A power protection circuit for a portable intelligent depth sounding system

Abstract

The invention discloses a portable intelligent sounding system power protection circuit, which belongs to the field of power circuits and includes two mosfet switches and a voltage comparison circuit; one mosfet switch and a voltage comparison circuit are connected to an external DC power supply, and the other mosfet switch is connected to an internal battery; both mosfet switches are connected to an external system load; and the voltage comparison circuit is connected to the two mosfet switches respectively. The invention can limit the voltage range of the external DC power supply input, and use the mosfet switch to isolate the internal and external power supplies, thereby reducing the voltage drop.

Description

Technical Field

[0001] The invention relates to the technical field of power supply circuits, and in particular to a power supply protection circuit for a portable intelligent depth sounding system. Background Art

[0002] In water depth measurement, there are often various complex working environments. The portable intelligent depth sounding system is durable, lightweight and portable. With its integrated advantages, it can be easily deployed on a small survey ship or temporary measurement platform. It is widely used in water depth measurement projects in various complex water conditions such as rivers, ports and coastal areas. In order to meet work needs, the portable intelligent depth sounding system can often use the system's internal lithium battery for power supply, or use an external DC power supply for power supply. If the internal lithium battery and the external DC power supply are not isolated and are connected in parallel to power the system, when the internal lithium battery of the system is insufficient, the external DC power supply will charge the lithium battery and generate a large charging current, which will damage the lithium battery and even burn the machine, which will cause great economic losses and delay the progress of the project.

[0003] In view of this situation, the current solution is to use a diode to isolate the external DC power supply from the internal lithium battery, preventing the external DC power supply current from flowing into the internal lithium battery, thereby protecting the instrument. Considering the actual use, there are the following disadvantages: (1) The diode has a large voltage drop, and the operating current of the entire system is large. Using a diode for isolation will result in a large power consumption and a significant reduction in efficiency; (2) Simply using a diode for isolation will cause the system power supply to become the internal battery and the external DC power supply, whichever has a higher voltage will work. When the voltages of the two are the same, they will work at the same time, consuming power together, and both need to be charged after work; (3) If the wrong high voltage is connected by mistake, the system will burn out directly. Summary of the invention

[0004] The object of the present invention is to provide a power protection circuit for a portable intelligent depth sounding system to solve the problems in the background technology.

[0005] In order to solve the above technical problems, the present invention provides a portable intelligent depth sounding system power protection circuit, comprising two mosfet switches and a voltage comparison circuit;

[0006] A mosfet switch and a voltage comparison circuit are connected to an external DC power supply, and another mosfet switch is connected to an internal battery; both mosfet switches are connected to an external system load;

[0007] The voltage comparison circuit is connected to two MOSFET switches respectively.

[0008] Optionally, the mosfet switch includes capacitors C1, C3, integrated circuits U1, U3, transistors Q1, Q8, MOS tubes Q3, Q4, Q5, Q6, and resistors R4, R5, R10, R12;

[0009] The VCC pins of the integrated circuits U1 and U3 are both connected to the voltage VCC5, and the Y pin of the integrated circuit U3 is connected to the base of the transistor Q1 through the resistor R5; the collector of the transistor Q1 is connected to the resistor R4, and the emitter is grounded; one end of the capacitors C1 and C3 are both connected to the voltage VCC5, and the other ends are both grounded;

[0010] The gate ends of MOS tubes Q3 and Q4 are both connected to the collector of transistor Q1, and the source ends are interconnected; the drain end of MOS tube Q3 is connected to pin 2 of 1121 model socket P2, and the drain end of MOS tube Q4 is connected to pin 1 of 1121 model socket P2;

[0011] The base of transistor Q8 is connected to resistor R12, the emitter is grounded, and the collector is connected to resistor R10; the source ends of MOS tubes Q5 and Q6 are interconnected, and the gate ends are connected to the collector of transistor Q8; the drain end of MOS tube Q6 is connected to pin 1 of 1121 model socket P2.

[0012] Optionally, pins 2 and 3 of the 1121 model socket P2 are interconnected, and pins 4 and 5 are grounded together.

[0013] Optionally, the voltage comparison circuit includes a capacitor C2, resistors R1, R2, R3, R6, R7, R8, R9, R11, transistor circuits Q2 and Q7, a fuse F1, and an integrated circuit LM393;

[0014] The integrated circuit LM393 includes a circuit U2C, a voltage comparator U2A and a voltage comparator U2B, the GND terminal of the circuit U2C is grounded, and the VCC terminal is connected to the voltage VCC5;

[0015] The first end of the resistor R1 is connected to the first end of the resistor R6; the 2 end of the transistor circuit Q2 is connected to the second end of the resistor R6, and the 1 end and the 3 end are connected to the voltage VCC5 through the resistor R2; the positive input end of the voltage comparator U2B is connected to the first end of the resistor R1 and the first end of the resistor R6, the negative input end is connected to the 3 end of the kick circuit Q2, and the output end is connected to the resistor R3;

[0016] The first end of the resistor R7 is connected to the first end of the resistor R11; the 2 end of the transistor circuit Q7 is connected to the second end of the resistor R11, and the 1 end and the 3 end are connected to the voltage VCC5 through the resistor R8; the negative input end of the voltage comparator U2A is connected to the first end of the resistor R7 and the first end of the resistor R11, the positive input end is connected to the 3 end of the transistor circuit Q7, and the output end is connected to the resistor R9;

[0017] The second end of the resistor R1 and the second end of the resistor R7 are connected to pin 1 of the 1121 model socket P1 through the fuse F1, and pin 5 of the 1121 model socket P1, the second end of the resistor R11 and pin 2 of the transistor circuit Q7 are all grounded.

[0018] Optionally, the transistor circuits Q2 and Q7 are both voltage reference chips TL431.

[0019] The portable intelligent sounding system power protection circuit provided by the present invention includes two mosfet switches and a voltage comparison circuit; one mosfet switch and a voltage comparison circuit are connected to an external DC power supply, and the other mosfet switch is connected to an internal battery; both mosfet switches are connected to an external system load; and the voltage comparison circuit is connected to the two mosfet switches respectively. The present invention can limit the voltage range of the external DC power supply input, and use the mosfet switch to isolate the internal and external power supplies, thereby reducing the voltage drop. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the principle of the power protection circuit of the portable intelligent depth sounding system provided by the present invention;

[0021] Figure 2 It is a schematic diagram of the structure of the mosfet switch circuit provided by the present invention;

[0022] Figure 3 It is a schematic diagram of the voltage comparison circuit structure provided by the present invention. DETAILED DESCRIPTION

[0023] The following is a further detailed description of a portable intelligent depth sounding system power protection circuit proposed by the present invention in combination with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer according to the following description and claims. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0024] The present invention provides a portable intelligent depth sounding system power protection circuit, the structure of which is as follows: Figure 1 As shown, it includes two MOSFET switches and a voltage comparison circuit; one MOSFET switch and a voltage comparison circuit are connected to an external DC power supply, and the other MOSFET switch is connected to an internal battery; both MOSFET switches are connected to an external system load; the voltage comparison circuit is respectively connected to the two MOSFET switches, and the logic gate circuit and the transistor serve as a driving circuit of the MOSFET switch.

[0025] like Figure 2As shown, the mosfet switch includes capacitors C1, C3, integrated circuits U1, U3, transistors Q1, Q8, MOS tubes Q3, Q4, Q5, Q6, and resistors R4, R5, R10, R12; the VCC pins of the integrated circuits U1 and U3 are connected to the voltage VCC5, the Y pin of the integrated circuit U3 is connected to the base of the transistor Q1 through the resistor R5; the collector of the transistor Q1 is connected to the resistor R4, and the emitter is grounded; one end of the capacitors C1 and C3 are connected to the voltage VCC5, and the other end is connected to ground; the gate terminals of MOS tubes Q3 and Q4 are connected to the collector of transistor Q1, and the source terminals are interconnected; the drain terminal of MOS tube Q3 is connected to pin 2 of 1121 model socket P2, and the drain terminal of MOS tube Q4 is connected to pin 1 of 1121 model socket P2; the base of transistor Q8 is connected to resistor R12, the emitter is grounded, and the collector is connected to resistor R10; the source terminals of MOS tubes Q5 and Q6 are interconnected, and the gate terminals are connected to the collector of transistor Q8; the drain terminal of MOS tube Q6 is connected to pin 1 of 1121 model socket P2.

[0026] Integrated circuit U1 uses a single dual-input positive AND gate from TI, model SN74LVC1G08, which can operate at a voltage of 1.65V to 5.5V. The A pin and B pin of integrated circuit U1 are used as inputs, and the Y pin is the AND gate output. The SN74LVC1G08 device performs Boolean functions or Y=A·B or Y=+AB in positive logic. As a CMOS device, the SN74LVC1G08 device has a high output drive to drive the transistor to conduct while maintaining low static power dissipation over a wide VCC operating range.

[0027] Integrated circuit U3 uses a single NOT gate introduced by TI, model SN74LVC1G04DBVR, which can operate at a VCC voltage of 1.65V to 5.5V. The A pin of integrated circuit U3 is used as input, and the Y pin is the NOT gate output. As a CMOS device, the SN74LVC1G08 device has a high output drive to drive the transistor to conduct while maintaining low static power dissipation in a wide VCC operating range.

[0028] like Figure 3As shown, the voltage comparison circuit includes a capacitor C2, resistors R1, R2, R3, R6, R7, R8, R9, R11, transistor circuits Q2 and Q7, a fuse F1, and an integrated circuit LM393; the integrated circuit LM393 includes a circuit U2C, a voltage comparator U2A, and a voltage comparator U2B, the GND terminal of the circuit U2C is grounded, and the VCC terminal is connected to the voltage VCC5; the first end of the resistor R1 is connected to the first end of the resistor R6; the 2 end of the transistor circuit Q2 is connected to the second end of the resistor R6, and the 1 end and the 3 end are connected to the voltage VCC5 through the resistor R2; the positive input end of the voltage comparator U2B is connected to the first end of the resistor R1 and the first end of the resistor R6, and the negative input The first end of the resistor R7 is connected to the first end of the resistor R11; the second end of the transistor circuit Q7 is connected to the second end of the resistor R11, and the first end and the third end are connected to the voltage VCC5 through the resistor R8; the negative input end of the voltage comparator U2A is connected to the first end of the resistor R7 and the first end of the resistor R11, the positive input end is connected to the third end of the transistor circuit Q7, and the output end is connected to the resistor R9; the second end of the resistor R1 and the second end of the resistor R7 are both connected to the 1 pin of the 1121 model socket P1 through the fuse F1, and the 5 pin of the 1121 model socket P1, the second end of the resistor R11 and the 2 pin of the transistor circuit Q7 are all grounded.

[0029] The voltage reference chip TL431 is used as the transistor circuit Q2 and Q7 to provide a 2.5V reference voltage. The voltage comparison circuit is used to limit the voltage range of the external DC input. When the voltage is higher than 16V or lower than 11V, the switch is disconnected and powered by an internal lithium battery. The integrated circuit LM393 contains two independent voltage comparators U2B and U2A, which can be operated by a single power supply within a wide voltage range. The quiescent current is independent of the power supply voltage, and the output can be connected to other open collector outputs to achieve line-and logic. Through the integrated circuit LM393, two-way voltage comparison can be achieved. Among them, pins 2, 3, 5, and 6 are the input terminals of the voltage comparator, and pins 1 and 7 are the output terminals of the voltage comparator; pins 1, 2, and 3 of the voltage comparator U2B are 16V voltage comparisons, and pins 5, 6, and 7 of the voltage comparator U2A are 11V voltage comparisons.

[0030] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A portable intelligent depth sounding system power protection circuit, characterized in that: It includes two mosfet switches and a voltage comparison circuit; A mosfet switch and a voltage comparison circuit are connected to an external DC power supply, and another mosfet switch is connected to an internal battery; both mosfet switches are connected to an external system load; The voltage comparison circuit is connected to two MOSFET switches respectively; The mosfet switch includes capacitors C1, C3, integrated circuits U1, U3, transistors Q1, Q8, MOS tubes Q3, Q4, Q5, Q6, and resistors R4, R5, R10, R12; the VCC pins of the integrated circuits U1 and U3 are connected to the voltage VCC5, and the Y pin of the integrated circuit U3 is connected to the base of the transistor Q1 through the resistor R5; the collector of the transistor Q1 is connected to the resistor R4, and the emitter is grounded; one end of the capacitors C1 and C3 are connected to the voltage VCC5, and the other end is grounded; The gate ends of MOS tubes Q3 and Q4 are both connected to the collector of transistor Q1, and the source ends are interconnected; the drain end of MOS tube Q3 is connected to pin 2 of 1121 model socket P2, and the drain end of MOS tube Q4 is connected to pin 1 of 1121 model socket P2; The base of transistor Q8 is connected to resistor R12, the emitter is grounded, and the collector is connected to resistor R10; the source ends of MOS tubes Q5 and Q6 are interconnected, and the gate ends are connected to the collector of transistor Q8; the drain end of MOS tube Q6 is connected to pin 1 of 1121 model socket P2; The voltage comparison circuit includes a capacitor C2, resistors R1, R2, R3, R6, R7, R8, R9, R11, transistor circuits Q2 and Q7, a fuse F1, and an integrated circuit LM393; The integrated circuit LM393 includes a circuit U2C, a voltage comparator U2A and a voltage comparator U2B, the GND terminal of the circuit U2C is grounded, and the VCC terminal is connected to the voltage VCC5; The first end of the resistor R1 is connected to the first end of the resistor R6; the 2 end of the transistor circuit Q2 is connected to the second end of the resistor R6, and the 1 end and the 3 end are connected to the voltage VCC5 through the resistor R2; the positive input end of the voltage comparator U2B is connected to the first end of the resistor R1 and the first end of the resistor R6, the negative input end is connected to the 3 end of the transistor circuit Q2, and the output end is connected to the resistor R3; The first end of the resistor R7 is connected to the first end of the resistor R11; the 2 end of the transistor circuit Q7 is connected to the second end of the resistor R11, and the 1 end and the 3 end are connected to the voltage VCC5 through the resistor R8; the negative input end of the voltage comparator U2A is connected to the first end of the resistor R7 and the first end of the resistor R11, the positive input end is connected to the 3 end of the transistor circuit Q7, and the output end is connected to the resistor R9; The second end of the resistor R1 and the second end of the resistor R7 are connected to pin 1 of the 1121 model socket P1 through the fuse F1, and pin 5 of the 1121 model socket P1, the second end of the resistor R11 and pin 2 of the transistor circuit Q7 are all grounded.

2. The portable intelligent depth sounding system power protection circuit according to claim 1, characterized in that: Pins 2 and 3 of the 1121 type socket P2 are interconnected, and pins 4 and 5 are grounded together.

3. The portable intelligent depth sounding system power protection circuit according to claim 1, characterized in that: The transistor circuits Q2 and Q7 are both voltage reference chips TL431.

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