JP2006320154A - Charging set of secondary battery charger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charging set of a secondary battery capable of preventing discorrective charging in the case of connecting a secondary battery to a charger in opposite polarity, and capable of detecting abnormality in the secondary battery and abnormal connection, with a simple configuration. <P>SOLUTION: A secondary battery is connected to a charging terminal, and a charging current is supplied to the secondary battery by way of the charging terminal. The polarity of the secondary battery connected to the charging terminal is detected by a polarity detecting part, and supply of charging current is controlled according to the result. The polarity detecting part comprises a switch part which comes in on state or off state depending on the polarity of connection to the charging terminal of the secondary battery, outputting binary level corresponding to the state. A charging control part controls supply of charging current based on the binary level. A connection detecting part can detect presence of connection regardless of polarity, positive or negative, of connection to the charging terminal of the secondary battery. Further, the polarity detecting part detects polarity of the secondary battery based on presence of the connection. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a charging device for a rechargeable battery.

  A charger for charging a rechargeable battery in a portable device by electrically contacting the charging terminal on the portable device side with a built-in rechargeable battery (battery, secondary battery) and the charging terminal on the charger side. Are known. For example, Patent Document 1 describes an example of a charger in a wireless headphone system.

  Some of such chargers have measures to prevent erroneous charging and overcharging when the charging terminal is connected in reverse polarity. For example, a device in which the physical shape and structure of the device and the charging device are devised so that the charging terminal on the device side and the charging terminal on the charger side do not come into contact with each other in the reverse polarity state is known. There is also known a charging circuit that enables charging regardless of the polarity to which the rechargeable battery is connected by using, for example, a diode bridge.

  Patent Documents 2 to 4 describe examples of chargers having a function of preventing erroneous charging when the rechargeable battery is attached to the charger with reverse polarity. Patent Document 5 describes an example of a battery charger having a function of detecting a short circuit between charging terminals, an abnormality of a rechargeable battery, and the like.

Japanese Patent No. 2770389 Japanese Patent Laid-Open No. 6-311657 JP 49-44243 Japanese Utility Model Publication No. 55-4631 JP-A-5-219655

  In the case where it is not possible to prevent erroneous charging due to the structure of the device and the charger, if a circuit that can be charged regardless of the polarity as described above is mounted, the cost of the charger itself increases and the charging efficiency may decrease. In some cases, a device such as a diode bridge cannot be mounted due to the structure of the device.

  Examples of the problems to be solved by the present invention include the above. The present invention provides a charging device for a rechargeable battery that enables prevention of erroneous charging when a rechargeable battery is connected with a reverse polarity to a charger and detection of a rechargeable battery abnormality or connection abnormality with a simple configuration. The purpose is to provide.

  In the first aspect of the present invention, the charging device for the rechargeable battery is connected to the charging terminal connected to the terminal of the rechargeable battery, a charging current supply unit that supplies a charging current to the rechargeable battery, and the charging terminal. A polarity detection unit that detects the polarity of the rechargeable battery; and a charge control unit that controls supply of a charging current to the rechargeable battery via the charging terminal based on a detection result of the polarity detection unit, The polarity detection unit is electrically connected between the charging control unit and the charging terminal, and is turned on or off according to the polarity of the rechargeable battery connected to the charging terminal. The charging control unit controls supply of the charging current based on the binary level output from the switch unit.

  In the invention according to claim 2, the charging device for the rechargeable battery is connected to the charging terminal connected to the terminal of the rechargeable battery, a charging current supply unit that supplies a charging current to the rechargeable battery, and the charging terminal. A polarity detection unit that detects the polarity of the rechargeable battery, a charge control unit that controls supply of a charging current to the rechargeable battery via the charging terminal based on a detection result of the polarity detection unit, and A connection detection unit that detects whether or not the rechargeable battery is connected, and the connection detection unit is connected or not regardless of whether the connection of the rechargeable battery to the charging terminal is positive or reverse polarity. The polarity detector detects the polarity of the rechargeable battery based on the presence or absence of the connection.

  In one embodiment of the present invention, a charging device for a rechargeable battery is connected to a charging terminal connected to a terminal of the rechargeable battery, a charging current supply unit that supplies a charging current to the rechargeable battery, and the charging terminal. A polarity detection unit that detects the polarity of the rechargeable battery; and a charge control unit that controls supply of a charging current to the rechargeable battery via the charging terminal based on a detection result of the polarity detection unit, The polarity detection unit is electrically connected between the charging control unit and the charging terminal, and is turned on or off according to the polarity of the rechargeable battery connected to the charging terminal. The charging control unit controls the supply of the charging current based on the binary level output from the switching unit.

  According to the charging device, the rechargeable battery is connected to the charging terminal, and a charging current is supplied to the rechargeable battery via the charging terminal. Further, the polarity detection unit detects the polarity of the rechargeable battery connected to the charging terminal, and the supply of the charging current is controlled according to the result. That is, when the rechargeable battery is connected to the charging terminal with a positive polarity, a charging current is supplied, and when the rechargeable battery is connected with a reverse polarity, no charging current is supplied.

  The polarity detection unit has a switch unit, and the switch unit is turned on or off according to the polarity of the connection to the charging terminal of the rechargeable battery, and outputs a binary level corresponding to those states. One of the binary levels indicates that the connection to the charging terminal of the rechargeable battery is positive, and the other level indicates that the connection to the charging terminal of the rechargeable battery is reverse polarity. Then, the charge control unit controls the supply of the charging current based on these binary levels. Therefore, when the polarity of the rechargeable battery and the charging terminal is mistakenly connected with the opposite polarity, the charging current is not supplied and erroneous charging can be prevented.

  In another embodiment of the present invention, a charging device for a rechargeable battery is connected to a charging terminal connected to a terminal of the rechargeable battery, a charging current supply unit that supplies a charging current to the rechargeable battery, and the charging terminal. A polarity detection unit that detects the polarity of the rechargeable battery, a charge control unit that controls supply of a charging current to the rechargeable battery via the charging terminal based on a detection result of the polarity detection unit, and A connection detection unit that detects whether or not the rechargeable battery is connected, and the connection detection unit is connected or not regardless of whether the connection of the rechargeable battery to the charging terminal is positive or reverse polarity. The polarity detection unit detects the polarity of the rechargeable battery based on the presence or absence of the connection.

  According to the charging device, the rechargeable battery is connected to the charging terminal, and a charging current is supplied to the rechargeable battery via the charging terminal. Further, the polarity detection unit detects the polarity of the rechargeable battery connected to the charging terminal, and the supply of the charging current is controlled according to the result. That is, when the rechargeable battery is connected to the charging terminal with a positive polarity, a charging current is supplied, and when the rechargeable battery is connected with a reverse polarity, no charging current is supplied.

  In addition, the charging device includes a connection detection unit that detects whether or not the rechargeable battery is connected to a charging terminal, and the connection detecting unit is configured such that the connection of the rechargeable battery to the charging terminal is positive or reverse polarity. Whether or not there is a connection can be detected. Then, the polarity detection unit detects the polarity of the rechargeable battery based on the presence or absence of the connection. Therefore, polarity detection or the like may be performed only when a rechargeable battery is connected.

  In one aspect of the charging device of the rechargeable battery, the charging device includes a charging current detecting unit that detects the charging current, and the charging control unit detects the charging current when the charging current detecting unit detects an abnormality in the charging current. Stop supplying. In this mode, for example, when a charging terminal is short-circuited or in an abnormal state such as when the rechargeable battery is in a significantly deteriorated state, this is detected when an excessive charging current flows than usual, and the supply of the charging current is stopped. can do. Therefore, safety in an abnormal state can be ensured.

  The other one aspect | mode of said charging device of a rechargeable battery is provided with the display part which displays the charge condition of the said rechargeable battery. According to this, the user can visually grasp the state of charge. In a preferred example, the display unit is configured by an LED or the like, a normal charging state is indicated by lighting of the LED, and an abnormal state is indicated by blinking of the LED.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an external view showing a schematic configuration of a wireless headphone which is an embodiment of a device to which the present invention is applied. FIG. 1A is a front view showing a state in which wireless headphones are attached to a charger, and FIG. 1B is a side view seen from the direction of arrow 17 in FIG.

  1A and 1B, a wireless headphone (hereinafter referred to as “headphone”) 10 is charged while being attached to a charger 15. The headphone 10 includes left and right speaker portions 11L and 11R and an arm 12 that holds them. As shown in FIG. 1A, the headphone 10 is mounted on a trapezoidal charger 15 as viewed from the front, with the arm 12 and left and right speaker portions 11L and 11R supported.

  A rechargeable battery (battery) 18 (see FIG. 2) is built in the headphones 10. In addition, the headphone 10 is provided with a charging terminal 13 a on the headphone side that is electrically connected to the rechargeable battery 18. On the other hand, a charging terminal 13b is provided on the charger 15 side. When the headphone 10 is attached to the charger 15 in an appropriate state, the charging terminal 13a on the headphone side is in electrical contact with the charging terminal 13b on the charger side. 1 (a) and 1 (b), the charging terminals 13a and 13b are illustrated as being provided at the central portion of the arm 12 and at the three positions of the left and right speaker portions 11L and 11R. However, this is merely an example of a plurality of positions where the charging terminals 13a and 13b can be arranged, and in actuality, it may be provided at any one location.

  The charger 15 is provided with a display unit 23 indicating that charging is in progress. The display part 23 is comprised by LED etc. which light up during charge.

  FIG. 2 shows the charging circuit 1 mounted on the charger 15. As illustrated, the charging circuit 1 includes a charging current supply circuit 20, a microprocessor 21 that functions as a charging control unit, a rechargeable battery connection detection circuit 22, a display unit 23 that includes LEDs, and a charging current detection circuit 24. , A polarity detection circuit 26 and a charging terminal 13b on the charger side.

  On the other hand, the headphone 10 includes a rechargeable battery 18 and a headphone-side charging terminal 13 a connected to the rechargeable battery 18. As described above, when the headphones 10 are correctly attached to the charger 15, the charging terminal 13 a on the headphone 10 side contacts the charging terminal 13 b on the charger side, and the rechargeable battery 18 in the headphone 10 is charged. Electrically connected to circuit 1.

  The charging current supply circuit 20 supplies the charging current Ichg to the rechargeable battery charging terminal 13b in response to the charging control signal S2 from the microprocessor 21. In a state where the rechargeable battery 18 is correctly connected, the charging current Ichg charges the rechargeable battery 18 via the charging terminals 13a and 13b.

  The rechargeable battery connection detection circuit 22 is a circuit that detects whether or not the rechargeable battery 18 is attached, and includes a power source 221, a diode 222, and two transistors Tr3 and Tr4. The power supply voltage Vcc is set higher than the voltage of the rechargeable battery 18.

  When the rechargeable battery 18 is attached, the diode 222 is turned on, the transistor Tr3 is turned on, and the transistor Tr4 is also turned on. Therefore, the collector voltage of the transistor Tr4 becomes a low level, and this is supplied to the microprocessor 21 as the rechargeable battery connection detection signal S1. On the other hand, when the rechargeable battery 18 is not attached, the charging terminal 13b is opened, and the diode 222 and the transistor Tr3 are turned off. Accordingly, the transistor Tr4 is also turned off, and a high level collector voltage is supplied to the microprocessor 21 as the rechargeable battery connection detection signal S1. That is, the rechargeable battery connection detection signal S1 supplied to the microprocessor 21 indicates that the rechargeable battery 18 exists when it is at the L level, and indicates that the rechargeable battery 18 does not exist when it is at the H level.

  Note that the diode 222 is turned on and the transistors Tr3 and Tr4 are also turned on when the rechargeable battery 18 is mounted with a reverse polarity and when the charging terminals 13a and 13b are short-circuited due to some abnormality. An L level rechargeable battery connection detection signal S 1 indicating that a battery is present is supplied to the microprocessor 21. That is, the rechargeable battery connection detection circuit 22 can detect the presence or absence of connection regardless of whether the connection of the rechargeable battery 18 to the charging terminals 13a and 13b is positive or reverse polarity.

  The polarity detection circuit 26 includes a transistor Tr1 that functions as a switch unit. When the rechargeable battery 18 is mounted with the correct polarity, the transistor Tr1 is turned off, and an H-level collector voltage is supplied to the microprocessor 21 as the polarity detection signal S4. On the other hand, when the rechargeable battery 18 is mounted with reverse polarity, the transistor Tr1 is turned on, and the L-level collector voltage is supplied to the microprocessor 21 as the polarity detection signal S4. That is, the polarity detection signal S4 indicates that the rechargeable battery 18 is connected with positive polarity (correct polarity) when at the H level, and the rechargeable battery 18 is connected with reverse polarity (incorrect polarity) when at the L level. Indicates that

  The charging current detection circuit 24 includes a transistor Tr2 and a resistor 241. In a case where polarity detection by the polarity detection circuit 26 is impossible and an abnormal state (for example, when the charging terminals 13a and 13b are short-circuited or the performance of the rechargeable battery 18 is significantly deteriorated), the resistor 241 An abnormal current (current greater than normal) flows in For this reason, the voltage applied to the resistor 241 exceeds the ON voltage of the transistor Tr2 due to the abnormal current, and the transistor Tr2 is turned ON. As a result, a base current flows through the transistor Tr2, and this is supplied to the microprocessor 21 as the abnormality detection signal S3.

  The display unit 23 is configured by an LED, and lighting of the display unit 23 is controlled by the microprocessor 21. The microprocessor 21 turns on the display unit 23 during normal charging. When abnormality of the rechargeable battery 18 is detected by the abnormality detection signal S3 and when it is detected by the polarity detection signal S4 that the connection of the rechargeable battery 18 is reverse polarity, the microprocessor 21 Blinks to notify the user that the connection of the rechargeable battery is abnormal. Further, the microprocessor 21 blinks the display unit 23 indicating an abnormal state until the rechargeable battery 18 is removed (that is, until the rechargeable battery connection detection signal S1 becomes H level) based on the rechargeable battery connection detection signal S1. Continue.

  Next, the charging process by the charging circuit 1 will be described. FIG. 3 is a flowchart of the charging process. The charging process described below is executed by the microprocessor 21 monitoring the rechargeable battery connection detection signal S1, the abnormal current detection signal S3, the polarity detection signal S4, and the like.

  First, the microprocessor 21 determines whether or not the rechargeable battery 18 is attached based on the rechargeable battery connection detection signal S1 (step S1). When the rechargeable battery 18 is not attached (step S1; No), the process ends.

  When the rechargeable battery is attached (step S1; Yes), the microprocessor 21 determines whether or not the connection of the rechargeable battery 18 is reverse polarity based on the polarity detection signal S4 (step S2). As described above, the polarity detection circuit 26 outputs the polarity detection signal S4 of H level when the polarity is positive and L level when the polarity is reverse. If it is not reverse polarity (step S2; No), since the rechargeable battery 18 is correctly connected to the charging circuit 1, the microprocessor 21 outputs a charging control signal S2 indicating the start of charging to the charging current supply circuit 20, Charging is started by supplying a charging current Ichg to the rechargeable battery 18 (step S3).

  Next, the microprocessor 21 determines whether or not an abnormal current is detected after the start of charging (step S4). If no abnormal current is detected (step S4; No), the microprocessor 21 turns on the display unit 23 (step S5). Thereby, the user can know that charging has started. On the other hand, if an abnormal current is detected (step S4; Yes), the microprocessor 21 stops supplying the charging current (step S6), and blinks the display unit 23 to notify the user that the abnormal state is present ( Step S7).

  Further, when it is determined in step S2 that the rechargeable battery 18 is connected in reverse polarity, the microprocessor 21 similarly notifies the user that the display unit 23 blinks and is in an abnormal state (step S7). .

  As described above, the microprocessor 21 charges the rechargeable battery 18. Note that the microprocessor 21 monitors the abnormal current detection signal S3 during charging, and if an abnormal current is detected after the start of charging, the microprocessor 21 stops supplying the charging current to stop the charging and displays the display unit 23. Flashes to notify the user of an abnormal condition.

  As described above, according to the present invention, it is possible to prevent erroneous charging due to reverse polarity connection of the rechargeable battery with a simple configuration, and to detect whether the rechargeable battery connection or the abnormal state of the rechargeable battery itself is to be charged. Can be controlled.

  More specifically, the charging circuit 1 of the rechargeable battery includes charging terminals 13a and 13b connected to the terminals of the rechargeable battery 18, a charging current supply circuit 20 that supplies the charging current Ichg to the rechargeable battery 18, and charging terminals 13a and 13b. Based on the detection result of the polarity detection circuit 26 and the polarity detection circuit 26 that detects the polarity of the rechargeable battery 18 connected to the battery, the supply of the charging current Ichg to the rechargeable battery 18 is controlled via the charging terminals 13a and 13b. And a microprocessor 21. The polarity detection circuit 26 is electrically connected between the microprocessor 21 and the charging terminals 13a and 13b, and is turned on or off depending on the polarity of the rechargeable battery 18 connected to the charging terminals 13a and 13b. The transistor Tr1 outputs a binary level corresponding to the state and the off state. The microprocessor 21 controls the supply of the charging current Ichg based on the binary level output from the transistor Tr1. Therefore, when the polarity of the rechargeable battery and the charging terminal is mistakenly connected with the opposite polarity, the charging current is not supplied and erroneous charging can be prevented.

  Further, the charging circuit 1 includes a rechargeable battery connection detection circuit 22 that detects whether or not the rechargeable battery 18 is connected to the charging terminals 13 a and 13 b. The rechargeable battery connection detection circuit 22 is connected to the charging terminals 13 a and 13 b of the rechargeable battery 18. Whether or not the connection is positive or reverse polarity is detected. The polarity detection circuit 26 detects the polarity of the rechargeable battery 18 based on the presence or absence of connection. Therefore, polarity detection or the like may be performed only when a rechargeable battery is connected.

It is an external view which shows schematic structure of the wireless headphones which are the Example of the apparatus to which this invention is applied. The charging circuit mounted in a charger is shown. It is a flowchart of a charging process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Charging circuit 10 Wireless headphones 11L, 11R Speaker part 12 Arm 13a, 13b Charging terminal 15 Charger 18 Rechargeable battery 20 Charging current supply circuit 21 Microprocessor 22 Rechargeable battery connection detection circuit 23 Display part 24 Charging current detection circuit 26 Polarity detection circuit

Claims (4)

A charging terminal connected to the terminal of the rechargeable battery;
A charging current supply unit for supplying a charging current to the rechargeable battery;
A polarity detector for detecting the polarity of the rechargeable battery connected to the charging terminal;
A charge control unit that controls supply of a charging current to the rechargeable battery via the charging terminal based on a detection result of the polarity detection unit;
The polarity detection unit is electrically connected between the charging control unit and the charging terminal, and is turned on or off according to the polarity of the rechargeable battery connected to the charging terminal. A switch unit that outputs a binary level corresponding to the state;
The charging control unit includes a charging device for controlling the supply of the charging current based on the binary level output from the switch unit. A charging terminal connected to the terminal of the rechargeable battery;
A charging current supply unit for supplying a charging current to the rechargeable battery;
A polarity detector for detecting the polarity of the rechargeable battery connected to the charging terminal;
Based on the detection result of the polarity detection unit, a charge control unit that controls supply of a charging current to the rechargeable battery via the charging terminal;
A connection detection unit that detects whether the rechargeable battery is connected to the charging terminal,
The connection detection unit detects the presence or absence of connection regardless of whether the connection to the charging terminal of the rechargeable battery is positive or reverse polarity,
The polarity detection unit detects the polarity of the rechargeable battery based on the presence or absence of the connection. A charging current detector for detecting the charging current;
3. The charging device for a rechargeable battery according to claim 1, wherein the charging control unit stops supplying the charging current when the charging current detecting unit detects an abnormality in the charging current. 4. The charging device for a rechargeable battery according to any one of claims 1 to 3, further comprising a display unit that displays a charging state of the rechargeable battery.

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