JP2008306925A - Charging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charging device that can charge batteries from at least two kinds of power sources. <P>SOLUTION: A charging device 100 is provided with DC/DC converters 105, 106 serving as a voltage conversion means, and AC/DC converter 109, a microcomputer 112, an external selection means 113, and a charging current detection circuit 111. The microcomputer 112 selects a power source for use according to a predetermined priority or a signal 11 from the external selection means 113, and turns only corresponding voltage conversion means. The voltage conversion means converts a voltage from the power source to a desired voltage. The charging current detection circuit 111 detects charging current, and sends it to the microcomputer 112. The microcomputer 112 sends a constant current control signal to a voltage detection means, and controls the charging current to a desired current value depending on the voltage detection means. A battery set 104 is charged from source of supply selected from at least two kinds of power sources. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a charging device that charges a nickel cadmium battery, a nickel hydride battery, or the like used as a power source for portable equipment such as a cordless electric tool.

  Conventionally, a charging device for charging a nickel cadmium battery (hereinafter referred to as a nickel cadmium battery) or a nickel metal hydride battery is charged by being supplied from a commercial power source.

  When charging from a commercial power source, the voltage is stepped down to a desired voltage by a step-down circuit that converts the voltage according to the commercial power source to be used, and rectified and smoothed by a rectifier circuit and a smoothing circuit. Further, the current is made constant by a constant current circuit, and the battery is charged through the charging current control element. Completion of charging is determined based on whether or not the temperature rise rate of the battery is equal to or greater than a predetermined value (see, for example, Patent Document 1).

A charge control circuit that performs charging using a similar circuit and determines whether or not charging is complete is based on whether or not the duration is equal to or longer than a predetermined period when the rate of temperature increase is equal to or higher than a predetermined value (for example, Patent Documents) 2), or the amount of temperature change per unit charging time or charging station time per unit changing temperature is calculated sequentially, and charging is completed when the value obtained by sequentially comparing two consecutive calculated values satisfies a predetermined value. There is also proposed a charging circuit (see, for example, Patent Document 3).
JP 62-193518 A (pages 1-6, FIG. 2) Japanese Laid-Open Patent Publication No. 2-24639 (page 3-4, FIG. 1) Japanese Utility Model Publication No. 3-34638 (first page, FIG. 1)

  However, for example, when a cordless power tool using a battery charged by the charging device as described above is used in a place where the commercial power is not supplied, the necessary battery is supplied according to the amount of work. It is necessary to charge in advance at the place where it is. For this reason, the user has to prepare several spare batteries when the amount of work is large.

  The present invention has been made in view of the above-described problems of conventional charging apparatuses, and an object thereof is to provide a charging apparatus capable of charging a battery from at least two types of power sources as well as commercial power sources. And

  In order to achieve the above object, the present invention is a charging device for receiving a power supply from a power source to charge a battery pack, wherein the solar cell can be connected as the power source. A charging device comprising: a first power conversion circuit that converts power generated in a cell; and an output terminal that outputs power from the first power conversion circuit to the battery pack. ing. The battery here is a secondary battery including a battery set in which a plurality of unit cells are connected in series.

  Moreover, it is preferable that the said charging device is comprised so that a commercial alternating current power supply can be further connected as said power supply.

  Moreover, it is preferable that the said charging device is further provided with the power converter circuit for alternating current which converts the electric power of the said commercial alternating current power supply into direct-current power.

  Moreover, it is preferable that the said charging device is comprised so that a vehicle-mounted battery can be further connected as said power supply.

  Moreover, it is preferable that the said charging device is further provided with the 2nd power converter circuit which converts the electric power of the said vehicle-mounted battery.

  In addition, the first power conversion circuit and the second power conversion circuit are connected in common to the output terminal, and between the first power conversion circuit and the output terminal, and the second It is preferable that a backflow prevention circuit for preventing a reverse current is interposed between the power conversion circuit and the output terminal.

  According to the present invention, since the battery can be charged using at least two types of power supplies as supply power, when using a cordless power tool or the like in a place where commercial power is not supplied, The battery can be charged with the car battery using the time to travel to. Moreover, if it puts it in the place where sunlight hits, it will become possible to charge also with a solar cell. Therefore, usability can be improved and work efficiency can be improved.

  A charging apparatus according to an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a block diagram showing a charging device 100 according to the present embodiment. As shown in FIG. 1, the charging device 100 includes DC / DC converters 105 and 106, diodes 107 and 108, an AC / DC converter 109, a relay 110, a charging current detection circuit 111, a microcomputer 112, connection terminals 131, 133, and 135, 137 and the like.

  The power supplies 101, 102, 103 are detachably connected to the connection terminals 131, 133, 135. The battery set 104 is detachably connected to the connection terminal 137. The power sources 101 and 102 are DC power sources such as car batteries and solar cells, and the power source 103 is an AC power source such as a commercial power source. The power supplies 101, 102, and 103 are supply power supplies. In this embodiment, the battery set 104 is used as a battery. The battery set 104 is formed by connecting a plurality of rechargeable cells in series.

  The DC / DC converters 105 and 106 are voltage conversion means for converting the voltage supplied from the DC power supplies 101 and 102 into a desired voltage for charging the battery set 104. The diodes 107 and 108 are diodes that rectify the output from the DC / DC converters 105 and 106. The AC / DC converter 109 is voltage conversion means for converting the AC voltage supplied from the AC power source 103 into a desired DC voltage.

  The relay 110 is a switch that turns on and off the output of the AC / DC converter 109. The charging current detection circuit 111 is a circuit that detects a charging current to the battery set 104.

  The microcomputer 112 is a control circuit that controls charge control of the battery set 104 and which power source supplies the battery set 104 to charge. Signals 1, 2, 3, 9, 10, and 11 are input to the microcomputer 112. In addition, the microcomputer 112 outputs signals 4, 5, 6, 7, 8, and 12. The microcomputer 112 has functions of a selection unit and a current control unit.

  Signals 1, 2, and 3 are power supply detection signals that are connected to the connection terminals 131, 133, and 135, respectively, and detect whether or not a power supply is connected to the connection terminals 131, 133, and 135. Signals 4, 6, and 8 are ON / OFF control signals that enable only the power supply selected by the microcomputer 112 and do not use any other power supply, and are respectively DC / DC converter 105, DC / DC Input to DC converter 106 and relay 110. Signals 5, 7, and 12 are constant current control signals for controlling the charging current. The signals 5 and 7 are input to the DC / DC converter 105 and the DC / DC converter 106, respectively, and the signal 12 is input to the AC / DC converter 109. The signal 9 is a battery voltage detection signal for detecting the battery voltage, and is output from the connection terminal 137. A signal 10 is a charging current detection signal from the charging current detection circuit 111. A signal 11 is a power supply selection signal from the external selection unit 113.

  The external selection means 113 is a changeover switch or the like, and is used when a user selects a power supply used for charging. The external selection unit 113 outputs a power supply selection signal corresponding to the selected power supply to the microcomputer 112.

  Next, the operation of the charging apparatus 100 will be described with reference to the circuit block diagram of FIG. 1 and the flowchart of FIG.

  First, the power source connected to the charging device 100 is detected by the microcomputer 112 (step 201). When the power supplies 101, 102, and 103 are connected to the connection terminals 131, 133, and 135, predetermined voltages are detected for the signals 1, 2, and 3, respectively. The microcomputer 112 detects whether or not a power source is connected based on this voltage.

  Next, it is selected which power source is used to charge the battery set 104 (step 202). As a selection method at this time, there is a method in which priorities are set in the microcomputer 112 in advance, and selection is made according to the priorities from the connection detection result in step 201. In addition, the external setting means 113 allows the user to freely select the power supply and set the priority order.

  Next, the battery set 104 enters a connection standby state (step 203). When the battery set 104 is connected to the connection terminal 137, the voltage is converted by the voltage conversion means corresponding to the power supply selected in step 202, and charging is started with the charging current corresponding to the selected power supply (step 204). .

  For example, if the power source selected in step 202 is 101, the DC / DC converter 105 is turned on by a signal 4 from the microcomputer 112, and the remaining DC / DC converter 106 and the relay 110 are turned off by signals 6 and 8.

  At this time, the battery set 104 is charged with a charging current corresponding to the selected power supply. As a method of constant current control during charging, the charging current detection circuit 111 detects the charging current flowing through the battery set 104 simultaneously with the start of charging, and sends a signal 10 to the microcomputer 112. The microcomputer 112 sends a signal 5 for constant current control to the DC / DC converter 105 of the power source 101 and performs charging so that the charging current is always constant.

  The microcomputer 112 sends the signal 7 to the DC / DC converter 106 when the power source 102 is used, and sends the signal 12 to the AC / DC converter 109 when the power source 103 is used. I do. The charging current is controlled to each current value corresponding to the selected power supply.

  Thereafter, in step 205, a full charge detection process is performed. The full charge detection can be performed by various known methods. For example, when the battery voltage of the battery set 104 input to the microcomputer 112 by the signal 9 drops by a predetermined amount from the peak voltage at the end of charging, a full charge is detected, -ΔV detection, the second floor according to the time of the battery voltage of the battery set 104 A second-order differential detection method or the like that detects full charge when the differential value becomes negative can be used. Also, a means (not shown) for measuring the temperature of the battery set 104 is provided, and a ΔT detection method for detecting a full charge when the temperature rise value of the battery set from the start of charging exceeds a predetermined value. One or a plurality of full charge detection methods such as a ΔT / Δt detection method for detecting a time point when the battery temperature increase rate (temperature gradient) per unit time increases rapidly can also be used.

  In step 205, if the microcomputer 112 determines that the battery set 104 is in a fully charged state, the power source 101 is selected, so that the microcomputer 112 outputs an off signal to the DC / DC converter 105 as a signal 4, Charging is stopped (step 206).

  Next, it is determined whether the battery set 104 is removed from the connection terminal 137 (step 207). The microcomputer 112 determines whether the battery set 104 is removed based on the voltage value of the battery voltage detection signal 9. If it is determined that the battery set 104 has been removed, the process returns to step 203 to wait for charging of the next battery set 104.

  As described above, according to charging apparatus 100 according to the present embodiment, battery set 104 can be charged using a plurality of power sources including a commercial power source as a supply power source.

  At this time, the microcomputer 112 detects whether or not a power source is connected to each of the connection terminals 131, 133, and 135, selects a supply power source according to a predetermined priority order, and charges the battery set 104 using the power source. It can be performed. It is also possible to control the selection of the power supply by sending the power supply to be used for the microcomputer 112 and the signal 11 indicating the priority order using the external selection means 113.

  The charging current detection circuit 111 detects the charging current, sends a signal 9 to the microcomputer 112, and feeds back to the DC / DC converters 105 and 106 and the AC / DC converter 109, thereby selecting the charging current of the battery set 104. It can be controlled to a desired current value according to the power source.

  If the charging apparatus 100 having the above configuration is used, the battery set 104 can be charged using a car battery or a solar battery even in a place where there is no commercial power supply, so that it is easy to use and work efficiency can be increased.

  As mentioned above, although preferred embodiment of the charging device by this invention was described referring an accompanying drawing, this invention is not limited to embodiment mentioned above. Those skilled in the art can make various modifications and improvements within the scope of the technical idea described in the claims.

  For example, one type of AC power source and two types of DC power sources are used, but two or more AC / DC converters may be provided so that a plurality of AC power sources can be used. The number of connection terminals for connecting the power supply may not be provided. For example, a configuration in which a solar battery or the like is always provided may be employed.

  The voltage conversion means such as a DC / DC converter is provided with the number of power supplies. For example, a voltage having a function of substituting a plurality of voltage conversion means by one, such as outputting an arbitrary voltage for an arbitrary input voltage. You may make it provide a conversion means.

  INDUSTRIAL APPLICABILITY The present invention is used as a charging device for charging a battery used in a device that is carried and used, such as a cordless electric tool.

FIG. 3 is a block circuit diagram showing the charging apparatus 100. 6 is a flowchart for explaining the operation of the charging apparatus 100.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Charging apparatus 101, 102, 103 Power supply 104 Battery set 105, 106 DC / DC converter 107, 108 Diode 109 AC / DC converter 110 Relay 111 Charging current detection circuit 112 Microcomputer 113 External selection means 131, 133, 135 Connection terminal 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 signals

Claims (6)

A charging device for charging a battery pack by receiving power from a power source,
A solar cell can be connected as the power source,
A first power conversion circuit for converting the power generated in the solar cell;
An charging terminal comprising: an output terminal that outputs power from the first power conversion circuit to the battery pack.   The charging device according to claim 1, wherein a commercial AC power source is further connectable as the power source.   The charging device according to claim 2, further comprising an AC power conversion circuit that converts electric power of the commercial AC power source into DC power.   The charging device according to any one of claims 1 to 3, wherein an in-vehicle battery is further connectable as the power source.   The charging device according to claim 4, further comprising a second power conversion circuit that converts electric power of the in-vehicle battery.   The first power conversion circuit and the second power conversion circuit are commonly connected to the output terminal, and are connected between the first power conversion circuit and the output terminal, and the second power. 6. The charging device according to claim 5, wherein a backflow prevention circuit for preventing a reverse current is interposed between the conversion circuit and the output terminal.

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