Silicon controlled rectifier drive circuit suitable for charger

Abstract

The utility model discloses a silicon controlled rectifier drive circuit suitable for a charger. The silicon controlled rectifier drive circuit comprises a single-chip microcomputer, a capacitor, a resistor, a silicon controlled rectifier and a transformer. Through superposition of the output voltage of the single-chip microcomputer and the secondary bus voltage of the transformer, an additional winding used for silicon controlled rectifier grid power supply in a traditional transformer is replaced, the transformer structure is simplified, and the production cost and the complexity of a peripheral circuit are reduced. The capacitor utilizes the characteristic that the voltage at the two ends of the capacitor cannot be suddenly changed, so that the stable transition from low voltage to superposed high voltage of the singlechip is realized, the silicon controlled rectifier grid is accurately driven to be conducted, and the stability and the reliability of the system are improved. In addition, the secondary bus voltage directly participates in the superposition process, complex electromagnetic interference in a traditional winding design is avoided, circuit interference is remarkably reduced, and the electromagnetic compatibility of the circuit is enhanced.

Description

TECHNICAL FIELD

[0001] The utility model relates to drive circuit technical field especially is related to a silicon controlled rectifier drive circuit suitable for charger. BACKGROUND

[0002] As a commonly used semiconductor device, silicon controlled rectifier is widely used in electric vehicle charger and other circuits to control the turn-on and turn-off of current. Its working principle is to realize the conduction from anode to cathode by applying a driving signal higher than the cathode voltage to the gate. In practical applications, the gate driving signal of silicon controlled rectifier needs to be provided by an external circuit, and the stability and reliability of the driving signal directly affect the working efficiency and system stability of the entire circuit.

[0003] In the prior art, in order to provide sufficient driving voltage for the gate of silicon controlled rectifier, an independent power supply voltage is usually generated by the secondary winding of the transformer. Although this method can meet the basic requirements of gate driving, it also brings the following significant problems:

[0004] 1. Complex transformer structure and high cost: The additional winding for the gate significantly increases the design and production difficulty of the transformer, resulting in complex manufacturing process and significantly increased bill of materials (BOM) cost.

[0005] 2. Serious circuit interference and poor system stability: The additional winding introduces additional electromagnetic interference, and the instability of the superimposed voltage may cause silicon controlled rectifier mis-conduction, thereby reducing the overall reliability of the system.

[0006] 3. Difficulty in passing electromagnetic compatibility (EMC) test: The complex winding design increases electromagnetic radiation in the circuit, making it more difficult for the system to pass the industry standard electromagnetic compatibility test, especially in high-reliability scenarios such as electric vehicle chargers.

[0007] In order to avoid the above problems, the industry also tries to improve the transformer design or optimize the peripheral circuit to reduce interference and complexity. For example, additional driving circuits such as optocoupler devices or more complex multi-stage driving modules are used. However, these methods usually introduce new problems: for example, the driving method of the optocoupler device can reduce some interference, but the additional device increases the design difficulty and overall cost of the circuit, and may also affect the long-term stability of the system due to the delay and aging problems of the optocoupler signal. The multi-stage driving module design is complex and occupies more PCB area, especially in small chargers where space is limited, making it difficult to implement.

[0008] Therefore, how to reduce the complexity of transformer winding design, reduce cost, and avoid introducing additional interference while ensuring system reliability and stability has become a technical problem to be solved by the utility model. UTILITY MODEL CONTENT

[0009] The technical problem solved by the utility model is to provide a silicon controlled rectifier driving circuit suitable for chargers to solve the problems of high complexity of transformer winding, serious interference and poor EMC performance in the prior art.

[0010] To solve the above technical problems, the utility model takes the technical scheme as follows:

[0011] A silicon controlled rectifier driving circuit suitable for chargers, comprising:

[0012] A single-chip microcomputer, whose output end is used to provide a control signal;

[0013] A capacitor, whose first end is connected to the output end of the single-chip microcomputer, and whose second end is connected to a resistor and the input end of a silicon controlled switch;

[0014] A resistor, whose first end is connected to the second end of the capacitor and the input end of the silicon controlled switch, and whose second end is connected to the positive pole of a secondary bus;

[0015] A silicon controlled rectifier, whose anode is connected to the positive pole of a secondary bus output, whose cathode is connected to the positive pole of a battery, and whose gate is used to receive a superimposed voltage from the capacitor and the single-chip microcomputer to control the conduction state of the silicon controlled rectifier;

[0016] A transformer, whose secondary winding output end is used to provide a secondary bus voltage, which is superimposed with the output voltage of the single-chip microcomputer through the capacitor and then transmitted to the gate of the silicon controlled rectifier;

[0017] When the output of the single-chip microcomputer becomes low, the voltage across the capacitor is charged through the resistor and becomes consistent with the secondary bus voltage;

[0018] When the output of the single-chip microcomputer becomes high, the capacitor transmits a superimposed voltage formed by superimposing the output voltage of the single-chip microcomputer and the secondary bus voltage to the gate of the silicon controlled rectifier under the drive of the output voltage of the single-chip microcomputer, so that the gate-cathode voltage of the silicon controlled rectifier reaches a level higher than the conduction threshold to realize the conduction of the silicon controlled rectifier.

[0019] As a further scheme of the utility model, the first end of the capacitor connected to the output end of the single-chip microcomputer is arranged on the side close to the single-chip microcomputer, the second end of the capacitor connected to the resistor is arranged on the side close to the resistor, and the capacitor and the resistor are arranged in parallel and spaced apart on the circuit board and fixedly connected through wires.

[0020] As a further scheme of the utility model, the resistance is connected to the gate of the thyristor through a switch welding point, and the welding point is coated with an insulating protective layer at a fixed position on the circuit board to prevent circuit failure caused by vibration or short circuit.

[0021] As a further scheme of the utility model, a protection diode is arranged between the output end of the single-chip microcomputer and the first end of the capacitor, the anode of the protection diode is connected to the output end of the single-chip microcomputer, and the cathode is connected to the anode of the single-chip microcomputer working power supply.

[0022] As a further scheme of the utility model, the anode of the thyristor is connected to the positive pole of the secondary bus through a wire, the wire is arranged along the surface of the circuit board and is fixed on the circuit board through a wire clamp.

[0023] As a further scheme of the utility model, a filter capacitor is arranged on the circuit board, the filter capacitor is connected in parallel with the secondary winding of the transformer and is used for filtering the secondary bus voltage.

[0024] As a further scheme of the utility model, the surface of the circuit board is covered with a metal shielding layer, and the shielding layer covers the single-chip microcomputer, the capacitor, the resistance and the thyristor.

[0025] Compared with the prior art, the utility model has the beneficial effects that:

[0026] 1. The output voltage of the single-chip microcomputer and the secondary bus voltage are superimposed, the design of the additional winding is replaced, the complexity of the transformer and the production cost are directly reduced, and the peripheral circuit structure is simplified and the cost is reduced due to the absence of the additional winding.

[0027] 2. The inherent characteristic of the capacitor, i.e. the voltage across the capacitor cannot be suddenly changed, makes the low voltage output by the single-chip microcomputer smoothly transit to the high voltage after superposition through the capacitor, and drives the gate of the thyristor. In this process, the capacitor not only plays a role in voltage transmission, but also effectively suppresses the instability phenomenon caused by voltage sudden change in the traditional circuit by superimposing the secondary bus voltage.

[0028] 3. Since the secondary bus voltage directly participates in the voltage superposition of the driving circuit, the complex superposition effect of electromagnetic interference in the traditional winding design is avoided, and the circuit interference is significantly reduced.

[0029] Additional aspects and advantages of the utility model will be partially given in the following description, some will become apparent from the following description, or will be understood by those skilled in the art through the practice of the utility model. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0031] Figure 1 The utility model discloses a schematic diagram of the silicon controlled rectifier drive charging circuit based on singlechip.

[0032] Figure 2 The utility model discloses a schematic diagram of the battery charging management circuit module.

[0033] Figure 3 The utility model discloses a working principle block diagram. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only some embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0035] Please refer to Figure 1 — Figure 3 In the embodiments of the present application, a silicon controlled rectifier drive circuit suitable for a charger comprises a singlechip U3, an output end of which is used to provide high-low level pulse control signals.

[0036] A capacitor C1, a first end of which is connected to the SW output end of the singlechip U3, and a second end of which is connected to a resistor R1.

[0037] The resistor R1, a first end of which is connected to the second end of the capacitor C1, and a second end of which is connected to the gate of a silicon controlled rectifier SCR1 through a switch tube (triode, photocoupler, etc.).

[0038] The silicon controlled rectifier SCR1, an anode of which is connected to the positive pole of the secondary bus of a transformer, a cathode of which is connected to the positive pole of a battery, and a gate of which is used to receive the superimposed voltage transmitted through the capacitor and the resistor to control the conduction state of the silicon controlled rectifier.

[0039] The transformer T1, a secondary winding output end of which is used to provide a secondary bus voltage, the secondary bus voltage being superimposed with the output voltage of the singlechip through the capacitor C1 and then being transmitted to the gate of the silicon controlled rectifier SCR1.

[0040] When the single-chip microcomputer output becomes low, the voltage across the capacitor C1 is charged to the same voltage as the secondary bus voltage through the resistor R1; the secondary bus refers to the common connection point of the voltage provided by the secondary winding of the transformer, and in this application, the positive electrode is connected to the anode of the thyristor, which is used to provide a stable operating voltage for the circuit. The voltage of the secondary bus is superimposed on the control signal voltage output by the single-chip microcomputer through the driving circuit composed of the capacitor C1 and the resistor R1, and then transmitted to the gate of the thyristor, thereby driving the thyristor to turn on. By directly involving the secondary bus voltage in the superposition process of the gate driving circuit, not only is the traditional transformer winding design simplified, the production cost is reduced, but also the electromagnetic interference problem in the traditional winding power supply scheme is effectively avoided, and the reliability and electromagnetic compatibility of the driving circuit are improved.

[0041] When the single-chip microcomputer output becomes high, the capacitor C1 will superimpose the output voltage of the single-chip microcomputer and the voltage across the capacitor C1 (the voltage across the capacitor C1) to form a superimposed voltage, and then transmit the superimposed voltage to the gate of the thyristor SCR1, so that the gate-cathode voltage of the thyristor SCR1 reaches a level higher than the turn-on threshold to realize the turn-on of the thyristor.

[0042] The first end of the capacitor connected to the output end of the single-chip microcomputer is arranged near the single-chip microcomputer, and the second end of the capacitor connected to the resistor is arranged near the resistor. The capacitor and the resistor are arranged in parallel and spaced apart on the circuit board and are fixedly connected by wires.

[0043] The resistor is connected to the gate of the thyristor through a switch welding point, and the welding point is coated with an insulating protective layer at a fixed position on the circuit board to prevent circuit failure caused by vibration or short circuit. A protection diode is provided between the output end of the single-chip microcomputer and the first end of the capacitor, the positive electrode of the protection diode is connected to the output end of the single-chip microcomputer, and the negative electrode is connected to the working power supply of the single-chip microcomputer. The anode of the thyristor is connected to the positive electrode of the secondary bus through a wire, and the wire is arranged along the surface of the circuit board and fixed on the circuit board by a wire clamp.

[0044] A filter capacitor is provided on the circuit board, which is connected in parallel with the secondary winding of the transformer, and is used to filter the voltage of the secondary bus. The surface of the circuit board is covered with a metal shielding layer, and the shielding layer covers the single-chip microcomputer, the capacitor, the resistor and the thyristor.

[0045] The utility model discloses a technical background for, because the positive pole of thyristor control circuit, when the grid G voltage is higher than the cathode K voltage, anode A can be conducted, and the traditional method is to have a set of winding of transformer specially for the gate power supply control switch, and the process of transformer and cost increase, and because of the superposition of voltage and the stability of whole circuit system is poor, and the interference is big, and EMC is very difficult to pass through, and the circuit of the application will no longer need the winding of transformer additional increase, and the process of transformer is simplified, and cost reduces, and the peripheral circuit also simplifies a lot, and the circuit interference also reduces a lot, and EMC is easy to pass through.

[0046] Based on this, compared with the traditional thyristor control circuit, the transformer T1 reduces a set of winding, and the output of singlechip and capacitor improve the grid G voltage of thyristor to singlechip voltage (5V) + secondary bus voltage V+, so that the Vgk voltage of thyristor is greater than the starting voltage of thyristor, and the thyristor is safely started, and the cost is reduced by reducing a winding output of transformer, and the stability of driving circuit and the anti-interference ability of circuit are improved, so that EMC is more easily passed.

[0047] Its working principle is that when the SW output of singlechip becomes low level (0), the voltage between the both ends of capacitor C1 charges through resistance R1 and finally becomes secondary bus voltage V+;When the SW output becomes high level (1), the voltage (relative to the negative pole of secondary bus) at the end of capacitor C1 connected resistance R1 becomes: 5V + V+> thyristor starting voltage, and the grid cathode voltage Vgk of thyristor = 5V + V+ minus battery positive voltage (B+) > thyristor starting voltage, and the control end of thyristor has starting current and opens, and the current flows from battery B+ to B- and charges the battery. This circuit utilizes the inherent characteristics of capacitor, and the voltage between the both ends of capacitor cannot be suddenly changed, so that the voltage of MCU is transmitted to the high potential end;And utilize the principle of voltage superposition, realize the low voltage control of singlechip high voltage output.

[0048] Embodiment 1

[0049] The embodiment provides a thyristor drive circuit suitable for electric vehicle charger, which is applied to the electric vehicle charger to realize efficient charging control of the battery, and solves the problems of complex transformer design, high cost, serious system interference and poor electromagnetic compatibility in the prior art.

[0050] Specifically, the charger includes a control unit (single-chip microcomputer), a power unit (including a transformer and a thyristor), and a driving circuit. The single-chip microcomputer serves as a core controller, and an output end thereof is connected to one end of a capacitor. The other end of the capacitor is connected to a gate of the thyristor through a resistor. An anode of the thyristor is connected to a positive electrode of a secondary bus, and a cathode thereof is connected to a positive electrode of a battery, for controlling opening and closing of a charging current. A secondary winding of the transformer provides a stable secondary bus voltage. The secondary bus voltage is superimposed with an output voltage of the single-chip microcomputer and then transmitted to the gate of the thyristor, thereby replacing a conventional winding power supply design.

[0051] In actual application, when the battery of the electric vehicle needs to be charged, the single-chip microcomputer sends a control signal to the driving circuit according to a real-time voltage and a charging state of the battery. When an output of the single-chip microcomputer becomes a low level, a voltage across the capacitor is consistent with the secondary bus voltage, and a switch tube (optocoupler or triode, etc.) is closed at this time. At this time, the thyristor is in a closed state, and the current is blocked from flowing to the battery. When the output of the single-chip microcomputer is a high level, the capacitor superimposes the output voltage (such as 5V) of the single-chip microcomputer with the secondary bus voltage (such as V+) by means of a voltage superposition characteristic thereof, to form a driving voltage (for example, 5V+V+) higher than a thyristor turn-on threshold value, and the driving voltage is transmitted to the gate of the thyristor. At this time, the thyristor is stably turned on, and the charging current flows from the positive electrode to the negative electrode of the battery, to provide efficient and stable charging for the battery.

[0052] Compared with a conventional design of using an additional winding of a transformer for power supply, the embodiment realizes accurate driving of the thyristor by means of inherent characteristics (voltage cannot be abruptly changed) of the capacitor and a smooth voltage superposition manner, and effectively avoids the problem of false turn-on caused by unstable voltage. In addition, the driving manner eliminates the design requirement of the additional winding of the transformer, thereby achieving the following effects: by eliminating the additional winding, the design and manufacturing process of the transformer are significantly simplified, the dependence on winding wire in a bill of materials is reduced, and the production cost is reduced; since the capacitor smoothly transmits the voltage superposition signal, the problem of unstable signal caused by electromagnetic interference in the conventional winding design is avoided, and the reliability of the system is greatly improved; since the design without the additional winding reduces electromagnetic interference caused by winding coupling in the circuit, the charger is more likely to pass the EMC standard, and is particularly suitable for scenarios such as electric vehicle chargers, which have high requirements on electromagnetic compatibility.

[0053] Embodiment 2

[0054] The embodiment is suitable for a multi-output intelligent charger of small household electronic devices, and realizes accurate charging control on different battery groups by means of the thyristor driving circuit of the application, while significantly reducing circuit complexity and cost, and improving stability and anti-interference ability of the charging system.

[0055] The specific application scenario is a household intelligent charger, which supports multiple specifications of battery packs, such as 3.7V lithium battery pack and 12V lead-acid battery pack. In this scenario, due to the multi-output requirement, the system requires stable and reliable current control when switching the charging path to avoid overcharging or undercharging of different battery packs caused by interference or misoperation.

[0056] The charger control module drives multiple silicon controlled rectifiers (SCRs) through single-chip microcomputer (SCM) output signals to selectively control the charging path. Each SCRs drive circuit includes SCM, capacitor, resistor and SCR. The secondary winding of the transformer provides a unified secondary bus voltage. The SCM output signal and the secondary bus voltage are transmitted to the gate of each SCR after voltage superposition through the capacitor, completing the control of the multi-path charging path.

[0057] For example, when the system needs to charge a 3.7V lithium battery pack, the SCM sends a high-level signal through the corresponding output terminal. After the signal is superimposed with the secondary bus voltage through the capacitor, it is transmitted to the gate of the SCR that controls the charging path, making it conductive. At this time, the charging current flows from the secondary bus through the anode of the SCR, the positive electrode of the lithium battery, the negative electrode of the lithium battery, and finally to the ground of the charger, completing the stable charging of the lithium battery pack. When switching to a 12V lead-acid battery pack, the SCM switches the signal output to another drive circuit, which drives the corresponding SCR to conduct, thereby achieving accurate charging of the lead-acid battery pack.

[0058] Traditional multi-output chargers usually use complex multi-winding transformer designs to provide independent drive voltage for each charging path. However, this design has the following problems: first, the transformer design is complex and costly; second, electromagnetic coupling between different windings can cause serious electromagnetic interference, affecting charging accuracy; third, the system stability is low and is prone to mis-conduction due to interference. This embodiment replaces the traditional multi-winding design by using the voltage superposition characteristics of SCM and capacitor, only one transformer secondary winding is needed to meet the driving needs of all charging paths, greatly simplifying the system design and reducing the use of components and production costs.

[0059] Experimental results show that in multi-output applications, the drive circuit of the present application not only significantly reduces the design and manufacturing costs of the transformer, but also effectively avoids the electromagnetic coupling interference problem between traditional windings. In addition, the stable voltage superposition characteristics of the capacitor ensure smooth transition of the drive signal when switching the charging path, avoiding mis-conduction between different paths, and overall improving the stability and safety of the charger.

[0060] Embodiment 3:

[0061] Referring to Figure 1 , the SCR drive charging circuit based on SCM. The circuit mainly includes the following functional modules:

[0062] AC rectification filter circuit: This part is composed of inductor (LF1), rectifier bridge (BD1) and filter capacitor (EC1, EC2), which is used to rectify the input alternating current (AC) to direct current (DC). The rectified direct current is further smoothed by the filter capacitor as the power supply voltage input of the subsequent circuit. This part ensures the stability of the input voltage and reduces the power supply fluctuation of the subsequent module.

[0063] Step-down and secondary rectification filter module: The step-down of alternating current is realized by transformer T1, and the secondary winding output is rectified by diode and processed by filter capacitor (such as C3) to form secondary bus voltage (V+). Compared with traditional design, the secondary winding of this circuit does not need to design additional gate supply winding, and only through the combination of this output voltage and subsequent circuit can meet the demand of gate drive, thereby reducing the design complexity and cost of transformer.

[0064] Silicon controlled rectifier drive control circuit: This module is the core innovation point of the circuit. The output end of the single-chip microcomputer is connected with the gate of silicon controlled rectifier (SCR1) through capacitor (such as C1), and the other end of the capacitor is connected with resistor R1, which is used to form a stable driving path. The output voltage of the single-chip microcomputer is superimposed with the secondary bus voltage (V+) and then transmitted to the gate of silicon controlled rectifier through the capacitor, so that it reaches the conduction condition. This design fully utilizes the voltage superposition characteristics of the capacitor and avoids the complexity of traditional additional winding power supply.

[0065] Single-chip microcomputer control module: The single-chip microcomputer is responsible for controlling the conduction and turn-off of silicon controlled rectifier, and its output signal is dynamically adjusted according to the charging state of the battery. When the single-chip microcomputer detects that charging is needed, it outputs high-low level pulse signal, which forms superimposed voltage through capacitor transmission to drive silicon controlled rectifier to conduct and complete the charging process of the battery; when the charging is completed or no charging is needed, the single-chip microcomputer outputs low level signal and turns off the gate drive voltage of silicon controlled rectifier and reduces the charging current to 0 to stop charging.

[0066] Charging current management circuit: The RCS detects the charging current and feeds back to the control chip to realize real-time monitoring and adjustment of the charging current, ensuring the safety and stability of the battery charging process; output filter and protection circuit: the final output is further processed by filter module and protection module (such as NTC thermistor) to provide stable charging current, and the protection circuit is protected from transient current impact.

[0067] See Figure 2, the battery charging management circuit module schematic diagram shows the core control part of battery charging management, including single-chip microcomputer output, thyristor drive and the monitoring and feedback loop related to the battery charging state. Through the cooperative work of the above-mentioned module, the embodiment realizes the following remarkable technical effects on the hardware level: by the capacitive superposition of the single-chip microcomputer output voltage and the secondary bus voltage, the additional winding of the transformer in the traditional design is successfully cancelled, the transformer design is significantly simplified and the cost is reduced. The thyristor drive signal is stable and has strong anti-interference ability, which avoids the misdirecting problem caused by electromagnetic interference in the traditional circuit. Intelligent control of the battery charging process is realized, which guarantees the charging efficiency and improves the reliability and safety of the system.

[0068] In the utility model, unless there is definite stipulation and limitation, the terms "mount", "set", "connect", "fix", "screw" and so on should be understood in broad sense, for example, can be fixed connection, also can be detachable connection, or be integrated, can be mechanical connection, also can be electrical connection, can be direct connection, also can be indirect connection through intermediate medium, can be the communication of two elements or the interaction of two elements, unless there is definite limitation, for the ordinary skilled in the art, can understand the specific meaning of the above terms in the utility model according to specific circumstances.

[0069] It is obvious for those skilled in the art that the utility model is not limited to the details of the above exemplary embodiments, and the utility model can be realized in other specific forms without departing from the spirit or basic features thereof. Therefore, no matter from which point, the embodiments should be regarded as exemplary and non-restrictive, the scope of the utility model is defined by the appended claims instead of the above description, and all changes falling within the meaning and scope of the essential elements of the claims should be included in the utility model.

Claims

1. A silicon controlled rectifier drive circuit suitable for use in a charger, characterized by, The utility model relates to a drive circuit of a silicon controlled rectifier, comprising: a single-chip microcomputer, an output end of which is used to provide a control signal; a capacitor, a first end of which is connected to the output end of the single-chip microcomputer, and a second end of which is connected to a resistor; a resistor, a first end of which is connected to the second end of the capacitor, and a second end of which is connected to a gate electrode of a silicon controlled rectifier; the silicon controlled rectifier, an anode of which is connected to a positive electrode of a secondary bus, a cathode of which is connected to a positive electrode of a battery, and the gate electrode of which is used to receive a superimposed voltage transmitted through the capacitor and the resistor to control a conduction state of the silicon controlled rectifier; a transformer, a secondary winding of which is used to provide a secondary bus voltage, the secondary bus voltage being transmitted to the gate electrode of the silicon controlled rectifier after being superimposed with an output voltage of the single-chip microcomputer through the capacitor; wherein, when the single-chip microcomputer outputs a low level, a voltage across the capacitor is consistent with the secondary bus voltage; when the single-chip microcomputer outputs a high level, the capacitor transmits a superimposed voltage formed by superimposing the output voltage of the single-chip microcomputer and the secondary bus voltage to the gate electrode of the silicon controlled rectifier under the drive of the output voltage of the single-chip microcomputer, so that a gate-cathode voltage of the silicon controlled rectifier reaches a level higher than a conduction threshold to realize the conduction of the silicon controlled rectifier.

2. A silicon controlled rectifier drive circuit for a charger according to claim 1, wherein The first end of the capacitor connected to the output end of the single-chip microcomputer is arranged on a side close to the single-chip microcomputer, the second end of the capacitor connected to the resistor is arranged on a side close to the resistor, and the capacitor and the resistor are arranged in parallel and spaced apart on a circuit board and fixedly connected through a wire.

3. A silicon controlled rectifier drive circuit for a charger according to claim 1, wherein The resistor is connected to the gate electrode of the silicon controlled rectifier through a switching welding point, and the welding point is fixed at a position on the circuit board and coated with an insulating protective layer.

4. A silicon controlled rectifier drive circuit for a charger according to claim 1, wherein A protection diode is arranged between the output end of the single-chip microcomputer and the first end of the capacitor, a positive electrode of the protection diode is connected to the output end of the single-chip microcomputer, and a negative electrode of the protection diode is connected to a positive electrode of a working power supply of the single-chip microcomputer.

5. A silicon controlled rectifier drive circuit for a charger according to claim 1, wherein The cathode of the silicon controlled rectifier is connected to the positive electrode of the battery through a wire, and the wire is arranged along a surface of the circuit board.

6. A silicon controlled rectifier drive circuit for a charger according to claim 1, wherein The drive circuit is arranged on the circuit board, a filter capacitor is arranged on the circuit board, and the filter capacitor is connected in parallel with the secondary winding of the transformer.

7. A silicon controlled rectifier drive circuit for a charger according to claim 1, wherein The drive circuit is arranged on the circuit board, and a metal shielding layer is arranged on a surface of the circuit board, the shielding layer covering the single-chip microcomputer, the capacitor, the resistor, and the silicon controlled rectifier.

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