KR20000014310A - Battery defective sensing device and method of portable communication terminal - Google Patents

Abstract

PURPOSE: A battery defective sensing device and method of portable communication terminal is provided to prevent unnecessary charge to the defective battery. CONSTITUTION: The battery defective sensing device of portable communication terminal comprises: an outer adapter providing charge current; a battery(51) having a protect circuit(52) and serving as a power supply; a charge circuit(40) operated under prescribed control, detecting under the appliance of said charge current, and uniformly maintain the charge current in accordance to said detected charge current and said battery voltage to supply it to said battery; a memory(20) having a battery state flag, and storing prescribed state value according to the error of the battery in said battery state flag; a display(80) displaying a battery defective alarm characters under prescribed control; an alarm(70) generating a battery defective sound; and a microprocessor(10) making said charge circuit into ON/OFF.

Description

Battery defect detection device and method of mobile communication terminal

The present invention relates to a battery charging device and method of a mobile communication terminal, and more particularly to a battery failure detection device and method that can detect whether the battery is defective during charging.

In general, in the case of a mobile communication terminal having a built-in charging function, a method of detecting a failure of a battery before starting charging is mainly a hardware method that prevents charging when the battery voltage level is lower than a predetermined level. Was used. This method is useful for detecting defects such as nickel-metal hydride batteries but has limitations in the case of lithium batteries.

Lithium batteries often have a built-in protection circuit for safety, and this protection circuit performs overcharge protection, over discharge protection, and temperature protection. In the case of a lithium battery with a built-in protection circuit, the protection circuit disconnects the power terminal to protect the battery when the battery is over discharged. Typically, the lower limit voltage for detecting battery over discharge is around 2.7V. If the battery voltage falls below this voltage, the protection circuit protects the battery by closing the MOSFET switch, and the battery terminal voltage becomes 0V. .

Although the overdischarge state of the lithium battery is abnormal, it does not cause a problem in use because it recovers again when an external charging current is applied. In the case of a desktop charger that charges from the outside of the mobile communication terminal, an independent power source is used as a power source, and since it is sometimes controlled by an independent microprocessor, the battery can be charged regardless of the operation of the mobile communication terminal. Has a function to recover when overdischarged. In the case of a battery that cannot be recovered even after several attempts to recover, the microprocessor determines that the battery is a bad battery and blinks an LED to notify the user of the battery failure.

The charging circuit embedded in the portable communication terminal is powered by the microprocessor itself, which controls the charging, so that it is impossible to detect when a bad battery is inserted. In this case, the method needs to protect the system to prevent the battery from over-discharging. That is, during operation of the mobile communication terminal, the battery inside the terminal is frequently checked to turn off the terminal power when the voltage falls below the threshold voltage, or to turn off the power supply by hardware at the threshold voltage. Protect. At this time, it should be at least 0.2V higher than the over-discharge protection voltage in the terminal system.

As described above, in the case of the charging circuit built in the portable communication terminal, it is best to prevent the overdischarge in the system because it causes a problem during overdischarge, but for this purpose, the voltage at least 0.2V higher than the overdischarge voltage of the battery protection circuit Since the power supply must be turned off, the battery usage efficiency is reduced.

In addition, even if overdischarge is prevented in the system, overdischarge due to battery overdischarge or overdischarge due to self-discharge of battery occurs. Therefore, in order to charge the over-discharged battery, the charging circuit must be designed to perform the charging operation regardless of the microprocessor. In this case, the reliability of the defective battery rather than the over-discharge battery is reduced. In other words, the charging circuit automatically performs the charging operation when the charging voltage is applied without the control of the processor. Thus, the charging circuit supplies the charging current as in the case of the normal battery even if the over-discharge battery or the defective battery is used. Since the microprocessor has no way of knowing whether the power source for driving the mobile communication terminal is a battery or a charging current, the microprocessor cannot detect even a defective battery.

As described above, since the power supply must be turned off at a voltage higher than the over-discharge voltage of 0.2V, the efficiency of the power supply is inferior.

In addition, in the case of a bad battery, even if the battery terminal is physically broken or the protection circuit is broken, the user may not know this, and the system may turn off when the charging adapter is removed from the terminal plug due to a wrong charge. .

Accordingly, an object of the present invention is to provide an apparatus and method capable of detecting a battery failure by determining whether system power is provided from a battery or a charging current.

In order to achieve the above object, the present invention provides a battery failure detection device of a mobile communication terminal, comprising: an external adapter for providing a charging current, a protection circuit, a battery for supplying power to the entire apparatus, and predetermined control; A charging circuit which receives the charging current and detects the charging voltage, maintains the charging current constant according to the detected charging voltage and the voltage of the battery, and supplies the battery to the battery; A memory for storing a predetermined state value according to whether or not the battery is abnormal in the battery state flag, a display unit for displaying a battery failure notification letter under predetermined control, an alarm unit for generating a battery failure alarm sound under predetermined control, and The battery is operated normally by turning on / off the operation of the charging circuit and periodically checking the battery for failure. If the battery status flag of the memory is set to reset, and if the battery status flag is set to bad, the battery normal state flag is set to three. Then, the alarm unit is controlled to generate a battery failure notification alarm and the display unit is controlled to display a battery failure notification character. It is characterized by consisting of a microprocessor.

In order to achieve the above object, the present invention provides a battery failure detection method of a mobile communication terminal having a memory having a battery state flag for indicating whether or not the battery is in a bad state, when the charge is started to check the state of the battery A first process, a second process of checking whether the battery is in a fully charged state when the state of the battery is normal, a third process of inspecting the battery state flag when the battery is in a full charge state during the inspection; A fourth step of increasing the battery check counter by 1 if the battery state flag is set and checking whether the battery check counter value is less than 10, and if the battery check counter value is 10 or more times It is characterized by consisting of a fifth step of alarming the battery failure, and terminating the charge.

1 is a block diagram of a battery failure detection device of a mobile communication terminal according to an embodiment of the present invention.

2 is a detailed circuit diagram of the charging circuit of FIG.

3 is a flowchart illustrating a battery failure detection method of a mobile communication terminal according to an exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals have the same reference numerals as much as possible even if displayed on different drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

1 is a block diagram of an apparatus for detecting a battery failure in a mobile communication terminal according to an exemplary embodiment of the present invention.

Hereinafter, referring to FIG. 1, the microprocessor 10 controls the overall operation of the portable communication terminal. The microprocessor 10 includes a ROM for storing a predetermined operating program and a RAM for temporarily storing data generated during the execution of the operating program. The memory 20 is a non-volatile memory such as an EEPROM and stores data such as a number of parameters and messages. In addition, the memory 20 has a battery state flag for indicating a defective state of the battery according to the present invention. If the state of the battery state flag is "1", it means that the battery is bad, and "0" indicates that it is not bad. The external adapter 30 receives an external power source and outputs a charging current. The charging circuit 40 operates under the control of the microprocessor 10, detects a charging voltage by applying the charging current, maintains a charging current constant according to the detected charging voltage and the voltage of the battery, and supplies the same to the battery. do. The battery unit 50 includes a battery 51 and a protection circuit 52 for protecting the battery 51, and supplies power to the entire mobile communication terminal. The RF unit 60 modulates and demodulates a radio signal transmitted and received through an antenna. The alarm unit 70 generates an alarm sound under the control of the microprocessor 10. Under the control of the microprocessor 10, the display unit 80 displays a plurality of pieces of information and an operation state of the portable communication terminal using text and icons.

Referring to the battery failure detection operation of the mobile communication terminal configured as described above, the external adapter 30 is connected to the external power supply terminal to output the charging current. The charging circuit 40 detects the charging voltage by receiving the charging current, maintains the charging current constant according to the detected charging voltage and the voltage of the battery, and outputs the charging current to the battery unit 50. The battery unit 50 receives a charging current from the charging circuit 40 and is charged. In addition, the battery unit 50 has a battery protection circuit 52 therein. The microprocessor 10 periodically turns on / off the charging circuit while the battery unit 50 is being charged through the external adapter 40 and the charging circuit 40. This is to determine whether the battery is defective. The microprocessor 10 determines whether the battery unit 50 is a bad battery by checking whether the portable communication terminal is operated by the power of the battery unit 50 even when the microprocessor 10 turns off the charging circuit 40. . When the microprocessor 10 turns off the charging circuit 40, since the charging operation is initialized and cannot return to the previous state, the current state of the battery 20 is stored in the battery status flag of the memory 20. This is to allow the microprocessor 10 to return to its previous state of charge and continue charging if the battery is not defective.

2 is a detailed circuit diagram of the charging circuit 40 and the battery unit 50 of FIG. Hereinafter, the configuration and operation of the charging circuit 40 by the microprocessor 10 will be described with reference to FIG. 2.

The charging circuit 40 includes a charging current supply unit 41, a charging voltage detection unit 43, a battery voltage detection unit 4k5, and a charging enable unit 47. The charging current supply unit 41 receives a charging current from the external adapter, receives a predetermined feedback current, and maintains and outputs a predetermined charging current amount. The charging current is applied to detect a charging voltage, and compares whether the charging voltage is greater than the first reference voltage. When the charging voltage is greater than the reference voltage, the charging current is supplied to the charging current supply unit. Is connected between the charging voltage detector 43 and the battery unit 50 to detect the voltage of the battery unit 50, and compares whether the detected voltage of the battery unit 50 is greater than a second reference voltage to the charging current supply unit. Supply the feedback current. The charging circuit is turned on / off under the control of the microprocessor 10.

The charging current supply unit 41 receives a charging current input from the external adapter as an emitter, receives a feedback current to a base terminal, and outputs a constant charging current to a collector terminal, and the transistor Q1. A capacitor C1 connected to the emitter terminal and the base terminal of the first terminal, a first resistor R1 connected in parallel with the capacitor C1, and an anode connected to the collector terminal of the transistor Q1 are connected to each other. The first diode D1 outputs the output charging current to the charging voltage detector 41 through a cathode.

The charging voltage detector 43 receives a charging current output from the first diode D1 of the charging current supply unit and generates a second resistor R2 that generates a predetermined first voltage drop, and the charging output from the charging current supply unit. A third resistor R3 that receives a current and generates a predetermined second voltage drop and a voltage generated by the voltage drop of the second resistor R2 and the third resistor R3 are differentially amplified and output. The first comparator U2 and the differential amplified voltage are applied, and the differential amplified voltage is compared with the second reference voltage. When the differential amplified voltage is greater than the first reference voltage, the feedback current is supplied to the charging current supply unit. It consists of a second comparator (U1) output to.

The battery voltage detector 45 is connected to the fourth resistor R4 connected to the battery unit 50 and the fourth resistor R4 in parallel, and divides the voltage provided from the battery unit 50 with the fourth resistor R4. And the voltage divided by the fifth resistor R5, the fourth resistor R4, and the fifth resistor R5 and the second reference voltage, and the divided voltage is greater than the second reference voltage. If larger, the third comparator U3 outputs a feedback current to the charging current supply part 41.

In addition, the charge enable unit 47 is connected to the fifth resistor R5, and a MOSFET which turns on / off the entire charging circuit 41 by receiving a control signal (Enable signal) from the microprocessor 10 to a gate terminal. Used.

The battery protection circuit 52 is connected to a CMOS inverter composed of MOSFET N-type and P-type and the gate terminals of the two MOSFETs at the negative terminal of the battery 51, and senses the voltage, charge / discharge current, temperature, etc. of the battery 51 The battery protection control unit (U5) to protect the.

3 is a flowchart illustrating a battery failure detection method of a mobile communication terminal according to an exemplary embodiment of the present invention.

2 and 3, the microprocessor 10 first checks the state of the battery unit 50 through the protection circuit 52 inside the battery unit 50 in step 301. The state of the battery unit 50 checked by the protection circuit is generally battery voltage, charge / discharge current, temperature, and the like. After checking the battery state, the microprocessor 10 determines whether the battery is normal by comparing the battery voltage preset in step 303 with the values for the charge / discharge current and the temperature. The normal determination of the state of the battery does not examine the state of the battery itself (physical disconnection, breakage of the protection circuit), but is related to the normality of the states related to charging as described above. As a result of determining whether the battery is normal, if abnormal, the microprocessor 10 controls the protection circuit 52 to terminate the charging.

If the battery is in a normal state, the microprocessor 10 proceeds to step 305 to check whether the battery 51 is fully charged. If the battery 51 is not fully charged, the microprocessor 10 returns to step 301 to retest the battery 51 and repeat the process. However, if the battery 51 is fully charged, the microprocessor 10 checks the battery status flag of the memory in step 307, and determines whether the battery status flag is reset (Reset = 0) in step 309. If the battery status flag is reset, the microprocessor 10 proceeds to step 311 to set the battery status flag to set (Set = 1). If the battery status flag is set to three, the microprocessor 10 stops charging the battery 51 in step 313. After the charging is finished in step 313, the microprocessor 10 proceeds to step 315 to check whether power is supplied from the battery 51. If no power is supplied from the battery 51, the microprocessor 10 will be forcibly shut down because no power is input. However, if power is supplied from the battery 51, the microprocessor 10 proceeds to step 317 to reset the battery status flag, and proceeds to step 319 to reset the battery check counter. After resetting the battery check counter, the microprocessor 10 proceeds to step 321 and flashes an alarm sound or LED through the alarm unit 70 to inform the user that the battery is in a fully charged state.

On the other hand, if the battery status flag is set (1) in step 309, the microprocessor 10 proceeds to step 323 to increase the number of battery check counter by one. Thereafter, the microprocessor 10 proceeds to step 324, and determines whether the number of battery test counts is within a predetermined number in step 324. The predetermined number of times is generally ten times. As a result of the comparison, when the number of battery check counters is less than or equal to 10, the microprocessor 10 proceeds to step 313 to terminate charging, and then repeats the process after step 315.

When the number of battery test counts is greater than 10, the microprocessor 10 proceeds to step 327 and notifies the user of the battery failure through the alarm unit 70 and the blinking of the LED. After the alarm is issued, the microprocessor 10 proceeds to step 329 to reduce the charging current and terminate.

In addition, the microprocessor 10 may generate a different alarm sound when the battery is fully charged and an alarm sound when the battery is bad, and notify the user of the current state of the battery 51.

As described above, the present invention checks whether there is an abnormality in the battery and informs the user of the battery failure when the battery of the mobile communication terminal using the battery is charged, thereby preventing unnecessary charging by the user. There is an advantage that can prevent the waste of power.

Another advantage of the present invention is that the user can solve the reliability problem of the mobile communication terminal that may be caused by a battery failure.

Claims (9)

In the battery failure detection device of a mobile communication terminal, An external adapter providing a charging current, A battery having a protection circuit and providing power to the apparatus in general; A charging circuit which operates under a predetermined control, detects a charging voltage by receiving the charging current, maintains a charging current constant according to the detected charging voltage and the voltage of the battery, and supplies the battery to the battery; A memory having a battery status flag and storing a predetermined status value according to whether or not a battery is abnormal in the battery status flag; A display unit for displaying a battery failure notification letter under predetermined control; An alarm unit for generating a battery bad alarm sound under predetermined control; Turn on / off the operation of the charging circuit, periodically inspect the battery for failure, and if the battery is normal, set the battery status flag of the memory to reset, if the battery is defective, set the battery steady state flag to three, and then the alarm unit. And a microprocessor for generating a battery failure notification alarm by controlling the display unit and displaying a battery failure by controlling the display unit. The method of claim 1, wherein the charging circuit, A charging current supply unit configured to receive a charging current from the external adapter, receive a predetermined feedback current, and maintain and output a predetermined charging current amount; A charging voltage detection unit configured to detect the charging voltage by receiving the charging current, and compare the charging voltage with the first reference voltage to supply the feedback current to the charging current supply unit when the charging voltage is greater than the reference voltage; A battery voltage sensing unit configured to detect a battery voltage and compare whether the battery voltage is greater than the second reference voltage to supply a feedback current to the charging current supply unit when the battery voltage is greater than the reference voltage; And a charging enable unit configured to turn on / off a charging circuit under the control of the controller. The method of claim 2, wherein the charging current supply unit, A transistor configured to receive a charging current input from the external adapter as an emitter and receive a feedback current to a base terminal and output a constant charging current to a collector terminal; A capacitor connected to the emitter end and the base end of the transistor; A first resistor connected in parallel with the capacitor, An anode is connected to the collector terminal of the transistor, the battery failure detection device of the mobile communication terminal, characterized in that the first diode for outputting the charging current output from the collector terminal to the charging voltage detector through a cathode. The method of claim 2, wherein the charging voltage detection unit, A second resistor receiving a charging current output from the charging current supply unit and generating a predetermined first voltage drop; A third resistor configured to receive a charging current output from the charging current supply unit and generate a predetermined second voltage drop; A first comparator for receiving the voltage generated by the second resistor and the third resistor to differentially amplify and output the voltage; A second comparator configured to receive the differential amplified voltage, compare the differential amplified voltage with a second reference voltage, and output a feedback current to the charging current supply unit when the differential amplified voltage is greater than the first reference voltage. Battery failure detection device of a mobile communication terminal, characterized in that made. The method of claim 2, wherein the battery voltage detection unit, A fourth resistor connected to the battery; A fifth resistor for dividing and outputting the voltage provided from the battery with the fourth resistor; And a third comparator for comparing the voltage divided by the fourth and fifth resistors with the second reference voltage and outputting a feedback current to the charging current supply unit when the divided voltage is greater than the second reference voltage. Battery failure detection device of a mobile communication terminal, characterized in that. The method of claim 2, wherein the charging enable portion, Battery failure detection device of a mobile communication terminal, characterized in that the field effect transistor. In the battery failure detection method of a mobile communication terminal having a memory having a battery status flag for indicating whether the battery is in a bad state, The first process of checking the state of the battery when charging is started, A second process of checking whether the battery is in a fully charged state when the state of the battery is normal; A third process of inspecting the battery state flag when the battery is in a fully charged state during the inspection; A fourth step of increasing a battery check counter by one if the battery state flag is set and checking whether the battery check counter value is less than 10; And a fifth process of warning of a battery failure and ending charging if the battery test counter value is 10 or more times. The method of claim 7, wherein And a sixth step of stopping the charging, resetting the battery status flag and the battery check counter, and alerting that the battery is fully charged when the battery check counter value is less than 10 in the fourth step. The method of claim 7, wherein If the battery state flag is determined to be in the reset state in the third process, the battery state flag is set to three, and then the charging is interrupted, the battery state flag and the battery test counter are reset, and the state of full charge is alarmed. And a seventh process of terminating the charging.