Portable mining product lithium battery transient protection circuit

Abstract

The invention discloses a portable mining product lithium battery transient protection circuit which comprises a bidirectional current detection and cut-off circuit, a current signal analysis and comparison control circuit and a high-frequency filtering and transient time constant calculation circuit. The bidirectional current detection and cut-off circuit is connected with the positive electrode end of the lithium battery and the positive electrode end of the mining product and controls the connection state between the lithium battery and the mining product. The current signal analysis and comparison control circuit is connected with the bidirectional current detection and cut-off circuit, receives an output short-circuit signal of the bidirectional current detection and cut-off circuit, and outputs a cut-off control signal or a connection control signal to the bidirectional current detection and cut-off circuit after comparing the output short-circuit signal with a preset value; the high-frequency filtering and transient time constant calculation circuit is connected with the bidirectional current detection and cut-off circuit and controls the cut-off duration of the bidirectional current detection and cut-off circuit.

Description

Technical Field

[0001] The present invention relates to the field of lithium battery protection, and particularly to a transient protection circuit for a lithium battery of a portable mining product. Background Art

[0002] With the progress of society and the development of technology, portable mining products are widely used. Mining explosion-proof products have corresponding requirements for lithium battery power supply. The latest industry standard stipulates that when the output terminal of the lithium battery used for power supply is short-circuited, the generated transient energy shall not be greater than 260 μJ to ensure the safe use of portable mining products. In the presence of explosive gases, even if the lithium battery is short-circuited, the heat generated by the mining product is not enough to ignite and explode the corresponding gas. For this reason, many experts in the industry have proposed different treatment methods. Patent No. ZL202220975698.9 discloses a transient suppression lithium battery mining protection circuit. Although it can achieve the protection effect of the lithium battery, the components and chips in its circuit are expensive, the cost is relatively high, and it is difficult to be widely promoted in mines. Therefore, it is necessary to improve it. Summary of the Invention

[0003] The purpose of the present invention is to provide a transient protection circuit for a lithium battery of a portable mining product with a simple structure, stability and reliability in view of the above problems.

[0004] To achieve the above purpose, the technical solution of the present invention is:

[0005] A transient protection circuit for a lithium battery of a portable mining product includes a bidirectional current detection and cut-off circuit, a current signal analysis and comparison control circuit, and a high-frequency filtering and transient time constant calculation circuit. The bidirectional current detection and cut-off circuit is respectively connected to the positive terminal of the lithium battery and the positive terminal of the mining product and controls the connection state therebetween; the current signal analysis and comparison control circuit is connected to the bidirectional current detection and cut-off circuit and receives the output short-circuit signal of the bidirectional current detection and cut-off circuit, and outputs a cut-off control signal or a connection control signal to the bidirectional current detection and cut-off circuit after comparison with a preset value; the high-frequency filtering and transient time constant calculation circuit is connected to the bidirectional current detection and cut-off circuit and controls the cut-off duration of the bidirectional current detection and cut-off circuit.

[0006] Further, the bidirectional current detection and cut-off circuit includes a resistor R1, a resistor R2, a switching transistor T1A, a switching transistor T1B, a switching transistor T2A, and a switching transistor T2B; the drain of the switching transistor T1B is connected to the positive terminal of the lithium battery, the source of the switching transistor T1B is connected to one end of the resistor R1, the other end of the resistor R1 is connected to the drain of the switching transistor T1A, the source of the switching transistor T1A is connected to the drain of the switching transistor T2B, the source of the switching transistor T2B is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the drain of the switching transistor T2A, and the source of the switching transistor T2A is connected to the positive terminal of the mining product.

[0007] Further, the resistors R1 and R2 are 1206 package resistors with a resistance of 0.035 ohms; the switching transistors T1A, T1B, T2A, and T2B are YJS2308A switching transistors.

[0008] Further, the current signal analysis and comparison control circuit includes a control chip U1; the IN pin of the control chip U1 is respectively connected to the source of the switching transistor T1B and one end of the resistor R1; the SENSE pin of the control chip U1 is respectively connected to the other end of the resistor R1 and the drain of the switching transistor T1A and receives the output short-circuit signal of the bidirectional current detection and cut-off circuit; the GATEP pin of the control chip U1 is respectively connected to the gate of the switching transistor T1B and the gate of the switching transistor T2B and outputs a cut-off control signal or a connection control signal to the switching transistors T1B and T2B; the GATE pin of the control chip U1 is respectively connected to the gate of the switching transistor T1A and the gate of the switching transistor T2A and outputs a cut-off control signal or a connection control signal to the switching transistors T1A and T2A; the OUT pin of the control chip U1 is connected to the positive terminal of the mining product; the ON pin and the GND pin of the control chip U1 are both grounded.

[0009] Further, the model of the control chip U1 is LTC4361TS8.

[0010] Further, the high-frequency filtering and transient time constant calculation circuit includes a capacitor C1, a resistor R4, and a resistor R3; one end of the capacitor C1 is respectively connected to the GATE pin of the control chip U1, the gate of the switching transistor T1A, one end of the resistor R4, and the gate of the switching transistor T2A, and the other end of the capacitor C1 is grounded; the other end of the resistor R4 is connected to one end of the resistor R3, and the other end of the resistor R3 is grounded.

[0011] Further, the resistor R3 is a 43K resistor, the resistor R4 is a 560K resistor, and the capacitor C1 is a 22pF capacitor.

[0012] Further, the negative terminals of the lithium battery and the mining product are both grounded.

[0013] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0014] When the present invention is in use, a bidirectional current detection and cut-off circuit supplies power to the mine-use product. When the load terminal is short-circuited, the bidirectional current detection and cut-off circuit outputs a signal CS. The signal CS is compared and processed with a preset value of the control chip U1. Then, the control chip U1 gives control signals GAP and GAN. The signals GAP and GAN control the switch tube to turn on the circuit between IN+ and OUT+ or cut off the circuit between IN+ and OUT+. The turn-off time of the switch tube is determined by a high-frequency filtering and transient time constant calculation circuit, which can quickly cut off the circuit between IN+ and OUT+, so that the transient heat generation during load short-circuit does not exceed the value specified in the national standard, playing a role in protecting the portable mine-use product. The circuit structure in the present invention is simple and stable, with few components and low cost, improving the use stability and reliability of mine-use equipment, effectively reducing the cost of the lithium battery protection circuit, being beneficial to improving the market competitiveness of portable mine-use products, and at the same time improving the safety of coal mine production and miners themselves, having excellent market promotion value. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0016] Figure 1 is the overall circuit structure diagram of the present invention;

[0017] Figure 2 is the circuit implementation structure diagram of the present invention. Detailed Embodiments

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts, any modifications, equivalent replacements, improvements, etc., shall be included in the protection scope of the present invention.

[0019] Such as Figure 1As shown in the figure, this embodiment discloses a transient protection circuit for a lithium battery of a portable mining product, which consists of a bidirectional current detection and cut-off circuit, a current signal analysis and comparison control circuit, and a high-frequency filtering and transient time constant calculation circuit. IN+ is the positive input terminal of the circuit, connected to the positive terminal of the lithium battery. OUT+ is the positive output terminal of the circuit, connected to the positive input terminal of the subsequent mining equipment. IN- and OUT- are the negative terminals of the lithium battery and the mining product respectively, and they are both connected to the GND terminal, where GND is the negative terminal of the device power supply, and here it is connected to the negative terminal of the lithium battery. GAP and GAN are control signals, OUTA is a bidirectional current signal, and CS is a current detection signal.

[0020] The bidirectional current detection and cut-off circuit includes resistor R1, resistor R2, switching transistor T1A, switching transistor T1B, switching transistor T2A, and switching transistor T2B. The drain of switching transistor T1B is connected to the positive terminal of the lithium battery. The source of switching transistor T1B is connected to one end of resistor R1. The other end of resistor R1 is connected to the drain of switching transistor T1A. The source of switching transistor T1A is connected to the drain of switching transistor T2B. The source of switching transistor T2B is connected to one end of resistor R2. The other end of resistor R2 is connected to the drain of switching transistor T2A. The source of switching transistor T2A is connected to the positive terminal of the mining product.

[0021] The bidirectional current detection and cut-off circuit consists of resistor R1, resistor R2, switching transistor T1A, switching transistor T1B, switching transistor T2A, and switching transistor T2B. Resistors R1 and R2 are 1206 package resistors with a resistance of 0.035 ohms. Switching transistors T1A, T1B, T2A, and T2B are YJS2308A switching transistors. Resistors R1 and R2 are used to control the short-circuit current in the entire circuit, and R1 detects this current. Switching transistors T1A, T1B, T2A, and T2B are used to turn on or cut off the connection state between IN+ and OUT+. When the output terminal is short-circuited, the lithium battery power supply part is turned off through the switching transistors, and the connection between the subsequent load and the lithium battery is cut off.

[0022] The current signal analysis and comparison control circuit includes a control chip U1. The IN pin of the control chip U1 is respectively connected to the source of the switching transistor T1B and one end of the resistor R1. The SENSE pin of the control chip U1 is respectively connected to the other end of the resistor R1 and the drain of the switching transistor T1A, and receives the output short - circuit signal of the bidirectional current detection and cut - off circuit. The GATEP pin of the control chip U1 is respectively connected to the gate of the switching transistor T1B and the gate of the switching transistor T2B, and outputs a cut - off control signal or a connection control signal to the switching transistor T1B and the switching transistor T2B. The GATE pin of the control chip U1 is respectively connected to the gate of the switching transistor T1A and the gate of the switching transistor T2A, and outputs a cut - off control signal or a connection control signal to the switching transistor T1A and the switching transistor T2A. The OUT pin of the control chip U1 is connected to the positive terminal of the mining product. The ON pin and the GND pin of the control chip U1 are both grounded.

[0023] The current signal analysis and comparison control circuit is composed of an integrated control chip U1, and the model of the control chip U1 is LTC4361TS8. The current detection signal CS enters the control chip U1, and the control chip U1 judges whether the current is short - circuited or overloaded. If it is a load short - circuit overload, the control chip U1 outputs control signals GAP and GAN for the use of the subsequent circuit part.

[0024] The high - frequency filtering and transient time - constant calculation circuit includes a capacitor C1, a resistor R4, and a resistor R3. One end of the capacitor C1 is respectively connected to the GATE pin of the control chip U1, the gate of the switching transistor T1A, one end of the resistor R4, and the gate of the switching transistor T2A, and the other end of the capacitor C1 is grounded. The other end of the resistor R4 is connected to one end of the resistor R3, and the other end of the resistor R3 is grounded.

[0025] The high - frequency filtering and transient time - constant calculation circuit is composed of a capacitor C1, a resistor R3, and a resistor R4. The resistor R3 is a 43K resistor, the resistor R4 is a 560K resistor, and the capacitor C1 is a 22pF capacitor. The resistors R3 and R4 are used to precisely adjust the transient time - constant. The capacitor C1 is used for filtering high - frequency and storing electrical energy at the same time. The capacitor C1, together with the resistors R4 and R3, forms a discharge - constant time circuit for determining the transient protection time.

[0026] According to the above description and relevant circuit knowledge, the values of the above - mentioned resistors R1, R2, R3, R4, and capacitor C1 can be calculated. As Figure 2 shown, it gives a specific application circuit and the values of each device, but all devices are not limited to these values, and other values are within the protection scope of this technical solution.

[0027] The working principle of the present invention is as follows: The current detection resistor R1 and the resistor R2 control the short-circuit current at the load end. A preset current value in the control chip U1 is formed according to the values of the resistors R1 and R2. When the load end is short-circuited, the resistor R1 detects and outputs a signal CS. The signal CS passes through the control chip U1 and is compared and processed with the preset current value in the control chip U1. Then, the control chip U1 gives control signals GAP and GAN. The control signals GAP and GAN control the switching tubes T1A, T1B, T2A, and T2B to turn on or cut off the circuit between IN+ and OUT+. The turn-off time of the switching tubes T1A, T1B, T2A, and T2B is determined by the resistors R3, R4, and the capacitor C1. Thus, in the case of a short-circuit of the load current, the connected circuit state between IN+ and OUT+ is quickly disconnected, so that the transient heat generation amount during the load short-circuit does not exceed the rated value, playing a role in protecting the portable mining products.

[0028] The present invention adds an RC filter according to the internal structure of the control chip U1 and the parameters of the MOS switching tubes, and at the same time adjusts the working time of the RC filter, achieving the effects of RC low-pass filtering and RC time parameter control; the RC time parameter can be corrected according to actual applications; moreover, the MOS switching tubes T1 / T2 are inexpensive, which can meet the transient protection requirements of the explosion-proof lithium battery while reducing the cost, further improving the use effect of the present invention.

[0029] The circuit structure in the present invention is simple and stable, with few components and low cost, improving the use stability and reliability of the mining equipment, effectively reducing the cost of the lithium battery protection circuit, being beneficial to enhancing the market competition advantage of the portable mining products, and at the same time improving the safety of coal mine production and the miners themselves, having excellent market promotion value.

Claims

1. A portable lithium battery transient protection circuit for mining products, characterized in that: The transient protection circuit of the lithium battery of the mining product includes a bidirectional current detection and cutoff circuit, a current signal analysis and comparison control circuit, and a high-frequency filtering and transient time constant calculation circuit. The bidirectional current detection and cutoff circuit is respectively connected to the positive terminal of the lithium battery and the positive terminal of the mining product and controls the connectivity between the two; the current signal analysis and comparison control circuit is connected to the bidirectional current detection and cutoff circuit and receives the output short-circuit signal of the bidirectional current detection and cutoff circuit, and outputs a cutoff control signal or a connectivity control signal to the bidirectional current detection and cutoff circuit after comparing with a preset value; the high-frequency filtering and transient time constant calculation circuit is connected to the bidirectional current detection and cutoff circuit and controls the cutoff duration of the bidirectional current detection and cutoff circuit.

2. The portable lithium battery transient protection circuit for mining products according to claim 1, characterized in that: The bidirectional current detection and cut-off circuit includes a resistor R1, a resistor R2, a switch tube T1A, a switch tube T1B, a switch tube T2A, and a switch tube T2B; the drain of the switch tube T1B is connected to the positive terminal of the lithium battery, the source of the switch tube T1B is connected to one end of the resistor R1, the other end of the resistor R1 is connected to the drain of the switch tube T1A, the source of the switch tube T1A is connected to the drain of the switch tube T2B, the source of the switch tube T2B is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the drain of the switch tube T2A, and the source of the switch tube T2A is connected to the positive terminal of the mining product.

3. The portable lithium battery transient protection circuit for mining products according to claim 2, characterized in that: The resistor R1 and the resistor R2 are 0.035 ohm 1206 package resistors; the switch tubes T1A, T1B, T2A and T2B are YJS2308A switch tubes.

4. The portable lithium battery transient protection circuit for mining products according to claim 2, characterized in that: The current signal analysis and comparison control circuit includes a control chip U1; the IN pin of the control chip U1 is respectively connected to the source of the switch tube T1B and one end of the resistor R1; the SENSE pin of the control chip U1 is respectively connected to the other end of the resistor R1 and the drain of the switch tube T1A and receives the output short-circuit signal of the bidirectional current detection and cut-off circuit; the GATEP pin of the control chip U1 is respectively connected to the gate of the switch tube T1B and the gate of the switch tube T2B and outputs a cut-off control signal or a connection control signal to the switch tube T1B and the switch tube T2B; the GATE pin of the control chip U1 is respectively connected to the gate of the switch tube T1A and the gate of the switch tube T2A and outputs a cut-off control signal or a connection control signal to the switch tube T1A and the switch tube T2A; the OUT pin of the control chip U1 is connected to the positive terminal of the mining product; the ON pin and the GND pin of the control chip U1 are both grounded.

5. The portable lithium battery transient protection circuit for mining products according to claim 4, characterized in that: The model of the control chip U1 is LTC4361TS8.

6. The portable lithium battery transient protection circuit for mining products according to claim 4, characterized in that: The high-frequency filtering and transient time constant calculation circuit includes a capacitor C1, a resistor R4, and a resistor R3; one end of the capacitor C1 is respectively connected to the GATE pin of the control chip U1, the gate of the switch tube T1A, one end of the resistor R4, and the gate of the switch tube T2A, and the other end of the capacitor C1 is grounded; the other end of the resistor R4 is connected to one end of the resistor R3, and the other end of the resistor R3 is grounded.

7. The portable lithium battery transient protection circuit for mining products according to claim 6, characterized in that: The resistor R3 is a 43K resistor, the resistor R4 is a 560K resistor, and the capacitor C1 is a 22pF capacitor.

8. The portable lithium battery transient protection circuit for mining products according to claim 1, characterized in that: The negative terminal of the lithium battery and the negative terminal of the mining product are both grounded.

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