Commercial power synchronous conversion circuit

Abstract

The utility model provides a commercial power synchronous conversion circuit, comprising an AC input interface, a square wave signal output interface, an isolation conversion circuit, an optical coupler isolation circuit, a voltage stabilization control circuit and a synchronous square wave generation circuit, through the above circuit, a transformer, a large capacitor or a high-cost chip is not needed, and the production cost is greatly reduced; high-low voltage electrical isolation is realized through the optical coupler isolation circuit, and the safety and the anti-interference capability of the system are effectively improved; through the isolation conversion circuit, noise and transient overvoltage are suppressed by adopting multiple filtering and a TVS diode, and high stability of 12V direct current output is ensured in combination with a surge current limiting design; 3.3 V square wave signals which are strictly synchronous with the mains supply are generated through the voltage stabilization control circuit and the synchronous square wave generation circuit, the precision is improved, meanwhile, multiple protection mechanisms such as fuses and safety capacitors are provided, and the reliability of the circuit is further improved.

Description

Technical Field

[0001] This utility model relates to the field of circuit technology, and more specifically, to a mains power synchronous conversion circuit. Background Technology

[0002] In related technologies, due to the influence of various factors, the mains voltage is variable, fluctuating, or even distorted. Because of the change in mains voltage, when the mains power is connected to the vehicle model recognition device, the camera in the recognition device is prone to flickering due to the unstable mains voltage. Therefore, it is necessary to convert the mains power into a stable square wave signal to be compatible with the vehicle model recognition device.

[0003] Most existing AC / DC conversion circuits employ the following methods to achieve their conversion function:

[0004] (1) A switching power supply, along with a large capacitor and a transformer, is used to achieve the conversion function.

[0005] (2) Use chips, such as Figure 1 As shown, the conversion function is achieved using the BM1Z002FJ chip and the BM2P129T chip.

[0006] Of the above implementation methods, (1) the scheme has the disadvantage of being bulky, and (2) the scheme relies on chips, which have high costs and complex peripheral circuits, further increasing production costs.

[0007] In view of this, the present invention proposes a mains power synchronous conversion circuit that is small in size and low in production cost. Utility Model Content

[0008] The purpose of this invention is to provide a small-sized, low-cost mains power synchronous conversion circuit.

[0009] A mains power synchronization conversion circuit is characterized by comprising an AC input interface, a square wave signal output interface, an isolation conversion circuit, an optocoupler isolation circuit, a voltage regulation control circuit, and a synchronous square wave generation circuit. The output terminal of the AC input circuit is connected to the input terminals of the isolation conversion circuit and the optocoupler isolation circuit, respectively. The output terminal of the isolation conversion circuit is connected to the output terminal of the optocoupler isolation circuit and the input terminal of the voltage regulation control circuit, respectively. The output terminals of the voltage regulation control circuit and the optocoupler isolation circuit are connected to the input terminal of the synchronous square wave generation circuit, respectively. The output terminal of the synchronous square wave generation circuit is connected to the square wave signal output interface. The AC input circuit includes an AC input port for connecting to 220V mains power. The isolation conversion circuit converts 220V AC power to 12V DC power and filters out high-frequency noise. The optocoupler isolation circuit converts 220V AC power to a 12V square wave signal. The voltage regulation control circuit generates and provides a stable low-voltage DC power supply. The synchronous square wave generation circuit converts the 12V square wave signal into a 3.3V square wave signal synchronized with the mains frequency.

[0010] In some implementations, the AC input interface is interface J2, and the square wave signal output interface is J3. The isolation conversion circuit includes an isolation conversion unit U2, capacitors C5, C6, C7, C8, and C4, a fuse F1, and a TVS diode D3. The output terminal of interface J2 is connected to the input terminal of the isolation conversion unit U2. The isolation conversion unit U2 is connected to the output terminal of the optocoupler isolation circuit and the input terminal of the voltage regulation control circuit. Capacitors C5 and C6 are connected to the side of the isolation conversion unit U2. Capacitor C5 is an energy storage capacitor, and capacitor C6 is a Y1 capacitor. Capacitors C5 and C6 are used to suppress common-mode noise and stabilize the DC bus voltage. The output terminal of the isolation conversion unit U2 is provided with capacitors C7, C8, TVS diode D3, and C4 in sequence. Capacitors C7, C8, and C4 all play a filtering role, and TVS diode D3 plays a role in suppressing transient overvoltage.

[0011] Furthermore, a resistor R5 and an inductor L1 are connected in sequence between the fuse F1 and pin 1 of the isolation conversion unit U2. The resistor R5 limits the surge current at the moment of power-on to prevent overcurrent damage to the subsequent isolation conversion unit U2 or capacitors C5 and C6. The inductor L1 serves to filter and store energy, ensuring stable DC side voltage and suppressing electromagnetic interference.

[0012] Furthermore, a capacitor C1 is provided between pins 1 and 2 of the isolation conversion unit U2. The capacitor C1 is a safety capacitor and serves as a filter.

[0013] In some embodiments, the optocoupler isolation circuit includes an optocoupler U3, resistors R75, R76, and R77. The output terminal of the AC input circuit is connected to the input terminal of the optocoupler U3, the output terminal of the optocoupler U3 is connected to the input terminal of the synchronous square wave generation circuit, the output terminal of the AC input circuit is connected to pin 5 of the optocoupler U3, resistor R77 serves to boost the voltage, resistor R75 is connected between pin 1 of interface J2 and pin 1 of optocoupler U3, resistor R75 serves to divide the voltage, and resistor R76 is provided between pins 1 and 2 of optocoupler U3, resistor R76 serves to ensure that the voltage between pins 1 and 2 of U3 does not exceed the rated value of resistor R76.

[0014] In some embodiments, the voltage regulation control circuit includes a three-terminal voltage regulator unit U4, resistors R78, R79, and R80. The output terminal of the AC input circuit is connected to the three-terminal voltage regulator unit U4, and the output terminal of the three-terminal voltage regulator unit U4 is connected to the input terminal of the synchronous square wave generation circuit. The three-terminal voltage regulator unit U4 is connected to resistors R78, R80, and R79. R78 and R80 form a voltage divider network that is adapted to the three-terminal voltage regulator unit U4 to provide a reference voltage. Resistor R79 serves to limit current and ensure the stability of signal transmission.

[0015] In some embodiments, the synchronous square wave generation circuit includes an NPN diode Q12, resistors R71, R73, and R74. The output terminal of the optocoupler isolation circuit is connected to the base of transistor Q12 through resistor R73. Resistor R74 is connected between the base and emitter of transistor Q12. Resistor R73 is a base bias resistor used to set the conduction threshold of Q12 and limit the base current to prevent overdrive. Resistor R74 is a pull-up resistor. The emitter of transistor Q12 is grounded. The collector of transistor Q12 is connected to resistor R71 and square wave signal output interface J3.

[0016] In some embodiments, a TVS diode D27 is also connected between the output of the optocoupler isolation circuit and the resistor R73 to protect the subsequent circuit from mains surges or voltage spikes.

[0017] In some implementations, the three-terminal voltage regulator unit U4 is specified as TL431.

[0018] In some implementations, the isolation conversion unit U2 is specified as LS03-13B12R3.

[0019] In some implementations, the optocoupler U3 is specified as 4N25.

[0020] The beneficial effects of this utility model are as follows: This utility model proposes a mains power synchronization conversion circuit, including an AC input interface, a square wave signal output interface, an isolation conversion circuit, an optocoupler isolation circuit, a voltage regulation control circuit, and a synchronous square wave generation circuit. This circuit eliminates the need for transformers, large capacitors, or expensive chips, significantly reducing production costs. The optocoupler isolation circuit achieves high and low voltage electrical isolation, effectively improving system safety and anti-interference capabilities. The isolation conversion circuit employs multiple filters and TVS diodes to suppress noise and transient overvoltage, combined with surge current limiting design, ensuring high stability of the 12V DC output. The voltage regulation control circuit and the synchronous square wave generation circuit generate a 3.3V square wave signal that is strictly synchronized with the mains power, improving accuracy. Furthermore, it incorporates multiple protection mechanisms such as fuses and safety capacitors, further enhancing circuit reliability. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a circuit structure in the prior art that uses a chip to implement the conversion.

[0022] Figure 2 This is a schematic diagram of the circuit structure of a mains power synchronization conversion circuit according to this application.

[0023] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this utility model. Detailed Implementation

[0024] The following embodiments are described to aid in understanding this application. These embodiments are not, and should not be, construed in any way as limiting the scope of protection of this application.

[0025] In the following description, those skilled in the art will recognize that throughout this discussion, components may be described as individual functional units (which may include subunits), but those skilled in the art will recognize that various components or portions thereof may be divided into individual components or may be integrated together (including integrated within a single system or component).

[0026] Furthermore, the connection between components or systems is not intended to be limited to a direct connection; on the contrary, data between these components may be modified, reformatted, or otherwise altered by intermediate components. Additionally, other or fewer connections may be used. It should also be noted that the terms "connection," "link," or "input" should be understood to include direct connections, indirect connections via one or more intermediate devices, and wireless connections. Example 1:

[0027] like Figure 2 The diagram shown is a schematic diagram of the circuit structure of a mains power synchronization conversion circuit according to this application.

[0028] A mains power synchronization conversion circuit is characterized by comprising an AC input interface, a square wave signal output interface, an isolation conversion circuit, an optocoupler isolation circuit, a voltage regulation control circuit, and a synchronous square wave generation circuit. The output terminal of the AC input circuit is connected to the input terminals of the isolation conversion circuit and the optocoupler isolation circuit, respectively. The output terminal of the isolation conversion circuit is connected to the output terminal of the optocoupler isolation circuit and the input terminal of the voltage regulation control circuit, respectively. The output terminals of the voltage regulation control circuit and the optocoupler isolation circuit are connected to the input terminal of the synchronous square wave generation circuit, respectively. The output terminal of the synchronous square wave generation circuit is connected to the square wave signal output interface. The AC input circuit includes an AC input port for connecting to 220V mains power. The isolation conversion circuit converts 220V AC power to 12V DC power and filters out high-frequency noise. The optocoupler isolation circuit converts 220V AC power to a 12V square wave signal. The voltage regulation control circuit generates and provides a stable low-voltage DC power supply. The synchronous square wave generation circuit converts the 12V square wave signal into a 3.3V square wave signal synchronized with the mains frequency.

[0029] The AC input interface is interface J2, and the square wave signal output interface is J3. The isolation conversion circuit includes an isolation conversion unit U2, capacitors C5, C6, C7, C8, and C4, a fuse F1, and a TVS diode D3. The output terminal of interface J2 is connected to the input terminal of the isolation conversion unit U2. The isolation conversion unit U2 is connected to the output terminal of the optocoupler isolation circuit and the input terminal of the voltage regulation control circuit. Capacitors C5 and C6 are connected to the side of the isolation conversion unit U2. Capacitor C5 is an energy storage capacitor, and capacitor C6 is a Y1 capacitor. Capacitors C5 and C6 are used to suppress common-mode noise and stabilize the DC bus voltage. The output terminal of the isolation conversion unit U2 is provided with capacitors C7, C8, TVS diode D3, and C4 in sequence. Capacitors C7, C8, and C4 all play a filtering role, and TVS diode D3 plays a role in suppressing transient overvoltage.

[0030] A resistor R5 and an inductor L1 are connected in sequence between the fuse F1 and pin 1 of the isolation converter unit U2. The resistor R5 limits the surge current at the moment of power-on to prevent overcurrent damage to the subsequent isolation converter unit U2 or capacitors C5 and C6. The inductor L1 plays a role in filtering and energy storage, ensuring stable DC side voltage and suppressing electromagnetic interference.

[0031] A capacitor C1 is also provided between pins 1 and 2 of the isolation converter unit U2. The capacitor C1 is a safety capacitor and plays a filtering role.

[0032] The optocoupler isolation circuit includes an optocoupler U3, resistors R75, R76, and R77. The output terminal of the AC input circuit is connected to the input terminal of the optocoupler U3, and the output terminal of the optocoupler U3 is connected to the input terminal of the synchronous square wave generation circuit. The output terminal of the AC input circuit is connected to pin 5 of the optocoupler U3. Resistor R77 acts as a voltage booster. Resistor R75 is connected between pin 1 of interface J2 and pin 1 of optocoupler U3, and resistor R75 acts as a voltage divider. Resistor R76 is provided between pins 1 and 2 of optocoupler U3. Resistor R76 ensures that the voltage between pins 1 and 2 of U3 does not exceed the rated value of resistor R76.

[0033] The voltage regulation control circuit includes a three-terminal voltage regulator unit U4, resistors R78, R79, and R80. The output terminal of the AC input circuit is connected to the three-terminal voltage regulator unit U4, and the output terminal of the three-terminal voltage regulator unit U4 is connected to the input terminal of the synchronous square wave generation circuit. The three-terminal voltage regulator unit U4 is connected to resistors R78, R80, and R79. R78 and R80 form a voltage divider network that is adapted to the three-terminal voltage regulator unit U4 to provide a reference voltage. Resistor R79 serves to limit current and ensure the stability of signal transmission.

[0034] The synchronous square wave generation circuit includes an NPN diode Q12, resistors R71, R73, and R74. The output terminal of the optocoupler isolation circuit is connected to the base of transistor Q12 through resistor R73. Resistor R74 is connected between the base and emitter of transistor Q12. Resistor R73 is a base bias resistor used to set the conduction threshold of Q12 and limit the base current to prevent overdrive. Resistor R74 is a pull-up resistor. The emitter of transistor Q12 is grounded. The collector of transistor Q12 is connected to resistor R71 and square wave signal output interface J3.

[0035] A TVS diode D27 is also connected between the output terminal of the optocoupler isolation circuit and the resistor R73 to protect the subsequent circuit from the effects of mains power surges or voltage spikes.

[0036] The specification of the three-terminal voltage regulator unit U4 is TL431.

[0037] The isolation converter unit U2 is LS03-13B12R3.

[0038] The specification of optocoupler U3 is 4N25.

[0039] The beneficial effects of this utility model are as follows: This utility model proposes a mains power synchronization conversion circuit, including an AC input interface, a square wave signal output interface, an isolation conversion circuit, an optocoupler isolation circuit, a voltage regulation control circuit, and a synchronous square wave generation circuit. This circuit eliminates the need for transformers, large capacitors, or expensive chips, significantly reducing production costs. The optocoupler isolation circuit achieves high and low voltage electrical isolation, effectively improving system safety and anti-interference capabilities. The isolation conversion circuit employs multiple filters and TVS diodes to suppress noise and transient overvoltage, combined with surge current limiting design, ensuring high stability of the 12V DC output. The voltage regulation control circuit and the synchronous square wave generation circuit generate a 3.3V square wave signal that is strictly synchronized with the mains power, improving accuracy. Furthermore, it incorporates multiple protection mechanisms such as fuses and safety capacitors, further enhancing circuit reliability.

[0040] Although this application discloses several aspects and embodiments, other aspects and embodiments will be obvious to those skilled in the art. Various modifications and improvements can be made without departing from the concept of this application, and these all fall within the scope of protection of this application. The various aspects and embodiments disclosed in this application are for illustrative purposes only and are not intended to limit this application. The actual scope of protection of this application is determined by the claims.

Claims

1. A mains power synchronous conversion circuit, characterized in that: The system includes an AC input interface, a square wave signal output interface, an isolation conversion circuit, an optocoupler isolation circuit, a voltage regulator control circuit, and a synchronous square wave generation circuit. The output of the AC input circuit is connected to the input of the isolation conversion circuit and the input of the optocoupler isolation circuit. The output of the isolation conversion circuit is connected to the output of the optocoupler isolation circuit and the input of the voltage regulator control circuit. The outputs of the voltage regulator control circuit and the optocoupler isolation circuit are connected to the input of the synchronous square wave generation circuit. The output of the synchronous square wave generation circuit is connected to the square wave signal output interface. The AC input circuit includes an AC input port for connecting to 220V AC mains power. The isolation conversion circuit converts 220V AC power to 12V DC power and filters out high-frequency noise. The optocoupler isolation circuit converts 220V AC power to a 12V square wave signal. The voltage regulator control circuit generates and provides a stable low-voltage DC power supply. The synchronous square wave generation circuit converts the 12V square wave signal into a 3.3V square wave signal synchronized with the AC mains frequency.

2. The mains power synchronization conversion circuit as described in claim 1, characterized in that: The AC input interface is interface J2, and the square wave signal output interface is J3. The isolation conversion circuit includes an isolation conversion unit U2, capacitors C5, C6, C7, C8, and C4, a fuse F1, and a TVS diode D3. The output terminal of interface J2 is connected to the input terminal of the isolation conversion unit U2. The isolation conversion unit U2 is connected to the output terminal of the optocoupler isolation circuit and the input terminal of the voltage regulation control circuit. Capacitors C5 and C6 are connected to the side of the isolation conversion unit U2. Capacitor C5 is an energy storage capacitor, and capacitor C6 is a Y1 capacitor. Capacitors C5 and C6 are used to suppress common-mode noise and stabilize the DC bus voltage. The output terminal of the isolation conversion unit U2 is provided with capacitors C7, C8, TVS diode D3, and C4 in sequence. Capacitors C7, C8, and C4 all play a filtering role, and TVS diode D3 plays a role in suppressing transient overvoltage.

3. The mains power synchronization conversion circuit as described in claim 2, characterized in that: A resistor R5 and an inductor L1 are connected in sequence between the fuse F1 and pin 1 of the isolation converter unit U2. The resistor R5 limits the surge current at the moment of power-on to prevent overcurrent damage to the subsequent isolation converter unit U2 or capacitors C5 and C6. The inductor L1 plays a role in filtering and energy storage, ensuring stable DC side voltage and suppressing electromagnetic interference.

4. The mains power synchronization conversion circuit as described in claim 2, characterized in that: A capacitor C1 is also provided between pins 1 and 2 of the isolation converter unit U2. The capacitor C1 is a safety capacitor and plays a filtering role.

5. The mains synchronous conversion circuit as described in claim 1, characterized in that: The optocoupler isolation circuit includes an optocoupler U3, resistors R75, R76, and R77. The output terminal of the AC input circuit is connected to the input terminal of the optocoupler U3, and the output terminal of the optocoupler U3 is connected to the input terminal of the synchronous square wave generation circuit. The output terminal of the AC input circuit is connected to pin 5 of the optocoupler U3. Resistor R77 acts as a voltage booster. Resistor R75 is connected between pin 1 of interface J2 and pin 1 of optocoupler U3, and resistor R75 acts as a voltage divider. Resistor R76 is provided between pins 1 and 2 of optocoupler U3. Resistor R76 ensures that the voltage between pins 1 and 2 of U3 does not exceed the rated value of resistor R76.

6. The mains synchronous conversion circuit as described in claim 1, characterized in that: The voltage regulation control circuit includes a three-terminal voltage regulator unit U4, resistors R78, R79, and R80. The output terminal of the AC input circuit is connected to the three-terminal voltage regulator unit U4, and the output terminal of the three-terminal voltage regulator unit U4 is connected to the input terminal of the synchronous square wave generation circuit. The three-terminal voltage regulator unit U4 is connected to resistors R78, R80, and R79. R78 and R80 form a voltage divider network that is adapted to the three-terminal voltage regulator unit U4 to provide a reference voltage. Resistor R79 serves to limit current and ensure the stability of signal transmission.

7. The mains power synchronization conversion circuit as described in claim 1, characterized in that: The synchronous square wave generation circuit includes an NPN diode Q12, resistors R71, R73, and R74. The output terminal of the optocoupler isolation circuit is connected to the base of transistor Q12 through resistor R73. Resistor R74 is connected between the base and emitter of transistor Q12. Resistor R73 is a base bias resistor used to set the conduction threshold of Q12 and limit the base current to prevent overdrive. Resistor R74 is a pull-up resistor. The emitter of transistor Q12 is grounded. The collector of transistor Q12 is connected to resistor R71 and square wave signal output interface J3.

8. The mains synchronous conversion circuit as described in claim 7, characterized in that: A TVS diode D27 is also connected between the output terminal of the optocoupler isolation circuit and the resistor R73 to protect the subsequent circuit from the effects of mains power surges or voltage spikes.

9. The mains synchronous conversion circuit as described in claim 6, characterized in that: The specification of the three-terminal voltage regulator unit U4 is TL431.

10. The mains power synchronization conversion circuit as described in claim 2, characterized in that: The isolation converter unit U2 is LS03-13B12R3.

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