Circuit for redundancy check of power supply voltage of electromagnetic valve

Abstract

The utility model discloses a redundancy check electromagnetic valve power supply voltage circuit. Each of the composite triode Q1 and the composite triode U1 is mainly formed by reversely connecting two triodes, and the composite triode Q1 is respectively connected with a power supply voltage, an electromagnetic valve power supply line VBATVR and an analog-to-digital conversion port M1ADVR1 of the MCU micro-control unit through resistors R1 to R2 and capacitors C1 to C3; the composite triode U1 is respectively connected with a power supply voltage, an electromagnetic valve power supply line VBATVR and a microcontroller port M1ADVR2 of the MCU micro-control unit through resistors R3 to R4 and capacitors C4 to C5. According to the utility model, the same solenoid valve power supply voltage signal is identified through two groups of different divider resistance ratios, the work of the solenoid valve voltage acquisition module is controlled through the high-side switch and the low-side switch by using different switch control modes, and the dark current of the controller is reduced in a sleep mode.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply voltage detection, in particular to a circuit for redundantly checking the power supply voltage of a solenoid valve. Background Art

[0002] ESC is a vehicle body stability system that can control the braking force of the car brakes by closing and opening the solenoid valve, so that the wheels are not locked and the best braking effect is achieved. Liquid inlet solenoid valve: a normally open solenoid valve, that is, when the power is off, the solenoid valve is open. During normal braking, the oil inlet solenoid valve is in a power-off and open state. The oil inlet solenoid valve closes the oil channel when power is on. Liquid outlet solenoid valve: a normally closed solenoid valve, that is, when the power is off, the solenoid valve is closed. During normal braking, the oil return solenoid valve is in a power-off and closed state, and the liquid outlet solenoid valve is open when power is on. Therefore, the coil magnetic force is an important parameter for the adjustment of the anti-lock braking system ABS, and the size of the coil magnetic force is directly related to the power supply voltage of the solenoid valve. In general designs, the voltage of the solenoid valve is directly collected by a voltage divider resistor, and the valve power supply is collected in a single channel. This method mainly has the following problems:

[0003] 1. The solenoid valve power supply voltage is not calibrated, making it impossible to know the accuracy of the collected signal, and there is a risk of single point failure.

[0004] 2. The solenoid valve directly uses a voltage-dividing resistor. Considering that the valve power supply is normal electricity, the dark current will inevitably increase. Utility Model Content

[0005] In order to solve the problems existing in the background technology, the utility model proposes a circuit for redundantly checking the power supply voltage of a solenoid valve.

[0006] The technical solution of the utility model is achieved in this way:

[0007] The utility model comprises a composite triode Q1, resistors R1 to R4, capacitors C1 to C5 and a composite triode U1; the composite triode Q1 is connected to a power supply voltage, a solenoid valve power supply line VBAT_VR and an analog-to-digital conversion port M1_AD_VR_1 of an MCU microcontroller unit via resistors R1 to R2 and capacitors C1 to C3 respectively, and the composite triode U1 is connected to a power supply voltage, a solenoid valve power supply line VBAT_VR and a microcontroller port M1_AD_VR_2 of an MCU microcontroller unit via resistors R3 to R4 and capacitors C4 to C5 respectively.

[0008] The composite transistor Q1 is mainly composed of two transistors connected in reverse, wherein the emitter of the first transistor is grounded, the base of the first transistor is connected to the power supply voltage, 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 solenoid valve power supply line VBAT_VR, the collector of the second transistor is grounded via resistors R1 and R2 in sequence, and at the same time, a capacitor C2 is connected in series between the emitter and collector of the second transistor, the emitter of the second transistor is grounded via capacitor C1, resistor R2 and capacitor C3 are connected in parallel, and an analog-to-digital conversion port M1_AD_VR_1 connected to the MCU micro control unit is led out between resistors R1 and R2.

[0009] The emitter of the second transistor of the composite transistor Q1 is grounded via capacitor C4.

[0010] The composite transistor U1 is mainly composed of two transistors, wherein the emitter of the first transistor is grounded, the base is connected to the power supply voltage, the collector is connected to the solenoid valve power supply line VBAT_VR via resistors R4 and R3 in sequence, the resistor R4 and the capacitor C5 are connected in parallel, and a microcontroller port M1_AD_VR_2 connected to the MCU microcontroller unit is led out between the resistor R4 and the resistor R3.

[0011] Beneficial effects of the utility model:

[0012] The circuit of the utility model can identify the same electromagnetic valve power supply voltage signal through two groups of different voltage-dividing resistor ratios.

[0013] The utility model circuit can utilize different switch control modes in hardware. The high-side switch and the low-side switch are used to control the operation of the solenoid valve voltage acquisition module. When the solenoid valve power supply line is normally powered, this switch helps to reduce the dark current of the controller in sleep mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The schematic diagram of a circuit for redundantly checking the power supply voltage of a solenoid valve. DETAILED DESCRIPTION

[0015] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0016] like Figure 1As shown, it includes an MCU microcontroller unit, a composite transistor Q1, resistors R1 to R4, capacitors C1 to C5 and a composite transistor U1; the composite transistor Q1 is used as a high-side switch, and the composite transistor Q1 is connected to the power supply voltage 3V3, the solenoid valve power supply line VBAT_VR and the analog-to-digital conversion port M1_AD_VR_1 of the MCU microcontroller unit through the resistors R1 to R2 and the capacitors C1 to C3 respectively; the composite transistor U1 is used as a low-side switch, and the composite transistor U1 is connected to the power supply voltage 3V3, the solenoid valve power supply line VBAT_VR and the microcontroller port M1_AD_VR_2 of the MCU microcontroller unit through the resistors R3 to R4 and the capacitors C4 to C5 respectively.

[0017] like Figure 1 As shown, the composite transistor Q1 is mainly composed of two transistors connected in reverse, wherein the emitter No. 1 of the first transistor is grounded, the base No. 2 of the first transistor is connected to the power supply voltage 3V3, the collector No. 6 of the first transistor is connected to the base No. 5 of the second transistor, the emitter No. 4 of the second transistor is connected to the solenoid valve power supply line VBAT_VR, the collector No. 3 of the second transistor is grounded via resistors R1 and R2 in sequence, and at the same time, a capacitor C2 is connected in series between the emitter No. 4 and the collector No. 3 of the second transistor, the emitter No. 4 of the second transistor is grounded via capacitor C1, the resistor R2 and the capacitor C3 are connected in parallel, and an analog-to-digital conversion port M1_AD_VR_1 connected to the MCU micro control unit is led out between the resistors R1 and R2.

[0018] The emitter No. 4 of the second transistor of the composite transistor Q1 is grounded via capacitor C4, that is, the electromagnetic valve power supply line VBAT_VR and the resistor R3 are connected to the ground via capacitor C4. At the same time, the electromagnetic valve power supply line VBAT_VR is connected to the composite transistor U1 via resistors R3 and R4 in sequence.

[0019] like Figure 1 As shown, the composite transistor U1 is also mainly composed of two transistors, where the emitter No. 1 of the first transistor is grounded, the base No. 2 is connected to the power supply voltage 3V3, the collector No. 6 is connected to the solenoid valve power supply line VBAT_VR through resistors R4 and R3 in sequence, the resistor R4 and the capacitor C5 are connected in parallel, and the microcontroller port M1_AD_VR_2 connected to the MCU microcontroller unit is connected between the resistor R4 and the resistor R3. The base No. 5, emitter No. 4 and collector No. 3 of the second transistor are all suspended.

[0020] In the specific implementation, the model of the composite triode Q1 is PUMD16, and the model of the composite triode U1 is PUMH9. The resistance value of the resistor R1 is 300K, the resistance value of the resistor R2 is 59K, the resistance value of the resistor R3 is 300K, the resistance value of the resistor R4 is 100K, the capacitance value of the capacitor C1 is 10nF, the capacitance value of the capacitor C2 is 10nF, the capacitance value of the capacitor C4 is 10nF, and the capacitance value of the capacitor C5 is 10nF.

[0021] The specific working mode of the utility model circuit includes two modes: normal mode and sleep mode

[0022] Normal Mode:

[0023] When the whole circuit is powered on, the controller outside the circuit converts and outputs the 3V3 power supply voltage to the base pin 2 of the first transistor of the composite transistor Q1 and the base pin 2 of the first transistor of the composite transistor U1, respectively, and then drives the base pin 5 of the second transistor of the composite transistor Q1 and the emitter pin 1 of the first transistor to be conductive, the base pin 5 of the second transistor of the composite transistor Q1 is connected to the ground, the emitter pin 4 of the second transistor of the composite transistor Q1 and the collector pin 3 of the second transistor are conductive, and the +12V voltage output by the solenoid valve power supply line VBAT_VR is loaded on the collector pin 3 of the second transistor of the composite transistor Q1, and is also loaded on the analog-to-digital conversion port M1_AD_VR_1 of the MCU microcontroller unit through the resistor R1. At this time, the valve supply voltage detected by the analog-to-digital conversion port M1_AD_VR_1 of the MCU microcontroller unit is:

[0024] VBAT_VR*(R1 / (R1+R2))=12V *(59K / (300K+59K))=1.97V

[0025] Wherein, VBAT_VR represents the voltage output by the solenoid valve power supply line VBAT_VR, and R1 and R2 represent the resistances of the resistor R1 and the resistor R2 respectively;

[0026] At this time, the current I1 consumed by the circuit where resistors R1 and R2 are located is: I1=VBAT_VR / (R1+R2)=12V / (300K+59K)=33.4uA

[0027] At the same time, it also drives the emitter pin 1 of the first transistor of the composite transistor U1 and the collector pin 6 of the first transistor to conduct. The +12V voltage output by the solenoid valve power supply line VBAT_VR is loaded on the pin 2 of the composite transistor U1, and is also loaded on the microcontroller port M1_AD_VR_2 of the MCU microcontroller unit through the resistor R3. At this time, the valve supply voltage detected by the microcontroller port M1_AD_VR_2 of the MCU microcontroller unit is:

[0028] VBAT_VR*(R1 / (R3+R4))=12V*(100K / (100K+300K))=3V

[0029] At this time, the current I2 consumed by the resistor R3 and resistor R4 loop is: I2=VBAT_VR / (R3+R4)=12V / (300K+100K)=30uA

[0030] Therefore, the total current consumed by the loop in normal mode is: I1+I2=33.4uA + 30uA=63.4uA

[0031] The MCU microcontroller unit compares the voltages of different ports under the solenoid valve power supply line VBAT_VR, that is, compares the voltage detected by the analog-to-digital conversion port M1_AD_VR_1 and the microcontroller port M1_AD_VR_2, thereby ensuring that the valve voltage is collected correctly.

[0032] Sleep Mode:

[0033] The controller is powered off. The system cannot collect the power supply voltage of the solenoid valve due to power failure. The system cannot output the 3V3 power supply voltage to the base pin 2 of the first transistor of the composite transistor Q1 and the base pin 2 of the first transistor of the composite transistor U1, which makes the voltage of the base pin 2 of the first transistor of the composite transistor Q1 and the base pin 2 of the first transistor of the composite transistor U1 both 0V.

[0034] The emitter pin No. 4 of the second transistor of the compound transistor Q1 is disconnected from the collector pin No. 3 of the second transistor, and the emitter pin No. 1 of the first transistor of the compound transistor U1 is disconnected from the collector pin No. 6 of the first transistor;

[0035] At this time, the current I1 consumed by the circuit where resistors R1 and R2 are located is: I1=VBAT_VR / (RQ+R1+R2)=12V / (10MΩ+300K+59K)=8.8uA

[0036] Among them, RQ is the internal resistance of the second transistor of the composite transistor Q1, which is roughly more than 10MΩ;

[0037] At this time, the current I2 consumed by the circuit where resistors R3 and R4 are located is: I2=VBAT_VR / (RU1+R3+R4)=12V / (10MΩ+300K+100K)=8.57uA

[0038] RU1 is the internal resistance of the first transistor of the composite transistor U1, which is approximately above 10MΩ.

[0039] Therefore, the total current consumed by the loop in sleep mode is: I1+I2=8.8uA + 8.57uA=17.37uA;

[0040] Because the solenoid valve is powered by normal electricity, its dark current will increase by 63.4uA-17.37uA=45.67uA compared to the case where the high and low side switch control of the compound transistor Q1 and the compound transistor U1 is cancelled.

[0041] The utility model can not only redundantly check and detect the supply voltage of the electromagnetic valve, but also reduce the dark current in the sleep mode compared with the normal mode, thereby meeting the limit value requirements of the dark current of the passenger car manufacturer and increasing the endurance of the vehicle battery.

[0042] Therefore, the utility model identifies the same solenoid valve supply voltage signal through two sets of different voltage-dividing resistor ratios. Using different switch control methods, the high-side switch and the low-side switch are used to control the operation of the solenoid valve voltage acquisition module. This switch helps reduce the dark current of the controller in sleep mode when the solenoid valve power supply line is normally powered.

Claims

1. A circuit for redundantly checking the supply voltage of a solenoid valve, characterized in that: It includes a composite transistor Q1, resistors R1 to R4, capacitors C1 to C5 and a composite transistor U1; the composite transistor Q1 is connected to the power supply voltage, the solenoid valve power supply line VBAT_VR and the analog-to-digital conversion port M1_AD_VR_1 of the MCU microcontroller unit via the resistors R1 to R2 and the capacitors C1 to C3 respectively, and the composite transistor U1 is connected to the power supply voltage, the solenoid valve power supply line VBAT_VR and the microcontroller port M1_AD_VR_2 of the MCU microcontroller unit via the resistors R3 to R4 and the capacitors C4 to C5 respectively.

2. A circuit for redundantly checking the supply voltage of a solenoid valve according to claim 1, characterized in that: The composite triode Q1 is mainly composed of two triodes connected in reverse.

3. A circuit for redundantly checking the supply voltage of a solenoid valve according to claim 2, characterized in that: The emitter of the first transistor in the composite transistor Q1 is grounded, the base of the first transistor is connected to the power supply voltage, 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 solenoid valve power supply line VBAT_VR, the collector of the second transistor is grounded via resistors R1 and R2 in sequence, and at the same time, a capacitor C2 is connected in series between the emitter and collector of the second transistor, the emitter of the second transistor is grounded via the capacitor C1, the resistor R2 and the capacitor C3 are connected in parallel, and an analog-to-digital conversion port M1_AD_VR_1 connected to the MCU micro control unit is led out between the resistors R1 and R2.

4. The circuit for redundantly checking the supply voltage of a solenoid valve according to claim 1, characterized in that: The emitter of the second transistor of the composite transistor Q1 is grounded via capacitor C4.

5. The circuit for redundantly checking the supply voltage of a solenoid valve according to claim 1, characterized in that: The composite transistor U1 is mainly composed of two transistors, wherein the emitter of the first transistor is grounded, the base is connected to the power supply voltage, the collector is connected to the solenoid valve power supply line VBAT_VR via resistors R4 and R3 in sequence, the resistor R4 and the capacitor C5 are connected in parallel, and a microcontroller port M1_AD_VR_2 connected to the MCU microcontroller unit is led out between the resistor R4 and the resistor R3.

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