Pure sine-wave compatible low-frequency inverter built around the SG3525A PWM controller and IR2110 gate drivers — engineered in-house for 24 V / 48 V battery systems.
The AuMi 1 kW inverter is a fully in-house designed power conversion system using a full H-bridge topology driven by the SG3525A current-mode PWM IC. Complementary gate drive is handled by the IR2110 high-side/low-side MOSFET driver, ensuring precise switching timings and bootstrap-powered high-side control. Four IRF3205 N-channel power MOSFETs form the H-bridge switching stage, and the output is boosted via an in-house wound EI-core step-up transformer to deliver 230 V AC at 50 Hz.
The design prioritises component availability, repairability, and thermal headroom. All semiconductors are chosen from in-stock inventory used across AuMi's power electronics lab. The SG3525A delivers stable dead-time control between the two bridge legs, preventing shoot-through while maintaining clean waveform symmetry.
A single IR2110 drives one leg of the H-bridge per IC (two ICs total), providing isolated high-side bootstrap gate drive without an isolated power supply — keeping the design compact and cost-effective. The IRF3205 MOSFETs (55 V, 110 A, 8 mΩ RDS(on)) offer generous current margins at 24 V and 48 V bus voltages.
Block diagram — AuMi 1 kW H-Bridge Inverter
Designed with industrial-grade component selection, field-repairability, and dual-voltage battery compatibility as core requirements.
Voltage-mode PWM IC with adjustable frequency, built-in dead-time, and soft-start for clean H-bridge control at 50 Hz.
High-side bootstrap gate drivers per bridge leg — isolated high-side switching without a separate isolated power supply.
55 V / 110 A N-channel MOSFETs with 8 mΩ RDS(on) — extremely low conduction losses and high current headroom at both 24 V and 48 V.
Configurable for 24 V or 48 V battery banks by selecting the corresponding transformer tap — ideal for both home inverter and solar systems.
AuMi-wound EI-core step-up transformer tuned for 24 V→230 V and 48 V→230 V with matched turns ratio and thermal design for 1 kW continuous.
Over-current shutdown via SG3525A current limit pin, thermal fuse on transformer, and input polarity protection on the DC bus.
Electrical parameters for the AuMi 1 kW H-Bridge Inverter.
| Power Stage | |
|---|---|
| Topology | Full H-Bridge (single-phase) |
| Output Power | 1000 W continuous |
| Output Voltage | 230 V AC ± 5% |
| Output Frequency | 50 Hz |
| Waveform | Modified sine (low-frequency stepped) |
| Input Voltage | 24 V DC / 48 V DC (selectable) |
| Input Current (24 V) | ≈ 50 A at full load |
| Input Current (48 V) | ≈ 25 A at full load |
| Typical Efficiency | > 92% |
| Control & Switching | |
|---|---|
| PWM Controller | SG3525A |
| Switching Frequency | 50 Hz (power), ~50 kHz (gate drive) |
| Dead-time | Adjustable via RT/CT on SG3525A |
| Gate Driver | IR2110 (2× per inverter) |
| Power Switch | IRF3205 N-MOSFET (4×) |
| Transformer | AuMi EI-core, in-house wound |
| OCP | SG3525A current limit |
| Thermal Protection | Thermal fuse on transformer |
| Cooling | Aluminium heatsink + natural convection |
All major semiconductors sourced from AuMi in-house inventory for rapid availability and serviceability.
| Ref | Component | Part No. | Qty | Function |
|---|---|---|---|---|
| U1 | PWM Controller | SG3525A | 1 | 50 Hz PWM generation, dead-time, soft-start, OCP |
| U2, U3 | Gate Driver | IR2110 | 2 | High-side/low-side MOSFET gate drive, bootstrap |
| Q1–Q4 | N-MOSFET | IRF3205 | 4 | H-bridge power switches (55 V, 110 A, 8 mΩ) |
| T1 | Step-up Transformer | AuMi EI-core | 1 | 24/48 V DC → 230 V AC, 1 kW, in-house wound |
| D1–D4 | Bootstrap Diode | UF4007 | 2 | IR2110 bootstrap supply |
| C1 | Bulk Capacitor | 4700 µF / 63 V | 1 | DC bus ripple filter |
| F1 | Thermal Fuse | 117°C | 1 | Transformer over-temperature protection |
| R1, R2 | Gate Resistor | 10 Ω | 8 | MOSFET gate switching speed control |
Power household appliances from 24 V or 48 V lead-acid or lithium battery banks during outages.
Off-grid inverter stage coupled with solar charge controllers and battery storage for rural electrification.
Low-cost standby inverter for critical industrial loads requiring 230 V AC backup.
Open design architecture makes it ideal as an education or R&D platform for power electronics development.
Contact AuMi engineers for custom specifications, volume pricing, or OEM integration.
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