JPH087788Y2 - Charger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a charging device having a function of detecting a charging state.

[Prior Art] One of the charging methods for a secondary battery is a method called joggle charging. When charging by this method, as shown in FIG. 2, when the battery voltage reaches a predetermined voltage, the supply of the charging current is stopped, and then, when the battery voltage drops to a predetermined value due to self-discharging or the like, the charging current is restarted. Supply. Thereafter, this operation is performed according to the battery voltage value. There is a configuration example shown in FIG. 4 as a charging device using a charging system such as the joggle charging control. In this charging device, the battery 2 that supplies power to the device 1 includes a charging circuit 3 including a charging detection circuit.
, And the circuit 3 is supplied with power from the charging power supply 4. Then, the current supplied from the charging power source 4 is detected by the charging completion detecting resistor 5 to judge the completion of charging.

[Problems to be Solved by the Invention] By the way, in the above charging device, when the secondary battery is not normally connected to the battery receiving portion, for example, even when the battery is not inserted, the charging power source and the charging circuit are not provided. Is a closed circuit, and a supply current flows through the charging completion detection resistor, so that it may be erroneously determined to be a fully charged battery or erroneously determined to be charging completed. Also, when the secondary battery is over-discharged, the internal impedance of the battery rises, so the charging current becomes a short cycle of ON-OFF even though it is hardly charged. ,
It may be mistaken for the completion of charging.

The present invention solves the above problems, and when the connection of the battery is not normal or it is an over-discharged battery,
An object of the present invention is to provide a charging device that can always perform proper charging without making an erroneous charge completion determination.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a joggle charge that supplies a charging current until the battery voltage reaches a predetermined voltage and supplies the charging current again when the battery voltage drops to a predetermined value. In a charging device having a charging circuit for controlling, it is determined that the battery connection is not normal when there is no repetition based on the detection means for detecting the ON-OFF repetition cycle of the charging current and the detection signal of this detection means. However, when the repetition cycle is equal to or greater than a predetermined value, it is determined that the battery is an overdischarged battery.

Further, at least one of the electrodes of the battery receiving portion is divided into a plurality of parts, and when a battery is attached to the receiving portion, the electrodes of the battery short-circuit the electrodes to close the charging circuit. is there.

[Operation] According to the above configuration, when the battery is charged,
The repetition cycle of ON / OFF of the charging current is detected, and based on this, the determination means determines that the battery is not connected or the battery is over-discharged. Further, in the case where the electrode of the battery receiving part is divided into a plurality of parts, if the battery is not attached to the battery receiving part and the plurality of electrodes are not short-circuited, the charging circuit is not closed, and similarly, Can be detected.

[Embodiment] A first embodiment of the charging device of the present invention will be described with reference to FIG.

In FIG. 1, a charging circuit 3 having a charging detection circuit that is connected to both electrodes of a secondary battery 2 and that enables joggling charging to the battery 2 is provided. A current-voltage conversion resistor 6 that detects ON-OFF as a change in voltage is connected. Further, it has a function of detecting a voltage drop across the resistor 6 and outputting it as a charging voltage value of the capacitor C, and a function of judging whether the output voltage value of the integrating circuit 7 has reached a predetermined value. The voltage detector 8 and the discrimination circuit 9 for discriminating the completion of charging during charging and non-charging of the battery 2 are provided at the subsequent stage of the voltage detector 8. The charging power source is not shown.

In the above configuration, when the connection of the battery 2 is not normal,
No voltage drop occurs in the resistor 6. Therefore, the capacitor C of the integrating circuit 7 is not charged. Therefore, the voltage detector 8 keeps the integration circuit 7 even after a predetermined time has elapsed.
Since the capacitor charging voltage of is not detected, the determination circuit 9
Determines that the connection of the battery 2 is not normal.

Further, when the battery 2 having an increased internal impedance due to over-discharging is connected, the internal voltage of the battery 2 is increased, so that the terminal voltage of the battery 2 rapidly increases immediately after the start of charging. Therefore, a predetermined voltage is reached even though only a small amount of electric charge is stored, the charging current is turned off, and the terminal voltage of the battery 2 suddenly drops this time. That is, the repetition rate of ON-OFF of the charging current is much faster than that of the completion of charging. As a result, the fluctuation of the voltage drop in the resistor 6 becomes faster, and the charge amount of the capacitor C of the integrating circuit 7 does not exceed the predetermined value. The voltage detector 8 detects a voltage equal to or lower than the predetermined value of the integration circuit 7, and the determination circuit 9 further determines that the battery 2 is an overdischarged battery.

The constant and the repetition rate of the integrating circuit 7 are identified by selecting an appropriate value based on the capacity of the battery and the like. Further, the integrating circuit 7, the voltage detector 8 and the judging circuit 9 may be constituted by a counter, a microprocessor or the like, and the state of the battery can be judged by identifying the repeating speed.

Next, a second embodiment will be described with reference to FIG. The basic configuration of this embodiment includes a charging device section and a portable machine section. The charging device section includes a charging circuit 3 including a charging detection circuit for charging the battery 2 built in the device 1 of the portable unit section.
And a charging completion detecting resistor 5 inserted on the + line between the charging circuit 3 and the charging power source 4. Then, in the portable unit, one electrode of the receiving portion of the battery 2 is divided into a plurality of electrodes 11a and 11b,
Only after the battery is normally installed, the electrodes 11a and 11b of the receiving portion are short-circuited by the electrodes of the battery 2, and the charging power source 4
To form a closed circuit for charging the charging circuit 3 from. Note that one output end of the charging circuit 3 is connected to the electrode 11a, and one end of the charging power supply 4, that is, one power supply line of the device 1 is connected to the electrode 11b.

According to this configuration, when the battery 2 is not normally connected to the battery receiving portion of the device 1, the electrode 11a and the electrode 11b do not contact each other via the electrode of the battery 2. Therefore, the path between the charging circuit 3 and the charging power source 4 is not connected, and the charging current does not flow to the charging completion detection circuit 5. From this non-charging current state, it is possible to determine that the battery 2 is not connected.

The configuration of the battery receiving portion according to the second embodiment is, for example, a wireless device such as a cordless phone or a car phone, an AV device such as a compact cassette player or a pocket TV, a home appliance such as a cordless iron, etc. It can be widely applied to. According to this configuration, not only the completion of charging but also the presence / absence of a battery and erroneous mounting can be detected.

Further, FIG. 3B shows a configuration example in which the charging circuit 3 in the second embodiment is attached to the portable device section side.

Further, the battery 2 and the device 1 do not have to be portable devices and may be in the same housing as the charging device.

The charging method of the charging circuit 3 is not limited to the joggle charging method, and a constant voltage charging method or the like may be used.

As described above, according to the present invention, the charging state of the battery is detected by the ON / OFF cycle of the charging current. Therefore, the battery is not normally connected to the charging device, or It is possible to accurately detect that the battery is over-discharged as a battery trouble.

In addition, as the electrode configuration of the battery receiving part in the device with a built-in battery, the charging circuit is closed only when the battery is installed, so it is possible to accurately detect whether or not the battery is installed and erroneous insertion. it can.

[Brief description of drawings]

FIG. 1 is a block diagram of a charging device according to a first embodiment of the present invention, FIG. 2 is a diagram showing charge / discharge characteristics during joggle charging, and FIGS. 3 (a) and 3 (b) are respectively according to the second embodiment. FIG. 4 is a block configuration diagram of a charging device, and FIG. 4 is a block configuration diagram of a conventional charging device. 2 ... Secondary battery, 3 ... Charging circuit including charging detection circuit by joggle charging, 4 ... Charging power source, 5 ... Charging completion detection circuit, 6 ... Current-voltage conversion resistor, 7 ... Integrating circuit,
8 ... Voltage detector, 9 ... Discrimination circuit, 11a, 11b ... Electrodes of battery receiving section.

Claims (2)

[Scope of utility model registration request] 1. A charging device having a charging circuit for supplying a charging current until the battery voltage reaches a predetermined voltage, and supplying a charging current again when the battery voltage drops to a predetermined value, the charging device having a charging circuit for controlling the joggle charge. Based on the detection means for detecting the ON-OFF repetition cycle and the detection signal of this detection means, it is judged that the battery connection is not normal when there is no repetition, and when the repetition cycle is a predetermined value or more, the overdischarged battery A charging device comprising: a determination unit that determines that 2. At least one electrode of the battery receiving portion is divided into a plurality of parts, and when a battery is mounted on the receiving portion, the electrodes of the battery short-circuit the electrodes so that the charging circuit is closed. A charging device characterized by being configured.