Introduction
This manual provides essential information for the safe and effective use of the Diymore 012359 20A 300W CC CV Step Down Module. This adjustable DC-DC buck converter is designed to regulate voltage and current from a wide input range of 6V to 40V DC down to an output range of 1.2V to 36V DC. It features high efficiency, large current screw terminals for convenient wiring, and integrated heat sinks for enhanced thermal performance.
Product Overview



The module is equipped with 75V/80A dual MOS tubes and high-frequency, low-resistance electrolytic capacitors for stable output and minimal ripple. Its design includes two heat sinks to optimize thermal performance and extend operational life.
Specifications
| Feature | Value |
|---|---|
| Manufacturer | diymore |
| Product Dimensions | 2.36 x 2.09 x 1.06 inches |
| Item Weight | 6.4 ounces |
| Item Model Number | 012359 |
| Brand | diymore |
| Power Source | DC |
| Mounting Type | PCB Mount |
| Current Rating | 15 Amps, 20 Amps |
| Input Voltage Range | 6V to 40V DC |
| Output Voltage Range | 1.2V to 36V DC |
| Efficiency | Up to 96% (measured at 20A, 24V to 12V conversion) |
Setup
Before connecting the module, ensure all power sources are disconnected. Observe proper polarity for input and output connections.
Wiring Connections
Connect the input voltage source (6-40V DC) to the 'IN+' and 'IN-' terminals. Connect your load to the 'OUT+' and 'OUT-' terminals. The module features large current 30A screw terminals for secure connections.

Initial Adjustment
Before connecting your load, it is crucial to adjust the output voltage and current. Use a multimeter to monitor the output. The module has two potentiometers:
- Voltage Adjustment (CV): Turn the potentiometer labeled 'CV' to set the desired output voltage.
- Current Adjustment (CC): Turn the potentiometer labeled 'CC' to set the desired output current limit.
Adjust these carefully, especially the current, to match your load's requirements. If there is a significant difference between input and output voltage, reduce the power and current settings to prevent overheating.
Operating Instructions
Once the module is wired and adjusted, you can power it on. The integrated ON/OFF switch allows for convenient control. Monitor the module's temperature during operation, especially under heavy loads.
Voltage and Current Control
The module operates in Constant Voltage (CV) and Constant Current (CC) modes. When the load current exceeds the set current limit, the module automatically switches to Constant Current mode, limiting the output current to the preset value. Otherwise, it operates in Constant Voltage mode, maintaining the set output voltage.
For charging applications, such as lithium-ion batteries, an anti-flow diode should be added to the output terminal to prevent reverse current flow.
Maintenance
To ensure optimal performance and longevity of your Diymore step-down module, follow these maintenance guidelines:
- Keep Clean: Regularly inspect the module for dust or debris accumulation, especially on the heat sinks. Use compressed air or a soft brush to gently clean the components.
- Ensure Ventilation: Always operate the module in a well-ventilated area. If operating under high loads or in enclosed spaces, consider adding active cooling, such as a fan, to prevent overheating.
- Check Connections: Periodically verify that all wiring connections to the screw terminals are secure and free from corrosion. Loose connections can lead to poor performance or damage.
- Avoid Overloading: Do not exceed the maximum specified input voltage, output current, or power ratings. Overloading can cause permanent damage to the module.
Troubleshooting
If you encounter issues with your Diymore step-down module, refer to the following common problems and solutions:
Common Issues and Solutions
- No Output Voltage / Module Not Working:
- Check all input and output wiring for correct polarity and secure connections.
- Ensure the input voltage is within the specified 6-40V range.
- Verify the ON/OFF switch is in the 'ON' position.
- If the indicator LED is on, the module is likely working, and the issue might be with the load or measurement.
- Module Gets Very Hot:
- This can occur when there is a large difference between input and output voltage, or when operating at high current.
- Reduce the output power and current.
- Ensure adequate ventilation. Consider adding an external fan for active cooling, especially if the heat sinks feel excessively hot.
- Verify the load is not drawing more current than the module is rated for.
- Output Voltage or Current is Unstable:
- Ensure the input power supply is stable and can provide sufficient current.
- Re-adjust the CV and CC potentiometers carefully using a multimeter.
- Check for any loose connections or damaged wiring.
- Module Failure (e.g., shorting out):
- Inspect the module for any visible damage, such as burnt components or poor soldering. Some units may have minor manufacturing imperfections that require careful inspection before use.
- Ensure the module was not subjected to reverse polarity or excessive voltage/current beyond its specifications.


Warranty & Support
Diymore is committed to providing quality products and customer satisfaction.
- Warranty: This product comes with an 18-month warranty.
- Returns: You may return the product within 30 days for a refund or replacement.
- Customer Support: For any questions, technical assistance, or support needs, please contact Diymore customer service. We aim to provide 24-hour customer support.
- Online Resources: Visit the official Diymore store on Amazon for additional product information and support: Diymore Store.





