JP6966852B2 - Battery connection judgment circuit, charging device, electronic device - Google Patents

Description

The present invention relates to a battery connection determination circuit for determining a battery connection direction, a charging device provided with the battery connection determination circuit, and an electronic device.

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

However, since the electronic device and the charging device are often configured so that the battery can be mounted even if the connection direction is opposite, the battery may be mounted in the connection direction opposite to the correct connection direction. If the battery is installed in the direction opposite to the correct connection direction, the electronic device will not operate, and the charging device will not only be unable to charge the battery, but also leak, for example, the battery. Etc. may occur.

As an example of the prior art aimed at solving such a problem, a circuit is provided in which the voltage of the reference power supply and the voltage of the battery are compared by a comparator to determine the connection direction of the battery, and reverse connection is detected. A device for stopping the charging / discharging of a battery at that time is known (see, for example, Patent Documents 1 and 2).

JP-A-2007-202396 Japanese Unexamined Patent Publication No. 2009-177037

However, in the above-mentioned prior art, it is necessary to provide a reference power source for generating a reference voltage. That is, the above-mentioned conventional technique has a complicated and large-scale configuration in which a reference power supply is provided, which may lead to a significant increase in the cost of the device.

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

<First aspect of the present invention>
The first aspect of the present invention is a first contact with which either the positive electrode terminal or the negative electrode terminal of the battery abuts, a second contact with which the other positive electrode terminal or the negative electrode terminal of the battery abuts, and the first contact point. The voltage of 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, the first determination signal is output, and the voltage of the second contact is the voltage of the first contact. It is a battery connection determination circuit including a comparison circuit that outputs a second determination signal when the voltage is higher than the voltage of.

The comparison circuit compares the voltage of the first contact with the voltage of the second contact, and outputs the first determination signal when the voltage of the first contact is higher. In this case, in the battery, the positive electrode terminal is in contact with the first contact, and the negative electrode terminal is in contact with the second contact. On the other hand, the comparison circuit outputs a second determination signal when the voltage of the second contact is higher. In this case, in the battery, the positive electrode terminal is in contact with the second contact, and the negative electrode terminal is in contact with the first contact. By comparing the voltage of the first contact with the voltage of the second contact to determine the connection direction of the battery in this way, it is not necessary to provide a reference power supply that generates a reference voltage. The connection direction can be determined.

Thereby, according to the first aspect of the present invention, it is possible to obtain an effect that a battery connection determination circuit for determining a battery connection direction can be provided at low cost.

<Second aspect of the present invention>
A second aspect of the present invention is, 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 calculated. The first comparator that outputs the first determination signal when the voltage of the second contact is higher than the voltage of the first contact is compared with the voltage of the first contact and the voltage of the second contact, and the voltage of the second contact is the said. It is a battery connection determination circuit including 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 a battery connection direction at a lower cost by a comparison circuit having an extremely simple configuration using two comparators as described above. can.

<Third aspect of the present invention>
A third aspect of the present invention is, in the first aspect or the second aspect of the present invention described above, the comparison circuit includes a resistor for pulling down the first contact and a resistor for pulling 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 mounted, 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 risk can be reduced.

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

By turning on / off the first to fourth switches of the switch circuit according to the judgment signal output by the comparison circuit in this way, the positive electrode terminal of the battery becomes the voltage output terminal of the power supply device regardless of the connection direction of the battery. The negative electrode terminal of the battery is connected to the ground terminal of the power supply device. Therefore, according to the fourth aspect of the present invention, in addition to the action and effect according to the first to third aspects of the present invention described above, the action and effect that the battery can be charged regardless of the connection direction of the battery can be obtained.

<Fifth aspect of the present invention>
A fifth aspect of the present invention comprises a battery connection determination circuit according to any one of the first to third aspects of the present invention described above, a load device operated by the power of the battery, a switch circuit, and the switch circuit. The switch circuit includes a control device for controlling, a first switch for turning on / off the connection between the voltage input terminal of the load device and the first contact, and a ground terminal of the load device and the first contact. A second switch that turns on / off the connection with the load device, a third switch that turns on / off the connection between the voltage input terminal of the load device and the second contact, and a ground terminal of the load device and the second contact. When the first determination signal is output from the comparison circuit, the control device turns on the first switch and the fourth switch, and the control device includes a fourth switch for turning on / off the connection. 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 an electronic device.

By turning on / off the first to fourth switches of the switch circuit according to the judgment signal output by the comparison circuit in this way, the positive electrode terminal of the battery becomes the voltage input terminal of the load device regardless of the connection direction of the battery. The negative electrode 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 effects of the first to third aspects of the present invention described above, it is possible to operate the electronic device with the electric power of the battery regardless of the connection direction of the battery. You can get the effect of being able to do it.

According to the present invention, it is possible to provide a battery connection determination circuit for determining a battery connection direction at low cost.

The circuit diagram which illustrated the structure of the charging device which concerns on this invention. A circuit diagram illustrating a state in which the positive electrode terminal of the battery is in contact with the first contact and the negative electrode terminal of the battery is in contact with the second contact. A circuit diagram illustrating a state in which the positive electrode terminal of the battery is in contact with the second contact and the negative electrode terminal of the battery is in contact with the first contact. The figure which showed the relationship between the output of the 1st comparator and the 2nd comparator, and ON / OFF of the 1st to 4th switches. The circuit diagram which illustrated the structure of the electronic device which concerns on this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
It is needless to say that the present invention is not particularly limited to the examples described below, and various modifications can be made within the scope of the invention described in the claims.

<First Example>
An embodiment of the charging device including the battery connection determination circuit according to the present invention will be described with reference to FIGS. 1 to 4.
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 charging power for a battery, and is a constant-voltage constant-current power supply that converts an input DC voltage into a charging voltage of the battery. The battery mounting portion 20 is a portion on which a battery is mounted, and includes a first contact TP1 and a second contact TP2. Either one of the positive electrode terminal and 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 with the voltage of the second contact TP2, outputs the first determination signal when the voltage of the first contact TP1 is higher than the voltage of the second contact TP2, and outputs the second determination signal. This circuit outputs a second determination signal when the voltage of the contact TP2 is higher than the voltage of 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 configured by an operational amplifier as an example. In the first comparator CP1, the non-inverting input is connected to the first contact TP1 and the inverting input is connected to the second contact TP2. In the second comparator CP2, the non-inverting input is connected to the second contact TP2, and the inverting input is 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. The first comparator CP1 and the second comparator CP2 may use, for example, a dedicated comparator IC (Integrated Circuit).

The resistor R1 is a resistor that pulls down the first contact TP1, one end of which is connected to the first contact TP1 and the other end of which is connected to the ground. The resistor R2 is a resistor that pulls down the second contact TP2, one end of which is connected to the second contact TP2 and the other end of which is connected to the ground. By pulling down the first contact TP1 and the second contact TP2 in this way, the potentials of the first contact TP1 and the second contact TP2 become the ground potential when the battery is not mounted on the battery mounting portion 20. Since it is maintained, the possibility that the output of the comparison circuit 30 becomes unstable can be reduced.

The switch circuit 40 includes first to fourth switches SW1 to SW4 that are ON / OFF controlled by the control device 50. In the first switch SW1, one contact is connected to the voltage output terminal Vout of the DC-DC converter 10, and the other contact is connected to the first contact TP1. In the second switch SW2, one contact is connected to the ground terminal GND of the DC-DC converter 10, and the other contact is connected to the first contact TP1. In the third switch SW3, one contact is connected to the voltage output terminal Vout of the DC-DC converter 10, and the other contact is connected to the second contact TP2. In the fourth switch SW4, one contact is connected to the ground terminal GND of the DC-DC converter 10, and the other contact is 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 that turns 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 battery charge state 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.

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

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

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

When the output voltage of the first comparator CP1 is at a high level, in the control device 50, the positive electrode terminal of the battery 21 is in contact with the first contact TP1 and the negative electrode terminal of the battery 21 is 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. As a result, the positive electrode terminal of the battery 21 is connected to the voltage output terminal Vout of the DC-DC converter 10, and the negative electrode 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 electrode terminal of the battery 21 is in contact with the second contact TP2 and the negative electrode terminal of the battery 21 is in contact with the first contact TP1 (FIG. 3), the voltage of the second contact TP2 is the first contact TP1. It becomes higher than the voltage. In this case, in the first comparator CP1, the voltage of the non-inverting input is lower than the voltage of the inverting input, so that the output voltage becomes low level. On the other hand, in the second comparator CP2, the voltage of the non-inverting input is higher than the voltage of the inverting input, so that the output voltage becomes a high level (H) (second determination signal).

When the output voltage of the second comparator CP2 is at a high level, in the control device 50, the positive electrode terminal of the battery 21 is in contact with the second contact TP2, and the negative electrode terminal of the battery 21 is 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. As a result, the positive electrode terminal of the battery 21 is connected to the voltage output terminal Vout of the DC-DC converter 10, and the negative electrode 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 is a reference for generating a reference voltage by comparing the voltage of the first contact TP1 with the voltage of the second contact TP2 and determining the connection direction of the battery 21. Since it is not necessary to provide a power supply, the connection direction of the battery 21 can be determined with a simple circuit configuration. Therefore, according to the present invention, it is possible to provide a battery connection determination circuit for determining the connection direction of the battery 21 at low cost.

Further, in the present invention, it is preferable that the comparison circuit 30 has an extremely simple configuration using two comparators (first comparator CP1 and second comparator CP2) as in the above-described embodiment. Thereby, the battery connection determination circuit for determining 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 and the negative terminal of the battery 21 is the DC-DC converter 10 regardless of the connection direction of the battery 21. 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 Example>
An example of an electronic device 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 device according to the present invention.

The embodiment of the electronic device shown in FIG. 5 is the first embodiment (the embodiment of the charging device shown in FIG. 1) in that the 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 configurations are the same as those in the first embodiment, the common components are designated by the same reference numerals and detailed description thereof will be omitted.

The load device 60 operates with the electric 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 unit 20 detected by a battery voltage detection circuit (not shown).

In the first switch SW1, one contact is connected to the voltage input terminal Vin of the load device 60, and the other contact is connected to the first contact TP1. In the second switch SW2, one contact is connected to the ground terminal GND of the load device 60, and the other contact is connected to the first contact TP1. In the third switch SW3, one contact is connected to the voltage input terminal Vin of the load device 60, and the other contact is connected to the second contact TP2. In the fourth switch SW4, one contact is connected to the ground terminal GND of the load device 60, and the other contact is connected to the second contact 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, in the control device 50, the positive electrode terminal of the battery 21 is in contact with the first contact TP1 and the negative electrode terminal of the battery 21 is 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. As a result, the positive electrode terminal of the battery 21 is connected to the voltage input terminal Vin of the load device 60, and the negative electrode 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, in the control device 50, the positive electrode terminal of the battery 21 is in contact with the second contact TP2, and the negative electrode terminal of the battery 21 is 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. As a result, the positive electrode terminal of the battery 21 is connected to the voltage input terminal Vin of the load device 60, and the negative electrode terminal of the battery 21 is connected to the ground terminal GND of the load device 60.

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

10 DC-DC converter 20 Battery mounting part 30 Comparison circuit 40 Switch circuit 50 Control device 60 Load device CP1 First comparator CP2 Second comparator SW1 to SW4 First to fourth switch TP1 First contact TP2 Second contact

Claims (5)

Battery connection judgment circuit including batteries and
The power supply device that supplies the charging power of the battery and
A switch circuit that connects the power supply device and the battery,
A control device for controlling the switch circuit is provided.
The battery connection determination circuit is
The first contact with which either the positive electrode terminal or the negative electrode terminal of the battery abuts,
The second contact with which the other of the positive electrode terminal or the negative electrode terminal of the battery abuts,
The voltage of 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, the first determination signal is output and the voltage of the second contact becomes A comparison circuit that outputs a second determination signal when the voltage is higher than the voltage of the first contact is provided.
When the first determination signal is output from the comparison circuit, the first contact is connected to the voltage output terminal of the power supply device via the switch circuit, and the second contact is connected to the ground terminal of the power supply device. Connect to
When the second determination signal is output from the comparison circuit, the second contact is connected to the voltage output terminal of the power supply device via the switch circuit, and the first contact is connected to the voltage output terminal of the power supply device. A charging device that connects to the ground terminal. In the charging device according to claim 1, the comparator compares the voltage of the first contact with the voltage of the second contact, and when the voltage of the first contact is higher than the voltage of the second contact. The first comparator that outputs the first determination signal compares the voltage of the first contact with the voltage of the second contact, and when the voltage of the second contact is higher than the voltage of the first contact, the said. A charging device comprising a second comparator that outputs a second determination signal. In the charging device according to claim 1 or 2, the comparison circuit includes a resistor that pulls down the first contact and a resistor that pulls down the second contact. In the charging device according to any one of claims 1 to 3.
The switch circuit has a first switch that turns on / off the connection between the voltage output terminal of the power supply device and the first contact, and a first switch that turns on / off the connection between the ground terminal of the power supply device and the first contact. The second switch, the third switch that turns on / off the connection between the voltage output terminal of the power supply device and the second contact, and the fourth switch that turns on / off the connection between the ground terminal of the power supply device and the second contact. Including the 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 turns off the second switch and the third switch 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. In the charging device according to any one of claims 1 to 3.
It has a load device that operates on the power of the battery instead of the power supply device.
The switch circuit has a first switch that turns ON / OFF the connection between the voltage input terminal of the load device and the first contact, and a first switch that turns ON / OFF the connection between the ground terminal of the load device and the first contact. The second switch, the third switch that turns on / off the connection between the voltage input terminal of the load device and the second contact, and the fourth switch that turns on / off the connection between the ground terminal of the load device and the second contact. Including switches,
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 turns off the second switch and the third switch 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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