JP2010233280A - Charging apparatus and method for discrimination of charger adapter, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To discriminate properties of a charger adaptor before starting charge, even while a battery is close to its full charge. <P>SOLUTION: A charging apparatus, which charges a battery with the charger adaptor connected thereto, includes a control transistor which performs voltage control and current control for charging the battery from a charger adaptor, a bypass circuit which draws in and bypasses a current of a limiter current or more via a control transistor from the charger adaptor, a detecting circuit which detects the value of a drawn-in current, and a control unit which activates the bypass circuit temporarily before starting charge control of the battery and determines the properties of the charger adaptor based on the current value that the detecting circuit has detected. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a determination method and a program for a charging device and a charger adapter, and particularly relates to a determination method and a program for a charging device and a charger adapter that determine that a nonstandard charger adapter is connected.

  A portable electronic device such as a cellular phone has a built-in charge control circuit for a battery pack (battery, secondary battery), is connected to a charger adapter (AC adapter), and a voltage is applied to the charging terminal. It is often equipped with a charging device that starts charging. If a non-regular charger adapter that is not standard is connected to such a charging device, the battery pack may not be charged and the portable electronic device may not operate. In addition, the charging device may fail.

  Therefore, Patent Document 1 describes a charging device that can identify the cause of failure of the charging device when a non-standard external DC power source such as an AC adapter is mounted. This charging device determines whether or not the AC adapter is within the standard only after the charging current starts to flow by monitoring the charging current.

JP 2007-209156 A

  The following analysis is given in the present invention.

  By the way, in the conventional charging device, when the battery is nearly fully charged, the charging current to the battery side hardly flows. Therefore, even if a non-standard charger adapter is connected, the charging current does not flow and the operation is continued without being recognized as non-standard. Thus, even if the same nonstandard charger adapter is used, it may not be determined that the adapter is nonstandard depending on the state of charge of the battery.

  Therefore, an object of the present invention is to provide a charging device, a method for determining a charger adapter, and a program capable of determining the characteristics of the charger adapter before charging even when the battery is almost fully charged. There is to do.

  A charging device according to one aspect of the present invention is a charging device that connects a charger adapter to charge a battery, and performs control for performing voltage control and current control for charging the battery from the charger adapter. A transistor, a bypass circuit that draws and bypasses the current greater than the limiter current from the charger adapter via the control transistor, a detection circuit that detects the current value of the drawn current, and temporarily before charging control of the battery A control unit that activates the bypass circuit and determines the characteristics of the charger adapter based on the current value detected by the detection circuit.

  According to another aspect of the present invention, a method for determining a charger adapter includes a step of connecting a charger adapter to a charging device for charging a battery, and temporarily starting the charging adapter before starting charging control of the battery. A step of drawing and bypassing a current greater than or equal to the limiter current, and a step of determining characteristics of the charger adapter based on a current value of the drawn current.

  A program according to still another aspect of the present invention includes a control transistor for performing voltage control and current control for charging a battery from a charger adapter, and a current greater than a limiter current from the charger adapter via the control transistor. The battery charging control is started in a computer that includes a bypass circuit that pulls in and bypasses and a detection circuit that detects a current value of the drawn current and connects the charger adapter to charge the battery. A process of temporarily activating the bypass circuit before and a process of determining the characteristics of the charger adapter based on the current value detected by the detection circuit are executed.

  According to the present invention, it is possible to determine the characteristics of the charger adapter before charging even when the battery is nearly fully charged.

It is a block diagram which shows the structure of the charging device which concerns on 1st Example of this invention. It is a figure which shows the characteristic in case a regular charger adapter is used. It is a figure which shows the characteristic in case a non-regular charger adapter is used. It is a figure which shows the characteristic in case the adapter determination circuit does not exist and the charge voltage of a battery is near a full charge voltage. It is a flowchart showing operation | movement of the charging device which concerns on 1st Example of this invention. It is a flowchart in determination of a charger adapter. It is a timing chart showing the determination method of the charger adapter which concerns on 1st Example of this invention. It is a flowchart showing operation | movement of the charging device which concerns on 2nd Example of this invention. It is a timing chart showing the determination method of the charger adapter which concerns on 2nd Example of this invention.

  A charging device (20 in FIG. 1) according to an embodiment of the present invention is a charging device that connects a charger adapter (1 in FIG. 1) and charges a battery (5 in FIG. 1). A control transistor (3 in FIG. 1) that performs voltage control and current control for charging the battery, and a bypass circuit (164, FIG. 1) that draws and bypasses current exceeding the limiter current from the charger adapter via the control transistor. 165), a detection circuit for detecting the current value of the drawn current (corresponding to 161 in FIG. 1), and a current detected by the detection circuit by temporarily activating the bypass circuit before starting the battery charging control. And a control unit (15 in FIG. 1) that determines the characteristics of the charger adapter based on the value.

  The detection circuit may obtain the current value from the gate voltage of the control transistor that is an FET.

  The control unit may determine that the charger adapter is irregular (non-standard) when the gate voltage indicates that the current value is greater than a predetermined value.

  The control unit may determine the current supply capability of the charger adapter by activating the bypass circuit and sequentially decreasing the value of the limiter current.

  The portable electronic device may include the above charging device.

  According to the charging device having the above-described configuration, it is possible to determine the characteristics of the charger adapter regardless of the charging state of the battery, and to take a safe measure. For example, it is possible to take measures against heat generation on the battery pack and the device body from the start of charging. Further, by varying the value of the limiter current, it is possible to determine how much capacity the charger adapter has. Furthermore, it can also be determined whether the charger adapter is suitable for the communication device.

  Hereinafter, it will be described in detail with reference to the drawings in accordance with embodiments.

  FIG. 1 is a block diagram showing the configuration of the charging apparatus according to the first embodiment of the present invention. In FIG. 1, a charging device 20 connects a charger adapter 1 that supplies a charging current to a battery (battery pack) 5 to charge the battery (battery pack) 5.

  The charging device 20 monitors the voltage between both ends of the detection resistor 2 for monitoring the charging current, the FET 3 for controlling the charging current and the charging voltage, the FET 4 for controlling on / off of the charging, and the detecting resistor 2 to obtain the charging current. Charge current sensing circuit 6 for converting voltage, amplifier 7 for controlling charge current for FET 3, amplifier 8 for controlling charge voltage for FET 3, buffer circuit 9 for turning on / off FET 4, and charger Adapter voltage detector 10 that monitors the voltage of adapter 1 to detect an abnormal voltage or a chargeable voltage, and current detection that detects the limiter current and the charging current of the completion current by inputting the voltage from charging current sensing circuit 6 Unit 11, a constant current reference circuit 12 for determining a charging current, a constant voltage reference circuit 13 for determining a charging voltage, and a battery for detecting a battery state. Voltage detection unit 14, charging control unit 15 comprises an adapter decision circuit 16.

  The charge control unit 15 includes a buffer circuit 9 and a reference circuit 12 based on information from the adapter voltage detection unit 10, current detection unit 11, battery voltage detection unit 14, adapter determination circuit 16, temperature information, and a signal from the CPU. , 13 and the adapter determination circuit 16 are controlled. Note that the charging control unit 15 may include a processor and control each unit by causing the processor to execute a program.

  The adapter determination circuit 16 includes a terminal voltage detection comparator 161 that monitors the gate voltage of the FET 3, a switch circuit 162 that switches so as to operate exclusively when the FET 4 is turned on / off, and a constant voltage A switch circuit 163 that feeds back a comparison voltage to the amplifier 8, a load resistor 164, and a current source 165 that is connected in series to the load resistor 164 and draws a limit current.

  The terminal voltage detection comparator 161 connects the charger adapter 1 and draws a current equal to or higher than the limit current into the load resistor 164 and the current source 165 corresponding to the bypass circuit when the FET 4 is turned off, that is, not charged. Bypassing, the gate voltage of the FET 3 at that time is detected. When the gate voltage of the FET 3 is equal to or higher than a certain voltage, the charging control unit 15 determines that the charger adapter 1 is an abnormal adapter that is not genuine.

  First, the operation of the charging device 20 when a regular charger adapter is used will be described. FIG. 2 is a diagram illustrating charging characteristics when the regular charger adapter 1 is used. When the charger adapter 1 is connected at time 0, trickle charging is performed with a small charging current until the battery voltage reaches a certain voltage (for example, 3 V) (period T1). When a certain voltage is exceeded, constant current charging is started, and charging is performed with a current that can be passed through the charger adapter 1 until the battery voltage reaches a full charge voltage (for example, 4.2 V) (period T2). When the voltage of the battery 5 reaches the full charge voltage, switching to the constant voltage charge is performed, and the FET 3 is charged while controlling the gate voltage so as not to exceed the full charge voltage (period T3). When it is detected that the charging current to the battery 5 side has been reduced by constant voltage charging and has fallen below a certain charging current, charging is completed by turning off the FETs 3 and 4 respectively (period T4).

  The amount of heat generated in this series of charging operations is the sum of the on-resistance of FETs 3 and 4 and the detection resistance 2 and the square of the current during constant current because FETs 3 and 4 are completely turned on during constant current charging. It is calculated from the product of The amount of heat generated during constant voltage charging is represented by the product of the difference between the charger voltage and the battery voltage and the charging current.

  Here, when a non-genuine product with no current limitation is used for the charger adapter 1, limiter control must be applied on the charge control side during constant current charging. Therefore, it is necessary to control the gate voltage of the FET 3 to limit the current. As shown in FIG. 3, the amount of heat generated at this time is a constant charging current, and is calculated by the potential difference between the voltage of the charger adapter 1 and the voltage of the battery 5, and therefore, compared with the heat generation during constant current charging in FIG. It becomes big. Therefore, when it is found that the charger adapter 1 is an unauthorized product, it is preferable to take measures such as reducing the charging current so as not to affect the heat generation.

  By the way, when the adapter determination circuit 16 does not exist and the charging voltage of the battery 5 is almost the full charging voltage as shown in FIG. The voltage can be monitored but the current does not flow to the limit current. For this reason, it cannot detect that it is a non-genuine product. Therefore, even if it is the same non-genuine charger adapter, it may be judged as non-genuine or not depending on the state of charge of the battery.

  On the other hand, the charging device 20 of the present invention can detect whether or not the charger adapter 1 is a genuine product by the adapter determination circuit 16 regardless of the state of charge of the battery 5.

  FIG. 5 is a flowchart showing the operation of the charging apparatus according to the first embodiment of the present invention. In FIG. 5, the charging device 20 represents a sequence until the charger adapter 1 is connected and the charger adapter 1 is determined.

  Charger adapter 1 is connected in the state of operation of battery 5 (step A1).

  The charging control unit 15 confirms the voltage of the charger adapter 1 with the adapter voltage detection unit 10 (step A2). If the voltage is higher than a certain level (Yes in step A2), the internal device may be destroyed. Therefore, the charging circuit is turned off by FET3 and FET4 (step A5).

  Then, charging is stopped so that there is no problem in system safety, or if it is determined that only the current is abnormal, a countermeasure such as performing only trickle charging is taken on the system side (step A9).

  Further, the fact that the charger adapter 1 is abnormal is displayed on an LCD screen or LED (not shown) to notify the user (step A10), and the series of operations is terminated.

  In step A2, if no abnormal voltage is seen in the charger adapter 1 (No in Step A2), trickle charging is performed until the hard reset is released (No in Step A3), that is, until the voltage at which the system starts up is reached. Perform (Step A4).

  When the voltage of the battery 5 rises, the hard reset is released, and the system starts up (Yes in Step A3), the FET3 and FET4 are turned off once to turn off the charging circuit (Step A6).

  In this state, the charging control unit 15 determines whether or not the charger adapter 1 is a genuine product (step A7). In this determination, when it is determined that the product is a genuine product (Yes in Step A7), normal charging is started (Step A8), and the series of operations is terminated.

  On the other hand, when it is determined that the charger adapter 1 is an unauthorized adapter (No in Step A7), the charging control unit 15 takes measures to stop charging so that there is no problem in system safety. Or if it is a judgment only of an electric current, countermeasures, such as performing only trickle charge, are taken (step A9), and it progresses to step A10.

  Next, the determination (step A7) of the charger adapter 1 will be described in more detail. FIG. 6 is a flowchart in the determination of the charger adapter 1. In FIG. 6, the charging adapter 1 is connected, the system is turned on, and the FETs 3 and 4 are turned off (corresponding to A6 in FIG. 5).

  When determining the charger adapter 1, the charging control unit 15 connects the switch circuits 162 and 163 to the constant current source side (load resistor 164 side) and controls to turn on the FET 3 (step B1).

  In this case, drawing is performed with a current larger than the current detected by the current detection unit 11 (current Ilimit of the current source 165) (step B2).

  The charging control unit 15 confirms the voltage of the charger adapter 1 by the adapter voltage detection unit 10 (step B3), and monitors the gate voltage of the FET 3 by the terminal voltage detection comparator 161 (step B4).

  When the voltage of the charger adapter 1 is abnormal (Yes in Step B3), the charge control unit 15 turns off the charging circuit (FETs 3 and 4 are turned off) for the safety of the device (Step B5), and the charger It is determined that the adapter 1 is an unauthorized charger adapter (step B6).

  In addition, when a current greater than the limiter current is drawn, the limiter current is protected on the charging circuit side, so that the current flowing out from the non-regular charger adapter 1 without current limitation can be suppressed to the limiter current. For this reason, the gate voltage of the FET 3 rises, and the terminal voltage detection comparator 161 outputs the H level (H in step B4: detection). Upon receiving this signal, the charging control unit 15 determines the charger adapter 1 as an irregular adapter (step B6), turns off the switch circuit 162 and the FET 3, and ends the current drawing (step B7).

  On the other hand, if the limiter is not applied, the FET 3 tries to pass the current Ilimit of the current source 165, so that the gate voltage of the FET 3 maintains the GND level, and the output of the terminal voltage detection comparator 161 remains at the L level. (L in step B4: non-detection), the charging control unit 15 determines the charger adapter 1 as a regular product adapter (step B8).

  The charge control unit 15 turns off the switch circuit 162 and the FET 3, ends the current draw (step B9), and starts normal charging.

  FIG. 7 is a timing chart showing a charger adapter determination method according to the first embodiment of the present invention. In FIG. 7, it is assumed that there is no voltage abnormality in the charger adapter 1. After the trickle charging period T1, in the adapter determination period T10, when the hardware reset is released and the system is started, charging is turned off once so that the battery voltage is not affected. Then, the gate voltage of the FET 3 is monitored by the terminal voltage detection comparator 161 by flowing a current, and the genuine / non-regular product of the charger adapter 1 is determined. In FIG. 7, with respect to the output of the charging voltage, battery voltage, charging current, FET3, FET4, and terminal voltage detection comparator 161, the solid line shows the behavior when a genuine charger adapter is connected, and the dotted line is a non-regular product. Shows the behavior when the charger adapter is connected. The non-genuine product is turned off after the determination.

  FIG. 8 is a flowchart showing the operation of the charging apparatus according to the second embodiment of the present invention. 6, the same reference numerals in FIG. 6 perform the same processing, and the description thereof is omitted. In the second embodiment, the charging control unit 15 recognizes the charger adapter 1 as a normal adapter, and then decreases the limiter current to increase the gate voltage of the FET 3. At this time, from the limiter current value when the terminal voltage detection comparator 161 outputs the H level, it is estimated how much the charger adapter 1 is a charger adapter.

  In step B8, after determining that the charger adapter 1 is a genuine charger adapter, the charging control unit 15 sets the charging current value determined by the constant current reference circuit 12 to a smaller limit current value. (Step B10), and the gate voltage of the FET 3 is confirmed (step B11). If there is more current than the changed limit current value, the gate voltage of the FET 3 rises and the terminal voltage detection comparator 161 becomes H level (H in step B11: detection). As a result, it is possible to determine the current capability of the genuine charger adapter (step B12).

  On the other hand, if the value of the charging current is lower than the changed limit current value, the terminal voltage detection comparator 161 is at L level (does not react) (L in step B11: non-detection), so the process returns to step B10. Set the limit current low.

  By repeating Steps B10 and B11, the current capability of the genuine charger adapter 1 can be determined by gradually reducing the limit current. When the determination of the current capability of the charger adapter 1 is completed, the switch circuits 162 and 163 are restored (step B13), the limiter current is reset (step B14), and the determination of the charger adapter 1 is completed.

  FIG. 9 is a timing chart showing a charger adapter determination method according to the second embodiment of the present invention. After the trickle charging period T1, in the adapter capability determination period T20, when the hardware reset is released, that is, when the system is started, charging is turned off once so that the battery voltage is not affected. Then, the terminal voltage detection comparator 161 monitors the gate voltage of the FET 3 by flowing a current to determine the capability of the charger adapter 1.

  In FIG. 9, when the limit current value is lowered by one step at timing t10 in the adapter capability determination period T20, and further, the limit current value is further lowered by one step at timing t11, the terminal voltage detection comparator 161 changes to H level. Yes. That is, the limit current value set at timing t11 indicates the current capability of the charger adapter 1.

  When the determination of the current capability of the charger adapter is completed, the battery adapter is reset at timing t12 and charging is started (period T2). At this time, when the current capability of the charger adapter 1 is low, the user may be notified of information such as an increase in charging time.

  It should be noted that the disclosures of the aforementioned patent documents and the like are incorporated herein by reference. Within the scope of the entire disclosure (including claims) of the present invention, the embodiments and examples can be changed and adjusted based on the basic technical concept. Various combinations and selections of various disclosed elements are possible within the scope of the claims of the present invention. That is, the present invention of course includes various variations and modifications that could be made by those skilled in the art according to the entire disclosure including the claims and the technical idea.

1 Charger adapter 2 Detection resistor 3, 4 FET
DESCRIPTION OF SYMBOLS 5 Battery 6 Charging current sense circuit 7, 8 Amplifier 9 Buffer circuit 10 Adapter voltage detection part 11 Current detection part 12, 13 Reference circuit 14 Battery voltage detection part 15 Charge control part 16 Adapter determination circuit 20 Charging apparatus 161 Terminal voltage detection comparator 162 163 Switch circuit 164 Load resistor 165 Current source

Claims (11)

A charging device for charging a battery by connecting a charger adapter,
A control transistor for performing voltage control and current control for charging the battery from the charger adapter;
A bypass circuit that draws and bypasses a current greater than a limiter current from the charger adapter via the control transistor;
A detection circuit for detecting a current value of the drawn current;
A controller that temporarily activates the bypass circuit before starting charge control of the battery, and that determines the characteristics of the charger adapter based on a current value detected by the detection circuit;
A charging device comprising:   The charging device according to claim 1, wherein the detection circuit obtains the current value from a gate voltage of the control transistor that is an FET.   The charging device according to claim 2, wherein the controller determines that the charger adapter is irregular when the gate voltage indicates that the current value is greater than a predetermined value.   2. The charging device according to claim 1, wherein the control unit determines the current supply capability of the charger adapter by activating the bypass circuit and sequentially decreasing the value of the limiter current.   A portable electronic device comprising the charging device according to claim 1. Connecting the charger adapter to a charging device for charging the battery; and
Temporarily bypassing the charger adapter by drawing a current higher than a limiter current before starting charge control of the battery; and
Determining the characteristics of the charger adapter based on the current value of the drawn current;
A method for determining a charger adapter, comprising:   The method of determining a charger adapter according to claim 6, wherein, in the determining step, when the current value is larger than a predetermined value, the charger adapter is determined to be irregular.   7. The method of determining a charger adapter according to claim 6, wherein in the determining step, the current supply capability of the charger adapter is determined by sequentially decreasing the value of the limiter current. A control transistor for performing voltage control and current control for charging the battery from the charger adapter, a bypass circuit for drawing a current higher than a limiter current from the charger adapter via the control transistor, and the drawn current A computer that constitutes a charging device that connects the charger adapter and charges the battery.
A process of temporarily activating the bypass circuit before starting charge control of the battery;
A process of determining characteristics of the charger adapter based on a current value detected by the detection circuit;
A program that executes   10. The program according to claim 9, wherein, in the determination process, when the current value is larger than a predetermined value, the charger adapter is determined to be irregular.   The program according to claim 9, wherein in the determination process, the current supply capability of the charger adapter is determined by sequentially decreasing the value of the limiter current.

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