Patent Application
20110057620
This application claims priority to Taiwan Application Serial Number 98130257, filed Sep. 8, 2009, which is herein incorporated by reference.
1. Technical Field
The present disclosure relates to a protection circuit. More particularly, the present disclosure relates to a charge/discharge protection circuit.
2. Description of Related Art
Most battery modules adapted in electronic apparatus nowadays can both charge and discharge. The battery module provides power to the electronic apparatus through by discharging process. On the other hand, a charging module in the electronic device charges the battery module through charging process. A larger current is generated charging process when the battery module discharges. However, the electronic apparatus dissipates the large current generated during the discharging process. Thus, the chance that the discharging process causes damage to the battery module is negligible. In contrast, though the current generated during the charging process of the battery module is quite small compared to the discharging process, the battery module may not be able to tolerate a slightly larger current or a higher temperature. When the current is a bit too large or the temperature is a bit too high, the battery module may be damaged. Furthermore, if the battery module burns because of the large current or the high temperature, it may injure the user of the electronic apparatus, which is an undesirable result. Therefore, a module to monitor the charging path during the charging process and disconnecting the charging path in time to prevent the occurrence of the dangerous result is needed.
In the conventional design, the charging path is substantially the same as the discharging path. When the said module detects an abnormal situation, such as a large current or a high temperature, the said module controls a switch on the path to disconnect the path during the charging or discharging process. However, if the said module itself is not able to properly operate, the battery module doesn't have another backup protection mechanism to prevent damage caused by the abnormal current/temperature situation.
Thus, a new charge/discharge protection circuit is needed to provide the battery module an improved protection mechanism. The present disclosure addresses such a need.
An object of the present disclosure is to provide a charge/discharge protection circuit adapted in an electronic apparatus, wherein the charge/discharge protection circuit comprises: a positive electrode, a ground for discharging, a switch module, a battery module, a negative electrode, a sensing device, and a control module. The switch module is electrically connected to the positive electrode. The battery module is electrically connected to the switch module and the ground for discharging to form a discharging path. The negative electrode is for charging. The sensing device is electrically connected to the battery module and the negative electrode to form a charging path together with the positive electrode, the switch module, the battery module and the negative electrode, wherein the sensing device passively disconnects the charging path when the charging path is abnormal. The control module actively turns the switch module open when the discharging path, the charging path or the battery module is abnormal.
Another object of the present disclosure is to provide a charging protection method adapted in a charge/discharge protection circuit comprising a charging path and a discharging path, wherein the charging protection method comprises the steps of: connecting the charging path to charge a battery module on the charging path; detecting whether the charging path or the battery module is abnormal; when the charging path or the battery module is abnormal, determining whether a switch module on the charging path is able to disconnect the charging path; and when the switch module is able to disconnect the charging path, the switch module turns open to actively disconnect the charging path; when the switch module is unable to disconnect the charging path, a sensing device on the charging path passively turns open to disconnect the charging path.
It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the disclosure as claimed.
The disclosure can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows:
Reference will now be made in detail to the present embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
Please refer to
The charge/discharge protection circuit 1 comprises: a positive electrode 100, a switch module 102, a battery module 104, a negative electrode 106, a sensing device 108, a control module 110 and a ground 112 for discharging. The charge/discharge protection circuit 1 is adapted in an electronic apparatus (not shown), wherein the battery module 104 in the charge/discharge protection circuit 1 provides power to the electronic apparatus. In contrast, a charging module (not shown) in the electronic apparatus is able to charge the battery module 104.
The switch module 102 is electrically connected to the positive electrode 100. The switch module 102 has two switches in
In the present embodiment, the battery module 104 is electrically connected to the switch module 102 and the ground 112 for discharging to form a discharging path together with the positive electrode 100, the switch module 102 and the ground 112. The positive electrode 100 and the ground 112 are further electrically connected to the electronic apparatus to provide the power of the electronic apparatus when the battery module 104 discharges through the discharging path.
The negative electrode 106 is for charging. The sensing device 108 is electrically connected to the battery module 104 and the negative electrode 106 to form a charging path together with the positive electrode 100, the switch module 102, the battery module 104 and the negative electrode 106. The positive electrode 100 and the negative electrode 106 are electrically connected to the charging module of the electronic apparatus. The charging module is able to charge the battery module 104 through the charging path.
The negative electrode 106 in the present embodiment is a pin of the communication port, wherein the pin can belong to an I2 C, a USB, a RS232 or a RS485 communication port. In different embodiment, the communication port can be a specific pin for charging solely or a data communication pin, such as a differential data communication pin, that is able to perform charging as well. In the later embodiment, there is no need to place an additional pin, which is an additional cost.
Please refer to
However, if the control module 110 itself is not able to properly operate, the charging path will not be disconnected when there is an abnormal situation. If there is no other backup protection mechanism to disconnect the charging path, the battery module 104, or even the electronic apparatus may suffer from the damage caused by the abnormal situation.
The sensing device 108 provides the backup protection mechanism to passively disconnect the charging path when the charging path is abnormal. In an embodiment, the sensing device 108 is a fuse that is able to break when the current of the charging path becomes larger than a value that the fuse is not able to stand for to passively disconnect the charging path. In another embodiment, the sensing device 108 is a temperature-sensing device or a temperature-controlled device that is able to break when the temperature of the charging path (especially the battery module 104) becomes larger than a value that the sensing device 108 is not able to stand for to passively disconnect the charging path. The devices described above are usually low power elements that are suitable to be placed on the charging path that generates a smaller current. Therefore, the sensing device 108 is able to provide a simple mechanism to passively disconnect the charging path when the control module 110 is not able to properly operate.
The number of the switches in the switch module 102 and the type of the battery module can be modified according to the different situations in different embodiments. It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present disclosure without departing from the scope or spirit of the disclosure.
Yet another embodiment of the present disclosure is a charging protection method adapted in the charge/discharge protection circuit 1 depicted in
The advantage of the present disclosure is to separate the charging and the discharging path and to place the low-power sensing device on the charging path to passively break the charging path when the control module is not able to properly operate to provide the protection mechanism.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present disclosure without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the present disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 98130257 | Sep 2009 | TW | national |
