JP3284160B2 - Power control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply control device for electronic equipment operated by a power supply from an external power supply such as an adapter.

[0002]

2. Description of the Related Art Conventionally, in a portable electronic device, a primary battery, a built-in secondary battery and a dedicated AC
A DC power supply from an adapter is used, and a configuration using an internal secondary battery is configured to be charged by a DC power supply from the dedicated AC adapter. In this way, the built-in secondary battery is used as a power supply source of the device body,
A power supply control device of a portable electronic device using a dedicated AC adapter as a power supply source of the device body and charging a built-in secondary battery will be described below with reference to FIG.

In FIG. 6, reference numeral 100 denotes a power supply terminal for receiving power supply from an AC adapter (not shown). When the AC adapter is not plugged in the power supply terminal 100, the + power supply terminal a and the intermediate terminal b are connected. In addition, when the ground terminal c is not connected, and when the AC adapter is plugged, the plug of the AC adapter is connected to the positive power terminal a and the ground terminal c, and the positive power terminal a and the intermediate terminal b are connected. Are disconnected.

Reference numeral 101 denotes a power switch for supplying power to the equipment main body 102. The fixed contact o is connected to the + power supply terminal a of the power supply terminal 100, and the movable contact a is connected to the equipment main body 10.
2, the movable contact b is connected to the intermediate terminal b via a resistor 103 for controlling charging current and a diode 104 for preventing backflow. One end of a chargeable / dischargeable secondary battery 105 is connected between the diode 104 and the intermediate terminal b, and the other end of the secondary battery 105 is connected to ground and grounded.

[0005] The operation of the power supply control device configured as described above will be described first when power is supplied to the device main body 102 by power supply from an AC adapter (not shown).

When a plug of an AC adapter (not shown) is connected to the power supply terminal 100, the + power supply terminal a and the intermediate terminal b are disconnected from each other at the power supply terminal 100, and the + power supply terminal a and the ground terminal c are connected. Power is supplied from the AC adapter. Then, in this state, when the power switch 101 is turned on, that is, when the fixed contact o and the movable contact a are connected, the power supplied from the AC adapter supplied to the + power supply terminal a is supplied to the device main body 102. Therefore, the device main body 102 is operated by power supply from an AC adapter (not shown).

When the power switch 101 is turned off with the plug of the AC adapter (not shown) connected to the power supply terminal 100, that is, when the fixed contact o and the movable contact b are connected, the power is supplied to the + power supply terminal a. After the power supply from the AC adapter is adjusted in current by the charging current limiting resistor 103, the power is supplied to the secondary battery 105 via the diode 104, and the secondary battery 105 is charged.
Therefore, the secondary battery 105 is charged by power supply from an AC adapter (not shown).

At this time, the intermediate terminal b is connected to the secondary battery 10
Although connected to the diode 104 in the same manner as 5, the current does not flow to the intermediate terminal b side because the + side power supply terminal a and the intermediate terminal b are not connected. Power switch 10
When the power supply 1 is turned on to supply power to the device main body 103, the + power supply terminal a and the intermediate terminal c are disconnected, and the fixed contact o and the movable contact a are connected in the power switch 101. Since the movable contact b is not connected, the power from the AC adapter supplied to the + power supply terminal a is not supplied to the secondary battery via the movable terminal b.

Next, a case where power is supplied to the device main body 102 by supplying power from the charged secondary battery 105 will be described.

When the plug of the AC adapter is not connected to the power supply terminal 100, the + power supply terminal a and the intermediate terminal b are connected to each other at the power supply terminal 100.
The power from the secondary battery 105 supplied to the intermediate terminal b is +
Is supplied to the side power terminal a. In this state, when the power switch 101 is turned on, that is, when the fixed contact o and the movable contact a are connected, the power supply from the secondary battery 105 supplied to the + power supply terminal a is supplied to the device main body 102. You. Therefore, the device main body 102 includes the built-in secondary battery 1.
It is operated by the power supply from 05.

At this time, the power supply from the secondary battery 105 is prevented from flowing to the movable terminal b by the backflow preventing diode 104. Also, such A
When the power switch 101 is turned off while the C adapter is not connected, the secondary battery 105 is prevented from discharging by forming a loop in the secondary battery 105.

Therefore, according to such a power supply control device, power can be supplied to the device main body 102 by using a dedicated AC adapter, and the power supply can be supplied when the power supply to the device main body 2 is not performed. The secondary battery 105 built in the control device can be charged,
Further, even when the dedicated adapter is not used, power can be supplied to the device main body 102 by the built-in secondary battery 105 charged.

[0013]

However, in the above-mentioned conventional apparatus, it is prerequisite that an AC adapter for supplying power to the apparatus main body should be a dedicated one based on the power consumption of the apparatus main body. The AC adapter is attached to the device main body, and the AC adapter that supplies power to the device main body is limited by the shape of the plug and the power supply terminal of the AC adapter. However, since the shape of a plug connected to a power supply terminal in an AC adapter that supplies power to a device main body is generally similar, a dedicated AC adapter is used.
If another AC adapter different from the adapter is connected, power may be supplied to the main unit by an AC adapter that uses different power. At this time, if the output voltage of the AC adapter is high, circuits or secondary Damaged batteries,
In addition, when the output voltage is low, there is a problem that the device main body operates abnormally.

According to the present invention, an AC power supply connected to a power supply terminal is provided.
It is an object of the present invention to provide a power supply control device that can prevent damage to a circuit inside a device main body and a secondary battery and abnormal operation of a device main body even when an adapter is not a dedicated one and uses different power. Is what you do.

[0015]

According to one aspect of the present invention, there is provided a power supply input terminal for receiving a power supply voltage from an external power supply, and a power supply switch for supplying power to an apparatus body. A power control device for supplying power supplied to the power input terminal to the main body of the device in response to an on operation of the power switch, wherein a voltage level of the power supplied to the power input terminal is digitally controlled.
A power supply voltage detecting means for converting and detecting; a level comparing means for comparing a voltage level detected by the power supply voltage detecting means with a reference voltage level; and a power input terminal based on a comparison result from the level comparing means. Control means for controlling the supply of supply power to the device main body input to the
The control means, when it is determined that the voltage level detected by the power supply voltage detection means is within a predetermined range of the reference voltage level based on the comparison result from the level comparison means, by turning on the power switch. While controlling to supply power to the device main body, when it is determined that the power is out of the predetermined range, control is performed so as not to supply power to the device main body regardless of the ON operation of the power switch.

According to a second aspect of the present invention, a power supply switch for connecting / disconnecting the power supply path is provided in a power supply path from the power input terminal to the device main body, and the control means controls the level comparison. When it is determined that the voltage level detected by the power supply voltage detecting means is within a predetermined range of the reference voltage level based on the comparison result from the means,
While the power supply switch is turned on by the operation of turning on the power switch to connect the power supply path, when it is determined that the power supply switch is out of the predetermined range, the power supply switch is turned on regardless of the operation of turning on the power switch. It is turned off to open the power supply path.

According to a third aspect of the present invention, a charge / discharge supply path is formed in parallel with a power supply path from the power supply input terminal to the device main body, and a chargeable / dischargeable secondary battery is provided in the charge / discharge supply path. And a charge control switch for supplying power to the secondary battery, wherein the control means adjusts the voltage level detected by the power supply voltage detection means based on a comparison result from the level comparison means to a reference voltage level. When determined to be within the predetermined range, the charging control switch is turned on to charge the secondary battery, while when determined to be out of the predetermined range, the charging control switch is turned off and the secondary battery is turned off. It does not charge the battery.

According to a fourth aspect of the present invention, a power supply switch for connecting / disconnecting the power supply path is provided in a power supply path from the power input terminal to the device main body, and the power supply control switch is interposed therebetween. A charge / discharge supply path is formed in parallel with the power supply path, and the charge / discharge supply path is provided with a chargeable / dischargeable secondary battery and a discharge control switch for supplying a charging voltage of the secondary battery to the device body, The control means, when it is determined that the voltage level detected by the power supply voltage detection means is within a predetermined range of the reference voltage level based on the comparison result from the level comparison means, by turning on the power switch. While the power supply switch is turned on to connect the power supply path, when the power supply switch is determined to be out of the predetermined range, the power supply switch is turned on by operating the power supply switch. And on the discharge control switch turns off the pitch in which to perform power supply to the apparatus body by the secondary battery.

[0019]

According to the first aspect of the present invention, when power is supplied from an external power supply to the power supply terminal, after the power supply voltage detecting means detects the voltage level of the power supply voltage, the level comparing means detects the power supply voltage. The voltage level is compared with the reference voltage level, and the control means determines based on the comparison result whether the power supply input to the power supply terminal can be used as the power supply of the device body. Then, when it is determined that the power can be used as the power supply of the device main body, the operation of the power switch for performing power supply to the device main body is enabled, and when it is determined that the power supply of the device main body cannot be used, The operation of the power switch is invalidated, and when the power switch is turned on at this time, the on operation is invalidated by the control means.

According to the second aspect of the present invention, when the control means determines whether the power supply input to the power supply terminal can be used as the power supply of the apparatus main body, it can be used as the power supply of the apparatus main body. If determined,
Based on the operation of the power switch, the control means causes the power supply switch provided in the power supply path from the power supply terminal to the device main body to be turned on / off, and it is determined that the power supply switch cannot be used as the power source of the device main body. In this case, the power supply switch is turned off regardless of the operation of the power switch.

According to the third aspect of the present invention, when the control means determines whether the power supply input to the power supply terminal can be used as the power supply of the equipment main body, it can be used as the power supply of the equipment main body. If determined,
The control means turns on the charge control switch and causes the secondary battery to be charged by the supply power input to the power supply terminal,
When it is determined that the secondary battery cannot be used as the power source of the device main body, the control means controls the charging control switch to be turned off so that the secondary battery is not charged.

According to the fourth aspect of the invention, when the control means determines whether the power supply input to the power supply terminal can be used as the power supply of the device main body, it can be used as the power supply of the device main body. If determined,
Based on the operation of the power switch, the control means causes the power supply switch provided in the power supply path from the power supply terminal to the device main body to be turned on / off, and it is determined that the power supply switch cannot be used as the power source of the device main body. In this case, the power supply switch is turned off regardless of the operation of the power switch, and the discharge control switch provided in the charge / discharge supply path formed in parallel with the power supply path based on the operation of the power switch is turned on / off. Perform the operation.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic block diagram showing an electric configuration of a power supply control device according to a first embodiment of the present invention. FIG. 2 is a flowchart showing operation control of the power supply control device.
FIG. 4 is a schematic block diagram showing an electric configuration of a power supply control device according to a second embodiment of the present invention. FIG. 4 is a flowchart showing charging operation control of the power supply control device. FIG. 5 is a power supply operation control of the power supply control device. It is a flowchart which shows.

[First Embodiment] In FIG. 1, reference numeral 1 denotes a power supply terminal for receiving power from an AC adapter (not shown);
Is a power supply switch provided on a power supply path between the power supply terminal 1 and the equipment main body, and 3 is a power supply switch provided in a power supply path between the power supply terminal 1 and the device main body. The power supply path is closed by the operation and the power supply input to the power supply terminal 1 is supplied to the apparatus main body, and the power supply path is opened by the operation of turning off the power supply switch 3 to supply the power to the apparatus main body 2 Is cut off.

Reference numeral 4 denotes an operation power supply circuit for generating operation power for operating each part of the power supply control device, and a resistor whose one end is connected to a power supply path between the power supply terminal 1 and the power supply switch 3 4a and a constant voltage zener diode 4b provided between the other end of the resistor 4a and the ground.
And a capacitor 4c provided between the other end of the resistor 4a and the ground and in parallel with the constant voltage zener diode 4b.

Reference numeral 5 denotes a power supply voltage detection circuit for detecting the voltage level of the power supply supplied to the power supply terminal 1, one end of which is connected to a power supply path between the power supply terminal 1 and the power supply switch 3. A voltage dividing resistor 5a, a voltage dividing resistor 5b provided between the other end of the voltage dividing resistor 5a and the ground, and an input from between the voltage dividing resistor 5a and the voltage dividing resistor 5b to convert an analog voltage level into a digital signal. A / D converter 5c for conversion
It is constituted by. The A / D converter 5c is supplied with operating power generated by the operating power supply circuit 4.

Reference numeral 6 denotes a power switch for supplying power to the device main body 2, and 7 denotes a control circuit for turning on / off the power supply switch 3 based on the operation of the power switch 6. The voltage level detected by the power supply voltage detection circuit 5 operated by the operating power generated by the power supply voltage detector 5 is compared with a preset reference voltage level, and the operation of the power switch 6 is validated or invalidated based on the comparison result. Things.

The operation control when the plug of the AC adapter (not shown) is connected to the power supply terminal 1 in the power supply control device configured as described above will be described.

When a power supply from an AC adapter (not shown) is input to the power supply terminal 1, the operating power supply circuit 4 is operated by the power supply from the power supply terminal 1, and
The operating power supply circuit 4 generates predetermined operating power and supplies it to the power supply voltage detecting circuit 5 and the control circuit 7.

On the other hand, the power supply voltage detection circuit 5 determines the voltage level of the power supply supplied to the power supply terminal 1 by the voltage dividing resistors 5a and 5a.
The A / D comparator 5c converts the detection result into a digital signal and outputs it to the control circuit 7. Then, the control circuit 7 compares the voltage level detected by the power supply voltage detection circuit 5 with a preset reference voltage level, and the voltage level of the power supply is within a predetermined range with respect to the preset reference voltage level. When it is determined that the operation of the power switch 6 in the control circuit 7 is valid, and when it is determined that the voltage level of the power supply is outside a predetermined range with respect to a preset reference voltage level, the control circuit 7 The operation of the power switch 6 in the step is invalidated.

That is, in the control circuit 7, the power supply terminal 1
When it is determined that the voltage level of the supply power input to the power supply is within a predetermined range of a preset reference voltage level, when the power switch 6 is operated to supply power to the device body 2, On the basis of the operation of the power switch 6, the control circuit 7 turns on the power supply switch 3 to close the power supply path so that power is supplied to the device main body. When it is determined that the input voltage level of the power supply is out of the predetermined range of the preset reference voltage level, even if the power switch 6 is operated to supply power to the device body 2, The control circuit 7 invalidates the operation of the power switch 6 and holds the power supply switch 3 in the off state.

The operation control of the control circuit 7 as described above will be described with reference to the flowchart shown in FIG.

This flowchart is obtained by receiving the supply of power from the operating power supply circuit 4, receiving the voltage level from the power supply voltage detection circuit 5, and starting the power supply to the main body 2 by operating the power switch 6. Once started, the process proceeds to step F1.

In step F1, it is determined whether or not the voltage level output from the power supply voltage detection circuit 5 is within a predetermined range of a preset reference voltage level. If it is determined that the voltage is within the predetermined range, the process proceeds to step F2. Then, the power supply switch 3 is turned on and the flow chart ends, and if it is determined that the voltage is not within the predetermined range, the flow shifts to step F3 where the power supply switch 3 is turned off and the flow chart is turned off. To end.

Therefore, the AC connected to the power supply terminal 1
The operation of the power switch 6 is invalidated in the control circuit 7 even if the adapter is not dedicated to the device main body 2 and the power consumption is different. Supply of power can be prevented.

The operating power supply circuit 4 must be adapted to be used in a wide power supply voltage range, but the power consumed by the A / D converter 5c and the control circuit 7 constituting the power supply voltage detection circuit 5 is low. Since a small one can be selected, it is relatively easy to deal with it.

When the power used by the AC adapter connected to the power supply terminal 1 in the control circuit 7 is different from the power used by the device body 2, the power switch 6
The on / off operation of the power supply switch 3 based on the above operation is invalidated, and the display unit and the notifying unit (not shown) inform the user that the AC adapter connected to the power supply terminal 1 is unusable. You may do it.

[Second Embodiment] In FIG. 3, portions common to FIG. 1 are denoted by common reference numerals. In FIG. 3, 1
Reference numeral 1 denotes a chargeable / dischargeable secondary battery which can be a power source of the device main body 2, one end of which is formed in parallel with a power supply path between the power supply terminal 1 and the device main body 2 with the power supply switch 3 interposed therebetween. The ground is connected to the other end while being connected to the charge / discharge supply path.

Reference numeral 12 denotes a charge control switch for supplying power to the secondary battery 11, one end of which is a power supply terminal 1.
One end of a resistor 13 is connected to the other end while being connected to a power supply path between the power supply terminal 3 and the power supply terminal 3.

Reference numeral 13 denotes a resistor for limiting the charging current of the secondary battery 11, one end of which is connected to the other end of the charge control switch 11, and the other end of which is connected to one end of the secondary battery 11 and the discharge control switch 14. One end is connected.

Reference numeral 14 denotes a discharge control switch for supplying the charging voltage of the secondary battery 11 to the main body 2, one end of which is connected to one end of the secondary battery 11 and the other end of the charging current limiting resistor 13. The other end is connected to a power supply path between the device main body 2 and the power supply switch 3. A charge control switch 12, a charge current limiting resistor 13, and a discharge control switch 14 are provided in the charge / discharge supply path.

Reference numeral 15 denotes a control circuit for turning on / off the power supply switch 3, the charge control switch 12, and the discharge control switch 14 based on the operation of the power switch 6, and the operation power generated by the operation power supply circuit 4. And compares the voltage level detected by the power supply voltage detection circuit 5 with a preset reference voltage level,
On / off control of each switch based on the operation of the power switch 6 is performed based on the comparison result. The control circuit 15
When the power switch 6 is not operated to supply power to the device body 2, the power supply switch 3
The on / off operation of each switch is performed so that the discharge control switch 14 is kept off and the charge control switch 12 is kept on.

The operation control in the power supply control device configured as described above when the plug of the AC adapter (not shown) is connected to the power supply terminal 1 will be described.

When a power supply from an AC adapter (not shown) is input to the power supply terminal 1, the power supply from the power supply terminal 1 causes the operation power supply circuit 4 to generate a predetermined operation power, and the power supply voltage detection circuit 5 and the control circuit 15, and the power supply voltage detection circuit 5 detects the voltage level of the power supply supplied to the power supply terminal 1 and outputs the detection result to the control circuit 15.

The control circuit 15 compares the voltage level detected by the power supply voltage detection circuit 5 with a preset reference voltage level, and determines that the voltage level of the power supply is within a predetermined range with respect to the preset reference voltage level. If it is determined that the voltage is within the range, the control circuit 15 causes the power supply switch 3 and the charge control switch 12 to be turned on / off based on the operation of the power supply switch 6, and the voltage level of the power supply is set to a predetermined reference. When it is determined that the voltage level is out of the predetermined range, the control circuit 15 causes the charge control switch 12 and the discharge control switch 14 to be turned on / off based on the operation of the power switch 6.

That is, when the control circuit 15 determines that the voltage level of the power supply input to the power supply terminal 1 is within a predetermined range of a preset reference voltage level, the power switch 6 controls the power supply to the equipment body 2. When an operation for supplying power is performed, the power supply switch 3
Is turned on to close the power supply path, and the power supply to the device main body 2 is performed by the power supply from the AC adapter input to the power input terminal 1, and the power switch 6 supplies power to the device main body 2. When you do not perform the operation to perform
The charging control switch 12 is turned on to close the charging supply path, and the secondary battery 11 is charged by the power supplied from the AC adapter input to the power input terminal 1.

On the other hand, when the control circuit 15 determines that the voltage level of the power supply input to the power supply terminal 1 is out of the predetermined range of the preset reference voltage level, the power switch 6 sends the signal to the equipment body 2. When the operation for supplying power to the secondary battery 11 is performed, the discharge control switch 14 is turned on to close the discharge supply path, and the secondary battery 11
The charge control switch 12 is kept off when the power supply to the device main body 2 is performed by the charging voltage charged to the power supply device 6 and the power switch 6 is not operated to supply power to the device main body 2. Then, the charging supply path is opened to prevent the secondary battery 11 from being charged by the power supply from the AC adapter input to the power input terminal 1.

Regarding the operation control of the control circuit 15 as described above, the charge control of the secondary battery 11 will be described first with reference to the flowchart shown in FIG.

When power is supplied from the operating power supply circuit 4 and a voltage level is input from the power supply voltage detection circuit 5 and the power switch 6 is operated so as not to supply power to the main body 2, This flowchart is started, and the process proceeds to step F11.

In step F11, it is determined whether or not the voltage level output from the power supply voltage detection circuit 5 is within a predetermined range of a preset reference voltage level. If it is determined that the voltage is within the predetermined range, the process proceeds to step F12. Then, the charging control switch 12 is turned on and the flow chart ends, and if it is determined that the voltage is not within the predetermined range, the flow shifts to step F13 where the charging control switch 12 is turned on.
Is turned off, and this flowchart ends.

Therefore, the AC connected to the power supply terminal 1
Even if the adapter is not dedicated to the device main body 2 and the power consumption is different, the control circuit 15 keeps the charge control switch in the off state. Charging can be prevented.

Next, an operation control for supplying power to the device body will be described.

When the power is supplied from the operating power supply circuit 4 and the voltage level from the power supply voltage detection circuit 5 is input, and the power switch 6 is operated to supply power to the main body 2, the flowchart is executed. Is started, and the routine goes to Step F21.

In step F21, it is determined whether or not the voltage level output from the power supply voltage detection circuit 5 is within a predetermined range of a preset reference voltage level. If it is determined that the voltage is within the predetermined range, the process proceeds to step F22. Then, in step F22, the power supply switch 3 is turned on to shift to step F23, where the discharge control switch 14 is turned off, and the flowchart ends.

On the other hand, if it is determined in step F21 that the voltage is not within the predetermined range, the flow shifts to step F24,
In step F24, the power supply switch 3 is turned off, and the process proceeds to step F25.
Is turned on, and this flowchart ends.

Therefore, the AC connected to the power supply terminal 1
Even when the adapter is not dedicated to the device main body 2 and the power used is different, the control circuit 15 uses the charging voltage charged in the secondary battery 11 as the power source of the device main body 2 to use the adapter. It is possible to prevent supply of power to the device main body 2 by using AC adapters of different powers,
The power supply to the device main body 2 can be performed based on the power supply operation to the device main body 2 by the power switch 6 regardless of the C adapter.

[0057]

As described above, according to the first and second aspects of the present invention, when the power supply terminal receives the power supply from the external power supply, the power supply voltage detecting means changes the voltage level of the power supply voltage. After the detection, the level comparing means compares the voltage level with the reference voltage level, and the control means determines whether the power supply input to the power supply terminal can be used as the power supply of the device body based on the comparison result. I do. If the control means determines that the power supply can be used as a power supply for the device main body, the control means turns on the power supply switch provided in the power supply path from the power supply terminal to the device main body based on the operation of the power switch. / Off operation, and when it is determined that the power cannot be used as the power source of the device body, the power supply switch is turned off regardless of the operation of the power switch operation, so that the power used at the power supply terminal is reduced. Even when different AC adapters are connected, it is possible to prevent the power supply from being supplied to the device main body 2 by the different AC adapters, so that the circuit breakage inside the device main body and the device main body can be prevented. Abnormal operation can be prevented.

According to the third aspect of the present invention, the control means determines whether the power supply input to the power supply terminal can be used as the power supply of the device main body, and determines that the power supply can be used as the power supply of the device main body. If the control means turns on the charge control switch to charge the secondary battery with the power supply input to the power supply terminal, and if it is determined that the secondary battery cannot be used as the power supply of the device body, the control means The means controls the charging control switch to be turned off so as not to charge the secondary battery, so that even when an AC adapter having a different power consumption is connected to the power supply terminal, such power consumption is reduced. Since charging of the secondary battery by different AC adapters can be prevented, damage to the built-in secondary battery can be prevented.

According to the fourth aspect of the present invention, the control means determines whether the power supply input to the power supply terminal can be used as the power supply of the device main body, and determines that the power supply can be used as the power supply of the device main body. In this case, based on the operation of the power switch, the control means may cause the power supply switch provided on the power supply path from the power supply terminal to the device main body to be turned on / off, and may be used as the power source of the device main body. If it is determined that the power supply switch cannot be operated, the power supply switch is turned off regardless of the operation of the power switch, and the discharge control switch provided in the charge / discharge supply path formed in parallel with the power supply path based on the operation of the power switch. By performing the on / off operation of the power supply, even when an AC adapter having a different power consumption is connected to the power supply terminal, such use is possible. Since it is possible to prevent the power supply to the device main body 2 from being supplied by an AC adapter having a different power, it is possible to prevent circuit breakage inside the device main body and abnormal operation of the device main body, and further connect to the power supply terminal 1. Power switch 6 regardless of the AC adapter
The power supply to the device main body 2 can be performed based on the power supply operation to the device main body 2 in.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing an electrical configuration of a power supply control device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing operation control of the power supply control device.

FIG. 3 is a schematic block diagram illustrating an electric configuration of a power supply control device according to a second embodiment of the present invention.

FIG. 4 is a flowchart showing charging operation control of the power supply control device.

FIG. 5 is a flowchart showing a power supply operation of the power supply control device.

FIG. 6 is a schematic block diagram showing an electrical configuration of a power supply control device as a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power supply terminal 2 Device main body 3 Power supply switch 4 Operating power supply circuit 5 Power supply voltage detection circuit 6 Power supply switch 7, 15 Control circuit 11 Secondary battery 12 Charge control switch 14 Discharge control switch

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H02M 1/00-11/00

Claims (4)

(57) [Claims] A power input terminal for receiving a power supply voltage from an external power supply; and a power switch for supplying power to a device main body. The power input terminal receives an input to the power input terminal in response to an on operation of the power switch. In the power supply control device for supplying the supplied power to the device main body, the voltage level of the supply power supplied to the power supply input terminal is adjusted.
Power supply voltage detecting means for performing digital conversion and detection; level comparing means for comparing a voltage level detected by the power supply voltage detecting means with a reference voltage level; and a power supply input based on a comparison result from the level comparing means. And control means for controlling the supply of power supplied to the terminal to the device main body, wherein the control means adjusts a voltage level detected by the power supply voltage detection means based on a comparison result from the level comparison means. When it is determined that the reference voltage level is within a predetermined range, control is performed to supply power to the device body by turning on the power switch, while when it is determined that the reference voltage level is out of the predetermined range, the power switch is turned off. A power supply control device that performs control so as not to supply power to a device body regardless of an on operation. 2. A power supply switch for connecting / disconnecting the power supply path is provided on a power supply path from the power input terminal to the device main body, and the control means controls the comparison result from the level comparison means. When it is determined that the voltage level detected by the power supply voltage detecting means is within a predetermined range of the reference voltage level, the power supply switch is turned on by turning on the power supply switch to connect the power supply path. 2. The power supply apparatus according to claim 1, wherein when the power supply switch is determined to be out of the predetermined range, the power supply switch is turned off to open the power supply path regardless of the operation of turning on the power switch. Power control unit. 3. A charge / discharge supply path is formed in parallel with a power supply path from the power supply input terminal to the device main body, and a chargeable / dischargeable secondary battery and the secondary battery are provided in the charge / discharge supply path. A charging control switch for performing power supply of the power supply, wherein the control unit determines that a voltage level detected by the power supply voltage detection unit based on a comparison result from the level comparison unit is within a predetermined range of a reference voltage level. When it is determined, the charge control switch is turned on to charge the secondary battery, while when it is determined that the charge is outside the predetermined range, the charge control switch is turned off to charge the secondary battery. The power supply control device according to claim 1, wherein there is no power supply. 4. A power supply switch for connecting / disconnecting the power supply path is provided in a power supply path from the power supply input terminal to the device main body, and the power supply control switch is sandwiched therebetween and parallel to the power supply path. Forming a charge / discharge supply path on the charge / discharge supply path, and providing a chargeable / dischargeable secondary battery and a discharge control switch for supplying the charging voltage of the secondary battery to the device main body. When it is determined that the voltage level detected by the power supply voltage detection means is within a predetermined range of the reference voltage level based on the comparison result from the level comparison means, the power supply switch is turned on by operating the power supply switch. When it is determined that the power supply path is out of the predetermined range, the power supply switch is turned off by turning on the power switch. Power control device according to claim 1 or claim 3, wherein the to perform power supply to the apparatus body by the secondary battery on the discharge control switch.