supply device 10 by the change in the output voltage of 1.

As described above, the telephone 20 using the nickel-hydrogen battery as the battery 22 is the power supply unit 10
When set to, the voltage V2 also changes, but a telephone 2 that uses a nickel-cadmium battery as the battery 22
When 0 is set in the power supply device 10, since the thermistor R22 is not built in, the voltage V2 does not change.

Therefore, the voltage V2 and the transistor Q2
It is possible to determine whether the battery 22 of the telephone 20 is a nickel-hydrogen battery or a nickel-cadmium battery from the output voltage of. Further, even if the voltage V2 does not change, if the output voltage of the transistor Q2 changes, rapid charging may be started.

Then, as shown in FIG.
When approaching 0%, the terminal voltage of the battery 22 gradually rises,
When the battery is charged up to almost 100%, the terminal voltage will decrease thereafter.
If it is detected by the control circuit 17 through R5, the quick charge can be terminated.

As described above, according to the power supply device 10, the battery 22 can be rapidly charged, and if the telephone set 20 is set in the power supply device 10, during or after rapid charging. Even if you make a call,
The battery 22 is not consumed and the battery 22 can be always kept in a fully charged state.

Although the thermistor R22 is integrated with the battery 22 in the above description, if the thermistor R22 is thermally coupled to the battery 22 and the temperature rise during rapid charging of the battery 22 can be detected, It may be a separate body. Further, in the above description, the present invention is applied to the power supply device 10 of the mobile phone 20.
However, the present invention can also be applied to a power supply device of general cordless electronic equipment such as a notebook type personal computer.

[0040]

According to the present invention, no special transformer is required as the converter transformer T1. Further, the direct-current voltage for quick charging can also be the voltage V16 which is the power source of the telephone 10.

Further, even if the control circuit 161 requires the starting voltage V13H higher than that in the steady operation, the starting voltage V1
Since it is not necessary to provide a tertiary coil in the converter transformer T1 in order to obtain 3H, it is advantageous in terms of downsizing, standardization, cost, etc. of the converter transformer T1. Alternatively, no special parts are required, which is also advantageous in this respect. Moreover, since the power supply circuit 12 can be downsized, the power supply device 10 can also be downsized.

Furthermore, in the constant voltage circuit 16, the transistor Q1 is driven by the PWM signal to drive the constant voltage V1.
Since 6 is obtained, there is less heat generation, and therefore battery 2
When the full charge of No. 2 is detected by the temperature change as described above, the detection is not affected.

[Brief description of drawings]

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

FIG. 2 is a connection diagram showing an example of a power supply system of a mobile phone.

FIG. 3 is a connection diagram showing an example of a power supply circuit.

FIG. 4 is a waveform diagram for explaining a power supply circuit.

FIG. 5 is a diagram showing characteristics when charging a battery.

[Explanation of symbols]

 10 power supply device 12 power supply circuit 13 rectifier circuit 14 voltage / current control circuit 16 constant voltage circuit 17 charging control circuit 18 constant voltage circuit 20 mobile phone 21 main circuit 22 secondary battery 24 voltage detection circuit Q1 constant voltage transistor Q2 for quick charging Transistor R22 Thermistor

Claims (3)

[Claims] 1. A power supply device having a switching power supply circuit, wherein a series circuit of a first diode and a first capacitor is connected to a secondary coil of a converter transformer, and the secondary coil is connected to a second diode. And a series circuit with a second capacitor are connected, and the first diode and the second diode are
The first capacitor and the second capacitor are connected in reverse polarity with respect to the secondary coil, and the first capacitor and the second capacitor are connected in series with each other, and a first DC voltage is extracted from the first capacitor, A power supply device adapted to take out a second DC voltage higher than the first DC voltage from the series circuit of the capacitor and the second capacitor. 2. The power supply device according to claim 1, wherein the second DC voltage is supplied to a power supply line of a load circuit as its starting voltage, and the first DC voltage is a third diode. Through the power supply line of the load circuit as an operating voltage in the steady state. 3. The power supply device according to claim 1 or 2, wherein the second DC voltage is taken out through a resistor.