Consumer-grade electrostatic spraying equipment serves as the core tool for household decoration, home appliance maintenance, automotive DIY painting, small hardware processing and craft creation. It relies on a high-voltage power supply to form a high-voltage electrostatic field between the spray gun nozzle and the workpiece, charging atomized coating particles so that they adhere evenly to the workpiece surface under electric field force. Featuring high coating utilization, uniform spraying, simple operation and excellent adaptability to miniaturized scenarios, it has gradually replaced traditional air spraying and become the mainstream product in the consumer spraying market. The high-voltage power supply is the core critical component of consumer-grade electrostatic spraying equipment. It provides stable negative high-voltage DC output for electrostatic spray guns and undertakes key functions including electrostatic field construction, coating particle charging and spraying effect regulation. Its miniaturization integration, output stability, safety protection, environmental adaptability, mass production consistency and cost controllability directly determine the spraying performance, operational safety, service life and market competitiveness of electrostatic spraying equipment. Consumer-grade electrostatic spraying scenarios impose differentiated technical requirements and core challenges completely different from industrial spraying power supplies: First, extreme miniaturization and lightweight requirements. Consumer electrostatic spraying equipment is divided into integrated handheld and portable split types. The internal installation diameter of integrated handheld spray guns is generally no more than 25 mm, with an axial length within 100 mm. The power supply must be integrated inside the gun handle with ultra-miniature and lightweight design: total weight ≤ 100 g and power density ≥ 150 W/in³. Traditional industrial spraying power supplies are bulky and heavy, failing to meet the installation demands of handheld consumer devices. Second, stringent personal safety protection requirements. Most operators of consumer spraying equipment are ordinary non-professional users lacking professional electrical safety knowledge. Complex usage scenarios easily lead to misoperation, spray gun short circuits and human contact with high-voltage terminals. Meanwhile, coatings and thinners are mostly flammable and explosive organic solvents with fire and explosion risks. The power supply must adopt non-bypass multi-level personal safety protection, limiting output short-circuit current strictly within 50 μA, and integrate double insulation, overvoltage/overcurrent protection, short-circuit protection, arc protection and flame-retardant design, fully complying with GB 4706.1 to eliminate electric shock, fire and explosion hazards. Third, wide-range adjustable high-stability constant-current output. Scenarios cover wall decoration, automotive paint, hardware workpieces and craft products. Different substrates and coatings require different electrostatic high voltage and charging current. The power supply needs continuously adjustable output voltage from -30 kV to -60 kV with constant-current characteristics. It maintains stable output current despite load fluctuations caused by changing spraying distances and workpiece shapes, ensuring consistent particle charging and uniform coating to avoid sagging, missing spray and uneven layers. Fourth, low power consumption and high efficiency. Most portable wireless spraying devices adopt lithium batteries with limited capacity. Static power consumption and conversion efficiency directly determine battery life. Requirements include static power consumption < 10 mW, peak conversion efficiency ≥ 88%, and high efficiency maintained from 10% to 100% load to extend battery endurance. Fifth, strong environmental adaptability and high reliability. Equipment operates in harsh environments with coating dust, organic solvent corrosion, high humidity, wide temperature variation, frequent start-stop and vibration impact. The power supply must achieve MTBF ≥ 5,000 hours, design life ≥ 3 years, excellent three-proof performance, and stable operation at -10 ℃ ~ +40 ℃ and 90% RH without corrosion from dust and solvents. Sixth, low electromagnetic interference and EMC compliance. Products must comply with GB 4343.1, avoiding interference with household appliances, mobile phones, Wi-Fi and other devices, while maintaining stable operation in complex home electromagnetic environments with low conducted and radiated EMI. Seventh, mass production consistency and low cost. For large-scale consumer manufacturing, the power supply requires a simple topology, fewer components, streamlined production processes and high yield. Material and production costs must be minimized while meeting performance and safety standards to support economical mass production. Targeting the core operational demands and technical challenges of high-voltage power supplies for consumer electrostatic spraying equipment, this methodology establishes a full-process universal technical framework covering miniaturized integrated topology design, multi-level personal safety protection, constant-current output optimization, mass production consistency control and civil environmental adaptability design. It meets the high-voltage power demands of integrated handheld and portable split spraying equipment, providing standardized design criteria for localization, mass production and performance upgrading of core components for domestic civil electrostatic spraying equipment. Focusing on miniaturization, high safety, low power consumption and low-cost mass production, the methodology adopts a universal framework: **high-frequency self-excited flyback topology + voltage multiplier rectifier + full-hardware safety protection**, combined with integrated cylindrical design and comprehensive safety protection system, breaking the limitations of traditional industrial power supplies with large size, high cost and insufficient safety protection. The high-frequency self-excited flyback topology features the simplest structure, minimal components, smallest size and lowest cost. Without complex digital control chips, it realizes high-frequency oscillation and high-voltage output via discrete devices, perfectly matching miniaturization, low-cost and mass production demands for consumer products. Combined with multi-stage voltage multiplier rectifiers, it achieves -30 kV ~ -60 kV high-voltage output in an ultra-compact size. Full-hardware constant-current control and safety protection circuits deliver nanosecond fault response to ensure user safety. The design follows eight core principles: 1. **Miniaturized Cylindrical Integrated Topology** Optimizing flyback and voltage multiplier integration for narrow handheld installation spaces, an axial layered + radial annular cylindrical 3D integration structure is adopted. The high-frequency oscillation unit, high-voltage transformer, multi-stage rectifier and safety protection unit are arranged axially with circular PCBs matching the gun handle inner cavity. High-temperature metal pins ensure electrical connection and mechanical fixation. Pot ferrite cores (outer diameter ≤ 20 mm) and high-temperature polyimide insulated windings minimize radial size. High-voltage capacitors and diodes are arranged annularly to shorten high-voltage loops and reduce parasitic parameters. All components adopt miniature SMD packaging, achieving overall size ≤ Φ25 mm × 100 mm and weight ≤ 100 g for seamless handheld integration. 2. **Multi-Level Personal Safety Protection System** As the core safety red line, it strictly complies with GB 4706.1 and builds a 5-level non-bypass protection system: current limiting → short-circuit protection → arc protection → double insulation → flame retardant explosion-proof. - Full-hardware constant-current limiting restricts short-circuit current ≤ 50 μA to prevent electric shock even with direct human contact. - High-speed comparators and thyristor circuits cut off high voltage within 100 ns during short circuits or overloads with automatic recovery. - Built-in arc detection instantly shuts down output to prevent ignition of flammable solvents. - Double insulation achieves ≥ 4,000 VAC isolation; the transformer adopts triple-insulated wires with ≥ 0.4 mm insulation thickness, and the entire module is vacuum epoxy encapsulated with insulated flame-retardant gun housing for complete electric shock prevention. - All materials and components adopt V-0 flame retardant grade to avoid open fire in explosive solvent environments. 3. **Wide-Range Adjustable Constant-Current Output Optimization** Adopting adjustable reference + constant-current closed-loop control, output voltage is continuously adjustable from -30 kV to -60 kV with precision better than ±5%. Dual closed loops (current inner loop + voltage outer loop) dynamically adjust oscillation frequency and duty cycle, limiting current fluctuation ≤ ±10% under variable spraying distances, workpieces and coatings to ensure uniform charging and coating quality without sagging or missing spray. Soft-start design prevents high-voltage impact and coating splashing during power-on. 4. **Low Power Consumption & High Efficiency Optimization** For lithium battery-powered portable devices: - Topology optimization realizes soft switching with peak efficiency ≥ 88% and ≥ 80% efficiency at 20% light load. - High-performance MOSFETs, high-voltage fast recovery diodes and high-permeability ferrite cores reduce conduction, switching and core losses. - Multi-power management reduces oscillation frequency in standby mode with static power < 10 mW; automatic sleep mode (static current < 10 μA) activates after 5 minutes of inactivity to extend battery life. 5. **Mass Production Consistency & Cost Optimization** - Simplified self-excited flyback topology limits total components ≤ 30, eliminating redundant digital circuits to reduce material costs and improve yield. - Universal civil-grade standard components ensure stable supply and sufficient parameter margins for batch consistency. - Full SMD modular design supports automatic SMT production; standardized vacuum epoxy encapsulation ensures consistent quality. - Automatic standardized testing fixtures realize batch performance and safety inspection to eliminate defective products. 6. **Civil Environmental Adaptability & High Reliability** - Wide-temperature components support stable operation at -10 ℃ ~ +40 ℃ with output fluctuation ≤ ±5%; over-temperature protection activates above 85 ℃. - Vacuum epoxy encapsulation achieves IP67 dustproof, moisture-proof and anti-corrosion performance against coating dust and organic solvents. - High-Tg FR-4 PCBs and reinforced soldering resist vibration and drop impact for handheld use. - All components adopt derating design with ≥ 3-year service life and MTBF ≥ 5,000 hours. 7. **Low EMI & EMC Design** - Source suppression: soft switching reduces dv/dt and di/dt; interleaved transformer winding minimizes leakage inductance and radiation interference. - Multi-stage EMI filters suppress conducted interference to meet GB 4343.1. - Integrated metal shielding provides ≥ 40 dB shielding effectiveness to control radiated EMI and ensure compatibility with home electromagnetic environments. 8. **Compliance & Maintainability Design** - Fully compliant with GB 4706.1, GB 4343.1 and GB 17625.1, supporting CE/UL international certifications for export. - Modular structure with standard interfaces enables quick replacement and easy after-sales maintenance; status indicators intuitively display operating and fault conditions. In summary, this full-process framework solves the core pain points of traditional industrial power supplies (bulky size, high cost, insufficient safety protection and poor adaptability to handheld consumer devices). It achieves ultra-miniaturization within Φ25 mm × 100 mm via cylindrical 3D integration, qualified personal safety protection per household electrical standards via 5-level safety systems, ≥ 88% efficiency and < 10 mW static power via full-link optimization, and low-cost mass production with high consistency via simplified topology and standardized components. The methodology is widely applicable to integrated handheld, portable split and lithium-battery wireless electrostatic spraying/flocking equipment, providing core technical support for domestic substitution, large-scale production and performance upgrading of civil electrostatic spraying core components.