JP2013074715A - Charging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide technique capable of completing normal and suitable charging without any charging error even if components which control a charging voltage and a charging current get out of order in a charging device.SOLUTION: A charging device 1 includes a voltage control circuit 12 and a current control circuit 11, and a component (shunt regulator) which controls the charging voltage of the voltage control circuit 12 and a component (shunt resistance) which controls the charging current of the current control circuit 11 are each provided double. The charging device includes a first processing section which is actualized by using processing of a microcomputer 2, and detects abnormality (fault) of each component, a second processing section which switches operation from a primary system to a secondary system when the abnormality (fault) of each component is detected, and a third processing section which makes an external display section display the state.

Description

  The present invention relates to a technology of a charging device (charger) for charging a secondary battery (such as a nickel cadmium battery or a lithium ion battery) used as a power source of a portable device such as a cordless electric tool. In particular, the present invention relates to a circuit / component for controlling a charging voltage and a charging current in a charging device.

  2. Description of the Related Art Conventionally, a secondary battery charging device is equipped with a circuit for controlling a charging voltage (voltage control circuit) and a circuit for controlling a charging current (current control circuit). For controlling the charging voltage, components / circuits such as a shunt regulator (voltage regulator) that can be controlled to a constant voltage are used. For the control of the charging current, components / circuits such as a shunt resistor (current detection resistor) capable of measuring (detecting) the current are used.

  However, when a component under control (for example, a shunt regulator or a shunt resistor) fails, overvoltage or overcurrent is not prevented or protected, and normal charging operation cannot be performed.

  There exists Unexamined-Japanese-Patent No. 2009-17651 (patent document 1) as a prior art example relevant to said problem. In Patent Document 1 (“overvoltage protection system”, etc.), a technique for detecting the voltage of a battery (cell / set) related to a charger (while the set voltage of the charger is increased, the cell voltage exceeds a value limited by a threshold value). An overvoltage protection system that guarantees that there is no such battery is disclosed, and there is a description that the battery voltage is detected and charging is stopped when there is an abnormality.

JP 2009-17651 A

  As described above, when a charging voltage or charging current control part (such as a shunt regulator or shunt resistor) fails in the charging device, overvoltage and overcurrent are not prevented or protected, and normal charging operation cannot be performed. . Therefore, a means for dealing with this problem is required. The above components are components / circuits that are required to have high reliability and high accuracy.

  However, in Patent Document 1, for example, the battery voltage is detected and charging is stopped when there is an abnormality. In this configuration, charging is normally stopped without overvoltage (overvoltage can be prevented). However, charging does not complete normally. That is, full charge (a state in which the battery is fully charged) cannot be realized by stopping the charging operation halfway. In particular, when the secondary battery is a lithium ion battery, since constant current / constant voltage control is generally performed, both the charging voltage and the charging current must be appropriately controlled.

  In addition, in order to complete the charging normally (full charge) in the charging device, not only the control of the charging voltage but also the control of the charging current are important factors. However, for example, in Patent Document 1, there is a description that the charging voltage is detected, but there is no description that the charging current is detected. If the charging device is not configured to appropriately detect and control both the charging voltage and charging current, preferably both the charging voltage and charging current, appropriate charging, particularly full charging cannot be realized.

  In view of the above, the main object of the present invention is to appropriately detect and control the charging voltage and charging current (preferably both the charging voltage and charging current) in the charging device, thereby preventing overvoltage and overcurrent related to charging. Even if parts that control the charging voltage or charging current (for example, shunt regulators or shunt resistors) break down while preventing or protecting them, normal and appropriate charging is completed without causing a charging error (incomplete charging). It is to provide a technology that can make it happen (realization of full charge).

  Still another object of the present invention is to provide a technique capable of promptly and appropriately dealing with a failure (abnormality) in a component / circuit that controls the charging voltage or charging current.

  In order to achieve the above object, a representative embodiment of the present invention is a charging device for charging a secondary battery (for example, a battery set including a plurality of battery cells connected in series), and in particular, controls a charging voltage. And a circuit for controlling a charging current (current control circuit), etc., and has the following configuration.

  In this charging device, first, a voltage control circuit or current that is a circuit unit including components and circuits (for example, a shunt regulator (voltage regulator) and a shunt resistor (current detection resistor)) that appropriately detect and control a charging voltage and a charging current. A control circuit is provided to prevent and protect overvoltage and overcurrent related to battery charging. In addition, even if the above-mentioned parts / circuits fail, the voltage control is performed so that normal and appropriate charging can be completed (realization of full charge) without causing a charging error. The configuration includes the following highly reliable circuit (function) related to the circuit and the current control circuit.

  As a high-reliability circuit for this charging device, the above components / circuits (voltage regulator, current detection resistor) that require high reliability and high accuracy are duplicated (one is the “primary system” and the other is “two”. It is referred to as “secondary system”. Then, the charging device monitors and determines the voltage and current states of the primary side component, and if an abnormality in the voltage or current is detected, it is determined that the component is faulty. By switching to the operation of the system parts, normal operation is continued. That is, the completion of normal charging is guaranteed.

  Furthermore, in this charging device, along with switching to the secondary system, the external display is made to indicate the state of failure (abnormality) of the primary system parts, and the state can be confirmed from the outside (user), Tell the need for maintenance replacement. As a result, even if the primary system component fails, it is possible to take a quick and appropriate action (maintenance and replacement of the component).

  (1) The present charging device includes, for example, a voltage control circuit including a component (voltage regulator) for controlling a voltage for charging a battery, and the voltage control circuit includes a first and a second that are duplicated. It comprises parts as well as switching elements for switching. The charging device includes a first processing unit that determines and detects a failure of the first component by monitoring a voltage in the first component of the primary system of the voltage control circuit and determining and detecting an abnormality. A second processing unit that immediately switches to the operation of the second component of the secondary system of the voltage control circuit when a failure of the component is detected. Further, the charging device includes an external display unit for displaying information to the outside, and when a failure of the primary system first component is detected, the display of predetermined information on the external display unit is immediately turned on. A third processing unit to be provided.

  (2) The charging device includes, for example, a current control circuit including a component (current detection resistor) that controls a charging current to the battery. As well as switching elements for switching. The charging device includes: a first processing unit that determines and detects a failure of the first component by monitoring current in the first component of the primary system of the current control circuit and determining and detecting abnormality; And a second processing unit that immediately switches to the operation of the second component of the secondary system of the current control circuit when a failure of the component is detected. Further, the charging device includes an external display unit for displaying information to the outside, and when a failure of the primary system first component is detected, the display of predetermined information on the external display unit is immediately turned on. A third processing unit to be provided.

  (3) The present charging device is configured to include both (1) and (2) above, for example.

  According to a typical embodiment of the present invention, in a charging device, by appropriately detecting and controlling a charging voltage and a charging current (preferably both a charging voltage and a charging current), an overvoltage and an overcurrent related to charging are controlled. Even if parts that control the charging voltage or charging current (for example, shunt regulators or shunt resistors) break down while preventing or protecting them, normal and appropriate charging is completed without causing a charging error (incomplete charging). Can be achieved (realization of full charge).

  Furthermore, when a component / circuit that controls the charging voltage or charging current is out of order (abnormal), it is possible to quickly take appropriate measures.

It is a figure which shows the structure of the charging device of one embodiment of this invention. It is a figure which shows the structure regarding the voltage control circuit in this Embodiment. It is a figure which shows the microcomputer processing example in the case of the voltage monitoring regarding the voltage control circuit in this Embodiment. It is a figure which shows the structure regarding the current control circuit in this Embodiment. It is a figure which shows the microcomputer processing example in the case of the current monitoring regarding the current control circuit in this Embodiment.

  Hereinafter, an embodiment (charging device) of the present invention will be described in detail based on the drawings.

[Summary]
The charging device according to the present embodiment has a high-reliability circuit (function) related to the components (shunt regulator) of the voltage control circuit shown in FIGS. The circuit includes a high-reliability circuit (function) related to a current control circuit component (shunt resistor) shown in FIG. In FIG. 2, due to the duplex configuration relating to the shunt regulator (21), even when the voltage of the primary system component (21) is abnormal, normal voltage control is continued by switching to the secondary system component (24). . In FIG. 4, due to the duplex configuration relating to the shunt resistor (41), normal current control is continued by switching to the secondary system component (44) even when the current of the primary system component (41) is abnormal. . In this way, this charging device guarantees the realization of full charge by continuing normal control on the voltage and current of charging by controlling to switch to the secondary system immediately based on the detection of abnormality (failure) in the primary system. To do. In addition, the charging device turns on the external display to immediately notify the necessity of maintenance replacement of the component (primary system) at the same time as the switching.

[Charging device]
FIG. 1 shows a circuit block configuration of a charging device (charger) 1 according to the present embodiment. The charging device 1 includes a microcomputer 2, a charging terminal 4, an external display unit 5, an external display control unit 6, a switching (SW) circuit power supply unit 7, a current control circuit 11, a voltage control circuit 12, a voltage detection circuit 13, and a current detection. The circuit 14 includes an overvoltage / high temperature detection circuit 15, an overvoltage detection circuit 16, a high temperature detection circuit 17, and the like. Reference numeral 19 denotes a capacity identification (5 V) circuit.

  The charging device 1 has a configuration in which a battery set (battery pack) (not shown) to be charged is detachably connected through a charging terminal 4 shown on the right side. Charging is performed by bringing the charging terminal 4 and the battery terminal of the battery set into contact with each other. The charging terminal 4 shows some terminals {L +, 5V, LS, T, −} as an example corresponding to the battery set. L + indicates a positive terminal of the battery set, 5V indicates a capacity identification terminal of the battery set and indicates a capacity of the battery set (for example, distinguishing between 1.5 Ah and 3.0 Ah), and LS indicates an abnormality detection terminal of the battery set. , T is an identification terminal of the battery set, and indicates the battery voltage of the battery set (that is, the number of cells, for example, 14.4V or 18.0V is discriminated), and-indicates the negative terminal of the battery set.

  The battery set is a set (pack) in which a plurality of battery cells (secondary batteries) are connected in series. The battery cell is a nickel cadmium battery or a lithium ion battery. The battery set is a known technique and will not be described in detail.

  The switching (SW) circuit power supply unit 7 includes an SW circuit 10 and is connected to a commercial power supply 3 including an AC cable for inputting AC 100V. The SW circuit 10 is a first switching control circuit including a smoothing capacitor and an FET (not shown). The SW circuit 10 smoothes the AC voltage of the commercial power supply 3 and supplies it to the current control circuit 11 and the like.

  The external display unit 5 is a part that displays various types of information related to the charging device 1 to the outside (user) of the charging device 1 and includes, for example, various LEDs. Particularly in the present embodiment, each LED (and corresponding character, etc.) for notifying the necessity of maintenance replacement according to the failure state of each primary system component of the current control circuit 11 and the voltage control circuit 12 is provided. Have. In addition, it has each existing LED etc. for displaying another state. When a failure of the primary system parts 11 and 12 is detected, the corresponding type of LED is immediately turned on (ON). The user can immediately recognize the necessity of maintenance replacement of the parts 11 and 12 of the charging device 1 by seeing the lighting of the LED. For example, the maintenance staff receives a request for maintenance replacement from the user, and repairs and replaces the parts 11 and 12 to return to the normal duplex system state.

  The external display control unit 6 gives a corresponding signal to the external display unit 5 based on an instruction (a3) from the microcomputer 2 when the parts 11 and 12 (primary shunt regulator and shunt resistor) fail. This is a circuit unit that performs control to turn on (light on) the corresponding LED of the external display unit 5.

  Note that the external display unit 5 and the external display control unit 6 are not limited to the form using LEDs, but may be a form using an alarm sound output for reporting a predetermined state / information to the outside.

  The current control circuit 11 (detailed in FIG. 4) includes components requiring high accuracy such as the shunt resistor 41 (current detection resistor) in FIG. 4 to be protected by the duplex configuration in the present embodiment. The current value (charging current) is controlled by the component. The current control circuit 11 is connected to the voltage control circuit 12, the microcomputer 2, the current detection circuit 14, and the like.

  The voltage control circuit 12 (specifically, FIG. 2) includes components (components requiring high accuracy) such as the shunt regulator 21 (voltage regulator) of FIG. 2 to be protected by the duplex configuration in the present embodiment. The voltage value (charging voltage) is controlled by the component. The voltage control circuit 12 is connected to the current control circuit 11, the microcomputer 2, the voltage detection circuit 13, and the like.

  The voltage detection circuit 13 is a circuit that detects the charging voltage of the battery set, and detects the charging voltage based on the signal at the L + terminal of the charging terminal 4. The voltage detection circuit 13 detects an overvoltage in the entire voltage of the battery set, and at that time, gives a signal b1 indicating the state of the overvoltage to the microcomputer 2.

  The current detection circuit 14 is a circuit that detects the charging current of the battery set, and detects the charging current by the current flowing between the positive terminal and the negative terminal of the charging terminal 4 (connected to the negative terminal side in the present embodiment). The current detection circuit 14 detects an overcurrent of the battery set, and at that time, gives a signal b2 indicating the state of the overcurrent to the microcomputer 2.

  15, 16, and 17 are configuration examples (known techniques) related to overvoltage detection / high temperature detection functions, and are detected when there is an abnormality such as overvoltage or high temperature in the battery set (or battery cell) during charging, Stop charging. In FIG. 1, 15 functions are configured by a microcomputer A / D (software processing), and 16 and 17 functions are configured by a hardware circuit. That is, the detection of the overvoltage and the high temperature is realized by the microcomputer and the hardware circuit in duplicate.

  The overvoltage / high temperature detection circuit 15 performs overvoltage detection and high temperature detection by a microcomputer A / D (software processing) based on a signal from the LS terminal of the charging terminal 4 or the like. In the overvoltage detection process of 15, an overcharge (overvoltage) state for each battery cell of the battery set is detected, and at that time, a signal b3 indicating the overcharge is given to the microcomputer 2. In the high temperature detection process 15, the high temperature state of the battery set is detected. At that time, a signal b 6 indicating the high temperature is given to the microcomputer 2.

  The overvoltage detection circuit 16 detects an overvoltage (overcharge) for each battery cell of the battery set by processing of the hardware circuit based on a signal from the LS terminal of the charging terminal 4, and at that time, the overcharge is detected. The signal b4 shown is given to the microcomputer 2.

  The high temperature detection circuit 17 detects the high temperature state of the battery set by processing of the hardware circuit based on the signal of the LS terminal of the charging terminal 4, and at that time, the b2 signal indicating the high temperature is sent to the microcomputer 2. give.

  The microcomputer 2 performs a control process for the entire charging device 1 by performing a predetermined calculation process using a known processor or memory built therein. This control process includes the processes shown in FIGS. The microcomputer 2 performs current setting (a1) for the current control circuit 11, and performs voltage setting (a2) for the voltage control circuit 12. External display control (a3) is performed from the microcomputer 2 to the external display control unit 6. The microcomputer 2 detects an overvoltage state and an overcurrent state of the battery set (overall voltage) based on the signals (b1, b2) from the respective units (13, 14) described above. Further, the microcomputer 2 detects a state such as an overvoltage or a high temperature of the battery set based on the signals (b3, b4, b6, b7) from the respective units (15-17) described above. Further, the microcomputer 2 identifies the battery set connected to the own device based on the signal b5 from the T terminal of the charging terminal 4. That is, the microcomputer 2 controls the charging current and the charging voltage according to the battery voltage (number of cells) of the battery set connected to the charging terminal 4 and performs optimum charging control.

  Further, the microcomputer 2 gives an external display control (ON instruction) signal (a3) to the external display control unit 6 when necessary as described later (when 11 and 12 parts are detected as failure). Thereby, a signal corresponding to the external display unit 5 is given from the external display control unit 6. Thereby, the designated LED of the external display unit 5 is turned on.

[Voltage control circuit]
FIG. 2 shows a circuit configuration relating to the voltage control circuit 12 of FIG. The voltage control circuit 12 includes an A / D conversion unit (monitoring unit) 20, a first shunt regulator 21, FET 22, and FET 23 that form a primary system, and a second shunt regulator 24 and FET 25 that form a secondary system. And FET 26. The shunt regulators 21 and 24 are components (voltage regulators) that control the charging voltage. Each FET (22, 23, 25, 26) is a switch element that can be controlled ON / OFF in accordance with a signal from the microcomputer 2.

  Normally, the primary side FETs 22 and 23 are turned on to operate the primary side component (21). When the primary side component (21) fails (when), the secondary side FETs 25 and 26 are turned ON to switch to the secondary side component (24).

  In the primary system, one ends of the FETs 22 and 23 are connected to both ends (points b and c) of the first shunt regulator 21, and the other end (point a) of the FET 22 is connected to + (plus or L + terminal). The other end (point d) of the FET 23 is connected to the ground (-terminal). The control terminals of the FETs 22 and 23 are connected to the microcomputer 2.

  In the secondary system, one end of the FETs 25 and 26 is connected to both ends of the second shunt regulator 24, and the other end of the FET 25 is connected to the primary point a (plus or L + terminal). The other end is connected to the primary point d (ground or negative terminal). The control terminals of the FETs 25 and 26 are connected to the microcomputer 2.

  The A / D conversion unit 20 is a circuit unit (functionally a voltage monitoring unit) including an analog / digital conversion processing function according to a known technique, and constantly monitors (detects) the voltage of the shunt regulator 21 on the primary side. . The A / D converter 20 is connected to both ends (points b and c) of the microcomputer 2 and the first shunt regulator 21, and the analog voltage of the first shunt regulator 21 detected between the points b and c. A digital value signal obtained by A / D converting the value is always output to the microcomputer 2 (c1).

  The microcomputer 2 determines an abnormality related to the voltage (detected voltage) of the primary shunt regulator 21 based on the signal (c1) from the A / D conversion unit 20 (for example, a comparison determination with a threshold value), and determines the abnormality. If detected, the first process is performed to determine that the component (21) is in a failure state. When the failure is detected, the ON / OFF to each FET (22, 23, 25, 26) is immediately performed. A second process for switching the operation from the primary system component (21) to the secondary system component (24) by performing OFF control is performed, and the external display control related to the voltage system is performed to the external display control unit 6 in accordance with the switching. A third process for giving a signal of (instruction) is performed.

  When viewed as a functional configuration related to control of the charging voltage, the charging device 1 is configured as a processing unit / circuit unit, and the first processing unit is the A / D conversion unit 20 in FIG. This is realized by processing (S101 in FIG. 3 and the like). The second processing unit is realized by the second processing (S103 in FIG. 3 and the like) of the microcomputer 2. The third processing unit is realized by the third processing (S105 in FIG. 3), the external display control unit 6, and the external display unit 5 of the microcomputer 2.

[Microcomputer processing (1)]
FIG. 3 shows an example of control processing in the microcomputer 2 in the configuration of FIG. 2 (in the case of voltage monitoring). S101 and the like represent processing steps. The microcomputer 2 repeatedly executes the process of FIG. 3 in response to the input of the signal (c1) from the A / D converter 20 described above.

  As a specific example of the set values for the charging device 1 and the battery set, the voltage of the shunt regulator (21) is in the range of 3.2 V (lower limit value) to 3.6 V (upper limit value) in a normal voltage control state. The microcomputer 2 detects a case out of the normal voltage range as an abnormal (that is, failure) state.

  (S101) In S101, the microcomputer 2 performs a first process (voltage abnormality determination process). In the first process, the state of Vs> 3.2 V (lower limit value) continues for 0.5 seconds (predetermined time) for the detected voltage (Vs) by the signal (c1) from the A / D converter 20. Determine whether or not. If it is continuous (Y), it is normal and the process proceeds to S102. If it is not continuous (N), it is determined that the voltage is abnormal, and the process proceeds to S103.

  (S102) In S102, similarly, the microcomputer 2 determines that the detected voltage (Vs) from the signal (c1) from the A / D converter 20 is in a state where Vs <3.6V (upper limit) is 0.5 seconds ( It is determined whether or not (predetermined time). If it is continuous (Y), it is normal and ends (repeated similarly). If it is not continuous (N), it is determined that the voltage is abnormal, and the process proceeds to S103.

  (S103, S104) In S103, S104, since the microcomputer 2 is in a voltage abnormal state, the second process (switching process) is performed. First, in S103, the microcomputer 2 outputs a signal for turning off the primary FET 22 and FET 23 (from the ON state to the OFF state) to the corresponding FETs 22 and 23 (d1, d2 in FIG. 2). In S104, the microcomputer 2 outputs a signal for turning on the secondary FET 25 and FET 26 (from the OFF state to the ON state) to the corresponding FETs 25 and 26 (d3 and d4 in FIG. 2).

  (S105) Subsequently, in S105, the microcomputer 2 performs a third process (external display ON process). The microcomputer 2 outputs a signal for turning on the external display relating to the voltage abnormality to the external display control unit 6 (e1 in FIG. 2). Upon receiving this signal (e1), the external display control unit 6 outputs an analog signal (e2) for turning on the corresponding external display to the external display unit 5. The corresponding LED of the external display unit 5 is turned on by this signal (e2). Thereby, the failure state of the component (21) is transmitted to the outside (user).

[Action etc. (1)]
In the configuration shown in FIGS. 1, 2, and 3, the primary shunt regulator 21 is normally operated to appropriately control the charging voltage for the battery set. However, when a failure due to a voltage abnormality of the component (21) is detected, in the case of the conventional technique (configuration of only the primary system), the control of the charging voltage cannot be performed and a charging error occurs. On the other hand, in the present embodiment, as a duplex configuration relating to the component (21) of the voltage control circuit 12, a secondary system component (24) is added and a corresponding control process (FIG. 3) is performed. When a voltage abnormality of the primary shunt regulator 21 is detected based on the monitoring of the A / D converter 20 and the microcomputer 2 determines that the component (21) has failed, the primary to secondary shunt regulator 24 is immediately activated. Switch to the operation. As a result, even if the primary side component (21) breaks down, the operation immediately switches to the operation of the secondary side component (24). Fully charged. Further, when the component (21) on the primary side breaks down, the microcomputer 2 instructs the external display unit 5 through the external display control unit 6, turns on a specific LED of the external display unit 5, and sends the component (21) to the outside. Inform the necessity of maintenance replacement due to failure. The user who confirms the display can immediately take measures such as maintenance and replacement of the component (21) or the circuit (12).

[Current control circuit]
Next, FIG. 4 shows a circuit configuration relating to the current control circuit 11 of FIG. The current control circuit 11 includes an A / D conversion unit (monitoring unit) 40, a first shunt resistor 41, an FET 42, and an FET 43 that form a primary system, and a second shunt resistor 44 and an FET 45 that form a secondary system. And FET 46. The shunt resistors 41 and 44 are components (current detection resistors) that control the charging current. Each FET (42, 43, 45, 46) is a switch element that can be controlled ON / OFF in accordance with a signal from the microcomputer 2.

  Normally, the primary side FETs 42 and 43 are turned on to operate the primary side component (41). When the primary side component (41) fails (hours), the secondary side FETs 45 and 46 are turned on to switch to the secondary side component (44).

  In the primary system, one ends of the FETs 42 and 43 are connected to both ends (points b and c) of the first shunt resistor 41. In the secondary system, one ends of FETs 45 and 46 are connected to both ends of the second shunt resistor 44. The other end of the secondary FET 45 is connected to the other end (point a) of the FET 42. The other end of the secondary FET 46 is connected to the other end (point d) of the FET 43. The control terminals of the FETs 42, 43, 45, 46 are connected to the microcomputer 2.

  The A / D conversion unit 40 is a circuit unit (functionally a current monitoring unit) including an analog / digital conversion processing function according to a known technique, and constantly monitors (detects) the current of the shunt resistor 41 on the primary side. . The A / D converter 40 is connected to both ends (points b and c) of the microcomputer 2 and the first shunt resistor 41, and the analog current of the first shunt resistor 41 detected between the points b and c. A digital value signal obtained by A / D converting the value is always output to the microcomputer 2 (f1).

  The A / D converter 40 outputs a signal (f1) obtained by converting the detected current into a voltage value to the microcomputer 2. Alternatively, the detection current value signal (f1) may be output from the A / D conversion unit 40 to the microcomputer 2, and the microcomputer 2 may convert the detection current value into a voltage value.

  The microcomputer 2 determines an abnormality related to the current (detected current) of the primary shunt resistor 41 based on the signal (f1) from the A / D converter 40 (for example, a comparison determination with a threshold value), and determines the abnormality. If detected, the first process is performed to determine that the component (41) is in a failure state. When the failure is detected, the ON / OFF to each FET (42, 43, 45, 46) is immediately performed. The second process of switching the operation from the primary system component (41) to the secondary system component (44) by performing OFF control is performed, and the external display control related to the current system is performed to the external display control unit 6 in accordance with the switching. A third process for giving a signal of (instruction) is performed.

  When viewed as a functional configuration relating to control of the charging current, the charging device 1 is configured as a processing unit / circuit unit, and the first processing unit is the A / D conversion unit 40 in FIG. This is realized by processing (S201 in FIG. 5 and the like). The second processing unit is realized by the second processing (S203 in FIG. 5) of the microcomputer 2. The third processing unit is realized by the third processing (such as S204 in FIG. 5) of the microcomputer 2, the external display control unit 6, and the external display unit 5.

[Microcomputer processing (2)]
FIG. 5 shows an example of control processing in the microcomputer 2 in the configuration of FIG. 4 (in the case of current monitoring). The microcomputer 2 repeatedly executes the process of FIG. 5 in response to the input of the signal (f1) from the A / D converter 40 described above.

  As a specific example of the setting values related to the charging device 1 and the battery set, the battery set is charged with a charging current of 7.5 A at the maximum with respect to the current of the shunt resistor (41). When the current (detection current) of the shunt resistor (41) is 10A (equivalent to 0.2V) or less, the microcomputer 2 determines that the current exceeds 10A (equivalent to 0.2V). ) Is detected.

  (S201) In S201, the microcomputer 2 performs a first process (current abnormality determination process). In the microcomputer 2, the detection voltage (Vs) obtained by converting the detection current (Is) by the signal (f1) from the A / D conversion unit 40 is 0 (state of Is> 10A) is 0. Judge whether it lasted for 5 seconds (predetermined time). If it is continuous (Y), it is determined that the current is abnormal, and the process proceeds to S202.

  (S202, S203) In S202, S203, since the microcomputer 2 is in a current abnormal state, the microcomputer 2 performs the second process (switching process). First, in S202, the microcomputer 2 outputs a signal for turning off the primary FETs 42 and 43 to the corresponding FETs 42 and 43 (g1 and g2 in FIG. 4). In S203, the microcomputer 2 outputs a signal for turning on the secondary FET 45 and FET 46 to the corresponding FETs 45 and 46 (g3 and g4 in FIG. 4).

  (S204) Subsequently, in S204, the microcomputer 2 performs a third process (external display ON process). The microcomputer 2 outputs a signal for turning on the external display relating to the current abnormality to the external display control unit 6 (h1 in FIG. 4). Upon receiving this signal (h1), the external display control unit 6 outputs a signal (h2) for turning on the corresponding external display to the external display unit 5. The corresponding LED of the external display unit 5 is turned on by this signal (h2). Thereby, the failure state of the component (41) is transmitted to the outside (user).

[Action etc. (2)]
In the configuration shown in FIGS. 1, 4 and 5, the primary shunt resistor 41 is normally operated to appropriately control the charging current for the battery set. However, when a failure due to a current abnormality of the component (41) is detected, in the case of the prior art (configuration of only the primary system), the charging current cannot be controlled and a charging error occurs. On the other hand, in the present embodiment, as a redundant configuration relating to the component (41) of the current control circuit 11, a secondary system component (44) is added, and a corresponding control process (FIG. 5) is performed. When a current abnormality of the primary shunt resistor 41 is detected based on the monitoring of the A / D conversion unit 40 and the microcomputer 2 determines that the component (41) is faulty, the primary system to the secondary system shunt resistor 44 is immediately activated. Switch to the operation. As a result, even if the primary part (41) breaks down, the operation immediately switches to the operation of the secondary part (44). Fully charged. Furthermore, when the component (41) on the primary side breaks down, the microcomputer 2 instructs the external display unit 5 through the external display control unit 6, turns on a specific LED of the external display unit 5, and sends the component (41) to the outside. Inform the necessity of maintenance replacement due to failure. The user who has confirmed the display can immediately take measures such as maintenance and replacement of the component (41) or the circuit (11).

  When the battery to be charged is a lithium battery, the lithium battery is generally charged by constant current / constant voltage control. On the other hand, a lithium battery can supply a large amount of electric power, but it is vulnerable to overvoltage and overcurrent and causes a reduction in battery life.

  The present invention is particularly effective when the battery to be charged is a lithium battery. If the voltage regulator breaks down, the output voltage of the charger cannot be controlled, and an overvoltage is applied to the battery. According to the present invention, even if one voltage regulator breaks down, it switches to the other voltage regulator that is normal, so that the output voltage can be controlled normally, no overvoltage is applied to the battery, and the battery life is reduced. It can suppress that it falls.

  Also, two current detection resistors are provided, and when one of the resistors breaks down, the other is switched to the other, so that low current control and full charge control can be performed normally.

[Effects]
As described above, according to the present embodiment, by appropriately detecting and controlling both the charging voltage and the charging current, while preventing and protecting the overvoltage and overcurrent related to charging, Even if the components (21, 41) for controlling the charging current fail, normal and appropriate charging can be completed without realizing a charging error (full charge can be realized). In the conventional charging device, since the control of the charging voltage and the charging current is only one system (primary), full charging cannot be realized if one of them fails. On the other hand, in the present embodiment, since there are two systems (primary and secondary) for controlling the charging voltage and the charging current, the secondary side remains even if any of the primary sides fails, and full charge can be realized.

  Furthermore, even when the above-mentioned parts fail, it is possible to quickly take appropriate measures such as immediately replacing the failed parts. When the user notices, there is no problem that a part has been out of order, and the full charge function is maintained.

  The charging device 1 of the present embodiment has a function (high reliability circuit) with relatively few parts and a simple circuit. Both voltage (FIG. 2 etc.) and current (FIG. 4 etc.) can be easily applied. It should be noted that the present invention is not limited to the form having both functions of the voltage (FIG. 2 and the like) and the current (FIG. 4 and the like), and may be a form of a charging device having only one function. It is done.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say. For example, the monitoring unit (20, 40) is separated / independent from 11, 12 or each processing (first to third processing) of the microcomputer 2 is separated / independent as each circuit unit (for example, hardware circuit). It is good also as the form which became.

  The present invention can be used for all charging devices related to various devices.

  1: charging device, 2: microcomputer, 3: commercial power supply (AC power supply), 4: charging terminal, 5: external display unit, 6: external display control unit, 7: SW circuit power supply unit, 10: SW circuit, 11: Current control circuit, 12: voltage control circuit, 13: voltage detection circuit, 14: current detection circuit, 15: overvoltage / high temperature detection circuit, 16: overvoltage detection circuit, 17: high temperature detection circuit, 20: A / D converter ( Voltage monitoring unit), 21: shunt regulator (primary side), 22, 23, 25, 26: FET, 24: shunt regulator (secondary side), 40: A / D conversion unit (current monitoring unit), 41: shunt Resistance (primary side), 42, 43, 45, 46: FET, 44: Shunt resistance (secondary side).

Claims (8)

A charging device for charging a battery,
A voltage control circuit having at least two voltage regulators and controlling a charging voltage to the battery by one voltage regulator;
A voltage monitoring unit for monitoring an output voltage from the voltage control circuit;
Control means for controlling the operation of the voltage control circuit by a voltage signal from the voltage monitoring unit,
The said control means is switched to the other voltage regulator, when there is abnormality in the output voltage from the said voltage control circuit, The charging device characterized by the above-mentioned. A charging device for charging a battery,
It has a voltage control circuit that controls the charging voltage to the battery,
The voltage control circuit includes a voltage regulator as a component,
The voltage control circuit includes first and second voltage regulators as a duplex configuration including the components, and a first switch element is connected to both ends of the first voltage regulator, and the second voltage regulator The second switch element is connected to both ends of the
During normal operation, the first voltage regulator is turned on by turning on the first switch element, and the second voltage regulator is turned off by turning off the second switch element.
A voltage monitoring unit that monitors and detects the voltage of the first voltage regulator and outputs a signal of the voltage value;
A first processing unit that performs a first process of determining a failure state due to a voltage abnormality of the first voltage regulator based on a voltage value signal from the voltage monitoring unit;
When the failure is detected, the first switch element is turned off and the second switch element is turned on to turn off the operation of the first voltage regulator and turn on the operation of the second voltage regulator. And a second processing unit that performs a second process of switching to a charging device. The charging device according to claim 2, wherein
An external display unit for displaying information to the outside, and an external display control unit for controlling the external display unit,
A third processing unit for performing a third process of controlling the external display unit to display information indicating a failure of the voltage regulator by instructing the external display control unit to perform control at the time of switching; The charging device characterized by this. A charging device for charging a battery,
A current control circuit having at least two current detection resistors and controlling a charging current to the battery by one of the current detection resistors;
A current monitoring unit for monitoring the current controlled by the current control circuit;
Control means for controlling the operation of the current control circuit by a current signal from the current monitoring unit,
The control device switches to the other current detection resistor when there is an abnormality in the charging current controlled by the current control circuit. A charging device for charging a battery,
It has a current control circuit that controls the charging current to the battery,
The current control circuit includes a current detection resistor as a component,
The current control circuit has first and second current detection resistors as a duplex configuration including the components, and a first switch element is connected to both ends of the first current detection resistor, and the second A second switch element is connected to both ends of the current detection resistor,
During normal operation, the first current detection resistor is turned on by turning on the first switch element, and the second current detection resistor is turned off by turning off the second switch element.
A current monitoring unit that monitors and detects the current of the first current detection resistor and outputs a signal of the current value;
A first processing unit that performs a first process of determining a failure state due to an abnormality in the current of the first current detection resistor based on a current value signal from the current monitoring unit;
When the failure is detected, the first switch element is turned off and the second switch element is turned on to turn off the operation of the first current detection resistor and turn on the operation of the second current detection resistor. And a second processing unit that performs a second process to be switched. The charging device according to claim 5, wherein
An external display unit for displaying information to the outside, and an external display control unit for controlling the external display unit,
A third processing unit that performs a third process of controlling the external display unit to display information indicating a failure of the current detection resistor by instructing the external display control unit to perform control at the time of switching; A charging device characterized by that. A charging device for charging a battery,
A voltage control circuit that controls the charging voltage to the battery, and a current control circuit that controls the charging current to the battery,
The voltage control circuit includes a voltage regulator as a component,
The current control circuit includes a current detection resistor as a component,
The voltage control circuit includes first and second voltage regulators as a duplex configuration including the components, and a first switch element is connected to both ends of the first voltage regulator, and the second voltage regulator The second switch element is connected to both ends of the
Regarding the voltage control circuit, the first voltage regulator is normally turned on by turning on the first switch element, and the second voltage regulator is turned off by turning off the second switch element.
The current control circuit has first and second current detection resistors as a duplex configuration including the components, and a first switch element is connected to both ends of the first current detection resistor, and the second A second switch element is connected to both ends of the current detection resistor,
With regard to the current control circuit, the first current detection resistor is normally turned on by turning on the first switch element, and the second current detection resistor is turned off by turning off the second switch element.
A voltage monitoring unit that monitors and detects the voltage of the first voltage regulator and outputs a signal of the voltage value; and monitors and detects the current of the first current detection resistor and outputs the signal of the current value A current monitoring unit, and
Based on a voltage value signal from the voltage monitoring unit, a process for determining a failure state due to a voltage abnormality of the first voltage regulator, and based on a current value signal from the current monitoring unit A first processing unit that performs a process of determining a failure state due to an abnormality in the current of the first current detection resistor;
When the failure relating to the voltage control circuit is detected, the operation of the first voltage regulator is turned off by turning off the first switch element and turning on the second switch element. The process of switching to turn on the operation, and the first current detection resistor by turning off the first switch element and turning on the second switch element when the failure relating to the current control circuit is detected And a second processing unit that performs a process of switching to turn on the operation of the second current detection resistor. The charging device according to claim 7, wherein
An external display unit for displaying information to the outside, and an external display control unit for controlling the external display unit,
A process for controlling the external display unit to display information indicating a failure of the voltage regulator by instructing control to the external display control unit at the time of switching related to the voltage control circuit, and the current control circuit A third processing unit that performs a process of controlling the external display unit to display information indicating a failure of the current detection resistor by giving a control instruction to the external display control unit at the time of switching; Charging device characterized.

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