Switching circuit, switching method, protection apparatus and battery module

Abstract

PROBLEM TO BE SOLVED: To prevent the contact of a switch from sticking without arranging a detection circuit.SOLUTION: In an electromagnetic switch 1, at least two driving coils L1 and L2 are arranged. The driving coil L1 performs operation which turns a switch SW1 off by a current flowing in the switch SW1 e.g. excess current. The driving coil L2 is excited or demagnetized with a drive circuit 2 and performs operation which turns the switch SW1 on or off. The drive circuit 2 excites or demagnetizes the driving coil L2 according to a control signal supplied from a control circuit 3. As a result, the switch SW1 is turned off by current flowing in the driving coil L1.

Description

technical field [0001] The present invention relates to a switching circuit, a switching method, a protection device, and a battery pack for protecting electrical parts, such as lithium ion secondary batteries, from overcurrent. Background technique [0002] In the past, when detecting an overcurrent in a circuit, a detection circuit was used to detect the current in order to judge whether the detected current was an overcurrent. For example, as shown in FIG. 1 , a detection circuit 151 is used to detect the current. The detected current is supplied to the control circuit 152 . Whether or not the supplied current is an overcurrent is judged by the control circuit 152 , and the judgment result is supplied to the drive circuit 153 as a control signal. [0003] The electromagnetic switch 154 is energized or demagnetized by the drive circuit 153 in accordance with the supplied control signal. As an example, the excited electromagnetic switch 154 is in the off state, and the d...

AI Technical Summary

Problems solved by technology

[0006] However, in such a circuit, when the detection circuit and the control circuit are damaged due to overcurrent, there is a high possibility that the electromagnetic switch will always be in the ON state.

[0007] In the past, it was impossible to confirm whether the electromagnetic switch 154 was in the cut-off state

Therefore, there is the following problem: When the electromagnetic switch 154 is damaged or the melting contact is welded, it cannot be disconnected.

[0013] Here, the battery pack shown in FIG. 4 has the following problem: in the battery block 2088 to which a plurality of batteries are connected, if one battery is short-circuited, an overcurrent flows through the battery, and its safety cannot be ensured.

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