JP2018153034A - Battery connection determination circuit, charger, electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery connection determination circuit for determining the connection direction of battery at a low cost.SOLUTION: A battery connection determination circuit includes a first contact TP1 on which any one of the positive electrode terminal and the negative electrode terminal of a battery abuts, a second contact TP2 on which the other of the positive electrode terminal and the negative electrode terminal of a battery abuts, and a comparison circuit 30 for comparing the voltage of the first contact TP1 and the voltage of the second contact TP2, outputting a first determination signal when the voltage of the first contact TP1 is higher than the voltage of the second contact TP2, and outputting a second determination signal when the voltage of the second contact TP2 is higher than the voltage of the first contact TP1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a battery connection determination circuit that determines a connection direction of a battery, a charging device including the battery connection determination circuit, and an electronic apparatus.

  In general, cylindrical dry batteries and secondary batteries are widely used as power sources for various electronic devices. Further, the secondary battery can be repeatedly used by charging, and a charging device is widely used as a device for charging the secondary battery. When mounting a battery on such an electronic device or charging device, it is necessary to check the polarity of the battery. That is, the battery needs to be mounted on the electronic device or the charging device in a correct connection direction in which the positive electrode terminal contacts the contact point with which the positive electrode terminal should contact and the negative electrode terminal contacts with the contact point with which the negative electrode terminal should contact.

  However, in many cases, the electronic device and the charging device are configured such that the battery can be mounted even when the connection direction is reverse. Therefore, there is a possibility that the battery is mounted in a connection direction opposite to the correct connection direction. If a battery is installed in the opposite direction to the correct connection direction, the electronic device will not operate, and the charging device will not be able to charge the battery, for example, battery leakage. Etc. may occur.

  As an example of the prior art aiming to solve such a problem, a circuit for judging the connection direction of the battery by comparing the voltage of the reference power supply and the voltage of the battery with a comparator is detected, and reverse connection is detected. A device for stopping charging / discharging of a battery when the battery is discharged is known (for example, see Patent Documents 1 and 2).

JP 2007-202396 A JP 2009-177037 A

  However, in the above-described conventional technology, it is necessary to provide a reference power source that generates a reference voltage. In other words, the above-described conventional technique has a complicated and large-scale configuration in which a reference power supply is provided, which may cause a significant increase in cost of the apparatus.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a battery connection determination circuit that determines the connection direction of the battery at a low cost.

<First Aspect of the Present Invention>
According to a first aspect of the present invention, a first contact with which one of a positive electrode terminal or a negative electrode terminal of a battery abuts, a second contact with which the other of the positive electrode terminal or the negative electrode terminal of the battery abuts, and the first contact Is compared with the voltage of the second contact, and when the voltage of the first contact is higher than the voltage of the second contact, a first determination signal is output, and the voltage of the second contact is the first contact And a comparison circuit that outputs a second determination signal when the voltage is higher than the voltage of the battery.

  The comparison circuit compares the voltage at the first contact with the voltage at the second contact, and outputs a first determination signal when the voltage at the first contact is higher. In this case, the battery has the positive electrode terminal in contact with the first contact and the negative electrode terminal in contact with the second contact. On the other hand, the comparison circuit outputs a second determination signal when the voltage at the second contact is higher. In this case, the battery has the positive electrode terminal in contact with the second contact and the negative electrode terminal in contact with the first contact. Thus, by comparing the voltage of the first contact and the voltage of the second contact to determine the connection direction of the battery, there is no need to provide a reference power source for generating a reference voltage. The connection direction can be determined.

  Thereby, according to the 1st aspect of this invention, the effect that the battery connection determination circuit which determines the connection direction of a battery can be provided at low cost is acquired.

<Second Aspect of the Present Invention>
According to a second aspect of the present invention, in the first aspect of the present invention described above, the comparison circuit compares the voltage of the first contact with the voltage of the second contact, and the voltage of the first contact is A first comparator that outputs the first determination signal when the voltage of the second contact is higher than the voltage of the second contact; and the voltage of the first contact is compared with the voltage of the second contact; And a second comparator that outputs the second determination signal when the voltage is higher than the voltage of the first contact.
According to the second aspect of the present invention, it is possible to provide a battery connection determination circuit for determining the connection direction of a battery at a lower cost by using a comparison circuit having a very simple configuration as described above. it can.

<Third Aspect of the Present Invention>
According to a third aspect of the present invention, in the first aspect or the second aspect of the present invention described above, the comparison circuit includes a resistor that pulls down the first contact and a resistor that pulls down the second contact. It is a battery connection determination circuit.
According to the third aspect of the present invention, when the battery is not attached, the potentials of the first contact and the second contact are maintained at the ground potential, so that the output of the comparison circuit becomes unstable. The fear can be reduced.

<Fourth aspect of the present invention>
According to a fourth aspect of the present invention, there is provided the battery connection determination circuit according to any one of the first to third aspects of the present invention described above, a power supply device that supplies charging power for the battery, a switch circuit, and the switch circuit. A control device for controlling the power supply, wherein the switch circuit is configured to turn on / off a connection between the voltage output terminal of the power supply device and the first contact, a ground terminal of the power supply device, and the first switch. A second switch for turning on / off the connection with the contact, a third switch for turning on / off the connection between the voltage output terminal of the power supply device and the second contact, a ground terminal of the power supply device, and the second contact A fourth switch for turning on / off the connection to the control circuit, and when the first determination signal is output from the comparison circuit, the control device turns on the first switch and the fourth switch, When the second switch and the third switch are turned OFF and the second determination signal is output from the comparison circuit, the first switch and the fourth switch are turned OFF, and the second switch and the third switch are turned ON. It is a charging device.

  Thus, by turning ON / OFF the first to fourth switches of the switch circuit in accordance with the determination signal output from the comparison circuit, the positive terminal of the battery is the voltage output terminal of the power supply device regardless of the connection direction of the battery. The negative terminal of the battery is connected to the ground terminal of the power supply device. Therefore, according to the 4th aspect of this invention, in addition to the effect by the 1st-3rd aspect of this invention mentioned above, the effect that a battery can be charged irrespective of the connection direction of a battery is acquired.

<Fifth aspect of the present invention>
According to a fifth aspect of the present invention, there is provided the battery connection determination circuit according to any one of the first to third aspects of the present invention described above, a load device that operates with the power of the battery, a switch circuit, and the switch circuit. A control device for controlling, the switch circuit comprising: a first switch for turning on / off a connection between the voltage input terminal of the load device and the first contact; a ground terminal of the load device; and the first contact. A second switch for turning on / off the connection to the load, a third switch for turning on / off the connection between the voltage input terminal of the load device and the second contact, a ground terminal of the load device, and the second contact And a fourth switch for turning on / off the connection of the control circuit, wherein the control device turns on the first switch and the fourth switch when the first determination signal is output from the comparison circuit. 2 The switch and the third switch are turned off, and when the second determination signal is output from the comparison circuit, the first switch and the fourth switch are turned off, and the second switch and the third switch are turned on. , Electronic equipment.

  Thus, by turning ON / OFF the first to fourth switches of the switch circuit in accordance with the determination signal output from the comparison circuit, the positive terminal of the battery is the voltage input terminal of the load device regardless of the connection direction of the battery. The negative terminal of the battery is connected to the ground terminal of the load device. Therefore, according to the fifth aspect of the present invention, in addition to the operational effects of the first to third aspects of the present invention described above, the electronic device can be operated with the power of the battery regardless of the connection direction of the battery. The effect that it can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the battery connection determination circuit which determines the connection direction of a battery can be provided at low cost.

1 is a circuit diagram illustrating a configuration of a charging device according to the present invention. The circuit diagram which illustrated the state which the positive electrode terminal of the battery contact | abutted to the 1st contact, and the negative electrode terminal of the battery contact | abutted to the 2nd contact. The circuit diagram which illustrated the state which the positive electrode terminal of the battery contact | abutted to the 2nd contact, and the negative electrode terminal of the battery contact | abutted to the 1st contact. The figure which showed the relationship between the output of a 1st comparator and a 2nd comparator, and ON / OFF of a 1st-4th switch. 1 is a circuit diagram illustrating a configuration of an electronic device according to the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In addition, this invention is not specifically limited to the Example demonstrated below, It cannot be overemphasized that a various deformation | transformation is possible within the range of the invention described in the claim.

<First embodiment>
An embodiment of a charging device including a battery connection determination circuit according to the present invention will be described with reference to FIGS.
FIG. 1 is a circuit diagram illustrating a configuration of a charging device according to the present invention.

  The charging device according to the present invention includes a DC-DC converter 10, a battery mounting unit 20, a comparison circuit 30, a switch circuit 40, and a control device 50.

  The DC-DC converter 10 is a “power supply device” that supplies battery charging power, and is a constant voltage constant current power source that converts an input DC voltage into a battery charging voltage. The battery mounting part 20 is a part in which a battery is mounted, and includes a first contact TP1 and a second contact TP2. Either the positive electrode terminal or the negative electrode terminal of the battery mounted on the battery mounting portion 20 contacts the first contact TP1. The second contact TP2 is in contact with the other of the positive electrode terminal or the negative electrode terminal of the battery mounted on the battery mounting portion 20.

  The comparison circuit 30 compares the voltage of the first contact TP1 and the voltage of the second contact TP2, and outputs a first determination signal when the voltage of the first contact TP1 is higher than the voltage of the second contact TP2, This circuit outputs a second determination signal when the voltage at the contact TP2 is higher than the voltage at the first contact TP1. The comparison circuit 30 includes a first comparator CP1, a second comparator CP2, and resistors R1 and R2.

  The first comparator CP1 and the second comparator CP2 are composed of operational amplifiers as an example. The first comparator CP1 has a non-inverting input connected to the first contact TP1, and an inverting input connected to the second contact TP2. The second comparator CP2 has a non-inverting input connected to the second contact TP2, and an inverting input connected to the first contact TP1. The outputs of the first comparator CP1 and the second comparator CP2 are connected to the control device 50, respectively. For example, a dedicated comparator IC (Integrated Circuit) may be used for the first comparator CP1 and the second comparator CP2.

  The resistor R1 is a resistor that pulls down the first contact TP1, and has one end connected to the first contact TP1 and the other end connected to the ground. The resistor R2 is a resistor that pulls down the second contact TP2, and has one end connected to the second contact TP2 and the other end connected to the ground. By pulling down the first contact point TP1 and the second contact point TP2 in this way, the potential of the first contact point TP1 and the second contact point TP2 is set to the ground potential when the battery is not attached to the battery attachment unit 20. Therefore, the possibility that the output of the comparison circuit 30 becomes unstable can be reduced.

  The switch circuit 40 includes first to fourth switches SW <b> 1 to SW <b> 4 that are ON / OFF controlled by the control device 50. The first switch SW1 has one contact connected to the voltage output terminal Vout of the DC-DC converter 10 and the other contact connected to the first contact TP1. The second switch SW2 has one contact point connected to the ground terminal GND of the DC-DC converter 10 and the other contact point connected to the first contact point TP1. The third switch SW3 has one contact connected to the voltage output terminal Vout of the DC-DC converter 10 and the other contact connected to the second contact TP2. The fourth switch SW4 has one contact point connected to the ground terminal GND of the DC-DC converter 10 and the other contact point connected to the second contact TP2.

  That is, the first switch SW1 is a switch that turns ON / OFF the connection between the voltage output terminal Vout of the DC-DC converter 10 and the first contact TP1. The second switch SW2 is a switch that turns ON / OFF the connection between the ground terminal GND of the DC-DC converter 10 and the first contact TP1. The third switch SW3 is a switch that turns on / off the connection between the voltage output terminal Vout of the DC-DC converter 10 and the second contact TP2. The fourth switch SW4 is a switch for turning on / off the connection between the ground terminal GND of the DC-DC converter 10 and the second contact TP2.

  The control device 50 is, for example, a known microcomputer control circuit, and controls the DC-DC converter 10 based on the state of charge of the battery of the battery mounting unit 20 detected by a charge state detection circuit (not shown). Further, the control device 50 controls ON / OFF of the first to fourth switches SW1 to SW4 based on the outputs of the first comparator CP1 and the second comparator CP2.

  FIGS. 2 and 3 are enlarged circuit diagrams illustrating the main part of the charging device according to the present invention, in which a battery 21 is mounted on the battery mounting unit 20. FIG. 2 illustrates a state in which the positive terminal of the battery 21 is in contact with the first contact TP1 and the negative terminal of the battery 21 is in contact with the second contact TP2. FIG. 3 illustrates a state in which the positive terminal of the battery 21 is in contact with the second contact TP2 and the negative terminal of the battery 21 is in contact with the first contact TP1. FIG. 4 is a diagram illustrating a relationship between the outputs of the first comparator CP1 and the second comparator CP2 and ON / OFF of the first to fourth switches SW1 to SW4.

When the battery 21 is not attached to the battery attachment part 20, the first contact TP1 and the second contact TP2 are pulled down, so that the non-inverting input and the inverting input of the first comparator CP1 are both at the ground potential. Become. Similarly, the non-inverting input and the inverting input of the second comparator CP2 are both set to the ground potential. Therefore, the output voltages of the first comparator CP1 and the second comparator CP2 are both low level (L). When both the output voltages of the first comparator CP1 and the second comparator CP2 are at the low level, the control device 50 turns off all of the first to fourth switches SW1 to SW4.
Although not normally possible, when both the output voltages of the first comparator CP1 and the second comparator CP2 are at a high level (H), the control device 50 determines that some abnormality has occurred, Also in this case, it is preferable to turn off all of the first to fourth switches SW1 to SW4.

  In a state where the positive terminal of the battery 21 is in contact with the first contact TP1 and the negative terminal of the battery 21 is in contact with the second contact TP2 (FIG. 2), the voltage of the first contact TP1 is higher than the voltage of the second contact TP2. Become high. In this case, since the voltage of the non-inverting input of the first comparator CP1 is higher than the voltage of the inverting input, the output voltage becomes a high level (H) (first determination signal). On the other hand, the output voltage of the second comparator CP2 is low because the voltage at the non-inverting input is lower than the voltage at the inverting input.

  When the output voltage of the first comparator CP1 is at a high level, the control device 50 has the positive terminal of the battery 21 in contact with the first contact TP1, and the negative terminal of the battery 21 in contact with the second contact TP2. (FIG. 2). Then, the control device 50 turns on the first switch SW1 and the fourth switch SW4, and turns off the second switch SW2 and the third switch SW3. Thereby, the positive terminal of the battery 21 is connected to the voltage output terminal Vout of the DC-DC converter 10, and the negative terminal of the battery 21 is connected to the ground terminal GND of the DC-DC converter 10.

  On the other hand, in a state where the positive terminal of the battery 21 is in contact with the second contact TP2 and the negative terminal of the battery 21 is in contact with the first contact TP1 (FIG. 3), the voltage of the second contact TP2 is equal to that of the first contact TP1. It becomes higher than the voltage. In this case, the output voltage of the first comparator CP1 is low because the voltage at the non-inverting input is lower than the voltage at the inverting input. On the other hand, since the voltage of the non-inverting input becomes higher than the voltage of the inverting input, the output voltage of the second comparator CP2 becomes high level (H) (second determination signal).

  When the output voltage of the second comparator CP2 is at a high level, the control device 50 has the positive terminal of the battery 21 in contact with the second contact TP2, and the negative terminal of the battery 21 in contact with the first contact TP1. (FIG. 3). Then, the control device 50 turns off the first switch SW1 and the fourth switch SW4, and turns on the second switch SW2 and the third switch SW3. Thereby, the positive terminal of the battery 21 is connected to the voltage output terminal Vout of the DC-DC converter 10, and the negative terminal of the battery 21 is connected to the ground terminal GND of the DC-DC converter 10.

  As described above, the battery connection determination circuit according to the present invention compares the voltage of the first contact TP1 and the voltage of the second contact TP2 to determine the connection direction of the battery 21, thereby generating a reference voltage. Since there is no need to provide a power source, the connection direction of the battery 21 can be determined with a simple circuit configuration. Therefore, according to the present invention, a battery connection determination circuit that determines the connection direction of the battery 21 can be provided at low cost.

  In the present invention, it is preferable that the comparison circuit 30 has a very simple configuration using two comparators (first comparator CP1 and second comparator CP2) as in the embodiment described above. Accordingly, a battery connection determination circuit that determines the connection direction of the battery 21 can be provided at a lower cost. In the charging device according to the present invention, the positive terminal of the battery 21 is connected to the voltage output terminal Vout of the DC-DC converter 10 regardless of the connection direction of the battery 21, and the negative terminal of the battery 21 is connected to the DC-DC converter 10. Since it is connected to the ground terminal GND, the battery 21 can be charged regardless of the connection direction of the battery 21.

<Second embodiment>
An embodiment of an electronic apparatus including the battery connection determination circuit according to the present invention will be described with reference to FIG.
FIG. 5 is a circuit diagram illustrating the configuration of the electronic apparatus according to the present invention.

  The embodiment of the electronic device illustrated in FIG. 5 is different from the first embodiment (the embodiment of the charging device illustrated in FIG. 1) in that a load device 60 is connected to the switch circuit 40 instead of the DC-DC converter 10. ) And the configuration is different. Since the other configuration is the same as that of the first embodiment, the same components are denoted by the same reference numerals and detailed description thereof is omitted.

  The load device 60 operates with the power of the battery mounted on the battery mounting unit 20. The control device 50 controls the load device 60 based on the battery voltage of the battery mounting part 20 detected by a battery voltage detection circuit (not shown).

  One contact of the first switch SW1 is connected to the voltage input terminal Vin of the load device 60, and the other contact is connected to the first contact TP1. The second switch SW2 has one contact point connected to the ground terminal GND of the load device 60 and the other contact point connected to the first contact point TP1. The third switch SW3 has one contact point connected to the voltage input terminal Vin of the load device 60 and the other contact point connected to the second contact point TP2. The fourth switch SW4 has one contact point connected to the ground terminal GND of the load device 60 and the other contact point connected to the second contact point TP2.

  That is, the first switch SW1 is a switch that turns ON / OFF the connection between the voltage input terminal Vin of the load device 60 and the first contact TP1. The second switch SW2 is a switch that turns on / off the connection between the ground terminal GND of the load device 60 and the first contact TP1. The third switch SW3 is a switch that turns ON / OFF the connection between the voltage input terminal Vin of the load device 60 and the second contact TP2. The fourth switch SW4 is a switch that turns ON / OFF the connection between the ground terminal GND of the load device 60 and the second contact TP2.

  When the output voltage of the first comparator CP1 is at a high level, the control device 50 has the positive terminal of the battery 21 in contact with the first contact TP1, and the negative terminal of the battery 21 in contact with the second contact TP2. (FIG. 2). Then, the control device 50 turns on the first switch SW1 and the fourth switch SW4, and turns off the second switch SW2 and the third switch SW3. Thereby, the positive terminal of the battery 21 is connected to the voltage input terminal Vin of the load device 60, and the negative terminal of the battery 21 is connected to the ground terminal GND of the load device 60.

  When the output voltage of the second comparator CP2 is at a high level, the control device 50 has the positive terminal of the battery 21 in contact with the second contact TP2, and the negative terminal of the battery 21 in contact with the first contact TP1. (FIG. 3). Then, the control device 50 turns off the first switch SW1 and the fourth switch SW4, and turns on the second switch SW2 and the third switch SW3. Thereby, the positive terminal of the battery 21 is connected to the voltage input terminal Vin of the load device 60, and the negative terminal of the battery 21 is connected to the ground terminal GND of the load device 60.

  Thus, in the electronic device according to the present invention, regardless of the connection direction of the battery 21, the positive terminal of the battery 21 is connected to the voltage input terminal Vin of the load device 60, and the negative terminal of the battery 21 is the ground terminal of the load device 60. Since it is connected to GND, the load device 60 can be operated with the power of the battery 21 regardless of the connection direction of the battery 21.

DESCRIPTION OF SYMBOLS 10 DC-DC converter 20 Battery mounting part 30 Comparison circuit 40 Switch circuit 50 Control apparatus 60 Load apparatus CP1 1st comparator CP2 2nd comparator SW1-SW4 1st-4th switch TP1 1st contact TP2 2nd contact

Claims (5)

A first contact with which either the positive electrode terminal or the negative electrode terminal of the battery contacts;
A second contact with which the other of the positive electrode terminal or the negative electrode terminal of the battery contacts,
The voltage of the first contact is compared with the voltage of the second contact, a first determination signal is output when the voltage of the first contact is higher than the voltage of the second contact, and the voltage of the second contact is And a comparison circuit that outputs a second determination signal when the voltage is higher than the voltage of the first contact.   2. The battery connection determination circuit according to claim 1, wherein the comparison circuit compares the voltage of the first contact with the voltage of the second contact, and the voltage of the first contact is higher than the voltage of the second contact. Sometimes the first comparator that outputs the first determination signal is compared with the voltage of the first contact and the voltage of the second contact, and the voltage of the second contact is higher than the voltage of the first contact. And a second comparator that outputs the second determination signal.   3. The battery connection determination circuit according to claim 1, wherein the comparison circuit includes a resistor that pulls down the first contact and a resistor that pulls down the second contact. The battery connection determination circuit according to any one of claims 1 to 3,
A power supply for supplying charging power for the battery;
A switch circuit;
A control device for controlling the switch circuit,
The switch circuit includes a first switch for turning on / off the connection between the voltage output terminal of the power supply device and the first contact, and a first switch for turning on / off the connection between the ground terminal of the power supply device and the first contact. 2 switch, a third switch for turning on / off the connection between the voltage output terminal of the power supply device and the second contact, and a fourth switch for turning on / off the connection between the ground terminal of the power supply device and the second contact. A switch,
When the first determination signal is output from the comparison circuit, the control device turns on the first switch and the fourth switch, turns off the second switch and the third switch, and outputs from the comparison circuit. A charging device that turns off the first switch and the fourth switch and turns on the second switch and the third switch when the second determination signal is output. The battery connection determination circuit according to any one of claims 1 to 3,
A load device that operates on the power of the battery;
A switch circuit;
A control device for controlling the switch circuit,
The switch circuit includes a first switch for turning on / off a connection between the voltage input terminal of the load device and the first contact, and a first switch for turning on / off a connection between the ground terminal of the load device and the first contact. 2 switch, a third switch for turning on / off the connection between the voltage input terminal of the load device and the second contact, and a fourth switch for turning on / off the connection between the ground terminal of the load device and the second contact. A switch,
When the first determination signal is output from the comparison circuit, the control device turns on the first switch and the fourth switch, turns off the second switch and the third switch, and outputs from the comparison circuit. An electronic device that turns off the first switch and the fourth switch and turns on the second switch and the third switch when the second determination signal is output.

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