Novel CP signal detection circuit

Abstract

A novel CP signal detection circuit disclosed by the present application comprises a sampling circuit and a control circuit which are connected with a detection object, the sampling circuit comprises a rectification module, a voltage division module and a following module, the rectification module is connected with the detection object, the rectification module is connected with the voltage division module, and the following module is connected with the voltage division module. The following module is connected with the control circuit, the following module comprises an operational amplifier and a first clamping diode, an output pin of the first clamping diode is connected with an in-phase input pin of the operational amplifier, an inverted input pin of the operational amplifier is connected with an output pin of the operational amplifier, and an output pin of the operational amplifier is connected with the output pin of the first clamping diode. And an output pin of the operational amplifier is connected with the control circuit. The voltage dividing module is arranged in front of the following module, and the voltage state of the obtained CP signal is segmented, so that the control circuit can distinguish the work more accurately. And the following module is provided with a clamping diode at an input pin of an operational amplifier, so that the control circuit is prevented from being damaged.

Description

Technical Field

[0001] This application generally relates to the technical field of automotive charging control circuits. Specifically, it relates to a CP signal detection circuit applied to charging piles. Background Art

[0002] With the rapid development of the electric vehicle industry, charging piles, as key supporting facilities for electric vehicles, are in increasing demand. The safe and efficient operation of charging piles is crucial for the popularization and promotion of electric vehicles. The CP detection circuit is mainly used to detect the connection status, charging requirements, and communication handshakes between the charging pile and the electric vehicle. Accurate CP detection can ensure a stable and reliable connection between the charging pile and the electric vehicle, enabling an orderly charging process. Most of the existing CP signal detection schemes collect the amplitude of the CP voltage through the ADC of the MCU, mainly suffering from low accuracy in CP sampling and damage to the control circuit when the output of the sampling circuit is too large. Summary of the Invention

[0003] A main objective of this application is to provide a CP signal detection circuit. By setting a voltage division module before the follower module, the voltage state of the obtained CP signal is segmented, which is beneficial for the control circuit to distinguish the operation more accurately in the later stage. And the follower module sets a clamping diode at the input pin of the operational amplifier to limit the input voltage of the control circuit and protect the control circuit from being damaged. Thus, at least to a certain extent, it overcomes one or more problems caused by the limitations and defects of the related technologies.

[0004] To achieve the above application objective, this application adopts the following technical solutions:

[0005] According to one aspect of this application, a novel CP signal detection circuit is provided, including a sampling circuit and a control circuit connected to the detection object. The sampling circuit includes a rectification module, a voltage division module, and a follower module. The rectification module is connected to the detection object, the rectification module is connected to the voltage division module, the follower module is connected to the control circuit. The follower module includes an operational amplifier and a first clamping diode. The output pin of the first clamping diode is connected to the non-inverting input pin of the operational amplifier. The inverting input pin of the operational amplifier is connected to the output pin of the operational amplifier. The output pin of the operational amplifier is connected to the control circuit.

[0006] According to an embodiment of this application, the voltage division module includes a first resistor and a second resistor. One end of the first resistor is connected to the rectification module, the other end of the first resistor is connected to one end of the second resistor and the non-inverting input pin of the operational amplifier, and the other end of the second resistor is grounded.

[0007] According to an embodiment of the present application, the resistance value of the first resistor is 10K ohms, and the resistance value of the second resistor is 3.3K ohms.

[0008] According to an embodiment of the present application, the following module further includes a second clamping diode, and the output pins of the second clamping diode are respectively connected to the output pin of the operational amplifier and the ADC port of the control circuit.

[0009] According to an embodiment of the present application, one input pin of the second clamping diode is connected to an input voltage of 3.3V, and the other input pin of the second clamping diode is grounded.

[0010] According to an embodiment of the present application, one input pin of the first diode is connected to an input voltage of 3.3V or 5V, and the other input pin of the second clamping diode is grounded.

[0011] According to an embodiment of the present application, the rectification module includes a rectifying diode, a third resistor, and a first capacitor. The anode of the rectifying diode is connected to the detection object, the cathode of the rectifying diode is connected to one end of the third resistor, the other end of the third resistor and one end of the first capacitor are connected to the voltage dividing module, and the other end of the first capacitor is grounded.

[0012] According to an embodiment of the present application, the application object is an AC charging pile.

[0013] In the present application, by setting a voltage dividing module before the following module, the voltage state of the obtained CP signal is segmented. In the later stage, the control circuit can calculate the digital quantity range of different voltages according to the conversion ratio of the voltage dividing circuit, which is beneficial for the control circuit to distinguish the work more accurately. And the following module sets a clamping diode at the input pin of the operational amplifier to limit the input voltage of the control circuit and protect the control circuit from being damaged.

[0014] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. Description of the Drawings

[0015] By referring to the drawings and describing its exemplary embodiments in detail, the above and other features and advantages of the present application will become more obvious.

[0016] Figure 1 is a schematic diagram of a CP signal detection circuit shown according to an exemplary embodiment;

[0017] Figure 2 is a circuit diagram of a sampling circuit shown according to an exemplary embodiment. Detailed Embodiments

[0018] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. Like reference numerals in the figures denote like or similar structures, and thus their detailed description will be omitted.

[0019] Referring to Figure 1 and Figure 2 , in one embodiment, the CP signal detection circuit includes a sampling circuit 1 connected to a detection object 3 and a control circuit 2. The sampling circuit 1 includes a rectification module 11, a voltage division module 12, and a follower module 13. The rectification module 11 is connected to the detection object 3, the rectification module 11 is connected to the voltage division module 12, and the follower module 13 is connected to the control circuit 2. The follower module 13 includes an operational amplifier U1B and a first clamping diode D9. The output pin of the first clamping diode D9 is connected to the non-inverting input pin 5 of the operational amplifier U1B. The inverting input pin 6 of the operational amplifier U1B is connected to the output pin 7 of the operational amplifier U1B. The output pin 7 of the operational amplifier U1B is connected to the control circuit 2. This CP signal detection circuit is mainly applied in new energy vehicles. When applied, the detection object can be a charging pile.

[0020] Referring to Figure 2 , in one embodiment, the rectification module 11 includes a rectification diode D17, a third resistor R41, and a first capacitor C37. The anode of the rectification diode D17 is connected to the detection object 3. The cathode of the rectification diode D17 is connected to one end of the third resistor R41. The other end of the third resistor R41 and one end of the first capacitor C37 are connected to the voltage division module 12. The other end of the first capacitor C37 is grounded. The input signal CP_in of the detection object is a positive and negative level with a certain frequency and duty cycle. The voltage of the positive level is 12V, and the voltage of the negative level is -12V. After being rectified by the rectification diode D17, the signal at the input end of the third resistor R41 is a positive level signal with the same frequency as CP_in. The first capacitor C37 is a filter capacitor and can also help improve the sampling accuracy.

[0021] Referring to Figure 2 , in one embodiment, the voltage division module 12 includes a first resistor R23 and a second resistor R24. One end of the first resistor R23 is connected to the output end of the third resistor R41. The other end of the first resistor R23 is connected to one end of the second resistor R24 and the non-inverting input pin of the operational amplifier U1B. The other end of the second resistor R24 is grounded. Preferably, the resistance value of the first resistor R23 is 10K ohms, and the resistance value of the second resistor R24 is 3.3K ohms.

[0022] Referring to Figure 2, in one embodiment, the following module 13 further includes a second clamping diode D4. The output pins of the second clamping diode D4 are respectively connected to the output pin of the operational amplifier U1B and the ADC port of the control circuit 2. Preferably, one input pin of the second clamping diode D4 is connected to the input voltage of 3.3V, and the other input pin of the second clamping diode is grounded. Further preferably, one input pin of the first diode D9 is connected to the input voltage of 3.3V or 5V, and the other input pin of the first clamping diode D4 is grounded.

[0023] The above are only the preferred embodiments of the application embodiments, and are not used to limit the application embodiments. For those skilled in the art, the application embodiments can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application embodiments shall be included in the protection scope of the application embodiments.

Claims

1. A novel CP signal detection circuit, characterized in that: It includes a sampling circuit and a control circuit connected to a detection object, the sampling circuit includes a rectifier module, a voltage divider module and a follower module, the rectifier module is connected to the detection object, the rectifier module is connected to the voltage divider module, the follower module is connected to the control circuit, the follower module includes an operational amplifier and a first clamping diode, the output pin of the first clamping diode is connected to the in-phase input pin of the operational amplifier, the inverting input pin of the operational amplifier is connected to the output pin of the operational amplifier, and the output pin of the operational amplifier is connected to the control circuit.

2. The CP signal detection circuit according to claim 1, characterized in that: The voltage divider module includes a first resistor and a second resistor, one end of the first resistor is connected to the rectifier module, the other end of the first resistor is connected to one end of the second resistor and the in-phase input pin of the operational amplifier, and the other end of the second resistor is grounded.

3. The CP signal detection circuit according to claim 2, characterized in that: The resistance value of the first resistor is 10K ohms, and the resistance value of the second resistor is 3.3K ohms.

4. The CP signal detection circuit according to claim 1, characterized in that: The follower module further includes a second clamping diode, and an output pin of the second clamping diode is respectively connected to an output pin of the operational amplifier and an ADC port of the control circuit.

5. The CP signal detection circuit according to claim 4, characterized in that: One input pin of the second clamping diode is connected to an input voltage of 3.3V, and the other input pin of the second clamping diode is grounded.

6. The CP signal detection circuit according to claim 1, characterized in that: One input pin of the first clamping diode is connected to an input voltage of 3.3V or 5V, and the other input pin of the second clamping diode is grounded.

7. The CP signal detection circuit according to claim 1, characterized in that: The rectifier module includes a rectifier diode, a third resistor and a first capacitor. The anode of the rectifier diode is connected to the detection object, the cathode of the rectifier diode is connected to one end of the third resistor, the other end of the third resistor and one end of the first capacitor are connected to the voltage divider module, and the other end of the first capacitor is grounded.

8. The CP signal detection circuit according to claim 1, characterized in that: The detection object is a charging pile.

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