阅读说明：本技术 一种自动识别输入正负极的dc-dc12v10a转换器 (DC-DC12V10A converter capable of automatically identifying input positive and negative poles ) 是由 马光路 董静 于 2021-07-16 设计创作，主要内容包括：本发明涉及汽车电路技术领域,尤其是一种自动识别输入正负极的DC-DC12V10A转换器,包括主电路和控制电路,所述控制电路由控制芯片、稳压电路、振荡电路和脉冲输出电路组成,本发明提供了一种具有自动识别输入正负极的DC-DC转换器,本发明提供了一种具有自动识别输入正负极的DC-DC转换器,该转换器通过一个大功率的整流桥,使输入的电压极性变成无极性的,这样就能完全的避免,输入电压极性不一致,而烧坏用电器的问题,本发明无论输入端的极性如何,输出端始终输出一个正向电压来给转换器内部电路供电,都能使转换器正常工作,输出DC12V10A低电压,为电动工具,设备提供工作电源。(The invention relates to the technical field of automobile circuits, in particular to a DC-DC12V10A converter capable of automatically identifying input positive and negative poles, which comprises a main circuit and a control circuit, wherein the control circuit consists of a control chip, a voltage stabilizing circuit, an oscillating circuit and a pulse output circuit, the invention provides a DC-DC converter capable of automatically identifying the input positive and negative poles, the polarity of input voltage is changed into nonpolarity through a high-power rectifier bridge, so that the problem that electrical appliances are burnt out due to inconsistent input voltage polarity can be completely avoided, no matter how the polarity of an input end is, an output end always outputs a positive voltage to supply power for an internal circuit of the converter, the converter can normally work, and the DC12V10A low voltage is output and is an electric tool, the device provides operating power.)

1. A DC-DC12V10A converter capable of automatically identifying input positive and negative poles is characterized in that: the circuit comprises a main circuit and a control circuit, wherein the main circuit comprises a polarity automatic switching circuit, and the control circuit comprises a control chip, a voltage stabilizing circuit, an oscillating circuit and a pulse output circuit.

2. The DC-DC12V10A converter for automatically identifying input positive and negative poles according to claim 1, wherein: the control chip is provided with eight pins including a 1 st pin COMP, a 2 nd pin VFB, a 3 rd pin ISENSE, a 4 th pin RT/CT, a 5 th pin GROUND, a 6 th pin OUTPUT, a 7 th pin VCC and an 8 th pin VREF.

3. The DC-DC12V10A converter for automatically identifying input positive and negative poles according to claim 2, wherein: the polarity automatic switching circuit comprises a rectifier bridge.

4. The DC-DC12V10A converter for automatically identifying input positive and negative poles according to claim 3, wherein: the main circuit comprises a power supply input end and a power supply output end which are arranged behind the automatic polarity switching circuit, the power supply input end and the power supply output end are both connected with a filter element, one path of the input power supply is connected with a VCC pin of a control chip, the other path of the input power supply is connected with an MOS (metal oxide semiconductor) tube, a filter capacitor, a Schottky diode, an energy storage inductor and an over-current detection resistor, and the anode of the filter capacitor and the drain of the MOS tube are both connected with the anode of the input power supply; the source electrode of the MOS tube is connected with the over-current detection resistor, the MOS tube is connected with an ISENSE pin of the control chip through the over-current detection resistor, and simultaneously connected with the energy storage inductor and the Schottky diode respectively, the Schottky diode is connected with the energy storage inductor, and the other end of the energy storage inductor is connected with the output filter capacitor and the transient suppression diode respectively.

5. The DC-DC12V10A converter for automatically identifying input positive and negative poles according to claim 4, wherein: the voltage stabilizing circuit consists of a voltage stabilizing module, two voltage regulating resistors, an optocoupler and a load resistor and is connected with a COMP pin and a VFB pin of the control chip, and the voltage stabilizing module provides 2.5V reference voltage for the VFB pin.

6. The DC-DC12V10A converter for automatically identifying input positive and negative poles according to claim 5, wherein: the oscillating circuit consists of a resistor and a capacitor and is connected with an RT-CT pin of the control chip.

7. The DC-DC12V10A converter for automatically identifying input positive and negative poles according to claim 6, wherein: and an OUTPUT pin of the control chip OUTPUTs pulses, and the pulses are respectively connected with the grid of the MOS tube through resistors to drive the MOS tube to work.

8. The DC-DC12V10A converter for automatically identifying input positive and negative poles according to claim 7, wherein: the energy storage inductor is an annular energy storage inductor.

9. The DC-DC12V10A converter for automatically identifying input positive and negative poles according to claim 8, wherein: the model of the control chip is YW/UTC 3845E.

Technical Field

The invention relates to the technical field of automobile circuits, in particular to a DC-DC12V10A converter capable of automatically identifying input positive and negative poles.

Background

In the current electric vehicle popularization age, electric tools and electric equipment related to the electric vehicle are also in variety, for example, an inflator special for the electric vehicle, a water pump special for the electric vehicle, an electric grinder special for the electric vehicle, a cotton candy machine special for the electric vehicle, an earthworm machine special for the electric vehicle, and other 12V low-voltage electric appliances. The electric tools and equipment are directly plugged into a charging port of an electric vehicle, are plug-and-play and are very convenient to use. However, the polarities of the positive electrode and the negative electrode output by the charging ports of the electric vehicles of different brands are not uniform and have no standard, so that the charging ports are very annoying to manufacturers and users. Tools, equipment and charging ports are often burnt out due to the fact that the positive electrode and the negative electrode are not opposite, and the whole vehicle circuit is seriously ignited. Causing great economic property loss. Whether a DC-DC converter capable of automatically identifying the positive electrode and the negative electrode exists or not becomes a technical problem to be solved.

Disclosure of Invention

The purpose of the invention is: the defects in the prior art are overcome, and the DC-DC12V10A converter capable of automatically identifying the input positive and negative electrodes is provided.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a DC-DC12V10A converter capable of automatically identifying input positive and negative electrodes comprises a main circuit and a control circuit, wherein the main circuit comprises a polarity automatic switching circuit, and the control circuit comprises a control chip, a voltage stabilizing circuit, an oscillating circuit and a pulse output circuit.

Furthermore, the control chip is provided with eight pins including a 1 st pin COMP, a 2 nd pin VFB, a 3 rd pin ISENSE, a 4 th pin RT/CT, a 5 th pin GROUND, a 6 th pin OUTPUT, a 7 th pin VCC, and an 8 th pin VREF.

Further, the polarity automatic switching circuit comprises a rectifier bridge.

Furthermore, the main circuit comprises a power supply input end and a power supply output end which are arranged behind the automatic polarity switching circuit, the power supply input end and the power supply output end are both connected with a filter element, one path of the input power supply is connected with a VCC pin of the control chip, the other path of the input power supply is connected with an MOS tube, a filter capacitor, a Schottky diode, an energy storage inductor and an overcurrent detection resistor, and the anode of the filter capacitor and the drain of the MOS tube are both connected with the anode of the input power supply; the source electrode of the MOS tube is connected with the over-current detection resistor, the MOS tube is connected with an ISENSE pin of the control chip through the over-current detection resistor, and simultaneously connected with the energy storage inductor and the Schottky diode respectively, the Schottky diode is connected with the energy storage inductor, and the other end of the energy storage inductor is connected with the output filter capacitor and the transient suppression diode respectively.

Furthermore, the voltage stabilizing circuit consists of a voltage stabilizing module, two voltage regulating resistors, an optocoupler and a load resistor, and is connected with a COMP pin and a VFB pin of the control chip, and the voltage stabilizing module provides 2.5V reference voltage for the VFB pin.

Furthermore, the oscillation circuit consists of a resistor and a capacitor and is connected with an RT-CT pin of the control chip.

Furthermore, the OUTPUT pin of the control chip OUTPUTs pulses, and the pulses are respectively connected with the grid electrode of the MOS tube through resistors to drive the MOS tube to work.

Further, the energy storage inductor is an annular energy storage inductor.

Furthermore, the model of the control chip is YW/UTC 3845E.

The technical scheme adopted by the invention has the beneficial effects that:

1. the invention provides a DC-DC converter with automatic identification input positive and negative poles, which changes the input voltage polarity into nonpolarity through a high-power rectifier bridge, thus completely avoiding the problem that the input voltage polarity is inconsistent and the electrical appliance is burnt.

2. The main circuit can realize polarity automatic switching circuit, energy storage and output overvoltage protection, and the control circuit plays a role in voltage stabilization in the circuit.

3. One path of the input power supply is connected with a VCC pin of the control chip to provide starting voltage for the control chip, and stable +12V working voltage is output through the fast recovery diode.

4. The voltage stabilizing circuit consists of a voltage stabilizing module, two voltage regulating resistors, an optical coupler and a load resistor and is connected with a COMP pin and a VFB pin of the control chip, the voltage stabilizing module provides 2.5V reference voltage for the VFB pin, when the output voltage is too low or too high, the voltage stabilizing module and the two voltage regulating resistors jointly act to provide sampling voltage, and the conduction pulse width of the MOS tube is controlled after the feedback of the optical coupler is compared with the 2.5V reference voltage in the VFB pin of the control chip, so that the output voltage is stable, and the output voltage is still not lower than 12V under the condition of a full load of 10A.

5. The OUTPUT pin of the control chip OUTPUTs pulses, the pulses are respectively connected with the grid electrode of the MOS tube through resistors to drive the MOS tube to work, and when the MOS tube is conducted, OUTPUT current is filtered by a filter capacitor to supply power to a load; when the load is short-circuited or exceeds the set maximum allowable current, the voltage of the ISENSE pin of the control chip rises, and the OUTPUT pulse of the OUTPUT pin is adjusted through the control chip, so that the MOS tube is cut off, the MOS tube is protected from being damaged, and an overcurrent protection circuit is formed; when the MOS tube is cut off, the energy storage inductor forms an energy storage circuit to convert magnetic energy into electric energy, the polarity of the electric energy is negative on the left and positive on the right, the Schottky diode is conducted to form a follow current circuit, and power is continuously supplied to the load, so that the load obtains smooth direct current; when the output voltage is higher than the set maximum allowable output voltage, the transient suppression diode is damaged by reverse breakdown to form an output overvoltage protection circuit; the output voltage of the converter is almost zero, so that the load is protected from being damaged.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise. Wherein

Fig. 1 is a circuit diagram of the present invention.

The circuit comprises a U1 control chip U2 optical coupler Q3 voltage stabilizing module D1 fast recovery diode D2 transient suppression diode D3 rectifier bridge Q1 MOS tube Q2 Schottky diode L1 annular energy storage inductor R4 control chip U1 starting resistor R3 overcurrent detection resistor R7 and R8 voltage regulating resistor.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic views illustrating only the basic structure of the present invention in a schematic manner, and thus show only the constitution related to the present invention. The present invention is described in detail by using schematic structural diagrams and the like, which are only examples and should not limit the protection scope of the present invention. In addition, the actual fabrication process should include three-dimensional space of length, width and depth.

As shown in fig. 1, a DC-DC12V10A converter for automatically identifying input positive and negative poles comprises a main circuit and a control circuit, wherein the main circuit comprises an automatic polarity switching circuit, and a rectifier bridge D3 in the automatic polarity switching circuit, when a positive voltage and a negative voltage are input to an input end, the output voltage outputs a positive voltage through the switching of two diagonal positive voltage diodes inside, so as to supply power to the main circuit and the control circuit; when the input end inputs voltages of upper negative and lower positive, the output voltage still outputs forward voltage through the conversion of two diagonal reverse voltage diodes inside, and the main circuit and the control circuit are powered; and the automatic identification of the input voltage is realized. The DC high voltage of a storage battery pack is input to a power input end of the main circuit, one path of the DC high voltage is connected with a pin 7 of a control chip U1 through a starting resistor R4 to provide starting voltage for the control chip U1, two capacitors C2 and C4 which are connected in parallel are connected behind the resistor R4 to filter power entering the control chip U1, the positive electrode of the capacitor C4 is connected with the cathode of a fast recovery diode D1, the anode of the fast recovery diode D1 is connected with the voltage of +12V, the cathode outputs the voltage of +12V, and stable working voltage is provided for the control chip U1; the power input end is also connected with the anode of an input power filter capacitor C9 and the drain of an MOS tube Q1, and the cathode of the power filter capacitor C9 is grounded; the gate of the MOS transistor Q1 is connected to pin 6 of the control chip U1 through a resistor R3. The source of the MOS transistor Q1 is connected with an overcurrent detection resistor R3, and is connected with the 3 rd pin of the control chip U1 through an overcurrent detection resistor R3, and is simultaneously connected with an energy storage inductor L1 and the cathode of a schottky diode Q2, and a schottky diode Q2 is connected with an energy storage inductor L1, and the other end of the energy storage inductor L1 is connected with the anode of a power output filter capacitor C8 and the cathode of a transient suppression diode D2; the cathode of the power supply output filter capacitor C8 and the anode of the transient suppression diode D2 are grounded.

The voltage stabilizing circuit consists of a voltage stabilizing module Q3, voltage regulating resistors R7 and R8, an optocoupler U2 and a load resistor R10, wherein a 1 st pin of the voltage stabilizing module Q3 is connected with a voltage output end of the converter after voltage division through the voltage regulating resistors R7 and R8, a 2 nd pin is grounded, a 3 rd pin provides 2.5V reference voltage for a 2 nd pin of a control chip U1 through the optocoupler U2, two pins of a light receiver of the optocoupler U2 are respectively connected with the 1 st pin and the 2 nd pin of the control chip U1, one pin of a light emitter is connected with an output voltage end through the resistor R9, and the other pin is respectively connected with a capacitor C7 and the 3 rd pin of the voltage stabilizing module Q3; when the output voltage is too low or too high, the voltage stabilizing module Q3 and the voltage regulating resistors R7 and R8 jointly act to provide sampling voltage, and the sampling voltage is fed back by the optical coupler U2 and compared with the 2.5V reference voltage in the 2 nd pin of the control chip U1 to control the conduction pulse width of the MOS transistor Q1, so that the output voltage is stable, and the output voltage is ensured to be still not lower than 12V under the condition that the converter is fully loaded with 10A.

The resistor R5 and the capacitor C3 form an oscillating circuit of the control chip U1 and are connected with the 4 th pin of the U1; the 6 th pin of the control chip U1 outputs pulses, which are respectively connected with the grid of the MOS tube Q1 through resistors R1 and R2 to drive the MOS tube Q1 to work, and when the MOS tube Q1 is switched on, the output current is filtered by a filter capacitor C8 through L1 to supply power to a load; when the load is short-circuited or exceeds the set maximum allowable current, the voltage of the 3 rd pin of the control chip U1 rises, the output pulse of the 6 th pin is adjusted through the control chip U1, the MOS tube Q1 is cut off, the MOS tube Q1 is protected from being damaged, and an overcurrent protection circuit is formed; when the MOS transistor Q1 is turned off, the energy storage inductor L1 forms an energy storage circuit to convert magnetic energy into electric energy, the polarity of the electric energy is negative left, positive right, and the schottky diode Q2 is turned on to form a freewheeling circuit to continue supplying power to the load, so that the load obtains a smooth direct current; when the output voltage is higher than the set maximum allowable output voltage, the transient suppression diode D2 is broken down in a reverse breakdown mode to form an output overvoltage protection circuit; the output voltage of the converter is almost zero, so that the load is protected from being damaged.

In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.