A CP signal detection circuit with a negative pressure detection circuit and a vehicle charger

Abstract

The present invention discloses a CP signal detection circuit with a negative pressure detection circuit and a vehicle charger, the circuit includes: a negative pressure detection circuit for processing a CP signal and a single chip microcomputer for judging whether a power supply device is faulty according to a signal processed by the negative pressure detection circuit, the negative pressure detection circuit specifically includes: a first resistor, a second resistor, and a first capacitor; the first end of the first resistor is connected to the CP signal receiving end of the vehicle charger, the second end of the first resistor is connected to the first end of the second resistor, the first end of the first capacitor and the first AD detection function pin of the single chip microcomputer, the second end of the second resistor is connected to the first power supply, and the second end of the first capacitor is grounded. Since the negative pressure detection circuit can process the ‑12V level signal in the CP signal, and the single chip microcomputer uses this as a basis to judge whether the power supply device is faulty, it can overcome the problem that the power supply device fault information cannot be detected in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle charging equipment, and in particular to a CP signal detection circuit with a negative pressure detection circuit and a vehicle charger. Background Art

[0002] With the development of science and technology, electric vehicles have received more and more attention in industrial production and daily life, especially pure electric vehicles or plug-in hybrid electric vehicles that need to be equipped with power batteries.

[0003] The power batteries of these electric vehicles need to be charged through an on-board charger. According to national standards, the on-board charger needs to receive CC and CP signals sent by the power supply equipment. Figure 1 This is a schematic diagram of connecting the power supply device to the vehicle charger, such as Figure 1 As shown in the figure, the CP signal is a charging handshake signal that shows different performances at different times, and can be divided into +12V level signal, -12V level signal, ±9V PWM signal and ±6V PWM signal. Figure 1 As shown, firstly, the +12V level signal of the CP signal is detected to determine whether the vehicle charger is connected to the power supply device. If the vehicle charger is connected to the power supply device, then the PWM signal of the CP signal is detected to determine whether the power supply device has a fault. If the power supply device has no fault and the power supply interface is fully connected to the vehicle charger, the control is as follows: Figure 1 The analog switch S2 shown is closed, so that the on-board charger system and the power supply equipment are in normal working state. Finally, during the charging process, the PWM signal duty cycle state is also monitored in real time. Once the PWM signal is abnormal, the charging is stopped within 3 seconds and the analog switch S2 is disconnected. Therefore, the reliability of the CP signal detection circuit will determine the safety of the entire system.

[0004] The CP detection circuit in the prior art does not detect the -12V level signal of the CP signal, and cannot detect the fault information of the power supply device. Summary of the invention

[0005] The object of the present invention is to provide a CP signal detection circuit with a negative pressure detection circuit and a vehicle charger, so as to achieve the purpose of detecting whether a power supply device is faulty and monitoring a PWM signal in real time.

[0006] In order to achieve the above-mentioned object, the present invention provides a CP signal detection circuit with a negative pressure detection circuit, comprising: a negative pressure detection circuit for processing a CP signal and a single chip computer for judging whether a power supply device is faulty according to the signal processed by the negative pressure detection circuit, wherein the negative pressure detection circuit specifically comprises: a first resistor, a second resistor, and a first capacitor;

[0007] The first end of the first resistor is connected to the CP signal receiving end of the vehicle charger, the second end of the first resistor is connected to the first end of the second resistor, the first end of the first capacitor and the first AD detection function pin of the single-chip microcomputer, the second end of the second resistor is connected to the first power supply, and the second end of the first capacitor is grounded.

[0008] Preferably, it also includes: an absorption filter circuit for absorbing instantaneous pulses and / or clutter signals generated when the CP signal is turned on or off, and the absorption filter circuit specifically includes: a TVS tube, a second capacitor and an inductor;

[0009] The first end of the TVS tube, the first end of the second capacitor and the first end of the inductor are connected to the CP signal receiving end, the second end of the TVS tube and the second end of the second capacitor are grounded respectively, and the second end of the inductor is connected to the first end of the first resistor.

[0010] Preferably, it further comprises: a first diode for isolating the CP signal in a non-negative voltage state;

[0011] A cathode of the first diode is connected to the second end of the inductor, and an anode of the first diode is connected to the first end of the first resistor.

[0012] Preferably, it also includes: a voltage stabilizing diode;

[0013] An anode of the voltage-stabilizing diode is connected to an anode of the first diode, and a cathode of the voltage-stabilizing diode is connected to a first end of the first resistor.

[0014] Preferably, it also includes: a positive pressure detection circuit for detecting whether the charging interface of the vehicle charger is connected to the charging socket of the power supply device, and the positive pressure detection circuit specifically includes: a second diode, a third resistor, a fourth resistor and a third capacitor;

[0015] The anode of the second diode is connected to the second end of the inductor, the cathode of the second diode is connected to the first end of the third resistor, the second end of the third resistor is connected to the first end of the fourth resistor, the first end of the third capacitor and the second AD detection function pin of the microcontroller, and the second end of the fourth resistor and the second end of the third capacitor are grounded respectively.

[0016] Preferably, it also includes: a national standard resistance detection circuit and a voltage supply circuit; wherein the national standard resistance detection circuit is used to detect whether the pull-down resistor of the charging socket meets the national standard resistance value, and the voltage supply circuit is used to provide a detection voltage for the national standard resistance detection circuit;

[0017] The voltage supply circuit specifically includes: a first triode, a second triode, a fifth resistor, a third diode and a second power supply;

[0018] The base of the first transistor is connected to the first control signal output terminal of the single chip microcomputer, the emitter of the first transistor is grounded, the collector of the first transistor is connected to the base of the second transistor, the emitter of the second transistor is connected to the second power supply, the collector of the second transistor is connected to the first end of the fifth resistor, the second end of the fifth resistor is connected to the anode of the third diode, and the cathode of the third diode is connected to the second end of the inductor;

[0019] The national standard resistance detection circuit specifically includes: a third triode, a sixth resistor, a seventh resistor, and a fourth capacitor;

[0020] The base of the third transistor is connected to the second control signal output terminal of the single-chip microcomputer, the emitter of the third transistor is grounded, the collector of the third transistor is connected to the first end of the sixth resistor, the second end of the sixth resistor is connected to the first end of the third resistor, the first end of the seventh resistor, the first end of the fourth capacitor and the cathode of the second diode, and the second end of the seventh resistor and the second end of the fourth capacitor are grounded respectively.

[0021] Preferably, it further comprises: a switch circuit for simulating a switch function, the switch circuit specifically comprising: a fourth transistor and an eighth resistor;

[0022] The base of the fourth transistor is connected to the third control signal output terminal of the single-chip microcomputer, the emitter of the fourth transistor is grounded, the collector of the fourth transistor is connected to the first end of the eighth resistor, and the second end of the eighth resistor is connected to the first end of the third resistor and the cathode of the second diode.

[0023] Preferably, it also includes: a PWM signal detection circuit for determining whether the vehicle charger is fully connected to the power supply device and the PWM signal duty cycle state, and the PWM signal detection circuit specifically includes: a fifth capacitor, a ninth resistor, a tenth resistor, an eleventh resistor, a first MOS tube, a second MOS tube, and a third power supply;

[0024] The first end of the fifth capacitor and the first end of the ninth resistor are connected to the PWM signal capture pin of the single-chip computer, the second end of the fifth capacitor is grounded, the second end of the ninth resistor is connected to the drain of the first MOS tube and the drain of the second MOS tube, the source of the second MOS tube is grounded, the source of the first MOS tube is connected to the first end of the tenth resistor, the second end of the tenth resistor is connected to the third power supply, the gate of the first MOS tube and the gate of the second MOS tube are connected to the first end of the eleventh resistor, and the second end of the eleventh resistor is connected to the first end of the third resistor and the cathode of the second diode.

[0025] To achieve the above object, the present invention further provides a vehicle charger, including a vehicle charger body, and also including the above CP signal detection circuit with negative pressure detection circuit.

[0026] A CP signal detection circuit with a negative pressure detection circuit provided by the present invention includes: a negative pressure detection circuit and a single-chip microcomputer, wherein the negative pressure detection circuit specifically includes: a first resistor, a second resistor, a first capacitor, and a first power supply; the specific connection method is that the CP signal receiving end of the vehicle charger is connected to the first end of the first resistor, the second end of the first resistor is connected to the first end of the second resistor, the first end of the first capacitor and the first AD detection function pin of the single-chip microcomputer, the second end of the second resistor is connected to the first power supply, and the second end of the first capacitor is grounded. Among them, the CP signal receiving end is used to receive the CP signal, the negative pressure detection circuit is used to process the -12V level signal in the CP signal, and the single-chip microcomputer is used to determine whether the power supply equipment is faulty, and the judgment basis is the CP signal processed by the negative pressure detection circuit. Since the negative pressure detection circuit can process the -12V level signal in the CP signal, and the single-chip microcomputer uses this as a basis to determine whether the power supply equipment is faulty, it can overcome the problem that the power supply equipment fault information cannot be detected in the prior art.

[0027] The vehicle charger provided by the present invention includes a CP signal detection circuit with a negative pressure detection circuit, and therefore also has the above-mentioned beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 This is a schematic diagram of the connection between the power supply device and the vehicle charger;

[0030] Figure 2A structural diagram of a CP signal detection circuit with a negative pressure detection circuit provided by an embodiment of the present invention;

[0031] Figure 3 A CP signal detection circuit diagram with a negative pressure detection circuit is provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The core of the present invention is to provide a CP signal detection circuit with a negative pressure detection circuit and a vehicle charger, so as to achieve the purpose of detecting whether the power supply equipment is faulty and monitoring the PWM signal in real time.

[0034] In order to enable those skilled in the art to better understand the solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0035] Figure 2 A structural diagram of a CP signal detection circuit with a negative pressure detection circuit provided by an embodiment of the present invention, Figure 3 A CP signal detection circuit diagram with a negative pressure detection circuit is provided in an embodiment of the present invention. Figure 2 As shown, the CP signal detection circuit with a negative pressure detection circuit includes: a negative pressure detection circuit 10 for processing a CP signal and a single chip computer 100 for judging whether a power supply device is faulty according to the signal processed by the negative pressure detection circuit 10. The negative pressure detection circuit 10 specifically includes the following Figure 3 Shown: a first resistor R1, a second resistor R2, and a first capacitor C1;

[0036] The first end of the first resistor R1 is connected to the CP signal receiving end of the vehicle charger, the second end of the first resistor R1 is connected to the first end of the second resistor R2, the first end of the first capacitor C1 and the first AD detection function pin A of the microcontroller, the second end of the second resistor R2 is connected to the first power supply 5V power supply, and the second end of the first capacitor C1 is grounded.

[0037] It should be noted that, according to regulations, the vehicle charger needs to receive the CP signal sent by the power supply device. The CP signal behaves differently at different times. Before confirming whether the vehicle charger is connected to the power supply device, the CP signal behaves as a +12V level signal; when confirming that the vehicle charger is connected to the power supply device, the vehicle charger self-checks without faults and the battery is in a rechargeable state, the CP signal behaves as a PWM signal; when an error occurs in the self-check of the power supply device, the CP signal behaves as a -12V level signal. It should also be noted that the first power supply can be not only the 5V power supply in this embodiment, but also a power supply of other values, which is not limited by the present invention.

[0038] like Figure 2 As shown, when an error occurs in the self-test of the power supply device, the state of the CP signal is switched to a -12V level signal and sent to the CP signal receiving end of the vehicle charger. The -12V level signal received by the CP signal receiving end flows through the negative pressure detection circuit 10. The negative pressure detection circuit 10 processes the -12V level signal of the CP signal and transmits the processed signal to the first AD detection function pin A of the microcontroller 100. If the first AD detection function pin A of the microcontroller receives the processed -12V level signal of the power supply device, it means that the vehicle charger detects the fault information of the power supply device.

[0039] In this embodiment, the CP signal detection circuit with a negative pressure detection circuit includes: a negative pressure detection circuit and a single-chip microcomputer, and the negative pressure detection circuit specifically includes: a first resistor, a second resistor, a first capacitor, and a first power supply; the specific connection method is that the CP signal receiving end of the vehicle charger is connected to the first end of the first resistor, the second end of the first resistor is connected to the first end of the second resistor, the first end of the first capacitor and the first AD detection function pin of the single-chip microcomputer, the second end of the second resistor is connected to the first power supply, and the second end of the first capacitor is grounded. Among them, the CP signal receiving end is used to receive the CP signal, the negative pressure detection circuit is used to process the -12V level signal in the CP signal, and the single-chip microcomputer is used to determine whether the power supply equipment is faulty, and the judgment basis is the CP signal processed by the negative pressure detection circuit. Since the negative pressure detection circuit can process the -12V level signal in the CP signal, and the single-chip microcomputer uses this as a basis to determine whether the power supply equipment is faulty, it can overcome the problem that the power supply equipment cannot be detected in the prior art.

[0040] Based on the above embodiment, in another embodiment, it further includes: Figure 3 The absorption filter circuit 70 shown is used to absorb the instantaneous pulse and / or clutter signal generated when the CP signal is turned on or off. The absorption filter circuit 70 specifically includes: a TVS tube D1, a second capacitor C2 and an inductor L1;

[0041] The first end of the TVS tube D1, the first end of the second capacitor C2 and the first end of the inductor L1 are connected to the CP signal receiving end, the second end of the TVS tube D1 and the second end of the second capacitor C2 are grounded respectively, and the second end of the inductor L1 is connected to the first end of the first resistor R1.

[0042] When the CP signal receiving end receives the CP signal, the TVS tube D1, the second capacitor C2 and the inductor L1 are turned on to absorb the instantaneous pulse and / or noise signal generated when the CP signal is turned on or off.

[0043] The absorption filter circuit in this embodiment can absorb the instantaneous pulses and / or noise signals generated when the power supply equipment and the vehicle are connected and disconnected, thereby preventing the instantaneous pulses and / or noise signals from interfering with the negative pressure detection of the CP detection circuit.

[0044] Based on the above embodiment, in another embodiment, the following is also included: Figure 3 The first diode D2 is used to isolate the CP signal in a non-negative voltage state;

[0045] A cathode of the first diode D2 is connected to the second end of the inductor L1 , and an anode of the first diode D2 is connected to the first end of the first resistor R1 .

[0046] Since the CP signal has different manifestations, when the CP signal is not in a negative voltage state, the first diode D2 in this embodiment isolates the CP signal that is not in a negative voltage state to avoid interference with the negative voltage detection of the CP detection circuit.

[0047] Based on the above embodiment, in another embodiment, the following is also included: Figure 3 The zener diode D3 shown has an anode connected to the anode of the first diode D2, and a cathode connected to the first end of the first resistor R1.

[0048] The voltage stabilizing diode in this embodiment plays a role in stabilizing the voltage, thereby preventing the drastic change of the current from damaging the related circuit components.

[0049] Based on the above embodiment, in another embodiment, the following is also included: Figure 2 The positive pressure detection circuit 20 shown is used to detect whether the charging interface of the vehicle charger is connected to the charging socket of the power supply device. The positive pressure detection circuit 20, such as Figure 3 Specifically shown are: a second diode D4, a third resistor R3, a fourth resistor R4 and a third capacitor C3;

[0050] The anode of the second diode D4 is connected to the second end of the inductor L1, the cathode of the second diode D4 is connected to the first end of the third resistor R3, the second end of the third resistor R3 is connected to the first end of the fourth resistor R4, the first end of the third capacitor C3 and the second AD detection function pin B of the microcontroller, and the second end of the fourth resistor R4 and the second end of the third capacitor C3 are grounded respectively.

[0051] It should be noted that the second diode D4 has the same isolation function and working mode as the first diode D2, which will not be described in detail here. Figure 2 As shown, when the CP signal receiving end of the vehicle charger receives the CP signal emitted by the power supply device and expressed as a +12V level signal, the +12V level signal flows from the CP signal receiving end into the positive pressure detection circuit 20, and is processed by the positive pressure detection circuit 20 to reach the second AD detection function pin B of the single-chip microcomputer. If the processed signal received by the single-chip microcomputer is in a preset interval, it indicates that the charging interface of the vehicle charger is connected to the charging socket of the power supply device. If the processed signal received by the single-chip microcomputer is not in the preset interval, it indicates that the charging interface of the vehicle charger is not connected to the charging socket of the power supply device. This embodiment does not limit the preset interval.

[0052] The positive pressure detection circuit of this embodiment can detect whether the charging interface of the vehicle charger is connected to the charging socket of the power supply device.

[0053] Based on the above embodiment, in another embodiment, the following is also included: Figure 2 The national standard resistance detection circuit 50 and the voltage providing circuit 60 shown; wherein the national standard resistance detection circuit 50 is used to detect whether the pull-down resistor of the charging socket meets the national standard resistance, and the voltage providing circuit 60 is used to provide a detection voltage for the national standard resistance detection circuit 50;

[0054] The voltage supply circuit 60, such as Figure 3 The specific components shown are: a first transistor T1, a second transistor T2, a fifth resistor R5, a third diode D5 and a second power supply 12V power supply;

[0055] The base of the first transistor T1 is connected to the first control signal output terminal F of the single chip computer, the emitter of the first transistor T1 is grounded, the collector of the first transistor T1 is connected to the base of the second transistor T2, the emitter of the second transistor T2 is connected to the second power supply 12V power supply, the collector of the second transistor T2 is connected to the first end of the fifth resistor R5, the second end of the fifth resistor R5 is connected to the anode of the third diode D5, and the cathode of the third diode D5 is connected to the second end of the inductor L1;

[0056] National standard resistance detection circuit 50, such as Figure 3Specifically shown are: a third transistor T3, a sixth resistor R6, a seventh resistor R7, and a fourth capacitor C4;

[0057] The base of the third transistor T3 is connected to the second control signal output terminal E of the single-chip computer, the emitter of the third transistor T3 is grounded, the collector of the third transistor T3 is connected to the first end of the sixth resistor R6, the second end of the sixth resistor R6 is connected to the first end of the third resistor R3, the first end of the seventh resistor R7, the first end of the fourth capacitor C4 and the cathode of the second diode D4, the second end of the seventh resistor R7 and the second end of the fourth capacitor C4 are grounded respectively.

[0058] When the vehicle charger is connected to the power supply device, Figure 3 As shown, the single chip microcomputer makes the first control signal output terminal F output a high level and the second control signal output terminal E output a low level, the first transistor T1 and the second transistor T2 are turned on, and the second power supply 12V power supply outputs current, which flows through the fifth resistor R5 and the third diode D5 and enters the positive voltage detection circuit 20, and the seventh resistor R7 and the fifth resistor R5 form a voltage divider. When the charging socket of the power supply device has a pull-down resistor, the pull-down resistor is connected in parallel with the seventh resistor R7, the voltage received by the second AD detection function pin B of the single chip microcomputer is reduced, and the second control signal output terminal E of the single chip microcomputer outputs a low level, and the pull-down resistor is connected in parallel with the seventh resistor R7, satisfying the following conditions: Figure 1 The national standard resistance value requirements of R22 shown in the figure; when the charging socket of the power supply device has no pull-down resistor, the voltage received by the second AD detection function pin B of the single-chip microcomputer is not reduced, and the single-chip microcomputer controls the second control signal output terminal E of the single-chip microcomputer to output a high level so that the sixth resistor R6 and the seventh resistor R7 are connected in parallel to meet the following requirements: Figure 1 The national standard resistance value requirement of R22 is shown. It should be noted that the second power supply can be not only a 12V power supply, but also a power supply of other values, which is not limited by the present invention. It should be noted that the third diode D5 has the same isolation function and working mode as the first diode D2, which will not be repeated here.

[0059] The national standard resistance circuit and voltage supply circuit of this embodiment make the pull-down resistor of the charging socket of each power supply device meet the national standard resistance value, which is convenient for CP signal detection and data analysis.

[0060] Based on the above embodiment, in another embodiment, the following is also included: Figure 2 The switch circuit 40 shown is used to simulate the switch function. Figure 3 Specifically shown are: a fourth transistor T4, an eighth resistor R8;

[0061] The base of the fourth transistor T4 is connected to the third control signal output terminal D of the single chip microcomputer, the emitter of the fourth transistor T4 is grounded, the collector of the fourth transistor T4 is connected to the first end of the eighth resistor R8, and the second end of the eighth resistor R8 is connected to the first end of the third resistor R3 and the cathode of the second diode D4.

[0062] When the on-board charger self-checks and there are no faults and the battery is in a chargeable state, such as Figure 3 As shown, the single chip microcomputer controls the third control signal output terminal D to send a signal, so that the fourth transistor T4 is turned on, and R6 is pulled down to the ground, simulating Figure 1 It should be noted that the use scenario of this switch is that the car charger is connected to the power supply equipment, and the car charger self-test is completed, and the switch needs to be turned off. Figure 1 The resistor R22 with a resistance value that meets the national standard is connected to the circuit.

[0063] The switch circuit of this embodiment is controlled by a signal, has a simple structure, and is easy to implement.

[0064] Based on the above embodiment, in another embodiment, the following is also included: Figure 2 The PWM signal detection circuit 30 shown is used to determine whether the vehicle charger is fully connected to the power supply device and the PWM signal duty cycle state. The PWM signal detection circuit 30, such as Figure 3 Specifically shown are: a fifth capacitor C5, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a first MOS transistor T5, a second MOS transistor T6, and a third power supply 3.3V power supply;

[0065] A first end of the fifth capacitor C5 and a first end of the ninth resistor R9 are connected to the PWM signal capture pin C of the single-chip computer, a second end of the fifth capacitor C5 is grounded, a second end of the ninth resistor R9 is connected to the drain of the first MOS tube T5 and the drain of the second MOS tube T6, a source of the second MOS tube T6 is grounded, a source of the first MOS tube T5 is connected to a first end of the tenth resistor R10, a second end of the tenth resistor R10 is connected to a third power supply 3.3V power supply, a gate of the first MOS tube T5 and a gate of the second MOS tube T6 are connected to a first end of the eleventh resistor R11, and a second end of the eleventh resistor R11 is connected to a first end of the third resistor R3 and a cathode of the second diode D4.

[0066] When the CP signal is in the PWM signal, such as Figure 3As shown, the PWM signal is sent to the first MOS transistor T5 and the second MOS transistor T6 through the eleventh resistor R11, wherein the first MOS transistor T5 is a P channel and the second MOS transistor T6 is an N channel. When the PWM signal is high, the N channel second MOS transistor T6 is turned on, and when the PWM signal is low, the P channel first MOS transistor T5 is turned on. A PWM signal with a high level of 3.3V, a low level of 0V, and a frequency within a set range is generated at the common drain of the first MOS transistor T5 and the second MOS transistor T6. This square wave signal is filtered by the ninth resistor R9 and the fifth capacitor C5 and then sent to the PWM signal capture pin C of the single chip microcomputer. If the PWM signal received by the PWM signal capture pin C of the single chip microcomputer is within the judgment interval, it means that Figure 1 The switch S1 shown is closed, and the charging voltage of the power supply device meets the requirements. The present invention does not limit the specific voltage value of the third power supply, which may be 3.3V in this embodiment or not, and the present invention does not limit it.

[0067] It should be noted that the PWM detection circuit of the present invention also has a wake-up function. If the power supply device has a scheduled charging function, when the power supply device is connected to the vehicle charger, the CP signal sent by the power supply device is not converted to a PWM signal state, but is still in a level signal state. When the scheduled time arrives or the remote APP issues a command to wake up the vehicle charger system, the power supply device sends a wake-up signal to control the state of the CP signal to switch to a PWM signal state. It can be understood that the wake-up signal is a voltage jump signal that causes the CP signal voltage to jump from 0V to 9V, a voltage jump signal that causes the CP signal voltage to jump from -9V to 0V, a frequency change signal that causes the frequency of the CP signal to change from 0 to 1KHz, or a signal that causes the duty cycle of the PWM signal to exceed 4%.

[0068] The PWM signal detection circuit of this embodiment can determine whether the switch is closed and wake up the vehicle charger system.

[0069] It is understandable that if the CP signal detection circuit with a negative pressure detection circuit in the above embodiment is sold or used as an independent product, it can be applied in a vehicle-mounted connector. Based on such an understanding, the present invention provides a vehicle-mounted connector, including a vehicle-mounted connector body, and also including a CP signal detection circuit with a negative pressure detection circuit provided by the present invention. Since the vehicle charger provided by the present invention includes a CP signal detection circuit with a negative pressure detection circuit, the embodiment of the CP signal detection circuit with a negative pressure detection circuit refers to the description of the above embodiment, and the beneficial effects are the same as those of the above embodiment, which will not be repeated here.

[0070] The above is a detailed introduction to a CP signal detection circuit with a negative pressure detection circuit and a vehicle charger provided by the present invention. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the embodiments can refer to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can refer to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0071] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A CP signal detection circuit with a negative pressure detection circuit, characterized in that: include: A negative voltage detection circuit for processing a -12V level signal in a CP signal and a single chip computer for judging whether a power supply device is faulty according to the signal processed by the negative voltage detection circuit, wherein the negative voltage detection circuit specifically comprises: a first resistor, a second resistor, and a first capacitor; The first end of the first resistor is connected to the CP signal receiving end of the vehicle charger, the second end of the first resistor is connected to the first end of the second resistor, the first end of the first capacitor and the first AD detection function pin of the single chip computer, the second end of the second resistor is connected to the first power supply, and the second end of the first capacitor is grounded; Correspondingly, it also includes: a positive pressure detection circuit for detecting whether the charging interface of the vehicle charger is connected to the charging socket of the power supply device, and the positive pressure detection circuit specifically includes: a second diode, a third resistor, a fourth resistor and a third capacitor; Correspondingly, it also includes: a switch circuit for simulating the function of a switch, and the switch circuit specifically includes: a fourth triode and an eighth resistor; The base of the fourth transistor is connected to the third control signal output terminal of the single chip microcomputer, the emitter of the fourth transistor is grounded, the collector of the fourth transistor is connected to the first end of the eighth resistor, and the second end of the eighth resistor is connected to the first end of the third resistor and the cathode of the second diode; Correspondingly, it also includes: a first diode for isolating the CP signal in a non-negative voltage state; A cathode of the first diode is connected to the second end of the inductor, and an anode of the first diode is connected to the first end of the first resistor.

2. The CP signal detection circuit with a negative pressure detection circuit as claimed in claim 1, characterized in that: Also includes: The absorption filter circuit is used to absorb the instantaneous pulse and / or clutter signal generated when the CP signal is turned on or off, and the absorption filter circuit specifically includes: a TVS tube, a second capacitor and an inductor; The first end of the TVS tube, the first end of the second capacitor and the first end of the inductor are connected to the CP signal receiving end, the second end of the TVS tube and the second end of the second capacitor are grounded respectively, and the second end of the inductor is connected to the first end of the first resistor.

3. The CP signal detection circuit with a negative pressure detection circuit as claimed in claim 2, characterized in that: Also includes: Zener diode; An anode of the voltage-stabilizing diode is connected to an anode of the first diode, and a cathode of the voltage-stabilizing diode is connected to a first end of the first resistor.

4. The CP signal detection circuit with a negative pressure detection circuit as claimed in claim 3, characterized in that: The anode of the second diode is connected to the second end of the inductor, the cathode of the second diode is connected to the first end of the third resistor, the second end of the third resistor is connected to the first end of the fourth resistor, the first end of the third capacitor and the second AD detection function pin of the microcontroller, and the second end of the fourth resistor and the second end of the third capacitor are grounded respectively.

5. The CP signal detection circuit with a negative pressure detection circuit as claimed in claim 4, characterized in that: Also includes: A national standard resistance detection circuit and a voltage supply circuit; wherein the national standard resistance detection circuit is used to detect whether the pull-down resistor of the charging socket meets the national standard resistance value, and the voltage supply circuit is used to provide a detection voltage for the national standard resistance detection circuit; The voltage supply circuit specifically includes: a first triode, a second triode, a fifth resistor, a third diode and a second power supply; The base of the first transistor is connected to the first control signal output terminal of the single chip microcomputer, the emitter of the first transistor is grounded, the collector of the first transistor is connected to the base of the second transistor, the emitter of the second transistor is connected to the second power supply, the collector of the second transistor is connected to the first end of the fifth resistor, the second end of the fifth resistor is connected to the anode of the third diode, and the cathode of the third diode is connected to the second end of the inductor; The national standard resistance detection circuit specifically includes: a third triode, a sixth resistor, a seventh resistor, and a fourth capacitor; The base of the third transistor is connected to the second control signal output terminal of the single-chip microcomputer, the emitter of the third transistor is grounded, the collector of the third transistor is connected to the first end of the sixth resistor, the second end of the sixth resistor is connected to the first end of the third resistor, the first end of the seventh resistor, the first end of the fourth capacitor and the cathode of the second diode, and the second end of the seventh resistor and the second end of the fourth capacitor are grounded respectively.

6. The CP signal detection circuit with a negative pressure detection circuit as claimed in claim 1, characterized in that: Also includes: The PWM signal detection circuit is used to determine whether the vehicle charger is fully connected to the power supply device and the PWM signal duty cycle state, and the PWM signal detection circuit specifically includes: a fifth capacitor, a ninth resistor, a tenth resistor, an eleventh resistor, a first MOS tube, a second MOS tube, and a third power supply; The first end of the fifth capacitor and the first end of the ninth resistor are connected to the PWM signal capture pin of the single-chip computer, the second end of the fifth capacitor is grounded, the second end of the ninth resistor is connected to the drain of the first MOS tube and the drain of the second MOS tube, the source of the second MOS tube is grounded, the source of the first MOS tube is connected to the first end of the tenth resistor, the second end of the tenth resistor is connected to the third power supply, the gate of the first MOS tube and the gate of the second MOS tube are connected to the first end of the eleventh resistor, and the second end of the eleventh resistor is connected to the first end of the third resistor and the cathode of the second diode.

7. A vehicle charger, comprising a vehicle charger body, characterized in that: It also includes a CP signal detection circuit with a negative pressure detection circuit as described in any one of claims 1-6.

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