Low-cost charging system CC1 detection circuit

Abstract

The utility model provides the charging system CC1 detection circuit with low cost. The CC1 detection circuit comprises an operational amplifier, a photoelectric coupler, a first adjusting resistor and a second adjusting resistor, the in-phase input end of the operational amplifier is connected with a signal end, and one end of the first adjusting resistor and one end of the second adjusting resistor are both connected to the inverted input end of the operational amplifier. The other end of the first adjusting resistor is grounded, the other end of the second adjusting resistor and a positive power supply terminal of the operational amplifier are connected to a positive electrode of a power supply, an output end of the operational amplifier is connected with a cathode of the photoelectric coupler, one path of a collector electrode of the photoelectric coupler is connected with positive power supply voltage through a fourth resistor, and the other path of the collector electrode is connected with negative power supply voltage through a fifth resistor. And the other path is connected to the MCU, and the emitter of the photoelectric coupler is grounded. The utility model relates to the technical field of charging pile detection.

Description

Technical Field

[0001] This utility model relates to the field of charging pile testing technology, and in particular to a low-cost charging system CC1 testing circuit. Background Technology

[0002] As the popularity of new energy vehicles increases, so too does the number of car charging stations. When using a charging station, it's crucial to check that the charging gun is properly connected to the car's charging port. An improper connection not only prevents the car from charging but can also damage it and potentially cause a fire or other safety hazard.

[0003] Currently, the detection circuits used for connecting charging guns to vehicles are complex and costly. Therefore, it is essential to develop a low-cost CC1 detection circuit for charging systems. Utility Model Content

[0004] To address the problems existing in the prior art, this utility model proposes a low-cost CC1 detection circuit for a charging system. The aim is to solve the problems of complex and costly CC1 detection circuits.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is: a low-cost charging system CC1 detection circuit, the CC1 detection circuit including an operational amplifier, an optocoupler, a first regulating resistor, and a second regulating resistor. The non-inverting input terminal of the operational amplifier is connected to the signal terminal. One end of the first regulating resistor and one end of the second regulating resistor are both connected to the inverting input terminal of the operational amplifier. The other end of the first regulating resistor is grounded. The other end of the second regulating resistor and the positive power supply terminal of the operational amplifier are both connected to the positive power supply terminal. The output terminal of the operational amplifier is connected to the cathode of the optocoupler. One path of the collector of the optocoupler is connected to the positive power supply voltage through a fourth resistor, and the other path is connected to the MCU. The emitter of the optocoupler is grounded.

[0006] Based on the above, using the operational amplifier as a comparator, when the voltage at the non-inverting input terminal of the operational amplifier is lower than the voltage at the inverting input terminal, the output terminal of the operational amplifier outputs a low level. The output signal is optically isolated by the optocoupler and transmitted to the MCU for detection. At this time, the detected voltage is at a low level. When the voltage at the non-inverting input terminal of the operational amplifier is higher than the voltage at the inverting input terminal, the output terminal of the operational amplifier outputs a high level. The optocoupler is not conducting, and the optocoupler output is pulled up to a high level by the fourth resistor and transmitted to the MCU for detection. At this time, the detected voltage is at a high level. The circuit structure of this utility model is simple, using only one operational amplifier as a comparator to determine whether the voltage of CC1 is within the set value, thus reducing manufacturing costs. Furthermore, by adjusting the resistance ratio of the first and second regulating resistors, the threshold value of the operational amplifier can be changed to achieve measurements with different requirements.

[0007] Furthermore, the CC1 detection circuit also includes a first resistor, a second resistor, a third resistor, a capacitor, and a light-emitting diode. One end of the first resistor and one end of the capacitor are both connected to the non-inverting input of the operational amplifier. The other end of the first resistor is connected to the positive terminal of the power supply, and the other end of the capacitor is grounded. The second resistor is connected to the anode of the light-emitting diode, the cathode of the light-emitting diode is connected to the output terminal of the operational amplifier, and the third resistor is connected to the anode of the optocoupler.

[0008] Based on the above, the first, second, and third resistors in the circuit can improve impedance matching, reduce signal reflection, and prevent signal oscillation. When the operational amplifier outputs a low level, the LED lights up; when the operational amplifier outputs a high level, the LED does not light up. This allows for a direct visual indication of whether the charging gun is properly connected to the tram.

[0009] To more clearly illustrate the above-mentioned features of this utility model and the objectives it aims to achieve, the present utility model will be further described below in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0010] Figure 1 This is the circuit schematic diagram of this utility model. Detailed Implementation

[0011] like Figure 1As shown, the CC1 detection circuit includes an operational amplifier U1, an optocoupler TF1, a first regulating resistor Rg, and a second regulating resistor Rf. The non-inverting input terminal of the operational amplifier U1 is connected to the signal terminal. One end of the first regulating resistor Rg and one end of the second regulating resistor Rf are both connected to the inverting input terminal of the operational amplifier U1. The other end of the first regulating resistor Rg is grounded. The other end of the second regulating resistor Rf and the positive power supply terminal of the operational amplifier U1 are both connected to the positive power supply. The output terminal of the operational amplifier U1 is connected to the cathode of the optocoupler TF1. One path of the collector of the optocoupler TF1 is connected to the positive power supply voltage through the fourth electrical group R4, and the other path is connected to the MCU. The emitter of the optocoupler TF1 is grounded.

[0012] The CC1 detection circuit also includes a first resistor R1, a second resistor R2, a third resistor, a capacitor C1, and a light-emitting diode LED1. One end of the first resistor R1 and one end of the capacitor C1 are both connected to the non-inverting input of the operational amplifier U1. The other end of the first resistor R1 is connected to the positive terminal of the power supply, and the other end of the capacitor C1 is grounded. The second resistor R2 is connected to the anode of the light-emitting diode LED1, and the cathode of the light-emitting diode LED1 is connected to the output terminal of the operational amplifier U1. The third resistor is connected to the anode of the optocoupler TF1.

[0013] The CC1 voltage of the national standard charging gun has three states: The first state is when the national standard charging gun is in the charging gun socket, the CC1 voltage is approximately 6V; the second state is when the national standard charging gun is lifted, the CC1 voltage is approximately 12V; and the third state is when the national standard charging gun is plugged in, the CC1 voltage is approximately 4V. By adjusting the ratio of the first adjustment resistor to the second adjustment resistor to 5:3, the voltage at the inverting input terminal of the operational amplifier U1 is made 4.5V; when CC1 is below 4.5V, the system determines that the national standard charging gun connection is complete.

[0014] The specific implementation of this embodiment is as follows: Using operational amplifier U1 as a comparator, when the voltage at the non-inverting input terminal of operational amplifier U1 is lower than the voltage at the inverting input terminal, the output terminal of operational amplifier U1 outputs a low level. The output signal is optically isolated through the optocoupler TF1 and transmitted to the MCU for detection. At this time, the detected voltage is at a low level. When the voltage at the non-inverting input terminal of operational amplifier U1 is higher than the voltage at the inverting input terminal, the output terminal of operational amplifier U1 outputs a high level. The optocoupler is not conducting, and the optocoupler output is pulled up to a high level by the fourth resistor R4 and transmitted to the MCU for detection. At this time, the detected voltage is at a high level.

[0015] The above description is only the optimal solution embodiment of this utility model and is not intended to limit this utility model. Various modifications or substitutions made by those skilled in the art to this utility model without departing from the essence and protection scope of this utility model should also be within the protection scope of this utility model.

Claims

1. A low-cost CC1 detection circuit for a charging system, characterized in that: The CC1 detection circuit includes an operational amplifier (U1), an optocoupler (TF1), a first regulating resistor (Rg), and a second regulating resistor (Rf). The non-inverting input of the operational amplifier (U1) is connected to the signal terminal. One end of the first regulating resistor (Rg) and one end of the second regulating resistor (Rf) are both connected to the inverting input of the operational amplifier (U1). The other end of the first regulating resistor (Rg) is grounded. The other end of the second regulating resistor (Rf) and the positive power supply terminal of the operational amplifier (U1) are both connected to the positive power supply. The output of the operational amplifier (U1) is connected to the cathode of the optocoupler (TF1). One path of the collector of the optocoupler (TF1) is connected to the positive power supply voltage through a fourth resistor (R4), and the other path is connected to the MCU. The emitter of the optocoupler (TF1) is grounded.

2. The low-cost charging system CC1 detection circuit according to claim 1, characterized in that: The CC1 detection circuit further includes a first resistor (R1), a second resistor (R2), a third resistor (R3), a capacitor (C1), and a light-emitting diode (LED1). One end of the first resistor (R1) and one end of the capacitor (C1) are both connected to the non-inverting input of the operational amplifier (U1). The other end of the first resistor (R1) is connected to the positive terminal of the power supply, and the other end of the capacitor (C1) is grounded. The second resistor (R2) is connected to the anode of the light-emitting diode (LED1), and the cathode of the light-emitting diode (LED1) is connected to the output terminal of the operational amplifier (U1). The third resistor (R3) is connected to the anode of the optocoupler (TF1).

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