An auxiliary IC control circuit for aerial work platforms

Abstract

This utility model relates to an auxiliary IC control circuit for aerial work platforms, comprising: an AC power supply, which, after filtering and rectification, has its positive DC terminal connected to one end of the primary winding of transformer T1 via a first inductor, and its negative terminal grounded; the other end of the primary winding is connected to the drain of MOSFET Q1, and its source is grounded via a first resistor; the gate receives a PWM modulation signal from the IC control circuit to achieve switching control, and an RCD buffer circuit is connected in parallel between the drain and source to absorb voltage spikes. The secondary side of transformer T1 has at least two secondary windings: the first path outputs a stable DC voltage Vout after filtering and rectification; the second path is rectified by diode D1 and cooperates with optocoupler PC1 to form an isolated feedback link, transmitting the output voltage information to the IC control circuit for dynamic adjustment. The shunt reference voltage source IC1 works in conjunction with the compensation circuit to ensure high consistency of the multiple output voltages.

Description

Technical Field

[0001] This utility model relates to the field of power electronic conversion technology, and in particular to an auxiliary IC control circuit for aerial work platforms. Background Technology

[0002] In the application of special equipment such as aerial work platforms, a stable and reliable power supply is one of the key factors in ensuring the safe operation and efficient work of the equipment. However, existing power supply systems often have many shortcomings and are unable to meet the increasingly complex working conditions. Specifically, traditional power conversion schemes usually adopt simple linear voltage regulation or non-isolated DC-DC conversion technology. Although these methods are relatively simple in structure, they have revealed obvious limitations in practical applications:

[0003] Due to the lack of effective electrical isolation measures, high-frequency noise generated during switching can easily interfere with other electronic equipment through conduction and radiation, affecting the normal operation of the entire system. This problem is particularly exacerbated in high-altitude working environments, where the presence of strong electromagnetic fields can lead to malfunctions or even breakdowns in the control system.

[0004] Meanwhile, the power devices (such as transistors) in traditional solutions operate in the linear region, resulting in high conduction losses. At the same time, there is no dedicated buffer circuit to absorb the peak voltage during the switching process, which significantly increases the switching losses and reduces the overall energy efficiency ratio.

[0005] Therefore, we propose an auxiliary IC control circuit for aerial work platforms.

[0006] The above content is only used to help understand the technical solution of this utility model and does not represent an admission that the above content is prior art. Utility Model Content

[0007] This invention proposes an auxiliary IC control circuit for aerial work platforms, aiming to solve the problems of insufficient electrical isolation and anti-interference capabilities, as well as low energy conversion efficiency and high losses in the prior art.

[0008] To achieve the above objectives, this utility model proposes an auxiliary IC control circuit for aerial work platforms, comprising: an AC power supply connected to an AC filter circuit, the AC power supply being sequentially connected to the AC filter circuit and a rectifier bridge; the positive terminal of the DC output of the rectifier bridge being connected to the first terminal of the primary winding of a transformer T1 through a first inductor, and the negative terminal being grounded; the second terminal of the primary winding of the transformer T1 being connected to the drain of a MOSFET Q1, the source of the MOSFET Q1 being grounded through a first resistor, and the gate of the MOSFET Q1 receiving the PWM modulation signal output by the IC control circuit through a second resistor to control the switching state; and an RCD buffer circuit being connected in parallel between the drain and source of the MOSFET Q1.

[0009] The secondary side of transformer T1 has at least two secondary windings. The first secondary winding is connected to a filter and rectifier circuit to output a first stable DC voltage Vout. The first end of the second secondary winding is connected to the negative terminal of diode D1, and the second end is grounded. The positive terminal of diode D1 is connected to the anode of the input side of optocoupler PC1, and diode D1 is also grounded through an electrolytic capacitor. The cathode of the input side of optocoupler PC1 is connected to the non-reference terminal of shunt reference voltage source IC1 through a third resistor. The collector of the output side of optocoupler PC1 is connected to the IC control circuit, and the emitter is grounded. The reference terminal of the shunt reference voltage source IC1 is connected to a compensation circuit.

[0010] Preferably, the input-side anode and input-side cathode of the optocoupler PC1 are connected to a fourth resistor, and a voltage divider resistor network is connected between the compensation circuit and the VREF terminal of the filter rectifier circuit.

[0011] Preferably, the compensation circuit includes: an operational amplifier U1, the inverting input terminal of the operational amplifier U1 is connected to the reference terminal of the shunt reference voltage source IC1 through a fifth resistor, and an RC compensation circuit is connected across the fifth resistor; the non-inverting input terminal of the operational amplifier U1 is grounded through a sixth resistor, and a first capacitor is connected between the non-inverting and inverting input terminals to achieve frequency compensation; the output terminal of the operational amplifier U1 is connected to the inverting input terminal through an integrator consisting of a seventh resistor and a second capacitor to form a closed-loop control.

[0012] Preferably, the output of the operational amplifier U1 is further driven by an eighth resistor to perform signal conditioning on the subsequent common-emitter amplifier circuit.

[0013] Preferably, the common-emitter amplifier circuit further includes: a transistor Q2, the base of which is connected to the output of operational amplifier U2 through an eighth resistor; a ninth resistor and a third capacitor are connected in parallel between the seventh resistor and the base of transistor Q2; the emitter of transistor Q2 is grounded through a tenth resistor; an eleventh resistor and a fourth capacitor are connected in parallel between the collector and emitter of transistor Q2; and the collector of transistor Q2 is also connected to the Vout terminal of the filter rectifier circuit in the first secondary winding through a Schottky diode D3.

[0014] The beneficial effects of this utility model's technical solution are as follows:

[0015] By using transformer T1 to achieve electrical isolation between the primary and secondary sides, the transmission path of high-frequency noise is effectively blocked. Combined with the high-frequency switching control of MOSFET Q1 and the parallel RCD buffer circuit, the peak voltage generated during the switching process can be efficiently absorbed, significantly reducing electromagnetic interference (EMI) and ensuring that the system can still operate stably in a strong electromagnetic environment.

[0016] The combination of the rectifier bridge and the filter circuit smooths the input AC power into a high-quality DC bus, providing an ideal foundation for subsequent DC-DC conversion; the MOSFET operates in switching mode rather than the nonlinear region, significantly reducing conduction losses; combined with the input filter array formed by the first inductor, it further suppresses conducted noise and improves the overall energy efficiency ratio.

[0017] An isolated feedback link consisting of optocoupler PC1 and shunt reference voltage source IC1 is introduced to achieve real-time monitoring and accurate correction of output voltage Vout. The operational amplifier U1 and its RC network and integrator design in the compensation circuit effectively eliminate system phase lag, keep loop gain stable across the entire frequency band, thereby keeping the load regulation rate at a low level and ensuring high consistency of multi-output voltage.

[0018] The first resistor connected in series with the source of the MOSFET has overcurrent protection. When a short circuit fault is detected, the IC control circuit can quickly shut down the PWM signal. Combined with the natural decay process formed by the leakage inductance of the transformer, the surge energy is limited to a safe range. The application of Schottky diode D3 prevents reverse current from flowing back into the control circuit, providing double protection for sensitive devices from abnormal operating conditions.

[0019] The transformer secondary side is equipped with at least two independent secondary windings, which not only meet the main power output requirements, but also allow for flexible expansion of auxiliary power supply branches; for example, after rectification by diode D1, it can supply power to low-voltage equipment such as sensors and communication modules; the voltage divider resistor network accurately matches the reference point under different load conditions, supporting energy distribution on demand; the distributed power supply architecture reduces wiring complexity, improves system integration, and adapts to the needs of multi-actuator collaborative control of aerial work platforms.

[0020] The common-emitter amplifier circuit serves as the subsequent driving unit, utilizing the high current gain characteristic of transistor Q2 to amplify the error signal a second time; the damping network composed of the ninth resistor and the third capacitor effectively attenuates high-frequency oscillation components; the tenth resistor sets a suitable static operating point to avoid crossover distortion; the eleventh resistor and the fourth capacitor are connected in parallel to improve transient response characteristics and ensure that the control signal is accurately transmitted to the load. Attached Figure Description

[0021] Figure 1 This is a circuit structure diagram of an embodiment of the subject matter of this utility model;

[0022] Figure 2 This is a partial circuit structure diagram of one side of an embodiment of the present invention;

[0023] Figure 3 This is a partial circuit structure diagram of another aspect of one of the embodiments of the present invention.

[0024] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0025] The solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0026] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this utility model are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0027] It should also be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component present. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component present.

[0028] Furthermore, descriptions involving terms such as "first" and "second" in this utility model are for descriptive purposes only (e.g., to distinguish identical or similar elements) and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" and "second" may explicitly or implicitly include at least one of those features. Additionally, technical solutions from different embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If a combination of technical solutions is contradictory or impossible to implement, such a combination should be considered nonexistent and not within the scope of protection claimed by this utility model.

[0029] See Figures 1-3 An auxiliary IC control circuit for an aerial work platform includes: an AC power supply connected to an AC filter circuit, and the AC power supply sequentially connected to the AC filter circuit and a rectifier bridge; the positive terminal of the DC output of the rectifier bridge is connected to the first terminal of the primary winding of a transformer T1 through a first inductor, and the negative terminal is grounded; the second terminal of the primary winding of the transformer T1 is connected to the drain of a MOSFET Q1, the source of the MOSFET Q1 is grounded through a first resistor, and the gate receives the PWM modulation signal output by the IC control circuit through a second resistor to control the switching state; an RCD buffer circuit is connected in parallel between the drain and source of the MOSFET Q1.

[0030] The secondary side of transformer T1 has at least two secondary windings. The first secondary winding is connected to a filter and rectifier circuit to output a first stable DC voltage Vout. The first end of the second secondary winding is connected to the negative terminal of diode D1, and the second end is grounded. The positive terminal of diode D1 is connected to the anode of the input side of optocoupler PC1, and diode D1 is also grounded through an electrolytic capacitor. The cathode of the input side of optocoupler PC1 is connected to the non-reference terminal of shunt reference voltage source IC1 through a third resistor. The collector of the output side of optocoupler PC1 is connected to the IC control circuit, and the emitter is grounded. The reference terminal of the shunt reference voltage source IC1 is connected to a compensation circuit.

[0031] By employing transformer T1 to achieve electrical isolation between the primary and secondary sides, and combining this with high-frequency switching control of MOSFET Q1 and an RCD buffer circuit to absorb voltage spikes, switching losses are significantly reduced and electromagnetic interference (EMI) is suppressed. The combination of the rectifier bridge and filter circuit ensures that the input AC power is smoothly converted into a high-quality DC bus, providing a reliable foundation for subsequent DC-DC conversion.

[0032] The input filter array, consisting of the first inductor and a large-capacity electrolytic capacitor, effectively suppresses conducted noise from the power cable; the first resistor connected in series with the source of the MOSFET provides overcurrent protection. When a short-circuit fault is detected, the IC control circuit can quickly shut off the PWM signal, and with the natural decay process formed by the transformer leakage inductance, the surge energy is limited to a safe range.

[0033] The transformer's secondary side features at least two independent secondary windings, which not only meet the main power output requirements but also allow for flexible expansion of auxiliary power supply branches. For example, the second secondary winding, after rectification by diode D1, can power low-voltage equipment such as sensors and communication modules, and can also distribute energy on demand by adjusting the duty cycle. This distributed power supply architecture reduces wiring complexity, improves system integration, and is particularly suitable for the collaborative control requirements of multiple actuators on aerial work platforms.

[0034] In one embodiment, the input anode and input cathode of the optocoupler PC1 are connected to a fourth resistor, and a voltage divider resistor network is connected between the compensation circuit and the VREF terminal of the filter rectifier circuit.

[0035] Furthermore, the compensation circuit includes: an operational amplifier U1, the inverting input terminal of the operational amplifier U1 is connected to the reference terminal of the shunt reference voltage source IC1 through a fifth resistor, and an RC compensation circuit is connected across the fifth resistor; the non-inverting input terminal of the operational amplifier U1 is grounded through a sixth resistor, and a first capacitor is connected between the non-inverting and inverting input terminals to achieve frequency compensation; the output terminal of the operational amplifier U1 is connected to the inverting input terminal through an integrator consisting of a seventh resistor and a second capacitor to form a closed-loop control.

[0036] In this embodiment, an isolated feedback link consisting of optocoupler PC1 and shunt reference voltage source IC1 enables real-time monitoring and dynamic correction of the output voltage Vout. The fourth resistor optimizes the optocoupler response speed, while the voltage divider resistor network precisely matches the reference point under different load conditions. Combined with the operational amplifier U1 and its RC network and integrator design in the compensation circuit, system phase lag is effectively eliminated, ensuring stable loop gain across the entire frequency band. This keeps the load regulation rate within a low range, ensuring high consistency of the multi-output voltages.

[0037] In one embodiment, the output of the operational amplifier U1 is further driven by an eighth resistor to perform signal conditioning on the subsequent common-emitter amplifier circuit.

[0038] Furthermore, the common-emitter amplifier circuit also includes: a transistor Q2, the base of which is connected to the output terminal of operational amplifier U2 through an eighth resistor, a ninth resistor and a third capacitor connected in parallel between the seventh resistor and the base of transistor Q2, the emitter of transistor Q2 being grounded through a tenth resistor, an eleventh resistor and a fourth capacitor connected in parallel between the collector and emitter of transistor Q2, and the collector of transistor Q2 being connected to the Vout terminal of the filter rectifier circuit in the first secondary winding through a Schottky diode D3.

[0039] In this embodiment, a common-emitter amplifier circuit is used as the subsequent driving unit. The high current gain characteristic of transistor Q2 is utilized to amplify the error signal a second time. Combined with a damping network consisting of the ninth resistor and the third capacitor, high-frequency oscillation components are effectively attenuated. The tenth resistor sets a suitable static operating point to avoid crossover distortion, while the eleventh resistor connected in parallel with the fourth capacitor further improves transient response characteristics. The application of Schottky diode D3 prevents reverse current from flowing back into the control loop, providing double protection for sensitive devices from abnormal operating conditions.

[0040] The above description is only a part or preferred embodiment of this utility model. Neither the text nor the drawings should limit the scope of protection of this utility model. All equivalent structural transformations made using the content of this utility model specification and drawings under the overall concept of this utility model, or direct / indirect applications in other related technical fields, are included within the scope of protection of this utility model.

Claims

1. An auxiliary IC control circuit for aerial work platforms, characterized in that, include: An AC power supply is connected to an AC filter circuit, which is then connected in sequence to the AC filter circuit and a rectifier bridge. The positive terminal of the DC output of the rectifier bridge is connected to the first terminal of the primary winding of transformer T1 through a first inductor, and the negative terminal is grounded. The second terminal of the primary winding of transformer T1 is connected to the drain of MOSFET Q1. The source of MOSFET Q1 is grounded through a first resistor, and the gate receives the PWM modulation signal output by the IC control circuit through a second resistor to control the switching state. An RCD buffer circuit is connected in parallel between the drain and source of MOSFET Q1. The secondary side of transformer T1 has at least two secondary windings. The first secondary winding is connected to a filter and rectifier circuit to output a first stable DC voltage Vout. The first end of the second secondary winding is connected to the negative terminal of diode D1, and the second end is grounded. The positive terminal of diode D1 is connected to the anode of the input side of optocoupler PC1, and diode D1 is also grounded through an electrolytic capacitor. The cathode of the input side of optocoupler PC1 is connected to the non-reference terminal of shunt reference voltage source IC1 through a third resistor. The collector of the output side of optocoupler PC1 is connected to the IC control circuit, and the emitter is grounded. The reference terminal of the shunt reference voltage source IC1 is connected to a compensation circuit.

2. The auxiliary IC control circuit for an aerial work platform according to claim 1, characterized in that, The input anode and input cathode of the optocoupler PC1 are connected to a fourth resistor, and a voltage divider resistor network is connected between the compensation circuit and the VREF terminal of the filter rectifier circuit.

3. The auxiliary IC control circuit for an aerial work platform according to claim 2, characterized in that, The compensation circuit includes: an operational amplifier U1, the inverting input terminal of the operational amplifier U1 is connected to the reference terminal of the shunt reference voltage source IC1 through a fifth resistor, and an RC compensation circuit is connected across the fifth resistor; the non-inverting input terminal of the operational amplifier U1 is grounded through a sixth resistor, and a first capacitor is connected between the non-inverting and inverting input terminals to achieve frequency compensation; the output terminal of the operational amplifier U1 is connected to the inverting input terminal through an integrator circuit consisting of a seventh resistor and a second capacitor to form a closed-loop control.

4. The auxiliary IC control circuit for an aerial work platform according to claim 3, characterized in that, The output of the operational amplifier U1 is also driven by an eighth resistor to perform signal conditioning on the subsequent common-emitter amplifier circuit.

5. The auxiliary IC control circuit for an aerial work platform according to claim 4, characterized in that, The common-emitter amplifier circuit further includes: a transistor Q2, the base of which is connected to the output of operational amplifier U2 through an eighth resistor; a ninth resistor and a third capacitor are connected in parallel between the seventh resistor and the base of transistor Q2; the emitter of transistor Q2 is grounded through a tenth resistor; an eleventh resistor and a fourth capacitor are connected in parallel between the collector and emitter of transistor Q2; and the collector of transistor Q2 is also connected to the Vout terminal of the filter and rectifier circuit in the first secondary winding through a Schottky diode D3.

6. The auxiliary IC control circuit for an aerial work platform according to claim 1, characterized in that, The shunt reference voltage source IC1 is set with an adjustable voltage regulator chip TL431.

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