DewinLVD SK120 DC Step Up/Down Converter User Manual

1. Introduction

This manual provides detailed instructions for the safe and effective operation of the DewinLVD SK120 DC 6-36V to 0-36V 120W 6A Step Up/Down Converter. This adjustable voltage-regulated power supply module is designed for a wide range of applications, including laboratory power supplies, outdoor camping, electric scooters, and golf carts. It features a full-view color LCD display, intelligent temperature control, and multiple protection functions.

2. Safety Information

Please read all safety warnings and instructions carefully before use to prevent electric shock, fire, or serious injury.

• Ensure proper ventilation to prevent overheating. The device includes a smart temperature control fan and heat sink.
• Do not exceed the specified input voltage (DC 6-36V) or output current (6A) and power (120W) limits.
• This product does not have reverse polarity protection for battery charging. Reverse polarity will damage the device. Battery charging requires professional knowledge. Non-professionals should not charge directly to prevent fire and explosion.
• Keep the device away from water, moisture, and flammable materials.
• Only use the device for its intended purpose.
• Disconnect power before making any connections or adjustments.

3. Product Overview

The DewinLVD SK120 is a versatile DC-DC converter module featuring a clear VA color LCD display for real-time monitoring of voltage, current, and power. It is equipped with user-friendly buttons and an encoder for precise control.

Figure 3.1: Front view of the SK120 converter, displaying input/output parameters.

Key features include:

• Input Voltage: DC 6-36V
• Output Voltage: DC 0-36V
• Output Current: 0-6A
• Output Power: 120W
• Display: Full-view VA Color LCD
• Storage: 10 groups of data storage
• Protection: Anti-reverse, undervoltage, overvoltage, overcurrent, overtemperature, overpower, timeout protection.
• Cooling: Intelligent temperature control fan and thickened heat sink.
• MPPT Function: Supports solar charging.

Figure 3.2: Internal view of the SK120 module, highlighting components and connection terminals.

4. Specifications

5. Setup and Wiring

Proper wiring is crucial for the safe and correct operation of the SK120 module. Refer to the diagram below for connection points.

Figure 5.1: Wiring diagram and key function introduction.

1. Input Connection: Connect your DC power source (6-36V) to the IN+ (Input positive) and IN- (Input negative) terminals. Ensure correct polarity.
2. Output Connection: Connect your load or device to the OUT+ (Output positive) and OUT- (Output negative) terminals. Ensure correct polarity.
3. External Temperature Probe (Optional): If using, connect the NTC temperature probe to the designated interface. This supports over-temperature protection and automatic shutdown.
4. Serial Communication Interface (Optional): For advanced users, this interface allows connection to X1-K485X module for 485 bus control or a WiFi module for remote control via a mobile app or web page.

Caution: Incorrect wiring can damage the device and connected equipment. Always double-check connections before applying power.

6. Operating Instructions

6.1. Key Function Introduction

Figure 6.1: Overview of button functions.

• VSET Button: Short press to set voltage. Long press to enter/exit data group interface.
• SW Button: Short press to switch input/output voltage display. Long press to enter/exit system setting interface.
• ISET Button: Short press to set current. Long press to enter/exit data group interface.
• Encoder Button: Short press to switch display (power W, capacity Ah, energy Wh, time h, temperature °C/wheel display). Long press to turn on/off the lock function.
• Power Button: Short press to turn on/off power output. Long press to clear capacity Ah/energy Wh/time h data.

6.2. Setting Voltage and Current

Figure 6.2: Steps for setting voltage and current.

1. On the main interface, short press the VSET button to set the voltage. The LCD will display "SET" on the lower line, and "CV" will flash to indicate the voltage position.
2. Rotate the encoder to adjust the voltage value.
3. After setting, short press the VSET button again to exit and save.
4. To set the current, short press the ISET button. The setting steps are identical to those for setting the voltage.

6.3. Quickly Setting Voltage or Current (System Parameter Setting)

In the system parameter setting interface (accessed by long pressing the SW button), you can set the parameter to FET CV (Default setting voltage CV), FET CC (Default setting current CC), or OFF (No action). Rotate the encoder in the main interface to quickly enter the voltage or current setting interface.

6.4. Input and Output Voltage Display

Figure 6.3: Switching between input and output display.

On the main interface, short press the SW button to toggle between displaying the input voltage (IN) and the output voltage (ON).

6.5. Checking Power, Capacity, Energy, Time, Temperature

On the main interface, short press the encoder button to cycle through various display modes:

• Power (W)
• Capacity (Ah)
• Energy (Wh)
• Time (h)
• Temperature (°C) (if external probe is connected)
• Wheel display (default main interface)

6.6. Lock Function

Figure 6.4: Using the lock function.

To prevent accidental changes, press and hold the encoder button for 2 seconds to lock the set voltage and current. A lock symbol will appear on the display. To unlock, press and hold the encoder button for another 2 seconds.

6.7. Data Group Function

The product supports 10 data groups (CD0 to CD9) for storing and recalling different voltage and current settings.

1. Long press the VSET button on the main interface to access the data group interface.
2. You can short press VSET or ISET to switch between constant voltage (CV) and constant current (CC) settings within a data group.
3. Rotate the encoder to select the desired data group (CD0-CD9).
4. After selecting a data group, long press the VSET / SW button or short press the encoder button to load the selected data group.

6.8. MPPT Solar Charging Function

Figure 6.5: MPPT solar charging setup.

The SK120 module supports Maximum Power Point Tracking (MPPT) for efficient solar charging. Connect a solar panel to the input and a battery to the output. The device will automatically optimize the charging process. An external temperature probe can be connected to the battery to support over-temperature protection, automatically stopping charging if the battery temperature exceeds safe limits.

Important Note: This product does not have reverse polarity protection for battery charging. Connecting the battery with reverse polarity will damage the device. Battery charging requires specific professional knowledge. Non-professionals should not attempt direct battery charging to prevent fire and explosion hazards.

7. Maintenance

• Keep the device clean and free from dust. Use a soft, dry cloth for cleaning.
• Ensure the ventilation openings are not blocked to maintain proper heat dissipation.
• Store the device in a dry environment when not in use.
• Avoid dropping or subjecting the device to strong impacts.

8. Troubleshooting

• No Display/No Power Output:
  • Check input power connections and ensure the input voltage is within the 6-36V range.
  • Verify that the power output is turned on (short press the Power button).
• Output Voltage/Current Not Stable:
  • Ensure connections are secure and free from loose wires.
  • Check if the load is within the specified output current and power limits.
  • Verify that the device is not in a protection state (e.g., overtemperature, overcurrent).
• Device Overheating:
  • Ensure adequate ventilation around the module.
  • Reduce the load if operating near maximum power for extended periods.
  • Check if the fan is operating correctly.
• Settings Cannot Be Changed:
  • Check if the lock function is active (long press the encoder button to unlock).

9. Warranty and Support

For warranty information and technical support, please refer to the product packaging or contact your retailer. Keep your purchase receipt as proof of purchase.