Non-polar charging circuit

Abstract

A non-polar charging circuit provided by the utility model comprises a full-bridge rectification circuit, a high-speed switch circuit, a temperature monitoring circuit, a processor circuit and an over-current protection circuit, the full-bridge rectification circuit is connected with a load through a high-speed switch, the processor circuit is connected with the high-speed switch, and the over-current protection circuit is connected with the high-speed switch. The temperature monitoring circuit and the over-current protection circuit are respectively connected with the processor circuit. Through a full-bridge rectification circuit formed by the two PMOS transistors and the two NMOS transistors, a non-polar power converter can be arranged in the equipment, and the equipment is prevented from being damaged due to polarity misconnection in the automatic charging process of the equipment; and overcurrent protection and temperature monitoring functions are set, so that the device can be disconnected in time when overcurrent and overtemperature conditions occur in the charging process of the device, and the device is further protected from being damaged.

Description

TECHNICAL FIELD

[0001] The utility model relates to a non-polarity charging circuit. BACKGROUND

[0002] Now mobile monitoring equipment in the field of hydrological monitoring station, such as hydrological lead fish, because the equipment needs to move on cable way, it is difficult to erect power supply line, and the power supply line will be damaged by wind and other natural influences, so now the monitoring equipment uses battery power supply, but because the field workstation is equipped with too many personnel, the monitoring equipment needs to have the function of automatic return charging, and in the unattended condition, the charging seat is fixed, and the electrode direction cannot be determined when the charging equipment returns to the charging position, in this case, the support of non-polarity input power charging circuit is needed. The existing non-polarity charging is realized by full-bridge rectifier bridge stack, but it is found in the actual application process that the charging efficiency is very low, and because the full-bridge rectifier bridge stack is composed of four rectifier diodes, there is a large voltage drop, when the charging current is large, a large amount of heat will be accumulated in the bridge stack. Like CN205583676U disclosed a kind of redundancy no-direction direct current power supply protection circuit, four diodes are used to form full-bridge rectifier circuit to form non-polarity power input, to avoid Ethernet switch being damaged in bad environment. But its full-bridge rectifier circuit is composed of four diodes, a large amount of heat will be generated in the process of power supply. UTILITARIAN CONTENT

[0003] To solve the above technical problems, the utility model provides a kind of non-polarity charging circuit.

[0004] The utility model is realized by the following technical schemes.

[0005] The utility model provides a kind of non-polarity charging circuit, including full bridge rectifier circuit, high-speed switch circuit, temperature monitoring circuit, processor circuit, overcurrent protection circuit, the full bridge rectifier circuit is connected with load by high-speed switch, the processor circuit is connected with high-speed switch, the temperature monitoring circuit and overcurrent protection circuit are connected with processor circuit respectively, the full bridge rectifier circuit includes two PMOS tubes Q2 and Q5 and two NMOS tubes Q3 and Q4, the gate of PMOS tube Q2 is connected with the anode of stabilivolt diode Z2 and resistance R12 respectively, the gate of PMOS tube Q5 is connected with the anode of stabilivolt diode Z4 and resistance R15 respectively, the gate of NMOS tube Q3 is connected with the cathode of stabilivolt diode Z3 and resistance R13 respectively, the gate of NMOS tube Q4 is connected with the cathode of stabilivolt diode Z5 and resistance R16 respectively, the cathode of stabilivolt diode Z2 and stabilivolt diode Z4 is connected with the output positive pole of rectifier bridge, the anode of stabilivolt diode Z3 and stabilivolt diode Z5 is connected with the output negative pole of rectifier, the other end of resistance R15 and resistance R16 and the source of PMOS tube Q2 and the drain of NMOS tube Q3 are connected with first power input terminal, the other end of resistance R12 and resistance R13 and the source of PMOS tube Q5 and the drain of NMOS tube Q4 are connected with second power input terminal.

[0006] The high-speed switch circuit includes two PMOS tubes Q1 and Q6 connected back to back, the drain and the gate of PMOS tube Q1 and PMOS tube Q6 are also connected in parallel with resistance R10 and stabilivolt diode Z1, the source of PMOS tube Q1 is connected with load, the source of PMOS tube Q6 is connected with the output positive pole of full bridge rectifier circuit, the gate of PMOS tube Q1 and PMOS tube Q6 is connected with resistance R8;Resistance R8 is connected with the collector of triode T1, the base of triode is connected with processor circuit through resistance R5, the emitter is grounded.

[0007] The processor circuit includes single-chip microcomputer U1, the P0.4 pin of single-chip microcomputer U1 is connected with the B end and the A end of NAND gate U4 through resistance R27, the P1.2 pin is connected with the A end of NAND gate U4, the NAND gate U4 and the P1.4 pin of single-chip microcomputer U1 are connected with the anode of diode D2 and diode D1 respectively, the cathode of diode D2 and diode D1 is connected with resistance R5.

[0008] The P0.5 and P0.6 pins of single-chip microcomputer U1 are also connected with resistance R18 and resistance R21 respectively, resistance R18 and resistance R21 are connected with resistance R14 and resistance R19 respectively, resistance R14 and resistance R19 are connected with the source of PMOS tube Q6 and the source of PMOS tube Q1 respectively.

[0009] The model of single-chip microcomputer is N76E003AT20.

[0010] The overcurrent protection circuit comprises a current collection circuit and a hysteresis comparison circuit, the current collection circuit comprises an operational amplifier U2B, the input positive terminal of the operational amplifier U2B is connected with a resistor R3, the input negative terminal is grounded through a resistor R4, the resistor R3 is connected with the hysteresis comparison circuit, the output terminal of the operational amplifier U2B is connected with a resistor R11, the resistor R11 is connected with a P0.7 pin of a single-chip microcomputer U1, and the input negative terminal and the output terminal of the operational amplifier U2B are further connected with a resistor R7;

[0011] The hysteresis comparison circuit comprises an operational amplifier U2A, the input positive terminal of the operational amplifier U2A is connected with a +3V3 power supply through a resistor R26 and grounded through the resistor R26, the input negative terminal is connected with a resistor R25, the resistor R25 is connected with the output negative terminal of the full-bridge rectifier circuit and the resistor R3, and the output terminal of the operational amplifier U2A is connected with a B terminal of an NAND gate U4.

[0012] The resistor R25 is further connected with a capacitor C2 and a capacitor C12 respectively, and the other ends of the capacitor C2 and the capacitor C12 are grounded.

[0013] The temperature monitoring circuit comprises a temperature sensor RT1, the temperature sensor RT1 is connected with a P3.0 pin of the single-chip microcomputer U1 through a resistor R22, and the two ends of the resistor R22 are grounded through a capacitor C9 and a resistor R23 respectively.

[0014] The device can be built-in non-polar power converter, the device is prevented from being damaged due to polarity connection error in the automatic charging process, overcurrent protection and temperature monitoring functions are arranged, the device is disconnected in time when overcurrent and overtemperature occur in the charging process, and the device is further protected from being damaged. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a principle structure schematic view of the utility model;

[0016] Figure 2 It is a full-bridge rectifier circuit principle schematic view of the utility model;

[0017] Figure 3 It is a principle view when different polar power sources are connected;

[0018] Figure 4 It is a two kinds of MOS tube characteristic curve schematic view of the utility model. DETAILED DESCRIPTION

[0019] The technical scheme of the utility model is further described below, but the scope of protection is not limited to the description.

[0020] AsFigure 1 As shown, a non-polar charging circuit includes a full-bridge rectifier circuit, a high-speed switch circuit, a temperature monitoring circuit, a processor circuit, an overcurrent protection circuit, the full-bridge rectifier circuit is connected with the load through the high-speed switch, the processor circuit is connected with the high-speed switch, the temperature monitoring circuit and the overcurrent protection circuit are respectively connected with the processor circuit, the full-bridge rectifier circuit includes two PMOS tubes Q2 and Q5 and two NMOS tubes Q3 and Q4, the gate of the PMOS tube Q2 is respectively connected with the anode of the voltage stabilizing diode Z2 and the resistor R12, the gate of the PMOS tube Q5 is respectively connected with the anode of the voltage stabilizing diode Z4 and the resistor R15, the gate of the NMOS tube Q3 is respectively connected with the cathode of the voltage stabilizing diode Z3 and the resistor R13, the gate of the NMOS tube Q4 is respectively connected with the cathode of the voltage stabilizing diode Z5 and the resistor R16, the cathodes of the voltage stabilizing diode Z2 and the voltage stabilizing diode Z4 are connected with the positive output end of the rectifier bridge, the anodes of the voltage stabilizing diode Z3 and the voltage stabilizing diode Z5 are connected with the negative output end of the rectifier, the other end of the resistor R15 and the resistor R16 and the source of the PMOS tube Q2 and the drain of the NMOS tube Q3 are connected with the first power input end, the other end of the resistor R12 and the resistor R13 and the source of the PMOS tube Q5 and the drain of the NMOS tube Q4 are connected with the second power input end. As shown in the figure, Figure 1 As shown, the load is a battery and its powered equipment, the equipment which needs to be charged and needs to be powered is connected in parallel with the high-speed switch, and the negative pole of the battery and the equipment is directly connected with the negative output end of the full-bridge rectifier circuit.

[0021] As shown in the figure, Figure 2 When the input positive / negative one end is connected with a power supply greater than 10V, the power supply positive flows to the drain (S pole) of the Q2 MOSFET tube through the internal protection diode of Q2, the gate (G pole) of Q2 is connected to the negative of the power supply through R12, at this time the VGS of Q2 is less than -3V, which meets the conduction condition of P-channel MOSFET, Q2 is fully on; the gate (G pole) of Q4 is connected to the positive of the power supply through R16, the S pole of Q4 is connected to the negative of the power supply, resulting in that the VGS of Q4 is greater than 3V, which meets the conduction condition of N-channel MOSFET, Q4 is fully on; the gate (G pole) of Q3 is connected to the negative of the power supply through R13, the S pole of Q3 is connected to the positive of the power supply, resulting in that the VGS of Q3 is less than 3V, which does not meet the conduction condition of N-channel MOSFET, Q3 is off. The gate (G pole) of Q5 is connected to the positive of the power supply through R15, the drain (S pole) of Q5 is connected with the drain (S pole) of Q2, resulting in that the VGS of Q5 is equal to 0V, which does not meet the conduction requirement of P-channel MOSFET, Q5 is off.

[0022] When the input positive / negative two ends are connected with a power supply greater than 10V:

[0023] The power supply is through the protection diode inside Q5, to the drain (S) of Q5 MOSFET tube, the gate (G) of Q5 is connected to the negative of the power supply through R15, at this time the VGS of Q5 is less than -3V, which meets the conduction condition of P-channel MOSFET, Q5 is fully on; the gate (G) of Q3 is connected to the positive of the power supply through R13, the drain (S) of Q3 is connected to the negative of the power supply, resulting in the VGS of Q3 being greater than 3V, which meets the conduction condition of N-channel MOSFET, Q3 is fully on; the gate (G) of Q4 is connected to the negative of the power supply through R16, the drain (S) of Q4 is connected to the positive of the power supply, resulting in the VGS of Q4 being less than 4.5V, which does not meet the conduction condition of N-channel MOSFET, Q4 is off. The gate (G) of Q2 is connected to the positive of the power supply through R12, the drain (S) of Q2 is connected to the drain (S) of Q5, resulting in the VGS of Q2 being equal to 0V, which does not meet the conduction requirement of P-channel MOSFET, Q2 is off.

[0024] As shown in Figure 3 , the red arrow and the blue arrow respectively represent the direction of the current when the power input end is connected to the power supply of different polarities.

[0025] As shown in Figure 4 , by selecting the type of MOSFET, the on-resistance of the two specifications of MOSFET tubes is 4.3 milliohms after being fully on. Therefore, the voltage drop generated on the two intersecting MOSFET tubes is very small, that is, the useless power consumption generated on them is very small.

[0026] Further, the high-speed switching circuit includes two PMOS tubes Q1 and Q6 connected back to back, and the drain and gate of the PMOS tube Q1 and the PMOS tube Q6 are also connected in parallel with the resistor R10 and the voltage stabilizing diode Z1, the source of the PMOS tube Q1 is connected with the load, the source of the PMOS tube Q6 is connected with the positive of the output end of the full-bridge rectifier circuit, and the gate of the PMOS tube Q1 and the PMOS tube Q6 connected in parallel is connected with the resistor R8; the resistor R8 is connected with the collector of the triode T1, the base of the triode is connected with the processor circuit through the resistor R5, and the emitter is grounded. Since the battery end, that is, the output end is a direct battery, when there is no power input, if a single P-MOSFET is used as a switch, the battery voltage will be conducted to the full-bridge rectifier circuit output end through the internal protection diode of the MOS tube, although it will not be conducted to the full-bridge input end, but the overall circuit has a single-chip microcomputer power supply connected to the full-bridge output end, and the battery cannot be completely blocked when there is no power input, and the battery power will be consumed additionally. Therefore, the bidirectional back-to-back P-MOSFET circuit is used to prevent the possibility of completely blocking the battery current from being consumed additionally when there is no input power supply.

[0027] The processor circuit includes a single-chip microcomputer U1, a P0.4 pin of the single-chip microcomputer U1 is connected with the B end and the A end of a NAND gate U4 through a resistor R27, a P1.2 pin is connected with the A end of the NAND gate U4, the B end of the NAND gate U4 and a P1.4 pin of the single-chip microcomputer U1 are respectively connected with the anode of a diode D2 and the anode of a diode D1, the cathodes of the diode D2 and the diode D1 are connected with a resistor R5. The P0.5 and P0.6 pins of the single-chip microcomputer U1 are respectively connected with a resistor R18 and a resistor R21, the resistor R18 and the resistor R21 are respectively connected with a resistor R14 and a resistor R19, the resistor R14 and the resistor R19 are respectively connected with the source of a PMOS tube Q6 and the source of a PMOS tube Q1.

[0028] The single-chip microcomputer is N76E003AT20.

[0029] The overcurrent protection circuit includes a current collection circuit and a hysteresis comparison circuit, the current collection circuit includes an operational amplifier U2B, the input positive end of the operational amplifier U2B is connected with a resistor R3, the input negative end is grounded through a resistor R4, the resistor R3 is connected with the hysteresis comparison circuit, the output end of the operational amplifier U2B is connected with a resistor R11, the resistor R11 is connected with a P0.7 pin of a single-chip microcomputer U1, the input negative end and the output end of the operational amplifier U2B are further connected with a resistor R7.

[0030] The hysteresis comparison circuit includes an operational amplifier U2A, the input positive end of the operational amplifier U2A is connected with a +3V3 power supply through a resistor R26 and is grounded through the resistor R26, the input negative end is connected with a resistor R25, the resistor R25 is connected with the negative electrode of the output end of a full-bridge rectifier circuit and the resistor R3, the output end of the operational amplifier U2A is connected with the B end of a NAND gate U4.

[0031] In the overcurrent protection circuit, the hysteresis comparison circuit can well prevent the protection oscillation phenomenon, and the fast interrupt response of the single-chip microcomputer can quickly process the overcurrent process, such as realizing the extended protection functions of protection locking, time interval protection and current limiting protection.

[0032] Further, the resistor R25 is further connected with a capacitor C2 and a capacitor C12, the other ends of the capacitor C2 and the capacitor C12 are grounded.

[0033] Further, the temperature monitoring circuit includes a temperature sensor RT1, the temperature sensor RT1 is connected with a P3.0 pin of the single-chip microcomputer U1 through a resistor R22, the two ends of the resistor R22 are respectively grounded through a capacitor C9 and a resistor R23. The temperature sensor RT1 is placed close to the six MOSFETs, and can measure the temperature on the board in real time, such as when the temperature is too high, the processor can execute the over-temperature protection.

Claims

1. A non-polar charging circuit, characterized in that: The system includes a full-bridge rectifier circuit, a high-speed switching circuit, a temperature monitoring circuit, a processor circuit, and an overcurrent protection circuit. The full-bridge rectifier circuit is connected to the load via a high-speed switch, and the processor circuit is connected to the high-speed switch. The temperature monitoring circuit and the overcurrent protection circuit are both connected to the processor circuit. The full-bridge rectifier circuit includes two PMOS transistors Q2 and Q5 and two NMOS transistors Q3 and Q4. The gate of PMOS transistor Q2 is connected to the anode of Zener diode Z2 and resistor R12, and the gate of PMOS transistor Q5 is connected to the anode of Zener diode Z4 and resistor R15. The gate of NMOS transistor Q3... The cathodes of Zener diode Z3 and resistor R13 are connected to each other respectively. The gate of NMOS transistor Q4 is connected to the cathode of Zener diode Z5 and resistor R16 respectively. The cathodes of Zener diodes Z2 and Z4 are connected to the positive terminal of the rectifier bridge output. The anodes of Zener diodes Z3 and Z5 are connected to the negative terminal of the rectifier output. The other ends of resistors R15 and R16, as well as the source of PMOS transistor Q2 and the drain of NMOS transistor Q3, are connected to the first power input terminal. The other ends of resistors R12 and R13, as well as the source of PMOS transistor Q5 and the drain of NMOS transistor Q4, are connected to the second power input terminal.

2. The non-polarity charging circuit as described in claim 1, characterized in that: The high-speed switching circuit includes two PMOS transistors Q1 and Q6 connected back-to-back. Resistors R10 and Zener diode Z1 are connected in parallel to the drains and gates of PMOS transistors Q1 and Q6. The source of PMOS transistor Q1 is connected to the load, and the source of PMOS transistor Q6 is connected to the positive output terminal of the full-bridge rectifier circuit. The gates of PMOS transistors Q1 and Q6 connected in parallel are connected to resistor R8. Resistor R8 is connected to the collector of transistor T1, and the base of the transistor is connected to the processor circuit through resistor R5. The emitter is grounded.

3. The non-polarity charging circuit as described in claim 1, characterized in that: The processor circuit includes a microcontroller U1. The P0.4 pin of the microcontroller U1 is connected to the B and A terminals of the NAND gate U4 through a resistor R27. The P1.2 pin is connected to the A terminal of the NAND gate U4. The P1.4 pin of the NAND gate U4 and the microcontroller U1 are respectively connected to the anodes of diodes D2 and D1. The cathodes of diodes D2 and D1 are connected to a resistor R5.

4. The non-polar charging circuit as described in claim 3, characterized in that: The P0.5 and P0.6 pins of the microcontroller U1 are also connected to resistors R18 and R21, respectively. Resistors R18 and R21 are connected to resistors R14 and R19, respectively. Resistors R14 and R19 are connected to the source of PMOS transistor Q6 and the source of PMOS transistor Q1, respectively.

5. The non-polar charging circuit as described in claim 4, characterized in that: The microcontroller model is N76E003AT20.

6. The non-polarity charging circuit as described in claim 1, characterized in that: The overcurrent protection circuit includes a current acquisition circuit and a hysteresis comparison circuit. The current acquisition circuit includes an operational amplifier U2B. The positive input terminal of the operational amplifier U2B is connected to a resistor R3, and the negative input terminal is grounded through a resistor R4. The resistor R3 is connected to the hysteresis comparison circuit. The output terminal of the operational amplifier U2B is connected to a resistor R11. The resistor R11 is connected to the P0.7 pin of the microcontroller U1. A resistor R7 is also connected between the negative input terminal and the output terminal of the operational amplifier U2B. The hysteresis comparator circuit includes an operational amplifier U2A. The positive input terminal of the operational amplifier U2A is connected to a +3V3 power supply through a resistor R26 and is also grounded through a resistor R26. The negative input terminal is connected to a resistor R25. The resistor R25 is connected to the negative output terminal of the full-bridge rectifier circuit and a resistor R3. The output terminal of the operational amplifier U2A is connected to the B terminal of the NAND gate U4.

7. The non-polarity charging circuit as described in claim 6, characterized in that: The resistor R25 is also connected to capacitors C2 and C12 respectively, and the other ends of capacitors C2 and C12 are grounded.

8. The non-polarity charging circuit as described in claim 1, characterized in that: The temperature monitoring circuit includes a temperature sensor RT1, which is connected to the P3.0 pin of the microcontroller U1 through a resistor R22. The two ends of the resistor R22 are grounded through a capacitor C9 and a resistor R23, respectively.

Images