Battery reverse connection prevention circuit with sound-light alarm

Abstract

The utility model discloses a battery anti-reverse connection circuit with sound and light alarm, including alarm control circuit and reverse connection protection circuit, alarm control circuit is by resistance R1, resistance R2, emitting diode D1, diode D2, triode Q1 and buzzer B1 composition, reverse connection protection circuit is by resistance R3, resistance R4 and MOS tube Q2 composition, diode D2 is freewheeling diode, triode Q1 is NPN type triode, MOS tube Q2 is N channel MOS tube, the utility model not only can provide reverse connection protection to circuit, prevent circuit board damage, avoid generating security risk, still can give alarm feedback signal in time under the condition that customer abnormal access battery, remind customer battery reverse connection, avoid user make error judgement, have broad application prospect, be favorable to popularization and application.

Description

Technical Field

[0001] This utility model relates to the field of electronic circuit technology, and in particular to a battery reverse connection protection circuit with audible and visual alarm. Background Technology

[0002] In electronic products, reverse battery connection can damage circuit boards and even pose safety risks. Furthermore, if there is no alarm after reverse connection, users may assume it's a poor connection or a product quality issue, failing to identify and troubleshoot the problem promptly. Chinese patent CN201320055131 provides a reverse connection protection circuit for a battery discharger, but this solution is not feasible. First, the switching transistor Q11 is incorrectly drawn; it should be a PMOS transistor for the circuit to function. Otherwise, even with a normal connection, the battery can only discharge through the MOS transistor's body diode, and the MOS transistor cannot conduct. Second, even with a PMOS transistor, diode D11 should be replaced with a Zener diode or removed during reverse connection to ensure a reliable high level on the drive pin of switching transistor Q11, effectively turning it off. Finally, this solution only provides reverse connection protection; there is no feedback after reverse connection, failing to serve as a warning. Therefore, there is an urgent need to develop a battery reverse connection protection circuit with audible and visual alarms to solve these technical problems.

[0003] In view of this, this usage information is hereby presented. Utility Model Content

[0004] The purpose of this invention is to provide a battery reverse connection protection circuit with audible and visual alarms. It not only provides reverse connection protection to the circuit, preventing damage to the circuit board and avoiding safety hazards, but also provides timely alarm feedback signals when the customer connects the battery incorrectly, reminding the customer that the battery is connected in reverse, thus preventing users from making incorrect judgments. It has broad application prospects and is conducive to its widespread application.

[0005] To achieve the above objectives, this utility model provides a battery reverse connection protection circuit with audible and visual alarms, comprising an alarm control circuit and a reverse connection protection circuit. The alarm control circuit consists of resistors R1 and R2, LEDs D1 and D2, transistor Q1, and a buzzer B1. The negative terminal of LED D1 is connected to the positive terminal of the battery, and its positive terminal is connected to the negative terminal of the battery through resistor R1. One end of resistor R2 is connected to the negative terminal of the battery, and the other end is connected to the positive terminal of diode D2 and the base of transistor Q1. The negative terminal of diode D2 is connected to the negative terminal of the battery. The emitter of transistor Q1 is connected to the positive terminal of the battery, and its collector is connected to the negative terminal of buzzer B1. The positive terminal of buzzer B1 is connected to the negative terminal of the battery. The reverse connection protection circuit consists of resistors R3 and R4, and a MOSFET Q2. The drain (D) of MOSFET Q2 is connected to the negative terminal of the battery. The battery is connected with its source (S) terminal connected to the negative terminal of the load, and its gate (G) terminal connected to resistors R3 and R4. The other end of resistor R3 is connected to the positive terminal of the battery, and the other end of resistor R4 is connected to the source (S) terminal of MOSFET Q2 and the negative terminal of the load. When the battery is correctly connected, LED D1 is reverse-biased and off, transistor Q1 is off, buzzer B1 is not conducting, the gate of MOSFET Q2 is high, MOSFET Q2 is conducting, and the battery current flows from the positive terminal of the battery into the load, and then returns to the negative terminal of the battery through MOSFET Q2. When the battery is reverse-biased, BAT- is high, BAT+ is low, LED D1 lights up, the base of transistor Q1 is high, transistor Q1 is conducting, buzzer B1 sounds an alarm, and since BAT+ is low, MOSFET Q2 is off, cutting off the power supply to the load and preventing reverse connection.

[0006] Preferably, the diode D2 is a freewheeling diode.

[0007] Preferably, the transistor Q1 is an NPN transistor.

[0008] Preferably, the MOS transistor Q2 is an N-channel MOS transistor.

[0009] The present invention provides a battery reverse connection protection circuit with audible and visual alarm, which has the following beneficial effects.

[0010] 1. This utility model can not only provide reverse connection protection for the circuit to prevent damage to the circuit board and avoid safety hazards, but also provide timely alarm feedback signals when the customer connects the battery abnormally, reminding the customer that the battery is connected in reverse and preventing the user from making incorrect judgments.

[0011] 2. The MOSFET Q2 of this utility model is an N-channel MOSFET. N-channel MOSFETs offer more selection options, more stable performance, and lower prices.

[0012] 3. This utility model has an alarm function after reverse connection, and the alarm function does not require a controller driver and is directly implemented by hardware, making the structure simpler. Attached Figure Description

[0013] Figure 1 The present invention provides a circuit diagram of a battery reverse connection protection circuit with audible and visual alarm. Detailed Implementation

[0014] The present invention will be further described below with reference to specific embodiments and accompanying drawings to help understand the content of the present invention.

[0015] like Figure 1 The diagram shown is a circuit diagram of a battery reverse connection protection circuit with audible and visual alarm provided by this utility model. This battery reverse connection protection circuit with audible and visual alarm includes an alarm control circuit and a reverse connection protection circuit. The alarm control circuit consists of resistors R1 and R2, LED D1, diode D2, transistor Q1, and buzzer B1. The negative terminal of LED D1 is connected to the positive terminal of the battery, and its positive terminal is connected to the negative terminal of the battery through resistor R1. One end of resistor R2 is connected to the negative terminal of the battery, and the other end is connected to the positive terminal of diode D2 and the base of transistor Q1. The negative terminal of diode D2 is connected to the negative terminal of the battery. The emitter of transistor Q1 is connected to the positive terminal of the battery, and its collector is connected to the negative terminal of buzzer B1. The positive terminal of buzzer B1 is connected to the negative terminal of the battery. Preferably, diode D2 is a freewheeling diode. Transistor Q1 is an NPN transistor.

[0016] The reverse connection protection circuit consists of resistors R3 and R4 and a MOSFET Q2. The drain (D) of MOSFET Q2 is connected to the negative terminal of the battery, the source (S) is connected to the negative terminal of the load, and the gate (G) is connected to resistors R3 and R4. The other end of resistor R3 is connected to the positive terminal of the battery, and the other end of resistor R4 is connected to the source (S) of MOSFET Q2 and the negative terminal of the load. Preferably, MOSFET Q2 is an N-channel MOSFET.

[0017] The working principle of this utility model is as follows: When the battery is correctly connected, LED D1 is reverse-biased and off, transistor Q1 is off, buzzer B1 is not conducting, the gate of MOSFET Q2 is high, MOSFET Q2 is conducting, and battery current flows from the positive terminal of the battery into the load, and then returns to the negative terminal of the battery through MOSFET Q2. When the battery is reverse-biased, BAT- is high, BAT+ is low, LED D1 lights up, the base of transistor Q1 is high, transistor Q1 is conducting, buzzer B1 sounds an alarm, and since BAT+ is low, MOSFET Q2 is off, cutting off the power supply to the load and preventing reverse connection.

[0018] This invention not only provides reverse connection protection for the circuit to prevent damage to the circuit board and avoid safety hazards, but also provides timely alarm feedback signals when the customer connects the battery incorrectly, reminding the customer that the battery is connected in reverse and preventing the user from making incorrect judgments.

[0019] This article uses specific examples to illustrate the inventive concept in detail. The description of the above embodiments is only for the purpose of helping to understand the core idea of ​​this utility model. It should be noted that any obvious modifications, equivalent substitutions or other improvements made by those skilled in the art without departing from the inventive concept should be included within the protection scope of this utility model.

Claims

1. A battery reverse connection protection circuit with audible and visual alarm, characterized in that, The system includes an alarm control circuit and a reverse connection protection circuit. The alarm control circuit consists of resistors R1 and R2, LED D1, diode D2, transistor Q1, and buzzer B1. The negative terminal of LED D1 is connected to the positive terminal of the battery, and its positive terminal is connected to the negative terminal of the battery through resistor R1. One end of resistor R2 is connected to the negative terminal of the battery, and the other end is connected to the positive terminal of diode D2 and the base of transistor Q1. The negative terminal of diode D2 is connected to the negative terminal of the battery. The emitter of transistor Q1 is connected to the positive terminal of the battery, and its collector is connected to the negative terminal of buzzer B1. The positive terminal of buzzer B1 is connected to the negative terminal of the battery. The reverse connection protection circuit consists of resistors R3 and R4 and MOSFET Q2. The drain (D) terminal of MOSFET Q2 is connected to the negative terminal of the battery, the source (S) terminal is connected to the negative terminal of the load, and the gate (G) terminal is connected to the negative terminal of the load. Resistors R3 and R4 are connected together. The other end of resistor R3 is connected to the positive terminal of the battery, and the other end of resistor R4 is connected to the source (S) terminal of MOSFET Q2 and the negative terminal of the load. When the battery is correctly connected, LED D1 is reverse-biased and off, transistor Q1 is off, buzzer B1 is not conducting, the gate of MOSFET Q2 is high, MOSFET Q2 is conducting, and battery current flows from the positive terminal of the battery into the load, then returns to the negative terminal of the battery through MOSFET Q2. When the battery is reverse-biased, BAT- is high, BAT+ is low, LED D1 lights up, the base of transistor Q1 is high, transistor Q1 is conducting, buzzer B1 sounds an alarm, and since BAT+ is low, MOSFET Q2 is off, cutting off the power supply to the load and preventing reverse connection.

2. A battery reverse connection protection circuit with audible and visual alarm as described in claim 1, characterized in that, The diode D2 is a freewheeling diode.

3. A battery reverse connection protection circuit with audible and visual alarm according to claim 2, characterized in that, The transistor Q1 is an NPN transistor.

4. A battery reverse connection protection circuit with audible and visual alarm according to claim 3, characterized in that, The MOSFET Q2 is an N-channel MOSFET.

Images