JPH0515082A - Power source supplying apparatus - Google Patents

Abstract

PURPOSE:To prevent a battery from being overcharged even when it is used for a body of electric-electronic apparatus, etc., containing a chargeable battery, and to improve a life and safety of an apparatus itself. CONSTITUTION:A power source supplying apparatus 1 for converting a voltage from a commercial power source 2 to a voltage usable for an apparatus body 3 comprises a current detector 4 for detecting a current flowing to the body, an output voltage converter 5 for converting the power source voltage to a first output voltage or a second output voltage lower than the first voltage to be output, a memory 6, a timer 7 for counting a predetermined time, and a CPU 8 for executing a control program stored in the memory. The CPU 8 outputs the first voltage from the converter 5 during a period until a predetermined time is elapsed in a state that the current is detected from when the current is detected, and outputs the second voltage from the converter 5 during a period from when the predetermined time is elapsed until the current is not detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention converts a power supply voltage from a commercial power source into a voltage that can be used in a device body such as an information processing device or electric / electronic equipment and outputs the voltage to the device body. The present invention relates to a power supply device capable of arbitrarily making electrical connection and disconnection with a main body.

[0002]

2. Description of the Related Art Conventionally, a power supply device of this type generally converts a power supply voltage from a commercial power supply into a constant voltage that can be used by the device body, and keeps outputting only this constant voltage to the device body. Is configured.

[0003]

However, in the above-mentioned prior art, since a constant voltage is constantly output to the device body, when the device body has a rechargeable battery, the device body is There is a problem that the battery is overcharged except when it has a special circuit.

In addition, since the power supply device is connected to a commercial power source and is in an operating state because the electrical connection and disconnection with the device body can be arbitrarily performed, the device body is disconnected from the power supply device. There are cases. In this case,
Unless the commercial power supply side is turned off, the power supply device continues to output a constant voltage, which causes a problem that the life and safety of the power supply device are impaired.

The present invention has been made by paying attention to the above-mentioned conventional problems, and it has been proposed that an electric / electrical device containing a rechargeable battery is built in.
An object of the present invention is to provide a power supply device capable of preventing the battery from being overcharged even when used in a device body such as an electronic device, and improving the life and safety of the power supply device itself. I am trying.

[0006]

In order to solve the above-mentioned problems, the present invention converts a power supply voltage from a commercial power supply into a voltage that can be used in a device body such as an electric / electronic device and outputs the voltage to the device body. In a power supply device capable of arbitrarily making electrical connection and disconnection with the device body, a current detection unit that detects the presence or absence of a current flowing in the device body, and the power supply voltage as a first output voltage. An output voltage conversion unit capable of converting to one of at least two output voltages including a second output voltage lower than the voltage and outputting the output voltage to the device main body, a memory storing a predetermined control program, and timing of a predetermined time. And a CPU for executing the control program
And the CPU outputs the first output voltage from the time when the current is detected by the current detector to the time when the predetermined time elapses while the current is being detected. The output voltage is configured to be output from the conversion unit, and the second output voltage is output from the output voltage conversion unit from the time when the predetermined time elapses until the current is no longer detected.

[0007]

When the device body is connected to the power supply device, the current detector detects the current. From the time of this detection until the predetermined time elapses in the state in which the current is detected, that is, in the state in which the device body is connected to the power supply device, the CP
U causes the output voltage conversion unit to output the first output voltage,
The device body is operated by the first output voltage. From the time when a predetermined time elapses until the current is no longer detected, that is, until the device body is disconnected from the power supply device,
The CPU causes the output voltage conversion unit to output a second output voltage lower than the first output voltage, and the device body continues to operate with the second output voltage.

[0008]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a power supply device according to an embodiment of the present invention.

This power supply device 1 converts a power supply voltage Va from a commercial power supply 2 into a voltage that can be used for an information processing device such as a personal computer and a word processor, and a device body 3 such as an electric / electronic device such as a facsimile. And outputs it to the device body 3. In addition, the power supply device 1
Can be electrically connected to and disconnected from the device body 3 by a switch (not shown) on the device body 3 side. The power supply voltage Va is, for example, 100
V, 50 Hz. The device body 3 also has a rechargeable battery built therein.

The power supply device 1 includes a current detection unit 4 for detecting a current flowing through the device body 3 and a first power supply voltage Va.
Output voltage V ₁ (for example, 12 V) or _{one of} the second output voltage V ₂ (for example, 8 V) lower than the output voltage V ₁ and output to the device body 3 is possible.
The memory 6 stores a predetermined control program, a timer 7 that measures a predetermined time (for example, 8 hours), and a CPU 8 that executes the control program of the memory 6.

The CPU 8 keeps the first output voltage V ₁ from the time when the current flowing through the device body 3 is detected by the current detector 4 until the predetermined time elapses while the current is being detected. Output from the output voltage converter 5,
From the time when the predetermined time has elapsed until the current is no longer detected by the current detector 4, the second output voltage V ₂
Is output from the output voltage converter 5.

A power supply device 1 according to the above embodiment will be described below.
The operation of will be described with reference to FIG.

When the commercial power supply 2 is turned on in step 20 shown in FIG. 2, the CPU 8 causes the output voltage converter 5 to output the first output voltage of 12 V according to the control program stored in the memory 6 (step 21). .. Next, in step 22, it is determined whether or not there is a current detected by the output voltage converter 5. When the answer to step 22 is negative (No), that is, when there is no current, it is determined that the device body 3 is not connected to the power supply device 1, and the CPU 8 outputs 12V.
The first output voltage is continuously output from the output voltage converter 5.

When the answer to step 22 is affirmative (Yes), that is, when the device body 3 is connected to the power supply device 1 and the current is detected by the current detector 4, the CPU 8 resets the timer 7 and starts. (Step 23).
As a result, the timer 7 starts measuring the predetermined time (8 hours).

Next, in step 24, it is determined again whether or not there is a current detected by the output voltage converter 5. When the device main body 3 is disconnected from the power supply device 1 and the current detected by the current detection unit 4 disappears, that is, when the answer to step 24 is negative (No), the CPU 8 outputs the first output voltage of 12V. Is continuously output from the output voltage converter 5.

When the answer to step 24 is affirmative (Yes), when the device body 3 is connected to the power supply device 1 and there is a current detected by the current detecting section 4, step 2
Go to 5. In step 25, the CPU 8 causes the timer 7
It is determined whether or not the predetermined time (8 hours) clocked by is elapsed. When the answer is negative (No), that is, when the predetermined time has not elapsed, the CPU 8 continues to output the first output voltage of 12V from the output voltage conversion unit 5. When the answer to step 25 becomes affirmative (Yes) after the elapse of the predetermined time, the CPU 8 causes the output voltage conversion unit 5 to output the second output voltage of 8 V according to the control program stored in the memory 6 ( Step 26).

Next, in step 27, the current detector 4
It is again determined whether or not there is a current detected by. The answer to step 27 is affirmative (Yes), that is, the device body 3
Is connected to the power supply device 1 and there is a current detected by the current detection unit 4, the CPU 8 continues to output the second output voltage of 8V from the output voltage conversion unit 5. When the answer to step 27 is negative (No), that is, when the device body 3 is disconnected from the power supply device 1 and the current detected by the current detection unit 4 is lost, the CPU 8 causes the CPU 8 to execute the step 21.
Then, the first output voltage of 12V is output from the output voltage converter 5.

As described above, in the power supply device 1, since the device body 3 is connected to the power supply device 1 and the current is detected by the current detector 4, the state in which the current is detected, that is, the device body 3 is Since the first output voltage of 12 V is output to the device body 3 until a predetermined time (for example, 8 hours) elapses in a state of being connected to the power supply device 1, it is built in the device body 3. The rechargeable battery is rapidly charged with the first output voltage of 12V only during the predetermined time. Then, the power supply device 1 is lower than the first output voltage from the time when the predetermined time has elapsed until the current is no longer detected by the current detection unit 4, that is, until the device body 3 is disconnected from the power supply device 1. Second output voltage (8V)
Is output to the device body 3, the battery is prevented from being overcharged, and the life and safety of the power supply device 1 are improved.

In the above embodiment, the first output voltage is 12V and the second output voltage is 8V. However, the present invention is not limited to this, and the first output voltage is, for example, 15V. And the second output voltage may be 0V.

[0021]

As described above, according to the present invention,
A power supply that converts a power supply voltage from a commercial power supply into a voltage that can be used in a device body such as an electric / electronic device and outputs the voltage to the device body, and that can be arbitrarily electrically connected to and disconnected from the device body. In the supply device, a current detection unit that detects the presence or absence of a current flowing through the device body, and the power supply voltage to one of at least two output voltages including a first output voltage and a second output voltage lower than the first output voltage. An output voltage converter capable of converting the output voltage to the device body, a memory storing a predetermined control program, a timer for measuring a predetermined time, and a CPU for executing the control program,
The CPU outputs the first output voltage from the output voltage converter from the time when the current is detected by the current detector to the time when the predetermined time elapses while the current is being detected. In addition, during the period from the time when the predetermined time has elapsed to the time when the current is no longer detected, the second
Since the output voltage of the device is configured to be output from the output voltage conversion unit, the state in which the current is detected from the time when the device body is connected to the power supply device and the current is detected by the current detection unit, that is, While the main unit is connected to the power supply device, the CPU
Means to output the first output voltage from the output voltage converter, the device main body is operated by the first output voltage, and after a predetermined time elapses, until the current is no longer detected by the current detector, that is, the device. Until the main body is disconnected from the power supply device, the CPU causes the output voltage conversion unit to output the second output voltage lower than the first output voltage, and the device main body continues to operate with the second output voltage. Therefore, even when used in a device body such as an electric / electronic device having a rechargeable battery built-in, the battery can be prevented from being overcharged and the life and safety of the power supply device itself can be improved. Can be planned.

[Brief description of drawings]

FIG. 1 is a block diagram showing a power supply device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of the power supply device shown in FIG.

[Explanation of symbols]

 1 power supply device 2 commercial power supply 3 device body 4 current detection unit 5 output voltage conversion unit 6 memory 7 timer 8 CPU

Claims (1)

Claim: What is claimed is: 1. A device for converting a power supply voltage from a commercial power source into a voltage that can be used in a device body such as an electric / electronic device and outputting the voltage to the device body. In a power supply device that can be arbitrarily connected and disconnected, a current detection unit that detects the presence / absence of a current flowing through the device body, a power supply voltage that is a first output voltage, and a second output voltage that is lower than the voltage. An output voltage conversion unit capable of converting the output voltage into one of at least two output voltages including the output voltage to the device main body, a memory storing a predetermined control program, a timer for measuring a predetermined time, and the control program. CPU to execute
And the CPU outputs the first output voltage from the time when the current is detected by the current detector to the time when the predetermined time elapses while the current is being detected. The converter is configured to output the second output voltage from the output voltage converter, from the time when the predetermined time has elapsed to the time when the current is no longer detected. Power supply device.