An electric bicycle battery power monitoring circuit

Abstract

The invention discloses an electric bicycle battery power monitoring circuit, which belongs to the technical field of electric vehicles, comprises a sampling circuit, a filtering circuit and a discrimination circuit, and solves the technical problem of using a modular circuit design to monitor the battery power of an electric vehicle. The invention adopts a logic circuit to directly measure the battery power of the electric vehicle, and adopts an indicator light to display the power, so that the remaining power value of the battery can be observed intuitively. The invention adopts a circuit to realize the monitoring of the battery power, does not need a single-chip computer and an AD chip, can be universally used for the detection of various electric vehicle batteries, has low cost and convenient wiring.

Description

Technical Field

[0001] The invention belongs to the technical field of electric vehicles, and in particular relates to a battery power monitoring circuit for an electric bicycle. Background Art

[0002] Electric vehicle batteries are the core energy supply for electric vehicles. Monitoring of electric vehicle batteries is an important part of the electric vehicle control system. Traditional electric vehicle monitoring circuits use sampling resistors and AD to monitor electric vehicles. However, since AD ​​requires a microcontroller such as a single-chip microcomputer to read its conversion value, the monitoring circuit of the electric vehicle must be programmed by the manufacturer before it can be used. The single-chip microcomputer models used by each manufacturer are different, which makes the programs in the electric vehicle single-chip microcomputers produced by each manufacturer different. Even the AD conversion programs used by different models of electric vehicles from a manufacturer are different, and modular production cannot be formed. Summary of the invention

[0003] The purpose of the present invention is to provide an electric bicycle battery power monitoring circuit, which solves the technical problem of using modular circuit design to monitor the battery power of an electric bicycle.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] An electric bicycle battery power monitoring circuit includes a sampling circuit, a filtering circuit and a discrimination circuit;

[0006] The sampling circuit includes a resistor R1 and a resistor R2, one end of the resistor R1 is connected to the positive electrode of the electric vehicle battery, and the other end is connected to the ground wire through the resistor R2;

[0007] The filtering circuit includes an operational amplifier IC1, a resistor R5, a resistor R3, a resistor R4, a capacitor C1, an operational amplifier IC2, a capacitor C2 and a resistor R9, a connection node between the resistor R2 and the resistor R1 is connected to the positive input terminal of the operational amplifier IC1, a negative input terminal of the operational amplifier IC1 is connected to one end of the capacitor C1 through the resistor R3, the other end of the capacitor C1 is connected to the positive input terminal of the operational amplifier IC2, the positive input terminal of the operational amplifier IC2 is also connected to the ground wire through the resistor R9, a connection node between the resistor R3 and the capacitor C1 is also connected to the ground wire through the capacitor C2, a negative input terminal of the operational amplifier IC2 is connected to the output terminal of the operational amplifier IC2, the output terminal of the operational amplifier IC2 is also connected to the connection node between the resistor R3 and the capacitor C1 through the resistor R4, and the output terminal of the operational amplifier IC1 is connected to the negative input terminal of the operational amplifier IC1 through the resistor R5;

[0008] The identification circuit includes inverter U1A, inverter U1B, inverter U1C, inverter U1D, inverter U1E, resistor R6, resistor R10, resistor R11, resistor R12, resistor R13, LED lamp D2, LED lamp D3, LED lamp D4, LED lamp D5, resistor R7, resistor R8, resistor R16, resistor R17, resistor R15, resistor R14 and field effect tube Q1. The output end of operational amplifier IC1 is connected to the positive electrode of diode D1, the negative electrode of diode D1 is connected to the input end of inverter U1A, and inverter U1A The input end of the inverter is connected to the input end of the inverter U1B through the resistor R6, the input end of the inverter U1B is connected to the input end of the inverter U1C through the resistor R10, the input end of the inverter U1C is connected to the input end of the inverter U1D through the resistor R11, the input end of the inverter U1D is connected to the input end of the inverter U1E through the resistor R12, and the input end of the inverter U1E is connected to the ground wire through the resistor R13;

[0009] The output end of the inverter U1A is connected to the positive electrode of the LED lamp D2, and the negative electrode of the LED lamp D2 is connected to the ground through the resistor R7. The output end of the inverter U1B is connected to the positive electrode of the LED lamp D3, and the negative electrode of the LED lamp D3 is connected to the ground through the resistor R8. The output end of the inverter U1C is connected to the positive electrode of the LED lamp D4, and the negative electrode of the LED lamp D4 is connected to the ground through the resistor R16. The output end of the inverter U1D is connected to the positive electrode of the LED lamp D5, and the negative electrode of the LED lamp D5 is connected to the ground through the resistor R17. The output end of the inverter U1E is connected to the G electrode of the field effect tube Q1 through the resistor R15, and the D electrode of the field effect tube Q1 is connected to the positive electrode of the electric vehicle battery through the resistor R14, and the S electrode is connected to the power supply end of the electric vehicle DC motor.

[0010] Preferably, the operational amplifier IC1 and the operational amplifier IC2 are both operational amplifiers LM741; the inverters U1A, U1B, U1C, U1D and U1E are all 74LS04.

[0011] Preferably, the inverter U1A, the inverter U1B, the inverter U1C, the inverter U1D and the inverter U1E are inverters in the same 74LS04 chip.

[0012] The electric bicycle battery power monitoring circuit described in the present invention solves the technical problem of using modular circuit design to monitor the battery power of an electric vehicle. The present invention uses a logic circuit to directly measure the battery power of the electric vehicle, and uses an indicator light to display the power, so that the remaining power value of the battery can be intuitively observed. The present invention uses a circuit to monitor the battery power, does not require a single-chip microcomputer and an AD chip, can be used for the detection of various electric vehicle batteries, has low cost, and is convenient for wiring. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a circuit diagram of the present invention. DETAILED DESCRIPTION

[0014] like Figure 1 The electric bicycle battery power monitoring circuit shown includes a sampling circuit, a filtering circuit and a discrimination circuit;

[0015] The sampling circuit includes a resistor R1 and a resistor R2, one end of the resistor R1 is connected to the positive electrode of the electric vehicle battery, and the other end is connected to the ground wire through the resistor R2;

[0016] The filtering circuit includes an operational amplifier IC1, a resistor R5, a resistor R3, a resistor R4, a capacitor C1, an operational amplifier IC2, a capacitor C2 and a resistor R9, a connection node between the resistor R2 and the resistor R1 is connected to the positive input terminal of the operational amplifier IC1, a negative input terminal of the operational amplifier IC1 is connected to one end of the capacitor C1 through the resistor R3, the other end of the capacitor C1 is connected to the positive input terminal of the operational amplifier IC2, the positive input terminal of the operational amplifier IC2 is also connected to the ground wire through the resistor R9, a connection node between the resistor R3 and the capacitor C1 is also connected to the ground wire through the capacitor C2, a negative input terminal of the operational amplifier IC2 is connected to the output terminal of the operational amplifier IC2, the output terminal of the operational amplifier IC2 is also connected to the connection node between the resistor R3 and the capacitor C1 through the resistor R4, and the output terminal of the operational amplifier IC1 is connected to the negative input terminal of the operational amplifier IC1 through the resistor R5;

[0017] The voltage of the electric vehicle battery is input to the positive input terminal of the operational amplifier IC1 after being divided by the resistors R1 and R2, and the negative terminal of the electric vehicle battery is the ground wire;

[0018] Op amp IC1 and op amp IC2 form a high-Q notch filter, which can effectively filter out the low-frequency interference generated by the electric vehicle motor, ensuring that the discrimination circuit will not be affected by low-frequency interference when discriminating the battery voltage, thereby ensuring the stability of the discrimination circuit.

[0019] The identification circuit includes inverter U1A, inverter U1B, inverter U1C, inverter U1D, inverter U1E, resistor R6, resistor R10, resistor R11, resistor R12, resistor R13, LED lamp D2, LED lamp D3, LED lamp D4, LED lamp D5, resistor R7, resistor R8, resistor R16, resistor R17, resistor R15, resistor R14 and field effect tube Q1. The output end of operational amplifier IC1 is connected to the positive electrode of diode D1, the negative electrode of diode D1 is connected to the input end of inverter U1A, and inverter U1A The input end of the inverter is connected to the input end of the inverter U1B through the resistor R6, the input end of the inverter U1B is connected to the input end of the inverter U1C through the resistor R10, the input end of the inverter U1C is connected to the input end of the inverter U1D through the resistor R11, the input end of the inverter U1D is connected to the input end of the inverter U1E through the resistor R12, and the input end of the inverter U1E is connected to the ground wire through the resistor R13;

[0020] The output end of the inverter U1A is connected to the positive electrode of the LED lamp D2, and the negative electrode of the LED lamp D2 is connected to the ground through the resistor R7. The output end of the inverter U1B is connected to the positive electrode of the LED lamp D3, and the negative electrode of the LED lamp D3 is connected to the ground through the resistor R8. The output end of the inverter U1C is connected to the positive electrode of the LED lamp D4, and the negative electrode of the LED lamp D4 is connected to the ground through the resistor R16. The output end of the inverter U1D is connected to the positive electrode of the LED lamp D5, and the negative electrode of the LED lamp D5 is connected to the ground through the resistor R17. The output end of the inverter U1E is connected to the G electrode of the field effect tube Q1 through the resistor R15, and the D electrode of the field effect tube Q1 is connected to the positive electrode of the electric vehicle battery through the resistor R14, and the S electrode is connected to the power supply end of the electric vehicle DC motor.

[0021] The level discrimination circuit composed of the inverter U1A, the inverter U1B, the inverter U1C, the inverter U1D and the inverter U1E has five voltage thresholds, which can be changed by adjusting the resistance values ​​of the resistors R6, R10, R11, R12 and R13; the upper and lower voltage limits of the electric vehicle battery used in this embodiment are 14.6V to 11V, and since the threshold level of the inverter is 0.45V, the five voltage thresholds used in this embodiment are respectively:

[0022] U1 = 0.45V × 14.6 = 6.6V;

[0023] U2 = 0.45V × 13.6 = 6.12V;

[0024] U3=0.45V×12.2≈5.5V;

[0025] U4=0.45V×11.5≈5.2V;

[0026] U5 = 0.45V × 11 = 4.95V;

[0027] Wherein U1, U2, U3, U4 and U5 are respectively the input terminal voltage of the inverter U1E, the input terminal voltage of the inverter U1D, the input terminal voltage of the inverter U1C, the input terminal voltage of the inverter U1B and the input terminal voltage of the inverter U1A;

[0028] The diode D1 adopts the constant current diode 1N5283, and its constant current is I=220uA. The resistance values ​​of the resistors R6, R10, R11, R12 and R13 can be calculated by Ohm's law.

[0029] Inverter U1A, inverter U1B, inverter U1C, inverter U1D and inverter U1E are all powered by the electric vehicle battery.

[0030] This embodiment uses five voltage thresholds, U1, U2, U3, U4 and U5, to monitor the battery power. When the battery voltage decreases and the threshold voltage of the inverter U1A is less than 6.6V, the inverter U1 outputs a low level, and the LED lamp D2 is turned off. Similarly, as the battery voltage decreases, the threshold voltage of the inverter is less than U1, U2, U3 and U4 in sequence, so that the LED lamp D2, LED lamp D3, LED lamp D4 and LED lamp D5 are turned off in sequence, so that the remaining battery power can be observed intuitively. When the inverter threshold voltage is less than U5, the battery voltage is too low, and the inverter U1E outputs a low level, which cuts off the field effect tube Q1 and disconnects the power supply circuit of the electric vehicle motor, thereby protecting the battery from running at too low a voltage for a long time.

[0031] The present invention can display the battery power by only selecting appropriate resistance values ​​of the resistors R6, R10, R11, R12 and R13, which is suitable for modular production requirements.

[0032] Preferably, the operational amplifier IC1 and the operational amplifier IC2 are both operational amplifiers LM741; the inverters U1A, U1B, U1C, U1D and U1E are all 74LS04.

[0033] Preferably, the inverter U1A, the inverter U1B, the inverter U1C, the inverter U1D and the inverter U1E are inverters in the same 74LS04 chip.

[0034] The electric bicycle battery power monitoring circuit described in the present invention solves the technical problem of using modular circuit design to monitor the battery power of an electric vehicle. The present invention uses a logic circuit to directly measure the battery power of the electric vehicle, and uses an indicator light to display the power, so that the remaining power value of the battery can be intuitively observed. The present invention uses a circuit to monitor the battery power, does not require a single-chip microcomputer and an AD chip, can be used for the detection of various electric vehicle batteries, has low cost, and is convenient for wiring.

Claims

1. An electric bicycle battery power monitoring circuit, characterized in that: Including sampling circuit, filtering circuit and discrimination circuit; The sampling circuit includes a resistor R1 and a resistor R2, one end of the resistor R1 is connected to the positive electrode of the electric vehicle battery, and the other end is connected to the ground wire through the resistor R2; The filtering circuit includes an operational amplifier IC1, a resistor R5, a resistor R3, a resistor R4, a capacitor C1, an operational amplifier IC2, a capacitor C2 and a resistor R9, a connection node between the resistor R2 and the resistor R1 is connected to the positive input terminal of the operational amplifier IC1, a negative input terminal of the operational amplifier IC1 is connected to one end of the capacitor C1 through the resistor R3, the other end of the capacitor C1 is connected to the positive input terminal of the operational amplifier IC2, the positive input terminal of the operational amplifier IC2 is also connected to the ground wire through the resistor R9, a connection node between the resistor R3 and the capacitor C1 is also connected to the ground wire through the capacitor C2, a negative input terminal of the operational amplifier IC2 is connected to the output terminal of the operational amplifier IC2, the output terminal of the operational amplifier IC2 is also connected to the connection node between the resistor R3 and the capacitor C1 through the resistor R4, and the output terminal of the operational amplifier IC1 is connected to the negative input terminal of the operational amplifier IC1 through the resistor R5; The identification circuit includes inverter U1A, inverter U1B, inverter U1C, inverter U1D, inverter U1E, resistor R6, resistor R10, resistor R11, resistor R12, resistor R13, LED lamp D2, LED lamp D3, LED lamp D4, LED lamp D5, resistor R7, resistor R8, resistor R16, resistor R17, resistor R15, resistor R14 and field effect tube Q1. The output end of operational amplifier IC1 is connected to the positive electrode of diode D1. The negative electrode of the diode D1 is connected to the input end of the inverter U1A, the input end of the inverter U1A is connected to the input end of the inverter U1B through the resistor R6, the input end of the inverter U1B is connected to the input end of the inverter U1C through the resistor R10, the input end of the inverter U1C is connected to the input end of the inverter U1D through the resistor R11, the input end of the inverter U1D is connected to the input end of the inverter U1E through the resistor R12, and the input end of the inverter U1E is connected to the ground wire through the resistor R13; The output end of the inverter U1A is connected to the positive electrode of the LED lamp D2, and the negative electrode of the LED lamp D2 is connected to the ground wire through the resistor R7. The output end of the inverter U1B is connected to the positive electrode of the LED lamp D3, and the negative electrode of the LED lamp D3 is connected to the ground wire through the resistor R8. The output end of the inverter U1C is connected to the positive electrode of the LED lamp D4, and the negative electrode of the LED lamp D4 is connected to the ground wire through the resistor R16. The output end of the inverter U1D is connected to the positive electrode of the LED lamp D5, and the negative electrode of the LED lamp D5 is connected to the ground wire through the resistor R17. The output end of the inverter U1E is connected to the G electrode of the field effect tube Q1 through the resistor R15, and the D electrode of the field effect tube Q1 is connected to the positive electrode of the battery of the electric vehicle through the resistor R14, and the S electrode is connected to the power supply end of the DC motor of the electric vehicle; The level discrimination circuit formed by inverter U1A, inverter U1B, inverter U1C, inverter U1D and inverter U1E has five different voltage thresholds.

2. The electric bicycle battery power monitoring circuit according to claim 1, characterized in that: The operational amplifier IC1 and the operational amplifier IC2 are both operational amplifiers LM741; the inverters U1A, U1B, U1C, U1D and U1E are all 74LS04.

3. An electric bicycle battery power monitoring circuit as claimed in claim 2, characterized in that: The inverter U1A, the inverter U1B, the inverter U1C, the inverter U1D and the inverter U1E are inverters in the same 74LS04 chip.

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