High-voltage isolation detection circuit

Abstract

The utility model discloses a high-voltage isolation detection circuit, which is characterized by further comprising an isolation circuit respectively connected with a voltage division circuit and an operational amplifier circuit, the isolation circuit comprises an isolation amplifier U1 and a capacitor C7 connected with the voltage division circuit and a pin 3 on the isolation amplifier U1, one end of the capacitor C4 is connected with a pin 1 on the isolation amplifier U1, and the other end of the capacitor C4 is grounded; the high-voltage isolation detection circuit provided by the utility model can detect kilovolt voltage, isolates high voltage from low voltage through the arrangement of the isolation circuit, protects electronic components of a low-voltage part from being broken down by the high voltage to cause damage, has the characteristics of high-voltage resistance and small damage to electronic components, and meanwhile, the isolation circuit also detects VINP (Voltage Inertial Inertia Potential). And through the isolation amplifier U1, the whole isolation circuit can be amplified by K times, so that the sampled voltage V1 is changed into K * V1, and the overall detection sensitivity and the high-voltage detection timeliness of the circuit can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy vehicles, in particular to a high-voltage isolation detection circuit. Background Art

[0002] At present, in the field of new energy vehicles, in order to comply with safety regulations and strengthen the protection of electronic equipment, more and more electronic equipment needs to add high-voltage isolation detection circuits. In the existing high-voltage detection circuit, there is no isolation circuit. The low-voltage circuit components are easily broken down by the high voltage, resulting in electronic component loss and affecting the normal operation of the vehicle. Therefore, a high-voltage isolation detection circuit is proposed. Utility Model Content

[0003] The main purpose of the present invention is to provide a method for effectively solving the problems in the background technology.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a high-voltage isolation detection circuit, including a voltage divider circuit, an operational amplifier circuit connected to the voltage divider circuit; characterized in that: it also includes an isolation circuit connected to the voltage divider circuit and the operational amplifier circuit respectively, the isolation circuit includes an isolation amplifier U1, a capacitor C7 connected to the voltage divider circuit and connected to pin 3 on the isolation amplifier U1, a capacitor C4 with one end connected to pin 1 on the isolation amplifier U1 and the other end connected to ground, a 5V power supply terminal connected to capacitor C4, a 3.3V power supply terminal connected to pin 8 of the isolation amplifier U1, and a 3.3V power supply terminal connected to the 3.3V power supply terminal. The other end of the source end is connected to the capacitor C1, the capacitor C5 is connected to the capacitor C1 and one end is grounded, the resistor R9 is connected to the 6th pin of the isolation amplifier U1, the capacitor C8 is connected to the other end of the resistor R9, and the resistor R7 is connected to the 7th pin of the isolation amplifier U1; the capacitor C5 is connected to the other end of the resistor R7, the 3rd pin, the 4th pin and the 5th pin of the isolation amplifier U1 are grounded, the 7th pin of the isolation amplifier U1 is also connected to the operational amplifier circuit through the resistor R7, the 6th pin of the isolation amplifier U1 is also connected to the operational amplifier circuit through the resistor R9, and the 2nd pin of the isolation amplifier U1 is also connected to the voltage divider circuit.

[0005] Preferably, the voltage divider circuit includes resistors R1, R2, and R3 connected in series with the high voltage input end, a resistor R4 connected to the other end of the resistor R3, and a resistor R5 connected to the other end of the resistor R4 and grounded at the other end, and the resistor R4 is connected to the isolation circuit.

[0006] Preferably, the operational amplifier circuit includes a resistor R6, a capacitor C2, a capacitor C6 and an operational amplifier U2 connected to the isolation circuit, and the other end of the resistor R6 and the other end of the capacitor C2 are connected to the ground. The operational amplifier circuit also includes a capacitor C6, a capacitor C9, a resistor R11 and an operational amplifier U2 connected to the isolation circuit, a 3.3V power supply terminal connected to pin 5 of the operational amplifier U2 and a capacitor C3 whose other end is connected to the ground, pin 2 of the operational amplifier U2 is grounded, a capacitor C9 and a resistor R11 connected to pins 1 and 4 of the operational amplifier U2, a resistor R10 and a resistor R8 connected to pin 1 of the operational amplifier U2, and the other end of the resistor R10 is grounded.

[0007] The utility model has the following beneficial effects: the circuit is a high-voltage isolation detection circuit that can detect voltages of thousands of volts. Through the setting of the isolation circuit 2, the high voltage is isolated from the low voltage, protecting the electronic components of the low voltage part from being broken down by the high voltage and causing damage. The utility model has the characteristics of high-voltage resistance and small damage to electronic devices. At the same time, the isolation circuit 2 also detects VINP in the isolation amplifier U1, and then through the isolation amplifier U1, the isolation circuit 2 as a whole can be amplified by K times, so that the sampled voltage V1 becomes K*V1, thereby improving the overall detection sensitivity and the timeliness of the high-voltage detection of the circuit.

[0008] By setting the voltage divider circuit 1, the high voltage of the input voltage divider circuit is divided, thereby protecting electronic components and circuits from damage by high voltage;

[0009] Through the setting of the operational amplifier circuit, the isolation circuit is amplified rail-to-rail, the non-inverting analog output is connected to the non-inverting input of the operational amplifier U2, and the inverting analog output is connected to the inverting input of the operational amplifier U2. After passing through the operational amplifier U2, it is amplified K times again and the amplified voltage is sent to the MCU, so that the amplified voltage can meet the use of the MCU. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a circuit principle block diagram of the utility model;

[0011] Figure 2 It is a circuit diagram of the voltage divider circuit of the utility model;

[0012] Figure 3 It is a circuit diagram of the isolation circuit of the utility model;

[0013] Figure 4 It is a circuit diagram of the operational amplifier circuit of the utility model.

[0014] Legend: 1. Voltage divider circuit; 2. Isolation circuit; 3. Operational amplifier circuit. DETAILED DESCRIPTION

[0015] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0016] like Figure 1-4 As shown, a high-voltage isolation detection circuit includes a voltage divider circuit 1 and an operational amplifier circuit 3 connected to the voltage divider circuit; characterized in that: it also includes an isolation circuit 2 connected to the voltage divider circuit 1 and the operational amplifier circuit 3 respectively, the isolation circuit 2 includes an isolation amplifier U1, a capacitor C7 connected to the voltage divider circuit 1 and connected to pin 3 of the isolation amplifier U1, a capacitor C4 with one end connected to pin 1 of the isolation amplifier U1 and the other end connected to ground, a 5V power supply terminal connected to capacitor C4, a 3.3V power supply terminal connected to pin 8 of the isolation amplifier U1, a capacitor C1 connected to the other end of the 3.3V power supply terminal, a capacitor C5 connected to capacitor C1 and one end of which is grounded, a resistor R9 connected to pin 6 of the isolation amplifier U1, a capacitor C8 connected to the other end of the resistor R9, a resistor R7 connected to pin 7 of the isolation amplifier U1; a capacitor C5 connected to the other end of the resistor R7, pins 3 and 4 of the isolation amplifier U1. Pin 1 and pin 5 are grounded, pin 7 of the isolation amplifier U1 is also connected to the operational amplifier circuit 3 through a resistor R7, pin 6 of the isolation amplifier U1 is also connected to the operational amplifier circuit 3 through a resistor R9, pin 7 of the isolation amplifier U1 is also connected to the operational amplifier circuit 3 through a resistor R7, and pin 2 of the isolation amplifier U1 is also connected to the voltage divider circuit 1; this circuit is a high-voltage isolation detection circuit that can detect voltages of thousands of volts. Through the setting of the isolation circuit 2, the high voltage is isolated from the low voltage, protecting the electronic components of the low voltage part from being broken down by the high voltage and causing damage. It has the characteristics of high voltage resistance and small damage to electronic devices. At the same time, the isolation circuit 2 also detects VINP in the isolation amplifier U1, and then through the isolation amplifier U1, the entire isolation circuit 2 can reach K times amplification, so that the sampled voltage V1 becomes K*V1, which improves the overall detection sensitivity and the timeliness of the high-voltage detection of the circuit.

[0017] In one embodiment, the voltage divider circuit 1 includes resistors R1, R2, and R3 connected in series with the high-voltage input end, a resistor R4 connected to the other end of the resistor R3, and a resistor R5 connected to the other end of the resistor R4 and grounded at the other end. The resistor R4 is connected to the isolation circuit 2. Through the setting of the voltage divider circuit 1, the high voltage of the input voltage divider circuit is divided, thereby protecting electronic components and circuits from damage by high voltage.

[0018] In one embodiment, the operational amplifier circuit 3 includes a resistor R6, a capacitor C2, a capacitor C6 and an operational amplifier U2 connected to the isolation circuit 2, and the other end of the resistor R6 and the other end of the capacitor C2 are connected to the ground. The operational amplifier circuit 3 also includes a capacitor C6, a capacitor C9, a resistor R11 and an operational amplifier U2 connected to the isolation circuit 2, a 3.3V power supply terminal connected to pin 5 of the operational amplifier U2 and a capacitor C3 with the other end connected to the ground, pin 2 of the operational amplifier U2 is grounded, a capacitor C9 and a resistor R11 connected to pins 1 and 4 of the operational amplifier U2, a resistor R10 and a resistor R8 connected to pin 1 of the operational amplifier U2, and the other end of the resistor R10 is grounded; through the setting of the operational amplifier circuit 3, the isolation circuit 2 is rail-to-rail amplified, the non-inverting analog output is connected to the in-phase input of the operational amplifier U2, the inverting analog output is connected to the inverting input of the operational amplifier U2, and after passing through the operational amplifier U2, it is amplified again by K times, and the amplified voltage is sent to the MCU so that the amplified voltage meets the use of the MCU.

[0019] The working principle of the present invention is as follows: the voltage divider circuit 1 is connected to the isolation circuit 2, the high voltage is first divided, and the voltage division value is sent to the non-inverting analog input of the isolation amplifier U1, and the inverting analog input is connected to the high voltage ground. After the isolation amplifier U1 detects the voltage, it amplifies the voltage by K times. The isolation circuit 2 is connected to the operational amplifier circuit 3, and after the operational amplifier U2 detects the voltage sent by the isolation circuit 2, it is connected rail-to-rail with the isolation circuit 2, and then the voltage is amplified again and the amplified voltage is sent to the MCU to achieve the purpose of isolation and high voltage collection.

[0020] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements are intended to fall within the scope of the present invention. The scope of protection claimed in this invention is defined by the appended claims and their equivalents.

Claims

1. A high-voltage isolation detection circuit, comprising a voltage divider circuit (1) and an operational amplifier circuit (3) connected to the voltage divider circuit; characterized in that: It also includes an isolation circuit (2) connected to the voltage divider circuit (1) and the operational amplifier circuit (3), respectively, wherein the isolation circuit (2) includes an isolation amplifier U1, a capacitor C7 connected to the voltage divider circuit (1) and connected to pin 3 of the isolation amplifier U1, a capacitor C4 connected at one end to pin 1 of the isolation amplifier U1 and at the other end to ground, a 5V power supply terminal connected to the capacitor C4, a 3.3V power supply terminal connected to pin 8 of the isolation amplifier U1, a capacitor C1 connected to the other end of the 3.3V power supply terminal, a capacitor C5 connected to the capacitor C1 and at one end to ground, a resistor R9 connected to pin 6 of the isolation amplifier U1, a capacitor C8 connected to the other end of the resistor R9, and a resistor R7 connected to pin 7 of the isolation amplifier U1; The capacitor C5 is connected to the other end of the resistor R7, the 3rd, 4th and 5th pins of the isolation amplifier U1 are grounded, the 7th pin of the isolation amplifier U1 is also connected to the operational amplifier circuit (3) through the resistor R7, the 6th pin of the isolation amplifier U1 is also connected to the operational amplifier circuit (3) through the resistor R9, the 7th pin of the isolation amplifier U1 is also connected to the operational amplifier circuit (3) through the resistor R7, and the 2nd pin of the isolation amplifier U1 is also connected to the voltage divider circuit (1).

2. A high-voltage isolation detection circuit according to claim 1, characterized in that: The voltage divider circuit (1) comprises a resistor R1, a resistor R2, and a resistor R3 connected in series with the high voltage input terminal, a resistor R4 connected to the other end of the resistor R3, and a resistor R5 connected to the other end of the resistor R4 and grounded at the other end. The resistor R4 is connected to the isolation circuit (2).

3. The high-voltage isolation detection circuit according to claim 1, wherein: The operational amplifier circuit (3) includes a resistor R6, a capacitor C2, a capacitor C6 and an operational amplifier U2 connected to the isolation circuit (2), and the other end of the resistor R6 and the other end of the capacitor C2 are connected to the ground. The operational amplifier circuit (3) also includes a capacitor C6, a capacitor C9, a resistor R11 and an operational amplifier U2 connected to the isolation circuit (2), a 3.3V power supply terminal connected to pin 5 of the operational amplifier U2 and a capacitor C3 with the other end connected to the ground, pin 2 of the operational amplifier U2 is grounded, a capacitor C9 and a resistor R11 connected to pins 1 and 4 of the operational amplifier U2, a resistor R10 and a resistor R8 connected to pin 1 of the operational amplifier U2, and the other end of the resistor R10 is grounded.

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