Automobile lamp precision rectification and peak voltage detection alarm circuit

Abstract

The utility model discloses an automobile lamp precision rectification and peak voltage detection alarm circuit, which comprises a rectification unit and a peak detection unit, and is characterized in that the rectification unit is used for rectifying an input alternating current signal to obtain a rectification result; and the peak value detection unit is used for carrying out peak value voltage detection on the rectification result, and outputting an alarm signal when the peak value voltage is higher than a set threshold value. By implementing the circuit provided by the utility model, the problem of distortion of an existing circuit adopting a diode for rectification can be solved, and voltage peak detection is realized by adopting a simple circuit.

Description

Technical Field

[0001] The utility model relates to the technical field of automobile headlights, in particular to a precise rectification and peak voltage detection and alarm circuit for automobile headlights. Background Art

[0002] In the existing technology, diodes are usually used for rectifying headlights, and TVS tubes are used to suppress peak voltages to ensure that LEDs can obtain stable current and voltage. However, there are some problems with diode rectification. First, due to the dead zone voltage of the diode, such as about 0.5V for silicon tubes and about 0.1V for germanium tubes, when the input voltage is lower than this value, the diode will cut off and the rectification circuit cannot output. Second, there is a voltage drop of 0.7V when the silicon diode is conducting, resulting in the rectified output voltage waveform being lower than the input voltage.

[0003] To solve these problems, existing circuits often use chips to detect voltage. Once the voltage or current is too high, the chip will receive a feedback signal and achieve step-down or current-limiting output internally. This is a good choice for complex circuits. However, for some simple circuits, the above rectification method is relatively complex.

[0004] Therefore, it is necessary to design a new circuit to overcome the distortion problems that occur in the existing circuits using diode rectification. Summary of the Utility Model

[0005] The technical problem to be solved by the utility model is to provide a precise rectification and peak voltage detection and alarm circuit for automobile headlights.

[0006] To solve the above technical problem, the purpose of the utility model is achieved by the following technical solutions: providing a precise rectification and peak voltage detection and alarm circuit for automobile headlights, including: a rectification unit and a peak detection unit, where the rectification unit is used to rectify the input AC signal to obtain a rectification result; the peak detection unit is used to detect the peak voltage of the rectification result, and when the peak voltage is higher than a set threshold, an alarm signal is output.

[0007] Its further technical solution is: the rectification unit includes an inverting proportional operation amplifier circuit and an inverting adder circuit; the inverting proportional operation amplifier circuit is connected to the inverting adder circuit; the inverting adder circuit is connected to the peak detection unit.

[0008] Its further technical solution is as follows: The inverting proportional operation amplifier circuit includes a first-stage integrated operational amplifier U2, and the inverting input terminal of the first-stage integrated operational amplifier U2 is connected to an AC input device; the output terminal of the first-stage integrated operational amplifier U2 is connected to the inverting adder circuit through a diode D2; a diode D4 is connected between the output terminal of the first-stage integrated operational amplifier U2 and the inverting input terminal of the first-stage integrated operational amplifier U2; a resistor R8 is connected in parallel with the diode D4.

[0009] Its further technical solution is as follows: The inverting adder circuit includes a second-stage integrated operational amplifier U1, and the inverting input terminal of the second-stage integrated operational amplifier U1 is connected to the diode D2; the output terminal of the second-stage integrated operational amplifier U1 is connected to the peak detection unit; the output terminal of the second-stage integrated operational amplifier U1 and the inverting input terminal of the second-stage integrated operational amplifier U1 are connected through a resistor R10; the output terminal of the second-stage integrated operational amplifier U1 is connected to the inverting input terminal of the first-stage integrated operational amplifier U2 through a circuit R9.

[0010] Its further technical solution is as follows: The peak detection unit includes a linear half-wave rectifier circuit and a voltage follower circuit; the inverting adder circuit is connected to the linear half-wave rectifier circuit; the linear half-wave rectifier circuit is connected to the voltage follower circuit.

[0011] Its further technical solution is as follows: The linear half-wave rectifier circuit includes a third integrated operational amplifier U3, and the non-inverting input terminal of the third integrated operational amplifier U3 is connected to the output terminal of the second-stage integrated operational amplifier U1; the output terminal of the third integrated operational amplifier U3 and the inverting input terminal of the third integrated operational amplifier U3 are respectively connected to the voltage follower circuit.

[0012] Its further technical solution is as follows: The output terminal of the third integrated operational amplifier U3 is connected to the voltage follower circuit through a diode D1; the inverting input terminal of the third integrated operational amplifier U3 is connected to the output terminal of the third integrated operational amplifier U3 through a diode D3; one end of a capacitor C1 is connected between the diode D1 and the voltage follower circuit, and the other end of the capacitor C1 is grounded through a resistor R1.

[0013] Its further technical solution is as follows: The voltage follower circuit includes a fourth integrated operational amplifier U4, and the non-inverting input terminal of the fourth integrated operational amplifier U4 is connected to the diode D1; the inverting input terminal of the fourth integrated operational amplifier U4 is connected to the inverting input terminal of the third integrated operational amplifier U3 through a resistor R7; the output terminal of the fourth integrated operational amplifier U4 is connected to the inverting input terminal of the fourth integrated operational amplifier U4.

[0014] Its further technical solution is: It further includes a resistor R4. One end of the resistor R4 is connected between the diode D1 and the non-inverting input terminal of the fourth integrated operational amplifier U4, and the other end is grounded.

[0015] The beneficial effects of the present utility model compared with the prior art are as follows: By setting a rectification unit and a peak detection unit, the present utility model uses the rectification unit for precision rectification, and then adopts the peak detection unit for peak voltage detection. When the voltage exceeds the threshold, an early warning is given in time, thus overcoming the distortion problem that occurs in the existing circuit using a diode for rectification, and realizing voltage peak detection with a simple circuit.

[0016] The following further describes the present utility model in conjunction with the accompanying drawings and specific embodiments. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the accompanying drawings required for the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a schematic block diagram of a precision rectification and peak voltage detection and alarm circuit for an automotive headlight provided by an embodiment of the present utility model;

[0019] Figure 2 It is a specific circuit schematic diagram of a precision rectification and peak voltage detection and alarm circuit for an automotive headlight provided by an embodiment of the present utility model;

[0020] Explanation of the markings in the figure:

[0021] 10. Rectification unit; 20. Peak detection unit; 30. Alarm unit. Detailed Embodiments

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, rather than all, of the embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present utility model.

[0023] It should be understood that when used in this specification and the appended claims, the terms "comprises" and "comprising" indicate the presence of the described features, wholes, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0024] It should also be understood that the terms used in the description of the present utility model herein are merely for the purpose of describing specific embodiments and are not intended to limit the present utility model. As used in the description of the present utility model and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0025] It should be further understood that the term "and / or" used in the description of the present utility model and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0026] Please refer to Figure 1 , Figure 1 , which is a schematic block diagram of a precise rectification and peak voltage detection and alarm circuit for an automotive headlight provided by an embodiment of the present utility model. It can be applied to the circuit of an automotive headlight, convert a weak AC voltage into a DC voltage output with extremely low loss, basically eliminate the adverse effects of the dead zone voltage and saturation voltage of the diode, and ensure that a very small input signal can generate a sufficient voltage output. The peak detection circuit output has a good holding function and will only be replaced until a larger peak voltage appears in the input voltage. When the peak voltage exceeds a certain value, an alarm will be triggered.

[0027] Please refer to Figure 1 , the above-mentioned precise rectification and peak voltage detection and alarm circuit for an automotive headlight includes: a rectification unit 10, a peak detection unit 20, and an alarm unit 30. The rectification unit 10 is used to rectify the input AC signal to obtain a rectification result; the peak detection unit 20 is used to detect the peak voltage of the rectification result and output an alarm signal when the peak voltage is higher than the set threshold; the alarm unit 30 is used to give an alarm according to the alarm signal.

[0028] In this embodiment, the rectification unit 10 is responsible for rectifying the input AC signal to obtain the rectified output result. Ensure that the voltage in the positive half-cycle or negative half-cycle of the signal is retained to achieve the purpose of eliminating the negative half-cycle signal.

[0029] The peak detection unit 20 detects the peak voltage of the rectified signal. By comparing the rectification result with the set threshold, when the peak voltage is higher than the set threshold, the peak detection unit 20 will output an alarm signal. This helps to detect whether there is an excessive voltage situation and possible faults during the operation of the headlight.

[0030] The alarm unit 30 gives an alarm according to the alarm signal output by the peak detection unit 20. This can be achieved by triggering a warning light, emitting a sound alarm, or sending an alarm message to the vehicle's central control system.

[0031] The working principle of this circuit is to rectify the headlight input signal precisely and detect the peak voltage of the rectification result to detect possible abnormal conditions. Once the detected peak voltage exceeds the set threshold, an alarm will be triggered to remind the driver to perform repairs or maintenance. This can promptly detect and handle possible problems in the operation of the headlights, improve driving safety, and extend the service life of the headlights.

[0032] In one embodiment, please refer to Figure 2 , the above rectification unit 10 includes an inverting proportional operation amplifier circuit and an inverting adder circuit; the inverting proportional operation amplifier circuit is connected to the inverting adder circuit; the inverting adder circuit is connected to the peak detection unit 20.

[0033] In one embodiment, please refer to Figure 2 , the above inverting proportional operation amplifier circuit includes a first-stage integrated operational amplifier U2, and the inverting input terminal of the first-stage integrated operational amplifier U2 is connected to an AC input device; the output terminal of the first-stage integrated operational amplifier U2 is connected to the inverting adder circuit through a diode D2; a diode D4 is connected between the output terminal of the first-stage integrated operational amplifier U2 and the inverting input terminal of the first-stage integrated operational amplifier U2; a resistor R8 is connected in parallel with the diode D4.

[0034] In one embodiment, please refer to Figure 2 , the above inverting adder circuit includes a second-stage integrated operational amplifier U1, and the inverting input terminal of the second-stage integrated operational amplifier U1 is connected to the diode D2; the output terminal of the second-stage integrated operational amplifier U1 is connected to the peak detection unit 20; the output terminal of the second-stage integrated operational amplifier U1 and the inverting input terminal of the second-stage integrated operational amplifier U1 are connected through a resistor R10; the output terminal of the second-stage integrated operational amplifier U1 is connected to the inverting input terminal of the first-stage integrated operational amplifier U2 through a circuit R9.

[0035] Specifically, when vin < 0, the first - stage integrated operational amplifier U2 outputs a high level, diode D4 conducts, diode D2 cuts off, the current flowing through resistor R8 is 0, and the negative feedback formed by diode D4 ensures that the first - stage integrated operational amplifier U2 operates in the linear region. According to the "virtual ground" characteristic of the operational amplifier, the voltages of pin 1 of the first - stage integrated operational amplifier U2 and pin 1 of the second - stage integrated operational amplifier U1 are both 0, so Vm is 0. At this time, the second - stage integrated operational amplifier U1 and resistors R9 and R10 form an inverting amplifier circuit, so the output voltage (the voltage of pin 4) of the second - stage integrated operational amplifier U1 is equal to - vin. When vin > 0, the first - stage integrated operational amplifier U2 outputs a low level, diode D4 cuts off, diode D2 conducts, and the output of the first - stage integrated operational amplifier U2 is Vm=-R8 * vin / R6=-vin. After the reverse addition operation of Vin and Vm, the output voltage (the voltage of pin 4) of U1 is equal to - R10 * vin / R9 - R10 * Vm / R5=-vin - 2Vm = vin. This realizes the precise rectification of the circuit.

[0036] In summary, the inverting proportional operation amplifier circuit is implemented by the first - stage integrated operational amplifier U2, and its inverting input terminal is connected to the AC input device. When the input voltage vin is less than 0, the first - stage integrated operational amplifier U2 outputs a high level, causing diode D4 to conduct and diode D2 to cut off. In this case, the current flowing through resistor R8 is 0, and the negative feedback through diode D4 ensures that the first - stage integrated operational amplifier U2 operates in the linear region. At this time, the voltages of pin 1 of the first - stage and second - stage operational amplifiers are both 0, so Vm is equal to 0. Therefore, the second - stage operational amplifier U1, resistors R9 and R10 form an inverting amplifier circuit, making the output voltage of the second - stage operational amplifier U1 equal to - vin.

[0037] The inverting adder circuit is implemented by the second - stage integrated operational amplifier U1. When the input voltage vin is greater than 0, the first - stage integrated operational amplifier U2 outputs a low level, causing diode D4 to cut off and diode D2 to conduct. At this time, the output of the first - stage integrated operational amplifier U2 is Vm=-R8vin / R6=-vin. Since the input and Vm undergo a reverse addition operation, the output voltage of the second - stage integrated operational amplifier U1 is equal to - R10vin / R9 - R10 * Vm / R5=-vin - 2Vm = vin. This realizes the precise rectification of the circuit.

[0038] Through the combination of the inverting proportional operation amplifier circuit and the inverting adder circuit, precise rectification is achieved, ensuring that the output result is consistent with the input signal; the negative - feedback mechanism ensures that the operational amplifier is in the stable operating region, improving the stability and reliability of the circuit; the use of components such as integrated operational amplifiers and diodes realizes an efficient circuit design and implementation.

[0039] In one embodiment, please refer to Figure 2, the above-mentioned peak detection unit 20 includes a linear half-wave rectifier circuit and a voltage follower circuit; the inverting adder circuit is connected to the linear half-wave rectifier circuit; the linear half-wave rectifier circuit is connected to the voltage follower circuit.

[0040] In one embodiment, please refer to Figure 2 , the above-mentioned linear half-wave rectifier circuit includes a third operational amplifier U3, the non-inverting input terminal of the third operational amplifier U3 is connected to the output terminal of the second-stage operational amplifier U1; the output terminal of the third operational amplifier U3 and the inverting input terminal of the third operational amplifier U3 are respectively connected to the voltage follower circuit.

[0041] In one embodiment, please refer to Figure 2 , the output terminal of the above-mentioned third operational amplifier U3 is connected to the voltage follower circuit through a diode D1; the inverting input terminal of the third operational amplifier U3 is connected to the output terminal of the third operational amplifier U3 through a diode D3; one end of a capacitor C1 is connected between the diode D1 and the voltage follower circuit, and the other end of the capacitor C1 is grounded through a resistor R1.

[0042] In one embodiment, please refer to Figure 2 , the above-mentioned voltage follower circuit includes a fourth operational amplifier U4, the non-inverting input terminal of the fourth operational amplifier U4 is connected to the diode D1; the inverting input terminal of the fourth operational amplifier U4 is connected to the inverting input terminal of the third operational amplifier U3 through a resistor R7; the output terminal of the fourth operational amplifier U4 is connected to the inverting input terminal of the fourth operational amplifier U4.

[0043] In one embodiment, please refer to Figure 2 , the circuit of this embodiment further includes a resistor R4, one end of the resistor R4 is connected between the diode D1 and the non-inverting input terminal of the fourth operational amplifier U4, and the other end is grounded.

[0044] Specifically, when the input signal (pin 3 of the third operational amplifier U3) is in the positive half cycle, the third operational amplifier U3 outputs a positive signal, making the diode D1 conduct and the diode D3 cut off. At the same time, the capacitor C1 is charged, driving the output voltage VOUT to change accordingly until VOUT is equal to the input signal (pin 3 of the third operational amplifier U3), and then the charging process stops. When the input signal (pin 3 of the third operational amplifier U3) decreases, the diode D1 cuts off, and VOUT remains the just peak voltage unchanged. In this way, the peak detection of the circuit is realized.

[0045] In summary, the linear half-wave rectifier circuit is implemented by the third integrated operational amplifier U3. When the input signal is in the positive half-cycle, the third integrated operational amplifier U3 outputs a positive signal, causing the diode D1 to conduct and the diode D3 to cut off. At the same time, the capacitor C1 starts to charge, making the output voltage VOUT follow the change of the input signal until VOUT equals the input signal and the charging stops.

[0046] The voltage follower circuit is implemented by the fourth integrated operational amplifier U4. It maintains the stability of the output through the resistor R7 connected to the inverting input terminal of the third integrated operational amplifier U3, and provides negative feedback through the connection between the inverting input terminal and the output terminal.

[0047] The circuit can accurately detect the peak value of the input signal and hold it at the output for subsequent use; the voltage follower circuit ensures the stability of the output through the negative feedback mechanism, reducing the drift and error of the circuit; the combination of the linear half-wave rectifier circuit and the voltage follower circuit realizes the accurate detection and tracking of the peak value of the input signal, ensuring the accuracy and reliability of the output.

[0048] The precision rectifier and peak voltage detection and alarm circuit for automotive headlights can effectively detect the peak value of the input signal and provide a stable and accurate output, which is suitable for various application scenarios that require peak detection.

[0049] The above-mentioned precision rectifier and peak voltage detection and alarm circuit for automotive headlights, by setting the rectification unit 10 and the peak detection unit 20, uses the rectification unit 10 for precision rectification, and then uses the peak detection unit 20 for peak voltage detection. When the voltage exceeds the threshold, an early warning is given in time, realizing the overcoming of the distortion problem that occurs in the existing circuit using diodes for rectification, and using a simple circuit to realize voltage peak detection.

[0050] The above is only the specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present utility model. Therefore, the protection scope of the present utility model shall be subject to the protection scope of the claims.

Claims

1. A precise rectification and peak voltage detection and alarm circuit for an automotive headlight, characterized in that, Comprising: A rectification unit and a peak detection unit. The rectification unit is used to rectify an input AC signal to obtain a rectification result. The peak detection unit is used to detect the peak voltage of the rectification result and output an alarm signal when the peak voltage is higher than a set threshold.

2. The precision rectification and peak voltage detection and alarm circuit for an automotive headlight according to claim 1, characterized in that, The rectification unit includes an inverting proportional operation amplifier circuit and an inverting adder circuit; the inverting proportional operation amplifier circuit is connected to the inverting adder circuit; the inverting adder circuit is connected to the peak detection unit.

3. The precision rectification and peak voltage detection and alarm circuit for an automotive headlight according to claim 2, characterized in that, The inverting proportional operation amplifier circuit includes a first-stage integrated operational amplifier U2. The inverting input terminal of the first-stage integrated operational amplifier U2 is connected to an AC input device; the output terminal of the first-stage integrated operational amplifier U2 is connected to the inverting adder circuit through a diode D2; a diode D4 is connected between the output terminal of the first-stage integrated operational amplifier U2 and the inverting input terminal of the first-stage integrated operational amplifier U2; a resistor R8 is connected in parallel with the diode D4.

4. The precision rectification and peak voltage detection and alarm circuit for an automotive headlight according to claim 3, wherein, The inverting adder circuit includes a second-stage integrated operational amplifier U1. The inverting input terminal of the second-stage integrated operational amplifier U1 is connected to the diode D2; the output terminal of the second-stage integrated operational amplifier U1 is connected to the peak detection unit; the output terminal of the second-stage integrated operational amplifier U1 and the inverting input terminal of the second-stage integrated operational amplifier U1 are connected through a resistor R10; the output terminal of the second-stage integrated operational amplifier U1 is connected to the inverting input terminal of the first-stage integrated operational amplifier U2 through a circuit R9.

5. The precision rectification and peak voltage detection and alarm circuit for an automotive headlight according to claim 4, characterized in that, The peak detection unit includes a linear half-wave rectification circuit and a voltage follower circuit; the inverting adder circuit is connected to the linear half-wave rectification circuit; the linear half-wave rectification circuit is connected to the voltage follower circuit.

6. The precision rectification and peak voltage detection and alarm circuit for an automotive headlight according to claim 5, wherein The linear half-wave rectification circuit includes a third integrated operational amplifier U3. The non-inverting input terminal of the third integrated operational amplifier U3 is connected to the output terminal of the second-stage integrated operational amplifier U1; the output terminal of the third integrated operational amplifier U3 and the inverting input terminal of the third integrated operational amplifier U3 are respectively connected to the voltage follower circuit.

7. The precision rectification and peak voltage detection and alarm circuit for an automotive headlamp according to claim 6, characterized in that, The output terminal of the third integrated operational amplifier U3 is connected to the voltage follower circuit through a diode D1; the inverting input terminal of the third integrated operational amplifier U3 is connected to the output terminal of the third integrated operational amplifier U3 through a diode D3; one end of a capacitor C1 is connected between the diode D1 and the voltage follower circuit, and the other end of the capacitor C1 is grounded through a resistor R1.

8. The precision rectification and peak voltage detection and alarm circuit for an automotive headlamp according to claim 7, characterized in that, The voltage follower circuit includes a fourth integrated operational amplifier U4. The non-inverting input terminal of the fourth integrated operational amplifier U4 is connected to the diode D1; the inverting input terminal of the fourth integrated operational amplifier U4 is connected to the inverting input terminal of the third integrated operational amplifier U3 through a resistor R7; the output terminal of the fourth integrated operational amplifier U4 is connected to the inverting input terminal of the fourth integrated operational amplifier U4.

9. The precision rectification and peak voltage detection and alarm circuit for an automotive headlamp according to claim 8, wherein It also includes a resistor R4. One end of the resistor R4 is connected between the diode D1 and the non-inverting input terminal of the fourth integrated operational amplifier U4, and the other end is grounded.

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