A lead-acid battery reverse connection protection circuit

Abstract

The utility model discloses a reverse connection protection circuit for a lead-acid battery, belonging to the technical field of battery protection. The utility model comprises a positive and negative pole input terminal (PWR), a reverse connection protection circuit and an abnormal indication circuit. The reverse connection protection circuit comprises a diode (D2) and a MOSFET (Q2). When the positive and negative poles of the battery are reversely connected, the diode (D2) is forward-conducted, so that the MOSFET (Q2) is turned off, thereby cutting off the circuit to prevent the circuit from being damaged. The abnormal indication circuit comprises an LED lamp (D4) and a current-limiting resistor (R6). When the positive and negative poles of the battery are reversely connected, the LED lamp (D4) is lit to indicate an abnormal state. The circuit also comprises a working indicator lamp (D5) and a current-limiting resistor (R1), which are used to light up when the battery is correctly connected and the circuit is working normally, indicating that the circuit is in a normal working state. The utility model can prevent the battery from being reversely connected to burn the product and increase the LED prompt when the battery is reversely connected. The utility model also comprises a working indicator lamp (D5) and a current-limiting resistor (R1) thereof, which are used to light up when the battery is correctly connected and the circuit is working normally, indicating that the circuit is in a normal working state ...

Description

Technical Field

[0001] The utility model relates to the technical field of battery protection, and more specifically to a reverse connection protection circuit for a lead-acid battery. Background Art

[0002] "Sulfurization" is the fatal killer of lead-acid batteries. More than 90% of battery failures and damages are caused by "sulfurization" (crystallization of lead sulfate) on the negative plate of the battery. Solving the "sulfurization" problem can greatly extend the service life of the battery. Composite pulse is a powerful tool for removing "sulfurization". The composite pulse desulfurizer uses high frequency, high voltage and composite pulse technology to effectively crush lead sulfate crystals and turn them into active material lead oxide, so that the battery can remain in a brand new state all year round, greatly improving the performance and use value of the battery.

[0003] This product mainly activates the sulfurized factors of the battery itself through high voltage and low current pulses, so that the battery can restore its capacity. The current products have the problem that if the positive and negative poles of the battery are connected in reverse, the product will burn out and cannot be used normally. Therefore, a lead-acid battery reverse connection protection circuit is urgently needed to solve the above problem. Utility Model Content

[0004] 1. Technical issues to be solved

[0005] In view of the problems existing in the prior art, the purpose of the utility model is to provide a lead-acid battery reverse connection protection circuit, which can prevent the battery from burning the product due to reverse connection, increase the LED prompt when reverse connection occurs, and has overcurrent protection and LED light prompts under various working conditions.

[0006] 2. Technical solution

[0007] To solve the above problems, the utility model adopts the following technical solutions.

[0008] A lead-acid battery reverse connection protection circuit, comprising:

[0009] Positive and negative input terminals (PWR), used to connect batteries;

[0010] The reverse connection protection circuit includes a diode (D2) and a MOSFET (Q2). When the positive and negative poles of the battery are connected in reverse, the diode (D2) is forward-conducted, causing the MOSFET (Q2) to be turned off, thereby cutting off the circuit to prevent the circuit from being damaged;

[0011] The abnormal indication circuit comprises an LED lamp (D4) and a current limiting resistor (R6). When the positive and negative poles of the battery are connected reversely, the LED lamp (D4) lights up to indicate an abnormal state.

[0012] Furthermore, the resistor (R6) is connected in series with the LED lamp (D4), connected between the negative electrode of the battery and the positive electrode of the diode (D2), the negative electrode of the diode (D2) is connected to the gate of the MOSFET (Q2), and is grounded through the resistor (R7), the source of the MOSFET (Q2) is grounded, and the drain is connected to the load circuit.

[0013] Furthermore, when the positive and negative poles of the battery are connected in reverse, the diode (D2) conducts in the forward direction, making the gate voltage of the MOSFET (Q2) a low voltage, thereby putting the MOSFET (Q2) in an off state, cutting off the normal working path of the circuit.

[0014] Furthermore, it also includes a control circuit, which includes a timer (U1), capacitors (C2, C3, C4, C5) and resistors (R3, R4, R5) for controlling the repair process of the battery.

[0015] Furthermore, the reverse connection protection circuit includes a fuse (F1) for cutting off the circuit when the current is too large to provide overcurrent protection. The fuse (F1) is connected between the positive pole of the power input terminal and the VCC of the circuit.

[0016] Furthermore, the reverse connection protection circuit also includes a working indicator light (D5) and a current limiting resistor (R1) thereof, which are used to light up when the battery is connected correctly and the circuit is working normally, indicating that the circuit is in a normal working state, and the working indicator light (D5) is connected between VCC and ground.

[0017] 3. Beneficial effects

[0018] This solution can prevent the battery from being reversed and burning the product, while adding an LED prompt when the battery is reversed, and has overcurrent protection and LED light prompts under various working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the protection circuit of the utility model. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model; it is obvious that the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the utility model without making creative work are within the scope of protection of the utility model.

[0021] Embodiment 1:

[0022] See also Figure 1 , a lead-acid battery reverse connection protection circuit, comprising:

[0023] Positive and negative input terminals (PWR), used to connect batteries;

[0024] The reverse connection protection circuit includes a diode (D2) and a MOSFET (Q2). When the positive and negative poles of the battery are connected in reverse, the diode (D2) is forward-conducted, causing the MOSFET (Q2) to be turned off, thereby cutting off the circuit to prevent the circuit from being damaged;

[0025] The diode (D2) model is 1N4007. 1N4007 is a general-purpose rectifier diode with high reverse voltage and large forward current capability. It is often used in power rectification, reverse protection and other occasions.

[0026] When the positive and negative poles of the battery are connected in reverse, the diode D2 (1N4007) is forward-conducted, and the gate voltage of the MOSFET (Q2) is pulled down to close to the ground potential, making it in the off state, thereby cutting off the normal working path of the circuit, preventing the reverse current from flowing into the circuit, and protecting other components from damage.

[0027] The model of MOSFET (Q2) is WSR80N06. WSR80N06 is an N-channel enhancement type MOSFET. WSR80N06 is mainly used for high current switching applications. It has low on-resistance and high current handling capability and is suitable for use as a switching element in a battery protection circuit.

[0028] When the positive and negative electrodes of the battery are connected correctly, the diode (D2) is reverse biased and does not conduct, and the gate voltage of the MOSFET (Q2) is pulled up to a higher voltage through the resistor R7, turning on the MOSFET (Q2).

[0029] After MOSFET (Q2) is turned on, current can flow to the load through MOSFET (Q2), and the circuit works normally.

[0030] When the positive and negative poles of the battery are connected in reverse, the diode (D2) conducts in the forward direction, causing the gate voltage of the MOSFET (Q2) to be pulled down to near the ground potential, turning off the MOSFET (Q2).

[0031] After the MOSFET (Q2) is turned off, the current cannot flow to the load through the MOSFET (Q2), thereby cutting off the circuit and preventing the reverse current from damaging other components in the circuit.

[0032] The abnormal indication circuit comprises an LED lamp (D4) and a current limiting resistor (R6). When the positive and negative poles of the battery are connected reversely, the LED lamp (D4) lights up to indicate an abnormal state.

[0033] The resistance value of the current limiting resistor (R6) is 3.3KΩ, and is used to limit the current of the LED lamp (D4) to protect the LED lamp (D4) from being burned.

[0034] The resistor (R6) is connected in series with the LED lamp (D4), and is connected between the negative electrode of the battery and the positive electrode of the diode (D2). The negative electrode of the diode (D2) is connected to the gate of the MOSFET (Q2) and is grounded through the resistor (R7). The source of the MOSFET (Q2) is grounded, and the drain is connected to the load circuit.

[0035] When the positive and negative poles of the battery are connected in reverse, the diode (D2) conducts in the forward direction, making the gate voltage of the MOSFET (Q2) a low voltage, thereby turning the MOSFET (Q2) off and cutting off the normal working path of the circuit.

[0036] The invention also comprises a control circuit, which comprises a timer (U1), capacitors (C2, C3, C4, C5) and resistors (R3, R4, R5) for controlling the repair process of the battery.

[0037] The model of the timer U1 is NE555P, and the circuit design of the control circuit part is the existing technology, and its specific connection relationship will not be repeated here.

[0038] Embodiment 2:

[0039] The reverse connection protection circuit also includes a fuse (F1), the fusing current of the fuse (F1) is 1.5A, which is used to cut off the circuit when the current is too large to provide overcurrent protection. The fuse (F1) is connected between the positive pole of the power input terminal and the VCC of the circuit.

[0040] Embodiment 3:

[0041] The reverse connection protection circuit also includes a working indicator light (D5) and a current limiting resistor (R1) thereof, which are used to light up when the battery is correctly connected and the circuit is working normally, indicating that the circuit is in a normal working state, and the working indicator light (D5) is connected between VCC and ground.

[0042] The resistance value of the current limiting resistor (R1) is 1KΩ, and is used to limit the current of the LED lamp (D5) to protect the LED lamp (D5) from being burned.

[0043] Working principle:

[0044] Reverse connection protection: When the positive and negative poles of the battery are connected in reverse, the diode (D2) conducts in the forward direction, making the gate voltage of the MOSFET (Q2) low, thereby turning the MOSFET (Q2) off and cutting off the normal working path of the circuit. At the same time, the LED light (D4) lights up to indicate the abnormal state.

[0045] Normal operation indication: When the battery is connected correctly and the circuit is working properly, the LED light (D5) lights up, indicating that the circuit is in normal working condition.

[0046] Overcurrent protection: When the current is too large, the fuse (F1) blows, cutting off the circuit and providing overcurrent protection.

[0047] The above are only preferred specific implementations of the utility model; however, the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and improved ideas of the utility model within the technical scope disclosed by the utility model, which should be included in the protection scope of the utility model.

Claims

1. A lead-acid battery reverse connection protection circuit, characterized in that: include: Positive and negative input terminals (PWR), used to connect batteries; The reverse connection protection circuit includes a diode (D2) and a MOSFET (Q2). When the positive and negative poles of the battery are connected in reverse, the diode (D2) is forward-conducted, causing the MOSFET (Q2) to be turned off, thereby cutting off the circuit to prevent the circuit from being damaged; The abnormal indication circuit comprises an LED lamp (D4) and a current limiting resistor (R6). When the positive and negative poles of the battery are connected reversely, the LED lamp (D4) lights up to indicate an abnormal state.

2. A lead-acid battery reverse connection protection circuit according to claim 1, characterized in that: The resistor (R6) is connected in series with the LED lamp (D4), and is connected between the negative electrode of the battery and the positive electrode of the diode (D2). The negative electrode of the diode (D2) is connected to the gate of the MOSFET (Q2) and is grounded through the resistor (R7). The source of the MOSFET (Q2) is grounded, and the drain is connected to the load circuit.

3. A lead-acid battery reverse connection protection circuit according to claim 2, characterized in that: When the positive and negative poles of the battery are connected in reverse, the diode (D2) conducts in the forward direction, making the gate voltage of the MOSFET (Q2) a low voltage, thereby turning the MOSFET (Q2) off and cutting off the normal working path of the circuit.

4. A lead-acid battery reverse connection protection circuit according to claim 3, characterized in that: The invention also comprises a control circuit, which comprises a timer (U1), capacitors (C2, C3, C4, C5) and resistors (R3, R4, R5) for controlling the repair process of the battery.

5. A lead-acid battery reverse connection protection circuit according to claim 1, characterized in that: The reverse connection protection circuit comprises a fuse (F1) for cutting off the circuit when the current is too large to provide overcurrent protection. The fuse (F1) is connected between the positive pole of the power input terminal and the VCC of the circuit.

6. A lead-acid battery reverse connection protection circuit according to claim 1, characterized in that: The reverse connection protection circuit also includes a working indicator light (D5) and a current limiting resistor (R1) thereof, which are used to light up when the battery is correctly connected and the circuit is working normally, indicating that the circuit is in a normal working state, and the working indicator light (D5) is connected between VCC and ground.

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