Valefod DC-DC 5A Buck Converter (Model VA-0189) Instruction Manual

1. Introducció

This manual provides detailed instructions for the Valefod DC-DC 5A Buck Converter, Model VA-0189. This module is designed to efficiently step down a higher DC input voltage to a lower, adjustable DC output voltage. It features a digital LED display for voltage monitoring and a potentiometer for precise output voltage ajust.

Figure 1: Two Valefod DC-DC 5A Buck Converter modules.

2. Característiques del producte

• High Precision Design: Features 36u thickened circuit boards, a high-Q inductance with an output LED indicator, and solid-state capacitors for effective high-frequency noise filtering.
• Entrada Voltage Rang: DC 4V to 38V. Note: Input voltage must be at least 1.5V higher than the desired output voltage (no boost function).
• Vol. De sortidatage Rang: Continuously adjustable from DC 1.25V to 36V.
• Corrent de sortida màxima: 5 Amperes.
• Mida compacta: Dimensions are 62mm x 38mm x 14mm (including potentiometer).
• Pantalla LED integrada: Digital voltmeter for monitoring input or output voltage.
• Adjustable Potentiometer: Allows for easy adjustment of the output voltage.

3. Notes importants de seguretat

• Voltage Diferencial: El volum d’entradatage must always be at least 1.5V higher than the output voltage. This module does not support voltage boosting.
• Polaritat: Do not reverse the polarity of the input and output connections. Incorrect wiring can damage the module.
• Current/Power Limits: Keep the output current under 5A and the total power under 75W. For prolonged operation at higher loads, a heat sink is recommended to prevent overheating.
• Ajust inicial: The factory setting for the output voltage may be high. It may be necessary to turn the blue potentiometer screw counter-clockwise approximately 7-15 full rotations before the output voltage begins to decrease.

4. Configuració i connexions

Follow these steps to set up your Valefod DC-DC Buck Converter:

1. Identificar terminals: Locate the "IN+" and "IN-" terminals for input, and "OUT+" and "OUT-" terminals for output.
2. Connexió d'entrada: Connect your DC power source (4V-38V) to the "IN+" (positive) and "IN-" (negative) terminals. Ensure correct polarity.
3. Connexió de sortida: Connect your load or device to the "OUT+" (positive) and "OUT-" (negative) terminals. Ensure correct polarity.
4. Vol inicialtage Comproveu: Before connecting a sensitive load, it is highly recommended to verify the output voltagi utilitzant un multímetre.

Figure 2: Module layout with input/output connections and controls.

Figura 3: Detallada view of the buck converter components.

5. Instruccions de funcionament

5.1. Ajustar el volum de sortidatage

El voltage is adjusted using the blue multi-turn potentiometer located on the module. A small screwdriver is required for this adjustment.

1. Encès: Connect the input power source. The LED display will illuminate.
2. Sortida del monitor: Use a multimeter to accurately measure the voltage across the "OUT+" and "OUT-" terminals. While the onboard LED display provides an indication, a multimeter offers higher precision for initial setup.
3. Adjust Potentiometer:
   • Gireu el cargol en sentit horari a augmentar el vol de sortidatage.
   • Gireu el cargol en sentit antihorari a disminuir el vol de sortidatage.
4. Initial Adjustment Note: As mentioned in the safety notes, the factory default voltage may be high. You might need to turn the potentiometer counter-clockwise for 7-15 full rotations before the voltage starts to drop. Each full rotation typically adjusts the voltage by approximately 1V.
5. Afinament: Adjust slowly until the desired output voltage is achieved on your multimeter.

5.2. Using the Digital Voltmeter

The module includes a digital LED display to show voltage readings. There are two buttons for controlling the display:

• Left Button ("ON/OFF"):
  • Premsa curta: Turns the digital voltmeter ON.
  • Premda llarga (1-4 segons): Turns the digital voltmeter OFF.
• Right Button ("Mode"):
  • Premsa curta: Toggles between displaying the input voltage (indicated by "IN" LED) and the output voltage (indicated by "OUT" LED).

6. Voltmeter Calibration (Optional)

For users requiring highly accurate voltage readings from the onboard digital display, the voltmeter can be calibrated. The calibration range is -0.5V to +0.5V, with a factory setting of 0.0V.

1. Activate Voltmeter: Short press the left "ON/OFF" button to ensure the digital display is active.
2. Entra al mode de calibratge: Long press the left "ON/OFF" button for more than 4 seconds.
   • The "IN" indicator LED will light up, signifying that input voltage measurement calibration has started.
3. Adjust Input Voltage Calibració:
   • Toqueu botó esquerre a reduir the calibration value.
   • Toqueu botó dret a augmentar the calibration value.
   • Since one unit of adjustment is less than 0.1V, you may need to tap the button 1-5 times continuously to observe a 0.1V change on the display.
4. Switch to Output Voltage Calibració: After calibrating the input voltage, long press the right "Mode" button for more than 2 seconds.
   • The "OUT" indicator LED will light up, signifying that output voltage measurement calibration has started.
5. Ajusta el volum de sortidatage Calibració: Use the left and right buttons as described in step 3 to adjust the output voltage calibration value.
6. Guardar i sortir: After completing both calibrations, long press the right "Mode" button for more than 2 seconds to save the adjusted values. The module will then return to normal voltage display mode. The calibrated values are retained even after power loss.

7. Manteniment

The Valefod DC-DC Buck Converter is designed for reliable operation with minimal maintenance. Observe the following guidelines:

• Neteja: Keep the module free from dust, dirt, and moisture. Use a soft, dry cloth for cleaning.
• Ventilació: Ensure adequate airflow around the module, especially when operating at higher currents or for extended periods. If necessary, attach the provided heat sink or ensure it is mounted in a well-ventilated enclosure.
• Connexions: Periodically check all input and output connections to ensure they are secure and free from corrosion.
• Condicions ambientals: Operate the module within its specified temperature and humidity ranges to ensure optimal performance and longevity.

Figure 4: Module with included heatsink and mounting hardware.

8. Solució De Problemes

If you encounter issues with your buck converter, consider the following troubleshooting steps:

• Sense Vol de sortidatage / Display Off:
  • Check input power supply: Ensure it is connected correctly and providing voltagdins del rang de 4V-38V.
  • Verify polarity: Confirm that input and output connections are not reversed.
  • Check for short circuits: Inspect output connections for any short circuits that might trigger protection.
  • Display ON/OFF: Short press the left button to ensure the digital display is turned on.
• Vol. De sortidatage Not Adjusting:
  • Initial High Voltage: Remember that the factory setting might be high. Turn the potentiometer counter-clockwise for 7-15 full rotations to bring the voltage down into an adjustable range.
  • Entrada Voltage Requisit: Assegureu-vos que l'entrada voltage is at least 1.5V higher than your target output voltage.
  • Potentiometer Functionality: If after many turns the voltage still doesn't change, the potentiometer might be faulty.
• Sobreescalfament del mòdul:
  • Corrent de càrrega: Reduce the load current. The module is rated for a maximum of 5A.
  • Potència de sortida: Ensure total output power does not exceed 75W.
  • Dissipador de calor: Attach the provided heat sink if operating at higher loads or for extended periods. Ensure good thermal contact.
  • Ventilació: Improve ventilation around the module.
• Inaccurate Voltmeter Display:
  • Calibració: Perform the voltmeter calibration procedure described in Section 6.
  • External Multimeter: Always use a calibrated external multimeter for precise voltage measurements, especially during critical setup.

9. Especificacions

Figure 5: Module dimensions.

10. Garantia i Suport

Valefod products are designed for quality and reliability. For any questions, technical assistance, or support regarding your DC-DC Buck Converter, please refer to the seller's contact information or the platform where the product was purchased.

Please retain your proof of purchase for any warranty claims. Specific warranty terms may vary by region and retailer.