Electronic device

Abstract

To suitably suppress an inrush current when a plurality of batteries is installed.SOLUTION: An electronic device 1 includes: a power supply circuit 10 in which a large-capacity capacitor 3 is connected in parallel to a power supply line 11 for supplying power to a main circuit S from two batteries 2 connected in series. The power supply circuit 10 has a bypass line 12 for short-circuiting a connection portion between a part of batteries 2 and the other one of the batteries 2 adjacent to the part of the batteries 2 to the power supply line 11 via a diode 5 and a resistor 6, so that power can be supplied to the main circuit S by only the battery 2, which is a part of the two batteries 2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electronic device. [Background technology]

[0002] Conventionally, in battery-powered electronic devices, such as electronic dictionaries, a large-capacity capacitor has been connected in parallel to the power supply line from multiple batteries to the main circuit as a measure to protect against momentary power outages in the event that the battery becomes dislodged due to an impact such as being dropped.

[0003] In such electronic devices, as the capacitor capacity increases, the inrush current increases when multiple batteries (power sources) are installed. For example, if a fuse is used, this can reduce the durability of the fuse and cause it to melt. For this reason, for example, as shown in Figure 4, some have taken measures to connect a resistor to suppress inrush current to the capacitor in series with a diode that serves as a current path during discharge. Furthermore, for example, in the techniques described in Patent Documents 1 and 2, the voltage of each part is detected and path switching is performed to prevent inrush current. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5440400 [Patent Document 2] Patent No. 5772530 Summary of the Invention [Problem to be solved by the invention]

[0005] However, even when the techniques described in Patent Documents 1 and 2 are used, power loss is large because power is supplied via a transistor for switching.

[0006] The present invention has been made in consideration of the above circumstances, and has an advantage of providing an electronic device that can suitably suppress inrush current when multiple batteries are attached. [Means for solving the problem]

[0007] In order to solve the above problem, the present invention provides an electronic device, a battery storage section capable of storing a plurality of batteries connected in series; a power supply circuit that supplies a voltage between a positive terminal and a negative terminal of the series connection to a main circuit; Equipped with In a first state in which some of the plurality of batteries are not properly stored in the battery storage section and the remaining batteries except for the some of the batteries are properly stored in the battery storage section, the power supply circuit bypasses the some of the batteries and detects a voltage between the positive terminal and the negative terminal of the remaining batteries connected in series. Through a current limiting resistor Supply to the main circuit In a second state in which all of the plurality of batteries are properly stored in the battery storage section, the voltage between the positive and negative terminals of the plurality of batteries connected in series is supplied to the main circuit without passing through a resistor that limits the current. Includes a bypass circuit. Effect of the Invention

[0008] According to the present invention, it is possible to effectively suppress inrush current when multiple batteries are installed. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a diagram illustrating a circuit configuration of an electronic device according to an embodiment. [Diagram 2] FIG. 2 shows the current path when only one of the batteries is installed in the battery box of the electronic device in FIG. 1, where (a) shows when only the first battery is installed and (b) shows when only the second battery is installed. [Diagram 3] FIG. 13 is a diagram illustrating a modification of the power supply circuit according to the embodiment. [Figure 4] FIG. 1 is a diagram illustrating a circuit configuration of a conventional electronic device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An embodiment of an electronic device according to the present invention will be described with reference to FIGS. 1 to 3. FIG. In addition, the embodiments described below are subject to various limitations that are technically preferable for implementing the present invention, but the scope of the present invention is not limited to the following embodiments and illustrated examples.

[0011] FIG. 1 is a diagram illustrating a schematic circuit configuration of an electronic device 1 according to the present embodiment. As shown in this figure, the electronic device 1 supplies power from two batteries 2 (a first battery 2a and a second battery 2b) that serve as power sources to a main circuit S via a power supply circuit 10, and operates this main circuit S to perform a specified function.

[0012] The power supply circuit 10 is provided with two batteries 2 , a capacitor 3 and a fuse 4 . The capacitor 3 is a large-capacity electrolytic capacitor for storing electricity. The capacitor 3 is connected in parallel to a power supply line 11 that supplies power from the two batteries 2 to the main circuit S. The fuse 4 is provided to protect the main circuit S from a current greater than the rated current, and is disposed in the power supply line 11.

[0013] In this embodiment, the two batteries 2 are, for example, long, cylindrical dry batteries with a nominal voltage of 1.5 V. These two batteries 2 are housed in a battery box 20 in a detachable manner. The battery box 20 houses two batteries 2 arranged side by side in the longitudinal direction (the vertical direction in FIG. 1) with the same poles of each battery facing the same direction.

[0014] The battery box 20 is provided with three metal terminal plates 21 that come into contact with the terminals of the batteries 2 (positive terminals 2p or negative terminals 2n). Of the three terminal plates 21, the positive terminal plate 21a and the negative terminal plate 21b are disposed at both ends of the battery box 20. Of these, the positive terminal plate 21a is connected to the positive power supply line 11p and is in contact with the positive terminal 2p of the first battery 2a, of the two batteries 2, whose positive terminal 2p faces the end. Meanwhile, the negative terminal plate 21b is connected to the negative power supply line 11n and is in contact with the negative terminal 2n of the second battery 2b, of the two batteries 2, whose negative terminal 2n faces the end. Of the three terminal plates 21, the intermediate terminal plate 21c is disposed between the two batteries 2 and is in contact with the positive terminal 2p of the second battery 2b and the negative terminal 2n of the first battery 2a. Specifically, the intermediate terminal plate 21c is in direct contact with the positive terminal 2p of the second battery 2b on one surface (the lower surface in FIG. 1) and is in contact with the negative terminal 2n of the first battery 2a on the other surface (the upper surface in FIG. 1) via a battery spring 22 described below.

[0015] Of the three terminal plates 21, the negative terminal plate 21b and the intermediate terminal plate 21c, which contact the negative terminal 2n of each battery 2, are provided with a conical metal battery spring 22. The battery spring 22 contacts the negative terminal 2n of each battery 2 as a terminal, and presses the battery 2 toward the positive side to ensure surface contact between the positive terminal 2p of the battery 2 and the terminal plate 21. The battery spring 22 also allows the battery 2 to be sandwiched and fixed between the positive terminal plate 21a or the negative terminal plate 21b and the intermediate terminal plate 21c, and allows the single battery 2 to be fixed in a state in which only one battery 2 is stored in the battery box 30 (connected to the power supply circuit 10). It should be noted that the battery spring 22 is not limited to a conical spring type, but may be a leaf spring type, a wire spring type, or the like.

[0016] In addition, the power supply circuit 10 is provided with a bypass line 12 that bypasses the other battery 2 other than one of the two batteries 2 so that power can be supplied to the main circuit S with only one of the batteries 2. This bypass line 12 shorts the connection portion between the two batteries 2 (i.e., the intermediate terminal board 21c) to the power supply line 11 via a diode 5 and a resistor 6, and specifically has a first bypass line 121 and a second bypass line 122.

[0017] The first bypass line 121 is a line that connects two diodes 5 (5a, 5b) connected in series in parallel to two batteries 2. The two diodes 5 are provided in the same number as the two batteries 2, corresponding to the two batteries 2. Each diode 5 is arranged with its anode facing the negative power supply line 11n and its cathode facing the positive power supply line 11p. The second bypass line 122 is a line that connects the connection between the two batteries 2 (that is, the intermediate terminal plate 21c) and a connection 123 between the two diodes 5 in the first bypass line 121 via a resistor 6.

[0018] Next, a current flow state when the battery 2 is attached to the battery box 20 in the electronic device 1 (connected to the power supply circuit 10) will be described. FIG. 2 shows the current path when only one of the two batteries 2 is installed in the battery box 20, where (a) shows when only the first battery 2a is installed and (b) shows when only the second battery 2b is installed.

[0019] 2(a), when only the first battery 2a of the two batteries 2 is installed in the battery box 20, the first battery 2a is connected to the main circuit S and capacitor 3 via the positive power line 11p, the negative power line 11n, half of the first bypass line 121 (the lower half in the figure), and the second bypass line 122, as shown by the thick lines in Fig. 2(a). As a result, a voltage of 1.5V from the single first battery 2a is applied to the capacitor 3 via the resistor 6. Thereafter, charging of the capacitor 3 is continued with the current limited by the resistor 6 until the second battery 2b is attached. The resistance value of resistor 6 for providing this charging current is determined by the predicted time (average time or shortest time) between when the user inserts the first battery and when the user inserts the next battery, the capacity of capacitor 3, the battery voltage, etc. In other words, the charging current value required to charge capacitor 3 until the voltage reaches a level at which inrush current is not a problem (the fuse will not melt) during the predicted time between when the user inserts the first battery and when the user inserts the next battery is calculated, and the resistance value of resistor 6 is determined so that charging is performed at this current value. Then, when the second battery 2b is installed, as shown in Figure 1, a voltage of 3V from the two batteries 2 is applied to the main circuit S and capacitor 3 via the power line 11 (11p, 11n) rather than the bypass line 12 with the resistor 6. In this state, capacitor 3 has already been sufficiently charged and the potential difference between the batteries and capacitor 3 is small, so even if the voltage of all the batteries is applied to capacitor 3 without going through a resistor, there will be no inrush current strong enough to blow the fuse.

[0020] On the other hand, as shown in Figure 2(b), when only the second battery 2b of the two batteries 2 is installed in the battery box 20, this second battery 2b is connected to the main circuit S and capacitor 3 via the second bypass line 122, half of the first bypass line 121 (the upper half in the figure), the positive power supply line 11p, and the negative power supply line 11n, as shown by the thick lines in Figure 2(b). As a result, a voltage of 1.5V from the single second battery 2b is applied to the capacitor 3 via the resistor 6. Thereafter, charging of the capacitor 3 is continued with the current limited by the resistor 6 until the first battery 2a is attached. The resistance value of resistor 6 for providing this charging current is determined by the predicted time (average time or shortest time) between when the user inserts the first battery and when the user inserts the next battery, the capacity of capacitor 3, the battery voltage, etc. In other words, the charging current value required to charge capacitor 3 until the voltage reaches a level at which inrush current is not a problem (the fuse will not melt) during the predicted time between when the user inserts the first battery and when the user inserts the next battery is calculated, and the resistance value of resistor 6 is determined so that charging is performed at this current value. Then, when the first battery 2a is installed, as shown in Figure 1, a voltage of 3V from the two batteries 2 is applied to the main circuit S and capacitor 3 through the power line 11 (11p, 11n) rather than the bypass line 12 with the resistor 6. In this state, capacitor 3 has already been sufficiently charged and the potential difference between the batteries and capacitor 3 is small, so even if the voltage of all the batteries is applied to capacitor 3 without going through a resistor, there will be no inrush current large enough to blow the fuse.

[0021] In this way, regardless of which of the two batteries 2 is installed first, the voltage of each of the two batteries 2 is applied to the capacitor 3 in stages via the resistor 6, one at a time. As a result, charging of the capacitor 3 begins with only some of the batteries 2 inserted while the current is limited by the resistor 6, and charging of the capacitor 3 is completed by the time all of the batteries 2 are inserted (or the capacitor 3 is charged until the voltage reaches a level at which inrush current does not become a problem), so inrush current is suppressed compared to when the entire voltage is applied all at once when multiple batteries are completely installed. Furthermore, the path change at this time is performed automatically without the need for a CPU to control circuit elements.

[0022] As described above, according to the electronic device 1 of this embodiment, the power supply circuit 10 has a bypass line 12 that shorts the connection portion (intermediate terminal board 21c) between the two batteries 2 to the power supply line 11 via a diode 5 and a resistor 6, so that power can be supplied to the main circuit S using only some of the two batteries 2. As a result, the voltage from the two batteries 2 is applied in stages, one at a time, via the resistor 6 to the large-capacity capacitor 3 connected in parallel to the main circuit S. This makes it possible to suppress inrush current compared to when the full voltage of multiple batteries is applied all at once when the installation of the batteries is complete. Also, when all the batteries 2 are inserted, no elements that cause power loss, such as resistors, diodes or transistors, are inserted in the current path, making it possible to suppress power loss compared to the past, when transistors for switching were required. This makes it possible to effectively suppress inrush current when two batteries 2 are installed. This in turn makes it possible to achieve both durability of the fuse 4 against inrush current and redundancy against momentary power outages by increasing the capacity of the capacitor 3.

[0023] Furthermore, according to the electronic device 1 of this embodiment, the bypass line 12 has a first bypass line 121 and a second bypass line 122. Of these, the first bypass line 121 connects two diodes 5 connected in series in parallel to the two batteries 2, and the second bypass line 122 connects a connection part (intermediate terminal board 21c) between the two batteries 2 and a connection part 123 between the two diodes 5 in the first bypass line 121 via a resistor 6. With this configuration, the voltage from the two batteries 2 can be applied to the capacitor 3 in stages, one battery at a time, regardless of which of the two batteries 2 is installed first.

[0024] Although the embodiment of the present invention has been described above, it goes without saying that the present invention is not limited to such an embodiment, and various modifications are possible without departing from the gist of the present invention.

[0025] For example, in the above embodiment, a case was described in which two batteries 2 are used as the power source, but as shown in FIG. 3(a), the number of batteries 2 may be three or more (four in the example of FIG. 3(a)). In this case, the bypass line 12 only needs to short-circuit a connection portion (i.e., intermediate terminal plate 21c) between some of the batteries 2 and other batteries 2 adjacent to the some of the batteries 2 to the power supply line 11 via a diode 5 and a resistor 6 so that power can be supplied to the main circuit S from only some of the batteries 2. Specifically, a first bypass line 121 of the bypass line 12 connects a plurality of diodes 5, which are the same in number as the plurality of batteries 2 and correspond to the plurality of batteries 2, and are connected in series, in parallel to the plurality of batteries 2. In addition, a second bypass line 122 connects a connection portion (i.e., intermediate terminal plate 21c) between two adjacent batteries 2 and a connection portion 123 between two diodes 5 in the first bypass line 121 that correspond to the two batteries 2 via a resistor 6. With this configuration, even when three or more batteries 2 are used as the power source, the same effects as those of the above embodiment can be obtained.

[0026] In the above embodiment, the battery box 20 accommodates two batteries 2 arranged in the longitudinal direction with the same poles facing in the same direction. However, as shown in Fig. 3(b), the battery box 20 may accommodate multiple batteries 2 (two in the example of Fig. 3(b)) arranged in the transverse direction with the same poles facing in opposite directions. In this case, the surface of the intermediate terminal plate 21c that comes into direct contact with the positive terminal 2p of the second battery 2b and the surface that comes into contact with the negative terminal 2n of the first battery 2a via the battery spring 22 are on the same side. This allows the batteries 2 to be suitably stored in the battery box 20 even in cases where it is difficult to line up the batteries 2 in the longitudinal direction due to layout constraints within the device or the like. Furthermore, as a result, the battery box 20 can be configured not only to store multiple batteries 2 with the same poles facing in opposite directions and lined up in the short direction, but also to store multiple batteries with the same poles facing in the same direction and lined up in the long direction, so that it is possible to fix only a portion of the multiple batteries 2 stored in the battery box, and in this state, power from the portion of the batteries 2 can be supplied to the large-capacity capacitor 3 via resistor 6 to charge the batteries.

[0027] Furthermore, in the above embodiment, a configuration has been described in which, regardless of which battery 2 is installed first, a voltage is applied to the main circuit S and capacitor 3 by that battery 2. However, if, for example, a specific battery 2 is always installed first (or multiple batteries 2 are installed in a specific order) due to structural features of the battery box 20, then it is sufficient to provide only a bypass line portion connecting that specific battery 2 to the power supply line 11. In other words, in this case, it is sufficient for the bypass line 12 to have only a line that shorts the terminal of that specific battery 2 to the power supply line 11 of the same polarity, and the diode 5 corresponding to that specific battery 2 and the first bypass line 121 portion that connects this diode 5 to the power supply line 11 are not necessary. For example, in the above embodiment, if the battery box 20 is configured so that the first battery 2a is always installed first, the diode 5a corresponding to this first battery 2a and the portion of the first bypass line 121 that connects this diode 5a to the power line 11p (the portion above the connecting portion 123 in Figure 1) are not necessary (see Figure 2(a)).

[0028] In addition, in the above embodiment, the battery 2 is a cylindrical dry battery, but the battery of the present invention is not limited to this and may be a shape other than cylindrical, or may be a battery other than a dry battery.

[0029] The electronic device to which the present invention can be applied is not particularly limited as long as it uses multiple batteries as a power source, but the present invention is particularly suitable for use in portable devices that use multiple batteries, such as electronic dictionaries, in which the batteries may fall out due to shock, such as being dropped.

[0030] Although several embodiments of the present invention have been described above, the scope of the present invention is not limited to the above-described embodiments, but includes the scope of the invention described in the claims and its equivalents. The inventions described in the claims originally attached to this application are set forth below. The claim numbers in the appended claims are the same as those in the claims originally attached to this application. [Additional Notes] <Claim 1> A power supply circuit is provided with a large-capacity capacitor connected in parallel to a power supply line that supplies power to a main circuit from a plurality of batteries connected in series, the power supply circuit has a bypass line that shorts a connection between the part of the plurality of batteries and another battery adjacent to the part of the batteries to the power supply line via a diode and a resistor so that power can be supplied to the main circuit using only the part of the plurality of batteries; electronic equipment. <Claim 2> The bypass line is a first bypass line that connects a plurality of diodes, the number of which is the same as the number of the plurality of batteries, corresponding to the plurality of batteries, and connected in series, in parallel to the plurality of batteries; a second bypass line that connects, via a resistor, a connection portion between two adjacent batteries and a connection portion between two diodes in the first bypass line that correspond to the two batteries; 2. The electronic device according to claim 1. <Claim 3> a battery storage section for detachably storing the plurality of batteries; the battery storage section is capable of fixing a portion of the batteries in a state in which only a portion of the plurality of batteries is stored therein, 3. The electronic device according to claim 1 or 2. <Claim 4> The battery storage section includes: The plurality of batteries are stored in a state where they are aligned in a longitudinal direction with the same poles of each battery facing in the same direction; a metal terminal plate is provided between two adjacent batteries, the metal terminal plate being in contact with the positive electrode of one of the two batteries and the negative electrode of the other battery; The bypass line is connected to the metal terminal plate. 4. The electronic device according to claim 3. <Claim 5> The metal terminal plate provided between two adjacent batteries sandwiches and fixes the stored battery together with another metal terminal plate provided at an end of the battery storage section. 5. The electronic device according to claim 4. <Claim 6> The metal terminal plate is provided between two adjacent batteries, and one surface of the metal terminal plate is in direct contact with the positive electrode of one of the batteries, and the other surface of the metal terminal plate is in direct contact with the negative electrode of the other battery via a metal battery spring. 6. The electronic device according to claim 4 or 5. <Claim 7> the battery storage section stores the plurality of batteries in a state where the batteries are arranged in a short direction with the same poles of each battery facing in opposite directions, a metal terminal plate is provided at an end of the battery storage section, which contacts the positive electrode of one of two adjacent batteries with the negative electrode of the other battery; The bypass line is connected to the metal terminal plate. 4. The electronic device according to claim 3. [Explanation of symbols]

[0031] 1 Electronic equipment 2 batteries 2a 1st battery 2b 2nd battery 2n negative terminal 2p positive terminal 3. Capacitor 4. Fuse 5. Diodes 6. Resistance 10 Power circuit 11 Power Line 11n Negative power supply line 11p Positive power line 12 Bypass Line 20 Battery box 21 Terminal board 21a Positive terminal board 21b Negative terminal board 21c Intermediate terminal board 22 Battery spring 121 First Bypass Line 122 Second Bypass Line 123 Connecting part S Main circuit

Claims

1. a battery storage section capable of storing a plurality of batteries connected in series; a power supply circuit that supplies a voltage between a positive terminal and a negative terminal of the series connection to a main circuit; Equipped with the power supply circuit includes a bypass circuit that, in a first state in which some of the plurality of batteries are not properly stored in the battery storage section and the remaining batteries except for the some of the batteries are properly stored in the battery storage section, bypasses the some of the batteries and supplies the voltage between the positive and negative terminals of the remaining batteries in a state in which they are connected in series to the main circuit via a resistor that limits current, and in a second state in which all of the plurality of batteries are properly stored in the battery storage section, supplies the voltage between the positive and negative terminals of the plurality of batteries in a state in which they are connected in series to the main circuit without passing through the resistor that limits current. electronic equipment.

2. the power supply circuit has a capacitor connected in parallel between the positive and negative terminals of the plurality of batteries connected in series, and when the plurality of batteries are stored in the battery storage section in sequence, the capacitor is charged with a current limited via the resistor.

2. The electronic device according to claim 1.

3. The first state is a state in which the some of the batteries are not housed in the battery housing section, or a state in which the some of the batteries are housed in the battery housing section but electrodes of the some of the batteries are not properly connected to electrodes of the other batteries.

2. The electronic device according to claim 1.

4. the plurality of batteries includes a first battery and a second battery; the battery storage section stores the first battery and the second battery in a state of being connected in series such that a negative electrode of the first battery and a positive electrode of the second battery are connected and a voltage between the positive electrode of the first battery and the negative electrode of the second battery can be supplied to the main circuit; the bypass circuit supplies a voltage between the positive electrode of the first battery and the negative electrode of the first battery to the main circuit when the first battery is stored in the battery storage section and the second battery is not stored in the battery storage section, and supplies a voltage between the positive electrode of the second battery and the negative electrode of the second battery to the main circuit when the second battery is stored in the battery storage section and the first battery is not stored in the battery storage section.

2. The electronic device according to claim 1.

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