Optimized reverse electromotive force circuit

Abstract

The utility model discloses an optimized counter electromotive force circuit, including anti-counter electromotive force power supply circuit, master control circuit and voltage feedback circuit, the master control circuit is respectively with anti-counter electromotive force power supply circuit and voltage feedback circuit electrical connection, the voltage feedback circuit includes photoelectric coupler U1, photoelectric coupler U1, photoelectric coupler U2, photoelectric coupler U3, photoelectric coupler U4, photoelectric coupler U5, photoelectric coupler U6, photoelectric coupler U7, photoelectric coupler U7, photoelectric coupler U8, photoelectric coupler U8, photoelectric coupler U8, photoelectric coupler U8, photoelectric coupler U8. The anode of the photoelectric coupler U1 is electrically connected with the output end VOUT through a resistor R28, the cathode of the photoelectric coupler U1 is grounded through a voltage-regulator tube U3, a resistor R33 is connected between the reference end and the anode of the voltage-regulator tube U3, two ends of the resistor R33 are connected with a resistor R32 in parallel, and the reference end of the voltage-regulator tube U3 is further electrically connected with the output end VOUT through a resistor R31. The optimized back electromotive force circuit disclosed by the utility model effectively solves the problem that a power supply is turned off due to a power supply protection mode caused by back electromotive force at an output end.

Description

Technical Field

[0001] The utility model belongs to the technical field of anti-back electromotive force, and in particular relates to an optimized back electromotive force circuit. Background Art

[0002] In the design of the motor drive solution, when the power supply supplies power to the motor, when the motor rotates forward and reverse, a very high reverse electromotive force will be generated. This electromotive force will force the internal power supply circuit of the power supply to lose power, resulting in abnormal output voltage. At this time, the client control board will detect the abnormal voltage, causing the control board to restart, affecting use.

[0003] Therefore, further improvements are made to the above problems. Utility Model Content

[0004] The main purpose of the utility model is to provide a circuit for optimizing reverse electromotive force, which effectively solves the problem that the power supply protection mode caused by the reverse electromotive force at the output end leads to power supply shutdown.

[0005] To achieve the above purpose, the utility model provides an optimized reverse electromotive force circuit, including a reverse electromotive force protection power supply circuit, a main control circuit and a voltage feedback circuit, wherein the main control circuit is electrically connected to the reverse electromotive force protection power supply circuit and the voltage feedback circuit respectively, wherein:

[0006] The voltage feedback circuit includes a photocoupler U1, an anode of the photocoupler U1 is electrically connected to an output terminal VOUT (V+) through a resistor R28, and a cathode of the photocoupler U1 is grounded through a voltage regulator U3, a resistor R33 is connected between a reference terminal and an anode of the voltage regulator U3, and two ends of the resistor R33 are connected in parallel to a resistor R32, and the reference terminal of the voltage regulator U3 is also electrically connected to an output terminal VOUT through a resistor R31;

[0007] The main control circuit includes a controller U2 and a field effect transistor Q1, the FB terminal (pin 2) of the controller U2 is electrically connected to the collector of the photocoupler U1, the GATE terminal (pin 6) of the controller U2 is electrically connected to the gate of the field effect transistor Q1 through a resistor R18, and the GATE terminal of the controller U2 is electrically connected to the VCC terminal (pin 5), and the source of the transistor Q1 is grounded through a resistor R23 in one way and electrically connected to the CS terminal of the controller U2 in the other way;

[0008] The anti-reverse electromotive force power supply circuit includes electrolytic capacitors EC2, EC3, EC4 and EC5. The GATE end of the controller U2 is electrically connected to the first end (pin 1) of the transformer TR1 through resistor R11, diode D4, resistor R12 and diode D2 in sequence. The cathode of the diode D4 is grounded through the electrolytic capacitor EC5, and the anode of the diode D4 is grounded through the electrolytic capacitor EC4, the electrolytic capacitor EC3 and the electrolytic capacitor EC2 respectively.

[0009] As a further preferred technical solution of the above technical solution, the end of the resistor R11 away from the controller U2 is also connected to the fourth end (pin 4) of the transformer TR1 through the resistor R1, and the fourth end of the transformer TR1 is also electrically connected to the input end Vin and the electrolytic capacitor EC1 respectively.

[0010] As a further preferred technical solution of the above technical solution, the drain of the field effect transistor Q1 is electrically connected to the sixth end (pin 6) of the transformer TR1, and a resistor R19 is connected between the gate and source of the field effect transistor Q1.

[0011] As a further preferred technical solution of the above technical solution, the eleventh terminal (pin 11) of the transformer TR1 is connected to the output terminal VOUT through a diode D6.

[0012] As a further preferred technical solution of the above technical solution, the cathode of the diode D6 is also electrically connected to the ninth end (pin 9) of the transformer TR1 through an electrolytic capacitor EC6. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The utility model discloses a circuit diagram of an optimized reverse electromotive force circuit. DETAILED DESCRIPTION

[0014] The following description is used to disclose the utility model so that those skilled in the art can implement the utility model. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the utility model defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the utility model.

[0015] The utility model discloses an optimized reverse electromotive force circuit. The specific embodiments of the utility model are further described below in conjunction with the preferred embodiments.

[0016] In the embodiments of the present invention, those skilled in the art will note that the output terminal VOUT and the input terminal Vin involved in the present invention may be regarded as prior art.

[0017] Preferred embodiments.

[0018] like Figure 1 As shown, the utility model discloses an optimized reverse electromotive force circuit, including a reverse electromotive force protection power supply circuit, a main control circuit and a voltage feedback circuit, wherein the main control circuit is electrically connected to the reverse electromotive force protection power supply circuit and the voltage feedback circuit respectively, wherein:

[0019] The voltage feedback circuit includes a photocoupler U1, an anode of the photocoupler U1 is electrically connected to an output terminal VOUT (V+) through a resistor R28, and a cathode of the photocoupler U1 is grounded through a voltage regulator U3, a resistor R33 is connected between a reference terminal and an anode of the voltage regulator U3, and two ends of the resistor R33 are connected in parallel to a resistor R32, and the reference terminal of the voltage regulator U3 is also electrically connected to an output terminal VOUT through a resistor R31;

[0020] The main control circuit includes a controller U2 and a field effect transistor Q1, the FB terminal (pin 2) of the controller U2 is electrically connected to the collector of the photocoupler U1, the GATE terminal (pin 6) of the controller U2 is electrically connected to the gate of the field effect transistor Q1 through a resistor R18, and the GATE terminal of the controller U2 is electrically connected to the VCC terminal (pin 5), and the source of the transistor Q1 is grounded through a resistor R23 in one way and electrically connected to the CS terminal of the controller U2 in the other way;

[0021] The anti-reverse electromotive force power supply circuit includes electrolytic capacitors EC2, EC3, EC4 and EC5. The GATE end of the controller U2 is electrically connected to the first end (pin 1) of the transformer TR1 through resistor R11, diode D4, resistor R12 and diode D2 in sequence. The cathode of the diode D4 is grounded through the electrolytic capacitor EC5, and the anode of the diode D4 is grounded through the electrolytic capacitor EC4, the electrolytic capacitor EC3 and the electrolytic capacitor EC2 respectively.

[0022] Specifically, the end of the resistor R11 away from the controller U2 is also connected to the fourth end (pin 4) of the transformer TR1 through the resistor R1, and the fourth end of the transformer TR1 is also electrically connected to the input end Vin and the electrolytic capacitor EC1 respectively.

[0023] More specifically, the drain of the field effect transistor Q1 is electrically connected to the sixth end (pin 6) of the transformer TR1, and a resistor R19 is connected between the gate and source of the field effect transistor Q1.

[0024] Furthermore, the eleventh terminal (pin 11) of the transformer TR1 is connected to the output terminal VOUT via a diode D6.

[0025] Furthermore, the cathode of the diode D6 is also electrically connected to the ninth terminal (pin 9) of the transformer TR1 through the electrolytic capacitor EC6.

[0026] For this utility model:

[0027] When Vout is connected to an inductive load, such as a motor power supply, when the motor switches forward and reverse, a reverse electromotive force will be generated, causing the voltage of the voltage feedback circuit to increase, and then fed back to the 2nd pin (FB) of the main control circuit U2 through the 4th pin of U1, so that the 6th pin (GATE) of U2 turns off the MOS tube Q1, forcing the voltage of the electrolytic capacitor EC5 to decrease, and the voltage of the 5th pin (VCC) of U2 to drop. When the reverse electromotive force appears and causes the voltage of the 5th pin (VCC) of U2 to drop, its power-off time can be extended (electrolytic capacitors EC2, EC3, EC4 are connected to the positive pole of the diode D4 to increase the power supply capacity to U2). Because the reverse electromotive force time is very short, the extended power-off time is sufficient to support the time for the reverse electromotive force to appear, thereby ensuring the output VOUT voltage. When the power is turned on, Vin charges the electrolytic capacitor EC5 through R1, and the electrolytic capacitor EC5 supplies power to the 5th pin (VCC) of U2 through the resistor R11 to start working. The electrolytic capacitor EC5 is connected to the cathode of the diode D4, so the voltage will not charge the electrolytic capacitors EC2, EC3, and EC4 through the diode D4, that is, it will not affect the overall startup time of the power supply. This circuit not only solves the problem of unstable output caused by reverse electromotive force, but also does not affect the overall startup time of the power supply.

[0028] It is worth mentioning that the technical features such as the output terminal VOUT and the input terminal Vin involved in this utility model patent application should be regarded as the prior art. The specific structure, working principle and possible control method and spatial layout method of these technical features can be selected by conventional methods in the field, and should not be regarded as the invention point of this utility model patent. This utility model patent will not be further elaborated.

[0029] For those skilled in the art, it is still possible to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present utility model should be included in the protection scope of the present utility model.

Claims

1. An optimized reverse electromotive force circuit, characterized in that: It includes a reverse electromotive force protection power supply circuit, a main control circuit and a voltage feedback circuit, wherein the main control circuit is electrically connected to the reverse electromotive force protection power supply circuit and the voltage feedback circuit respectively, wherein: The voltage feedback circuit includes a photocoupler U1, an anode of the photocoupler U1 is electrically connected to an output terminal VOUT via a resistor R28, and a cathode of the photocoupler U1 is grounded via a voltage regulator tube U3, a resistor R33 is connected between a reference terminal and an anode of the voltage regulator tube U3, and two ends of the resistor R33 are connected in parallel to a resistor R32, and the reference terminal of the voltage regulator tube U3 is also electrically connected to an output terminal VOUT via a resistor R31; The main control circuit includes a controller U2 and a field effect transistor Q1, the FB terminal of the controller U2 is electrically connected to the collector of the photocoupler U1, the GATE terminal of the controller U2 is electrically connected to the gate of the field effect transistor Q1 through a resistor R18, and the GATE terminal of the controller U2 is electrically connected to the VCC terminal, and the source of the field effect transistor Q1 is grounded through a resistor R23 in one way and electrically connected to the CS terminal of the controller U2 in the other way; The anti-reverse electromotive force power supply circuit includes electrolytic capacitors EC2, EC3, EC4 and EC5. The GATE end of the controller U2 is electrically connected to the first end of the transformer TR1 through resistor R11, diode D4, resistor R12 and diode D2 in sequence. The cathode of the diode D4 is grounded through the electrolytic capacitor EC5, and the anode of the diode D4 is grounded through the electrolytic capacitor EC4, the electrolytic capacitor EC3 and the electrolytic capacitor EC2 respectively.

2. The optimized reverse electromotive force circuit according to claim 1, characterized in that: One end of the resistor R11 away from the controller U2 is also connected to the fourth end of the transformer TR1 through the resistor R1, and the fourth end of the transformer TR1 is also electrically connected to the input end Vin and the electrolytic capacitor EC1 respectively.

3. The optimized reverse electromotive force circuit according to claim 2, characterized in that: The drain of the field effect transistor Q1 is electrically connected to the sixth end of the transformer TR1 , and a resistor R19 is connected between the gate and source of the field effect transistor Q1 .

4. The optimized reverse electromotive force circuit according to claim 3, characterized in that: The eleventh terminal of the transformer TR1 is connected to the output terminal VOUT via a diode D6.

5. The optimized reverse electromotive force circuit according to claim 4, characterized in that: The cathode of the diode D6 is also electrically connected to the ninth terminal of the transformer TR1 through the electrolytic capacitor EC6.

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