Driving control circuit based on optocoupler isolation

Abstract

The utility model belongs to the technical field of circuits, and discloses a drive control circuit based on optocoupler isolation, which comprises an optocoupler U2, a port INPUT + is connected with one end of a resistor R1, the other end of the resistor R1 is connected with one end of a resistor R2, the other end of the resistor R2 is connected with one end of a resistor R3, one end of a resistor R4, one end of a capacitor C1 and a control electrode of a voltage-regulator tube U1, the other end of the resistor R3, the other end of the resistor R4, the other end of the capacitor C1 and the anode of the voltage-regulator tube U1 are connected with a port AGND, the cathode of the voltage-regulator tube U1 is connected with the cathode of the optocoupler U2 and one end of the resistor R6, the anode of the optocoupler U2 is connected with one end of the resistor R5, and the other end of the resistor R5 and the other end of the resistor R6 are connected with a port V0. The beneficial effects of the utility model are that the control circuit which uses the input voltage as the reference to control the MOS tube drive is provided, so that the operation logic of the bidirectional optical storage inverter is more reliable and safer.

Description

Technical Field

[0001] The utility model relates to the technical field of circuits, in particular to a drive control circuit based on optocoupler isolation. Background Technique

[0002] After a long period of development, the switching power supply based on digital chip control has occupied a very important position in the field of power electronics. With the iteration of chips and the optimization of control algorithms, digital chips have mature application solutions in industrial control, communication, and control. Sometimes when the utilization rate of the IO ports of digital chips is too high, the turn-on of the drive can be directly controlled by transmitting a turn-off signal through a hardware circuit, and this function is generally realized through an optocoupler circuit.

[0003] The optocoupler, also known as the optoelectronic coupler, is an electro-optical-electrical conversion device. It can achieve electrical isolation and signal transmission and is an important part of electrical isolation and interconnection technologies. The optocoupler mainly consists of a light-emitting diode and a photosensitive triode (or photosensitive diode). When the electrical signal at the input end acts on the light-emitting diode, it emits a light signal. The light signal is converted into an output electrical signal by the photosensitive triode (or photosensitive diode) after isolation. Since there is isolation between the light-emitting diode and the photosensitive triode, no current will flow between them, achieving electrical isolation. The optocoupler has the advantages of good isolation effect, fast transmission speed, strong anti-interference ability, high reliability, etc., and is widely used in various electrical control and communication fields.

[0004] Therefore, it is necessary to provide a drive control circuit based on optocoupler isolation to control the on and off of the drive with a hardware circuit, so as to achieve additional input voltage control for the circuit and devices. Content of the Utility Model

[0005] The utility model discloses a drive control circuit based on optocoupler isolation, which can effectively solve the technical problems involved in the background technique.

[0006] To achieve the above object, the technical solution of the utility model is as follows:

[0007] A drive control circuit based on optocoupler isolation includes an optocoupler U2. One end of port INPUT+ is connected to one end of resistor R1. The other end of resistor R1 is connected to one end of resistor R2. The other end of resistor R2 is connected to one end of resistor R3, one end of resistor R4, one end of capacitor C1, and the control electrode of voltage regulator diode U1. The other end of resistor R3, the other end of resistor R4, the other end of capacitor C1, and the anode of voltage regulator diode U1 are connected to port AGND. The cathode of voltage regulator diode U1 is connected to the cathode of optocoupler U2 and one end of resistor R6. The anode of optocoupler U2 is connected to one end of resistor R5. The other end of resistor R5 and the other end of resistor R6 are connected to port V0.

[0008] Port CONTROLLED1 is connected to one end of capacitor C2 and one end of resistor R8. The other end of capacitor C2 is connected to port AGND and one end of resistor R7. The other end of resistor R7 is connected to the emitter of optocoupler U2. The collector of optocoupler U2 is connected to the base of triode Q1. The other end of resistor R8 is connected to the emitter of triode Q1. The collector of triode Q1 is connected to port CONTROLLED2.

[0009] As a preferred improvement of the present utility model: Port V0 is connected to a power supply module.

[0010] As a preferred improvement of the present utility model: Port INPUT+ is connected to a voltage module to be measured.

[0011] As a preferred improvement of the present utility model: The model of optocoupler U2 is LTV-357T.

[0012] As a preferred improvement of the present utility model: The voltage regulator diode U1 is AZ431.

[0013] As a preferred improvement of the present utility model: Port CONTROLLED1 and port CONTROLLED2 are connected to a circuit to be controlled.

[0014] As a preferred improvement of the present utility model: Port INPUT+ is connected to port MPPT_INPUT+, port CONTROLLED1 is connected to port 12VS, and port CONTROLLED2 is connected to pin 1 of chip U8;

[0015] Pin 3 of the chip U8 is connected to the drain of the MOS transistor Q2. The source of the MOS transistor Q2 is connected to one end of the resistor R10, one end of the capacitor C3, and the port AGND. The other end of the capacitor C3 is connected to the other end of the resistor R10, one end of the resistor R9, the gate of the MOS transistor Q2, and the positive terminal of the diode D1. The other end of the resistor R9 is connected to the negative terminal of the diode D1 and the port DRVH1;

[0016] Pin 4 of the chip U8 is connected to one end of the capacitor C4, the collector of the triode Q4, one end of the capacitor C5, one end of the capacitor C6, and the port H1COM. Pin 5 of the chip U8 is connected to one end of the resistor R11. The other end of the resistor R11 is connected to the base of the triode Q4 and the base of the triode Q3. The emitter of the triode Q3 is connected to the emitter of the triode Q4 and one end of the resistor R12. The other end of the resistor R12 is connected to the port H1DRV. Pin 6 of the chip U8 is connected to the port VCCH1, the other end of the capacitor C4, the collector of the triode Q3, the other end of the capacitor C5, and the other end of the capacitor C6.

[0017] As a preferred improvement of the present invention: The port MPPT_INPUT+ is connected to the input voltage detection port of the bidirectional photovoltaic energy storage inverter. The port V0 is connected to a 12V power supply. The port 12VS is connected to 12V direct current. The port DRVH1 is connected to an input control signal. The port VCCH1 is connected to 15V direct current. The port H1DRV is connected to the gate of the MOS transistor to be controlled and driven by the bidirectional photovoltaic energy storage inverter. The port H1COM is connected to the source of the MOS transistor to be controlled and driven by the bidirectional photovoltaic energy storage inverter.

[0018] As a preferred improvement of the present invention: The model of the chip U8 is LTV-314W-TA1.

[0019] The beneficial effects of the present invention are as follows:

[0020] Disclosed is a voltage comparison drive control circuit based on optocoupler isolation. Based on this control method, the circuit mainly includes a voltage comparison circuit and a drive control circuit. Combining the above basic circuits can provide a voltage division control method for the input photovoltaic voltage of the bidirectional photovoltaic energy storage inverter, making the operation logic of the bidirectional photovoltaic energy storage inverter more reliable and safe, and having strong feasibility. Description of the Drawings

[0021] To more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only 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, where:

[0022] Figure 1 It is a schematic diagram of a drive control circuit based on optocoupler isolation of the present utility model;

[0023] Figure 2 It is the circuit of the embodiment of the present utility model Figure 1 ;

[0024] Figure 3 It is the circuit of the embodiment of the present utility model Figure 2 。 Detailed implementation manners

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in combination with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0026] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0027] In addition, the descriptions such as "first" and "second" in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0028] In the present invention, unless otherwise clearly defined and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the internal connection of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0029] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0030] Please refer to Figure 1 As shown, the present utility model provides a drive control circuit based on optocoupler isolation, including an optocoupler U2. One end of port INPUT+ is connected to one end of resistor R1. The other end of resistor R1 is connected to one end of resistor R2. The other end of resistor R2 is connected to one end of resistor R3, one end of resistor R4, one end of capacitor C1, and the control electrode of voltage regulator U1. The other end of resistor R3, the other end of resistor R4, the other end of capacitor C1, and the anode of voltage regulator U1 are connected to port AGND. The cathode of voltage regulator U1 is connected to the cathode of optocoupler U2 and one end of resistor R6. The anode of optocoupler U2 is connected to one end of resistor R5. The other end of resistor R5 and the other end of resistor R6 are connected to port V0, that is, a voltage comparison circuit. Port CONTROLLED1 is connected to one end of capacitor C2 and one end of resistor R8. The other end of capacitor C2 is connected to port AGND and one end of resistor R7. The other end of resistor R7 is connected to the emitter of optocoupler U2. The collector of optocoupler U2 is connected to the base of triode Q1. The other end of resistor R8 is connected to the emitter of triode Q1. The collector of triode Q1 is connected to port CONTROLLED2, that is, a control circuit. The port V0 is connected to a power supply module. The port INPUT+ is connected to a voltage to be measured module. The model of optocoupler U2 is LTV-357T. The voltage regulator U1 is AZ431. The port CONTROLLED1 and the port CONTROLLED2 are connected to a circuit to be controlled. The core control method is mainly that the AZ431 voltage regulator tube voltage division circuit samples whether the input voltage reaches the threshold, and then transmits the collected signal through the LTV-357T optocoupler isolation, controls the on and off of the base of the triode through the LTV-357T optocoupler, thereby controlling the on and off of the collector to emitter of the triode, and realizing the transmission of signals of port CONTROLLED1 and port CONTROLLED2.

[0031] Embodiment, a voltage comparison MOS tube drive control circuit based on optocoupler isolation

[0032] Please refer to Figures 2 - 3As shown, the port INPUT+ is connected to the port MPPT_INPUT+, the port CONTROLLED1 is connected to the port 12VS, and the port CONTROLLED2 is connected to pin 1 of the chip U8; pin 3 of the chip U8 is connected to the drain of the MOS transistor Q2, the source of the MOS transistor Q2 is connected to one end of the resistor R10, one end of the capacitor C3 and the port AGND, the other end of the capacitor C3 is connected to the other end of the resistor R10, one end of the resistor R9, the gate of the MOS transistor Q2 and the positive terminal of the diode D1, and the other end of the resistor R9 is connected to the negative terminal of the diode D1 and the port DRVH1; pin 4 of the chip U8 is connected to one end of the capacitor C4, the collector of the triode Q4, one end of the capacitor C5, one end of the capacitor C6 and the port H1COM, pin 5 of the chip U8 is connected to one end of the resistor R11, the other end of the resistor R11 is connected to the base of the triode Q4 and the base of the triode Q3, the emitter of the triode Q3 is connected to the emitter of the triode Q4 and one end of the resistor R12, the other end of the resistor R12 is connected to the port H1DRV, and pin 6 of the chip U8 is connected to the port VCCH1, the other end of the capacitor C4, the collector of the triode Q3, the other end of the capacitor C5 and the other end of the capacitor C6. In this embodiment, the port MPPT_INPUT+ is connected to the input voltage detection port of the bi-directional photovoltaic energy storage inverter, the port V0 is connected to the 12V power supply, the port 12VS is connected to 12V direct current, the port DRVH1 is connected to the input control signal, the port VCCH1 is connected to 15V direct current, the port H1DRV is connected to the gate of the MOS transistor to be controlled and driven in the bi-directional photovoltaic energy storage inverter, the port H1COM is connected to the source of the MOS transistor to be controlled and driven in the bi-directional photovoltaic energy storage inverter, and the model of the chip U8 is LTV-314W-TA1.

[0033] Specifically, this circuit is applied to provide a hardware circuit for the bi-directional photovoltaic energy storage inverter, and a control method for controlling the MOS transistor drive by dividing the input photovoltaic voltage. Through this circuit, the input photovoltaic voltage of the bi-directional photovoltaic energy storage inverter will be added to the hardware circuit to control the drive of the photovoltaic circuit, and the control effect is realized based on the resistor voltage division circuit and the power supply drive control circuit, and the function of turning on with a constant input photovoltaic voltage is realized. Through the voltage comparison circuit and the MOS transistor drive control circuit, the on-off of the drive is controlled by the hardware circuit, so as to realize additional input voltage control for the bi-directional photovoltaic energy storage inverter. Combining the above basic circuit can provide a control method for the bi-directional photovoltaic energy storage inverter to control the MOS transistor drive based on the input photovoltaic voltage, making the operation logic of the bi-directional photovoltaic energy storage inverter more reliable and safe, and having strong feasibility.

[0034] Through the voltage comparison circuit ( Figure 2 ) and the MOS transistor drive control circuit ( Figure 3) Use a hardware circuit to control the on / off of the drive, thereby achieving additional input voltage control for the bidirectional photovoltaic energy storage inverter. The basic principle of this circuit is to use an optocoupler as an electrical isolation and signal conversion component. When the input voltage exceeds 18V, after the voltage on the voltage-dividing resistor in parallel with the AZ431 voltage regulator tube reaches the 2.5V threshold, the AZ431 voltage regulator tube conducts, enabling the optocoupler's ports 1 and 2, thereby sending an optical signal to turn on the photosensitive triode at the other end of the optocoupler. The control signal output through the optocoupler is used to control the enabling of the optocoupler between the drive end IO port and the push-pull tube, thereby controlling the on / off of the drive.

[0035] Input voltage comparison circuit: mainly used to compare whether the input voltage reaches the set threshold voltage. When the voltage on the voltage-dividing resistor in parallel with the AZ431 voltage regulator tube reaches 2.5V, it proves that the input voltage reaches the predetermined voltage value, and the AZ431 voltage regulator tube conducts, enabling the photodiodes at ports 1 and 2 of the LTV-357 optocoupler to emit an optical signal to turn on the photosensitive triodes at ports 3 and 4 at the other end of the optocoupler. The port MPPT_INUPT is the input PV voltage, and the port V0 is the 12V battery input of the bidirectional inverter, used to supply power to the optocoupler and transmit signals.

[0036] MOS transistor drive circuit: In this circuit, the optocoupler LTV-357T's ports 3 and 4 receive the optical signal generated by the light-emitting diodes inside ports 1 and 2 in the input voltage comparison circuit, and the photosensitive triode across it conducts, thereby generating a voltage difference between the two pins of the transistor Q1, causing the transistor to conduct. The 12VS DC power from the low-voltage auxiliary source can drive the drive isolation optocoupler LTV-314W, and the drive signal of the IO port is pushed and pulled into the drive signal of the MOS transistor through the subsequent totem pole; when the ports 3 and 4 of the optocoupler LTV-357T are not conducting, the drive of the IO cannot pass through the optocoupler, thereby controlling the on and off of the MOS transistor drive. The diode between the IO port and Q2 serves to accelerate the discharge speed of Q2, and the function of the Q3 and Q4 totem poles is to amplify the signal output from the drive isolation optocoupler LTV-314W and amplify its peak value to the value of VCCH1. The port DRVH1 is connected to the PWM drive control signal given by the single-chip microcomputer, and its function is to provide the drive signal for controlling the MOS. 12VS is the 12V DC power supplied by the low-voltage auxiliary source, used to drive the optocoupler. VCCH1 is the 15V DC power supplied by the high-voltage auxiliary source, used as the standard value for the totem pole bootstrap circuit, and the 3V control signal from the single-chip microcomputer is bootstrapped to a 15V control signal through the totem pole. H1DRV is the 15V control signal for driving the MOS after passing through the bootstrap circuit, used to connect to the G pole of the MOS transistor controlled by the subsequent stage. H1COM is the S pole of the subsequent-stage MOS transistor, and the drive signal needs to be grounded with the subsequent-stage MOS transistor. The high- and low-voltage auxiliary sources are step-down circuits that supply power to generate 12V and 15V DC, which will not be elaborated here.

[0037] Working principle:

[0038] The core control method mainly uses the AZ431 voltage regulator diode voltage division circuit to sample whether the input voltage reaches the threshold, and then transmits the collected signal through the LTV-357T optocoupler to the on-off circuit on the enabling end side of the LTV-314W drive isolation optocoupler. The on-off of the transistor base is controlled through the LTV-357T optocoupler, so as to control the on-off of 12VS from the collector to the emitter of the transistor, and thus control the enabling end of the LTV-314W drive isolation optocoupler, so as to realize the control of the MOS transistor drive.

[0039] This set of control circuits can be used in various MOS transistor drive control circuits. In the circuit that needs to add hardware condition judgment, the base of the transistor can be controlled through this set of AZ431 voltage regulator diode voltage division and optocoupler signal transmission, so as to give a control effect to both ends of the collector and emitter of the transistor. By connecting the collector and emitter of the transistor in series into the circuit to be controlled as expected, the on-off control of this drive control circuit can be realized.

[0040] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the illustrated examples shown and described here.

Claims

1. A drive control circuit based on optocoupler isolation, characterized in that: It includes an optocoupler U2. One end of port INPUT+ is connected to one end of resistor R1. The other end of resistor R1 is connected to one end of resistor R2. The other end of resistor R2 is connected to one end of resistor R3, one end of resistor R4, one end of capacitor C1, and the control electrode of voltage regulator U1. The other end of resistor R3, the other end of resistor R4, the other end of capacitor C1, and the anode of voltage regulator U1 are connected to port AGND. The cathode of voltage regulator U1 is connected to the cathode of optocoupler U2 and one end of resistor R6. The anode of optocoupler U2 is connected to one end of resistor R5. The other end of resistor R5 and the other end of resistor R6 are connected to port V0; Port CONTROLLED1 is connected to one end of capacitor C2 and one end of resistor R8. The other end of capacitor C2 is connected to port AGND and one end of resistor R7. The other end of resistor R7 is connected to the emitter of optocoupler U2. The collector of optocoupler U2 is connected to the base of triode Q1. The other end of resistor R8 is connected to the emitter of triode Q1. The collector of triode Q1 is connected to port CONTROLLED2.

2. The drive control circuit based on optocoupler isolation according to claim 1, wherein: The port V0 is connected to the power supply module.

3. The drive control circuit based on optocoupler isolation according to claim 1 is characterized in that: The port INPUT+ is connected to the voltage module to be measured.

4. A drive control circuit based on optocoupler isolation according to claim 1, characterized in that: The model of the optocoupler U2 is LTV-357T.

5. A drive control circuit based on optocoupler isolation according to claim 1, characterized in that: The voltage regulator U1 is AZ431.

6. The drive control circuit based on optocoupler isolation according to claim 1, characterized in that: The port CONTROLLED1 and the port CONTROLLED2 are connected to the circuit to be controlled.

7. The driving control circuit based on optocoupler isolation according to claim 1, characterized in that: The port INPUT+ is connected to port MPPT_INPUT+. The port CONTROLLED1 is connected to port 12VS. The port CONTROLLED2 is connected to pin 1 of chip U8; Pin 3 of chip U8 is connected to the drain of MOS transistor Q2. The source of MOS transistor Q2 is connected to one end of resistor R10, one end of capacitor C3, and port AGND. The other end of capacitor C3 is connected to the other end of resistor R10, one end of resistor R9, the gate of MOS transistor Q2, and the positive end of diode D1. The other end of resistor R9 is connected to the negative end of diode D1 and port DRVH1; Pin 4 of chip U8 is connected to one end of capacitor C4, the collector of triode Q4, one end of capacitor C5, one end of capacitor C6, and port H1COM. Pin 5 of chip U8 is connected to one end of resistor R11. The other end of resistor R11 is connected to the base of triode Q4 and the base of triode Q3. The emitter of triode Q3 is connected to the emitter of triode Q4 and one end of resistor R12. The other end of resistor R12 is connected to port H1DRV. Pin 6 of chip U8 is connected to port VCCH1, the other end of capacitor C4, the collector of triode Q3, the other end of capacitor C5, and the other end of capacitor C6.

8. A drive control circuit based on optocoupler isolation according to claim 7, characterized in that: The port MPPT_INPUT+ is connected to the input voltage detection port of the bidirectional photovoltaic energy storage inverter. The port V0 is connected to a 12V power supply. The port 12VS is connected to 12V direct current. The port DRVH1 is connected to an input control signal. The port VCCH1 is connected to 15V direct current. The port H1DRV is connected to the gate of the MOS transistor to be controlled and driven in the bidirectional photovoltaic energy storage inverter. The port H1COM is connected to the source of the MOS transistor to be controlled and driven in the bidirectional photovoltaic energy storage inverter.

9. The drive control circuit based on optocoupler isolation according to claim 7, characterized in that: The model of the chip U8 is LTV-314W-TA1.

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