DC-DC 400W Buck Power Module – Adjustable CV CC | GUANDO
DC-DC 400W Buck Power Module – Adjustable CV CC | GUANDO
GUANDO 400W DC-DC Step-Down Buck Power Module — Adjustable Voltage & Current
Meet the GUANDO SZ-BK0612 — a high-efficiency, 400W non-isolated BUCK (step-down) power module designed for makers, engineers, and electronics enthusiasts. Whether you need a reliable bench power supply, a battery charging solution, or an LED driver, this compact module delivers continuously adjustable voltage and current with impressive efficiency. Made in Mainland China.
Key Features
- Wide Input Range: Accepts 10.5V–60V DC input, compatible with most common power supplies on the market.
- Adjustable Output: Continuously adjustable output voltage (0–45V) and current (0.2–15A) to suit virtually any load requirement.
- High Efficiency: Step-rectifier design achieves up to 92–97% conversion efficiency depending on input/output conditions.
- High Output Power: Up to 400W peak (with forced cooling); 280W / 12A maximum continuous output in a well-ventilated environment.
- Constant Voltage & Constant Current (CV/CC): Dual-mode operation with a dedicated red CC indicator light that illuminates during constant-current operation for at-a-glance status monitoring.
- Built-in Protections: Input undervoltage protection (auto-shuts output below ~10.5V), input reverse-polarity fuse protection (15A fuse), and short-circuit protection via constant-current limiting.
- Easy Connections: Built-in 25A screw terminal block — no soldering required.
- Status Indicator: Blue LED working indicator light confirms the module is active.
Technical Specifications
| Model | SZ-BK0612 |
| Module Type | Non-Isolated BUCK (Step-Down) |
| Input Voltage | 10.5V – 60V DC |
| Output Voltage | 0V (+1V) – ~Input × 0.8 (max 45V) |
| Output Current | 0.2A – 15A (continuously adjustable) |
| Peak Output Power | 400W (forced cooling required) |
| Continuous Output Power | 280W / 12A (ventilated environment) |
| Conversion Efficiency | Up to 97% |
| Working Frequency | 100 kHz |
| Operating Temperature | -10°C to +85°C (add cooling above 65°C) |
| Input Fuse | 15A (replaceable) |
| Connection Terminal | Built-in 25A screw terminal (no soldering) |
| Module Dimensions | 60mm × 60mm × 45mm |
| Net Weight | 170g (packaged: ~180g) |
| Country of Origin | Made in Mainland China |
How to Adjust Voltage & Current
Voltage Adjustment: Use a flat-head screwdriver to turn the CV (blue) potentiometer on the module. Rotate clockwise to increase voltage and counter-clockwise to decrease it. Monitor with a multimeter for precision.
Current Adjustment: Set your multimeter to the 10A or 20A current range. Set output voltage to ~5V, then turn the CC (blue) potentiometer fully counter-clockwise (~20 turns) to bring current to minimum. Short-circuit the output terminals through the multimeter, then rotate the CC potentiometer clockwise until the desired current value is reached. Note: If the module shows no output after turning CC fully counter-clockwise, this is normal — current is set to 0A. Simply rotate clockwise to restore output.
Important Safety Notes
- This is a step-down (buck) only module — input voltage MUST always be higher than output voltage.
- Never reverse-connect input or output terminals. Reverse input will blow the input fuse; reverse output will damage the control board beyond repair.
- When charging batteries or driving inductive loads (e.g., motors), add an anti-backfeed diode on the output.
- Do NOT short-circuit the input negative and output negative poles directly — this bypasses constant-current detection and can damage the module and connected load.
- For continuous operation above 280W or 12A, add forced cooling (a fan on the heatsink and magnetic ring).
- The control board has weather-resistant conformal coating — avoid physical impact or dropping.
Learn more: OSHA on eye and face protection
Frequently Asked Questions
Q: What is the maximum output power of the DC-DC 400W buck power module?
A: The module can deliver up to 400W peak output power, but this requires active forced cooling (a fan on the heatsink and magnetic ring). In a naturally ventilated environment, the maximum continuous output power is 280W at up to 12A. Exceeding these limits without proper cooling may damage the module.
Q: Can this step-down module be used to charge lithium or lead-acid batteries?
A: Yes — the CV/CC (constant voltage / constant current) dual-mode operation makes this module well suited for charging batteries. The red CC indicator light turns on during constant-current charging so you can monitor charging status at a glance. However, you must add an anti-backfeed diode on the output when the module is connected to a battery to prevent reverse current flow.
Q: What input voltage range does this buck module support?
A: The module accepts a wide input range of 10.5V to 60V DC, making it compatible with most common bench power supplies, solar panels, and other DC sources available on the market. The output voltage can be set from near 0V up to approximately 80% of the input voltage (maximum 45V).
Q: Is soldering required to connect this power module?
A: No soldering is needed. The module features a built-in 25A screw terminal block for both input and output connections, making setup quick and tool-minimal — just a flat-head screwdriver for the terminals and potentiometer adjustments.
Production & Packaging Notice
To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.