CN217060332U

CN217060332U - Lithium battery protection board turn-off current detection circuit

Info

Publication number: CN217060332U
Application number: CN202220083465.8U
Authority: CN
Inventors: 江文书; 林松苍; 陈丹丹
Original assignee: Guangdong Beite Electronics Co ltd
Current assignee: Guangdong Beite Electronics Co ltd
Priority date: 2022-01-13
Filing date: 2022-01-13
Publication date: 2022-07-26
Anticipated expiration: 2032-01-13

Abstract

The utility model discloses a lithium battery protection board turn-off current detection circuitry, including two-way constant voltage constant current source module, controllable current limiting resistance module, multiplexed output composite module and MCU control circuit, the input of controllable current limiting resistance module and multiplexed output composite module is connected respectively to the output of two-way constant voltage constant current source module. This lithium battery protection board shutoff current detection circuitry is through concatenating controllable current limiting resistor with two-way constant voltage constant current source return circuit end to enable work according to the test needs, have the flexibility of use, test process is simple's advantage, and the protection shutoff current directly reads the voltage drop on the current limiting resistor and calculates the current value, makes the test quick, and the productivity effect is high.

Description

Lithium battery protection board turn-off current detection circuit

Technical Field

The utility model relates to a lithium battery protection shield current test circuit technical field specifically is a lithium battery protection shield turn-off current detection circuitry.

Background

With the use of a large number of lithium batteries and lithium iron phosphate batteries, the safety performance detection of the used protection board is very important, the safety tests of the protection board include over-voltage charging, over-current charging, under-voltage discharging, over-current discharging, short circuit and the like in the safety tests of the protection board, when the protection board enters a protection state, the corresponding protection board charging electric MOS (metal oxide semiconductor) tube is enabled to be turned off, but due to differences of devices and differences of manufacturing processes, the MOS tube is not completely enabled to be turned off actually, and micro current can also flow through, and if the micro current is too large in the protection state, the battery can be damaged, so that the detection of the micro current which flows through the protection board after the protection of the relevant enabling MOS tube is turned off is very important after the protection board enters the protection state, and the detection is also an important index for judging whether the protection board is normal or not.

The current testing method is characterized in that an ammeter is connected in series to a power supply end required by testing a protection board section, if the protection board is tested in a multi-section mode, a multi-path ammeter needs to be connected externally, or current series meter collection is directly filled to a P +/P-end at the rear end of the protection board after the protection board is turned off and protected, and the size, the process difficulty and the cost of production equipment are increased regardless of which method for testing.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a lithium battery protection shield turn-off current detection circuitry concatenates controllable current-limiting resistor through holding two-way constant voltage constant current source return circuit to enable work according to the test needs, have and use in a flexible way, test simple process's advantage, and the protection turn-off current directly reads the voltage drop on the current-limiting resistor and calculates the current value, makes the test quick, and the productivity effect is high, can solve the problem among the prior art.

In order to achieve the above object, the utility model provides a following technical scheme: the utility model provides a lithium battery protection shield turn-off current detection circuitry, includes two-way constant voltage constant current source module, controllable current limiting resistance module, multiplexed output combination module and MCU control circuit, the input of controllable current limiting resistance module and multiplexed output combination module is connected respectively to the output of two-way constant voltage constant current source module, and the input of multiplexed output combination module is connected to the output of controllable current limiting resistance module, and the input of two-way constant voltage constant current source module, controllable current limiting resistance module and multiplexed output combination module is connected respectively to MCU control circuit's output.

Preferably, the controllable current-limiting resistance module is composed of an operational amplifier U1 and a MOS transistor Q3, wherein a pin 1 of the operational amplifier U1 is connected with a resistor R13 and receives an I-FB signal, pins 3 and 4 of the operational amplifier U1 are respectively connected with a resistor R10 and a resistor R9, a resistor R10 is connected with a resistor R5 and is connected with a source electrode of the MOS transistor Q3, a resistor R9 is connected with a resistor R6 and is connected with a drain electrode of the MOS transistor Q3, and a gate electrode of the MOS transistor Q3 is connected with a resistor R8 and receives an R-COM signal.

Preferably, the multi-output combined module comprises a relay K1, a relay K2, a relay K3 and a relay K4, wherein the relay K1 is connected with a source electrode of a MOS transistor Q2, the relay K2 is connected with a resistor R1 and a resistor R2 which are connected in series, the resistor R2 is connected with a drain electrode of the MOS transistor Q2, the relay K3 is connected with a drain electrode of the MOS transistor Q1, the relay K4 is connected with a resistor R1 and a resistor R2 which are connected in series, and the resistor R1 is connected with a source electrode of the MOS transistor Q1.

Preferably, the bidirectional constant-voltage constant-current source module receives a VSET signal and an ISET signal output by the MCU control circuit, and outputs an R-COM signal to control the on/off of the MOS transistor Q3.

Preferably, the bidirectional constant-voltage constant-current source module outputs K1-COM signals, K2-COM signals, K3-COM signals and K4-COM signals to control the relay K1, the relay K2, the relay K3 and the relay K4 to pull in respectively.

Compared with the prior art, the beneficial effects of the utility model are as follows:

this lithium battery protection board turn-off current detection circuitry, through using two-way constant voltage constant current source module at the front end to the return circuit is in concatenating controllable current limiting resistance module, and the output of different return circuits is selected to rear end multiple output combination module, makes short circuit controllable current limiting resistance module when test protection, and when the test turn-off current, the controllable current limiting resistance module of messenger's energy reads the voltage drop conversion on the controllable current limiting resistance module and becomes the current value, therefore whole test method integrated level is high, the debugging simple process, low in production cost.

Drawings

FIG. 1 is a block diagram of the module of the present invention;

FIG. 2 is a schematic circuit diagram of the present invention;

fig. 3 is a circuit diagram of the bidirectional constant voltage and constant current source module of the present invention.

In the figure: 1. a bidirectional constant-voltage constant-current source module; 2. a controllable current limiting resistance module; 3. a multi-channel output combined module; 4. and the MCU control circuit.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Please refer to fig. 1-3, a circuit for detecting turn-off current of a lithium battery protection board, includes a bidirectional constant voltage constant current source module 1, a controllable current limiting resistor module 2, a multi-path output combination module 3 and an MCU control circuit 4, wherein an output end of the bidirectional constant voltage constant current source module 1 is connected to input ends of the controllable current limiting resistor module 2 and the multi-path output combination module 3, an output end of the controllable current limiting resistor module 2 is connected to an input end of the multi-path output combination module 3, and an output end of the MCU control circuit 4 is connected to input ends of the bidirectional constant voltage constant current source module 1, the controllable current limiting resistor module 2 and the multi-path output combination module 3.

The controllable current limiting resistance module 2 is composed of an operational amplifier U1 and a MOS transistor Q3, wherein a pin 1 of the operational amplifier U1 is connected with a resistor R13 and receives an I-FB signal, pins 3 and 4 of the operational amplifier U1 are respectively connected with a resistor R10 and a resistor R9, a resistor R10 is connected with a resistor R5 and connected with a source electrode of the MOS transistor Q3, a resistor R9 is connected with a resistor R6 and connected with a drain electrode of the MOS transistor Q3, and a gate of the MOS transistor Q3 is connected with a resistor R8 and receives an R-COM signal.

In the above, the bidirectional constant-voltage and constant-current source module 1 receives the VSET signal and the ISET signal output by the MCU control circuit 4, and outputs the R-COM signal to control the on/off of the MOS transistor Q3, so the controllable current-limiting resistor module 2 is connected in series to the loop of the bidirectional constant-voltage and constant-current source module 1, and the voltage drop of the controllable current-limiting resistor module 2 is monitored and collected in real time and converted into a current value, that is, the turn-off current of different sections of sites tested by the protection board.

The multiplexed output combined module 3 is composed of a relay K1, a relay K2, a relay K3 and a relay K4, the source electrode of a MOS tube Q2 is connected with the relay K1, the relay K2 is connected with a resistor R1 and a resistor R2 which are connected in series, the drain electrode of the MOS tube Q2 is connected with the resistor R2, the drain electrode of a MOS tube Q1 is connected with the relay K3, the resistor R1 and the resistor R2 which are connected in series are connected with the relay K4, and the source electrode of the MOS tube Q1 is connected with the resistor R1.

In the above, the MCU control circuit 4 outputs the K1-COM signal and the K3-COM signal to respectively control the relay K1 and the relay K3 to pull in, so that the bidirectional constant-voltage constant-current source module 1 can output and connect the P-/TP loop to detect a section of protection function.

Because the MCU control circuit 4 outputs a K2-COM signal and a K4-COM signal to respectively control the attraction of the relay K2 and the relay K4, the two-way constant-voltage constant-current source module 1 can realize the two-stage protection function of switching on the TP/B-loop detection by outputting the signals.

Because the MCU control circuit 4 outputs K1-COM signals and K4-COM signals to respectively control the relay K1 and the relay K4 to suck, the protection function of connecting the output of the bidirectional constant-voltage constant-current source module 1 with the P-/B-loop detection whole section can be realized.

This lithium battery protection board shutoff current detection circuitry, through use two-way constant voltage constant current source module 1 at the front end, and the loop is in concatenating controllable current limiting resistance module 2, the output of different return circuits is selected to rear end multiple output composite module 3, make short circuit controllable current limiting resistance module 2 when test protection, during the test shutoff current, make controllable current limiting resistance module 2 of enabling, read the voltage drop conversion of controllable current limiting resistance module 2 and become the current value, consequently, the whole test method integrated level is high, the debugging simple process, low in production cost.

In summary, the following steps: this lithium battery protection board shutoff current detection circuitry through concatenating controllable current limiting resistor with two-way constant voltage constant current source return circuit end to enable work according to the test needs, have the flexibility of use, test process is simple's advantage, and the protection shutoff current directly reads the voltage drop on the current limiting resistor and calculates the current value, makes the test quick, and the productivity effect is high, therefore can effectively solve prior art problem.

It should be noted that, in this document, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a lithium battery protection board shutoff current detection circuitry, includes two-way constant voltage constant current source module (1), controllable current limiting resistance module (2), multiplexed output combination module (3) and MCU control circuit (4), its characterized in that: the output end of the bidirectional constant-voltage constant-current source module (1) is connected with the input ends of the controllable current-limiting resistor module (2) and the multi-path output combined module (3) respectively, the output end of the controllable current-limiting resistor module (2) is connected with the input end of the multi-path output combined module (3), and the output end of the MCU control circuit (4) is connected with the input ends of the bidirectional constant-voltage constant-current source module (1), the controllable current-limiting resistor module (2) and the multi-path output combined module (3) respectively.

2. The lithium battery protection board off-current detection circuit as set forth in claim 1, wherein: the controllable current limiting resistor module (2) is composed of an operational amplifier U1 and a MOS transistor Q3, wherein a pin 1 of the operational amplifier U1 is connected with a resistor R13 and receives an I-FB signal, pins 3 and 4 of the operational amplifier U1 are respectively connected with a resistor R10 and a resistor R9, meanwhile, a resistor R10 is connected with a resistor R5 and is connected with a source electrode of the MOS transistor Q3, a resistor R9 is connected with a resistor R6 and is connected with a drain electrode of the MOS transistor Q3, and a grid electrode of the MOS transistor Q3 is connected with a resistor R8 and receives an R-COM signal.

3. The lithium battery protection board off-current detection circuit as set forth in claim 1, wherein: the multiplexed output combined module (3) is composed of a relay K1, a relay K2, a relay K3 and a relay K4, the source electrode of a MOS tube Q2 is connected with the relay K1, the relay K2 is connected with a resistor R1 and a resistor R2 which are connected in series, the drain electrode of the MOS tube Q2 is connected with a resistor R2, the drain electrode of the MOS tube Q1 is connected with a relay K3, the resistor R1 and the resistor R2 which are connected in series are connected with the relay K4, and the source electrode of the MOS tube Q1 is connected with the resistor R1.

4. The lithium battery protection board off-current detection circuit as set forth in claim 1, wherein: the bidirectional constant-voltage constant-current source module (1) receives VSET signals and ISET signals output by the MCU control circuit (4) and outputs R-COM signals to control the MOS transistor Q3 to be switched on and off.

5. The lithium battery protection board off current detection circuit as claimed in claim 1, wherein: the bidirectional constant-voltage constant-current source module (1) outputs K1-COM signals, K2-COM signals, K3-COM signals and K4-COM signals to respectively control the relay K1, the relay K2, the relay K3 and the relay K4 to pull in.