CN216915764U

CN216915764U - Analog current control circuit based on rain-proof short circuit interference

Info

Publication number: CN216915764U
Application number: CN202121753994.6U
Authority: CN
Inventors: 柴晓兰; 马振波; 王书仓
Original assignee: Zhejiang Sitis Technology Co ltd
Current assignee: Zhejiang Sitis Technology Co ltd
Priority date: 2021-07-29
Filing date: 2021-07-29
Publication date: 2022-07-08
Anticipated expiration: 2031-07-29

Abstract

The utility model discloses an analog current control circuit based on rainwater short circuit interference prevention, and relates to the technical field of electronic circuits. Comprises a high level input end connected with the positive pole of the driver/bulb and providing a high level input; a reference end of the reference voltage comparator is externally connected with an input signal end, and an anode of the reference voltage comparator is grounded; the voltage stabilizing and dividing unit comprises a first voltage dividing resistor, a voltage stabilizing tube and a second voltage dividing resistor; the first end of the first divider resistor is connected with the high-level input end, and the second end of the first divider resistor is connected with the negative electrode of the voltage-stabilizing tube and the cathode of the reference voltage comparator; the anode of the voltage-stabilizing tube is connected with the first end of the second voltage-dividing resistor and is used as the output end of the voltage-stabilizing voltage-dividing unit to output an analog voltage. The utility model avoids the phenomenon that the drive module on the vehicle works by mistake due to rainwater.

Description

Analog current control circuit based on rainwater short circuit interference prevention

Technical Field

The utility model relates to the technical field of electronic circuits, in particular to an analog current control circuit based on rainwater short circuit interference prevention.

Background

With the development of technology, more and more driving modules are integrated on the vehicle, such as a high-low beam driving module control, a turn signal driving module control and the like. When the vehicle is exposed in rainy days, the switch is likely to contact rainwater to cause rainwater short circuit, and micro current is generated, so that the circuit is interfered by the rainwater short circuit to abnormally work. Therefore, how to develop a control circuit capable of avoiding the short-circuit interference of rainwater is one of the problems to be solved urgently.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide an analog current control circuit based on rainwater short circuit interference prevention, which avoids the phenomenon that a driving module on a vehicle works mistakenly due to rainwater.

In order to achieve the purpose, the utility model provides the following technical scheme:

an analog current control circuit based on rain-proof short circuit interference comprises

The high-level input end is connected with the positive electrode of the driving/bulb and provides a high-level input;

a reference end of the reference voltage comparator is externally connected with an input signal end, and an anode of the reference voltage comparator is grounded;

the voltage stabilizing and dividing unit comprises a first voltage dividing resistor, a voltage stabilizing tube and a second voltage dividing resistor; the first end of the first divider resistor is connected with the high-level input end, and the second end of the first divider resistor is connected with the negative electrode of the voltage-stabilizing tube and the cathode of the reference voltage comparator; the anode of the voltage-stabilizing tube is connected with the first end of the second voltage-dividing resistor and is used as the output end of the voltage-stabilizing voltage-dividing unit to output an analog voltage.

Compared with the prior art, the utility model has the beneficial effects that: the utility model identifies whether the input signal end inputs a normal low current or a short-circuit signal caused by rainwater short circuit through the reference voltage comparator, and the analog voltage output by the output end of the voltage-stabilizing voltage-dividing unit is a high level under the condition of inputting the normal low current; on the contrary, under the condition of a short-circuit signal caused by rainwater short circuit, the analog voltage output by the output end of the voltage-stabilizing voltage-dividing unit is zero level; therefore, the interference to the circuit in the vehicle caused by the short circuit of the rainwater is avoided.

Further, the voltage stabilizing and voltage dividing circuit further comprises an anti-reverse connection unit, wherein the anti-reverse connection unit is arranged between the voltage stabilizing and voltage dividing unit and the high-level input end and comprises a diode VD 1.

Furthermore, the device also comprises an anti-interference unit, wherein the anti-interference unit is connected with the input signal end and comprises a plurality of capacitors connected in parallel.

Further, the overvoltage protection circuit further comprises an overvoltage protection unit, wherein the overvoltage protection unit is arranged between the reference voltage comparator and the input signal end and comprises a diode VD3 connected in an opposite mode.

Further, the reference voltage comparator has a model number ME 432.

Drawings

Fig. 1 is a schematic block diagram of a circuit according to an embodiment of the present invention.

Fig. 2 is a specific circuit diagram of an embodiment of the utility model.

In the figure: 10. a high level input terminal; 11. an anti-reverse connection unit; 12. an input signal terminal; 13. an overvoltage protection unit; 14. an anti-interference unit; 15. a reference voltage comparator; 16. a voltage stabilizing and dividing unit; 17. a drive module; 18. and a ground terminal.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

Referring to fig. 1 and fig. 2, the present embodiment provides an analog current control circuit based on rain short circuit interference, including:

a high level input terminal 10, connected to the positive terminal of the driver/bulb, providing a high level input VCC + 12V;

a ground terminal 18 providing ground GND;

an input signal terminal 12 for providing an input signal;

the reference voltage comparator 15 adopts a reference voltage comparator Q1 with model number ME432, a reference end R thereof is externally connected with the input signal end 12, an anode a is grounded, and a cathode K is connected with the voltage-stabilizing voltage-dividing unit 16. The reference terminal of the reference voltage comparator 15 is also connected to the high level input terminal 10 through a resistor R3 and a resistor R2.

The voltage stabilizing and dividing unit 16 comprises a first voltage dividing resistor R1, a voltage stabilizing tube DZ1 and a second voltage dividing resistor R4; the first end of the first voltage-dividing resistor R1 is connected with the high-level input end 12, and the second end of the first voltage-dividing resistor R1 is connected with the cathode of the voltage-regulator tube DZ1 and the cathode K of the reference voltage comparator 15; the anode of the voltage regulator DZ1 is connected to the first end of the second voltage divider resistor R4, and serves as the output end of the voltage regulator voltage divider 16, outputting an analog voltage to the DIM pin of the driving module 17. When the DIM pin of the driving module 17 receives a high level, the load works; the operation unit operates when receiving a zero level (ground signal). It is worth mentioning that the voltage regulator DZ1 is a 3.6V voltage regulator with model number MM3Z3V6VT 1G.

When a normal low-current negative signal is input, the voltage is about 0.7V and is less than the reference voltage 1.25V of the reference voltage comparator 15, the reference voltage comparator 15 does not work, and the circuit is broken between the anode A and the cathode K. And at the point B and the point C in the voltage stabilizing and dividing unit 16, the voltage is divided according to the normal working voltage, and the point C outputs a high level, so that the rear-end driving module works. When rainwater and other negative signals are in short circuit, the signal impedance is increased, the signal is similar to the situation that the negative signal is connected with the resistance input of more than 1K, the voltage input to the reference end of the reference voltage comparator 15 is higher than the reference voltage by 1.25V, the reference voltage comparator 15 works, the cathode K is conducted with the anode A, the voltage of the point B is directly pulled down to zero potential in the voltage-stabilizing voltage-dividing unit 16, therefore, the output end (point C) also outputs zero level, and the rear-end driving module does not work.

In this embodiment, in order to avoid the circuit reverse connection, the voltage divider further includes a reverse connection preventing unit 11, where the reverse connection preventing unit 11 is disposed between the voltage divider 16 and the high level input end 10, and includes a diode VD 1.

When the circuit is in misoperation, an input signal is unstable, and high-frequency pulses can be generated, so that the normal operation of the circuit is influenced. In order to solve the interference caused by the malfunction, the present embodiment further includes an anti-interference unit 14, where the anti-interference unit 14 is connected to the input signal terminal 12, and includes a plurality of capacitors connected in parallel, such as the capacitor C6, the capacitor C7, and the capacitor C8 in fig. 2, and plays a role in absorbing the high-frequency pulse, so as to eliminate the interference caused by the malfunction.

In this embodiment, the overvoltage protection device 13 is further included, and the overvoltage protection device 13 is disposed between the reference voltage comparator 14 and the input signal terminal 12 and includes a diode VD3 connected in reverse. When a normal low-current negative signal is input, the diode VD2 is under reverse bias, and only weak reverse current flows through the diode VD3, which is called leakage current; when rainwater is in short circuit with other negative signals, the reverse current is increased sharply, the diode VD3 is broken down, and the unidirectional conducting characteristic is lost.

At the moment when the output end of the voltage-stabilizing voltage-dividing unit 16, i.e. the point C, is switched between high and low levels, the DIM pin of the driving module 17 is damaged. In order to avoid this phenomenon, a capacitor C5 is further included, and the capacitor C5 is connected in parallel with the second voltage-dividing resistor R4 to protect the DIM pin of the driving module 17.

It will be evident to those skilled in the art that the utility model is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the utility model being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims

1. An analog current control circuit based on rain-proof short circuit interference is characterized by comprising

the reference end of the reference voltage comparator is externally connected with the input signal end, and the anode of the reference voltage comparator is grounded;

2. The analog current control circuit based on rainwater short circuit interference prevention according to claim 1, characterized by further comprising an anti-reverse connection unit, wherein the anti-reverse connection unit is arranged between the voltage-stabilizing voltage-dividing unit and the high-level input end and comprises a diode VD 1.

3. The analog current control circuit based on rainwater short circuit interference prevention according to claim 1, characterized by further comprising an anti-interference unit, wherein the anti-interference unit is connected with the input signal end and comprises a plurality of capacitors connected in parallel.

4. The analog current control circuit based on rainwater short circuit interference prevention is characterized by further comprising an overvoltage protection unit, wherein the overvoltage protection unit is arranged between the reference voltage comparator and the input signal end and comprises a diode VD3 connected in reverse.

5. The analog current control circuit based on rainwater short circuit interference prevention according to claim 1, wherein the model of the reference voltage comparator is ME 432.