MegaWatt S-350-12 Adjustable DC Power Supply User Manual

1. Introduction

This manual provides detailed instructions for the safe and efficient operation of your MegaWatt S-350-12 Adjustable DC Power Supply. This unit is designed to provide stable and filtered DC power for various applications, including HAM and CB radio equipment. Please read this manual thoroughly before use and retain it for future reference.

2. Safety Information

Always observe the following safety precautions to prevent injury or damage to the unit and connected equipment:

• Ensure the power supply is disconnected from the AC mains before making any connections or adjustments.
• Do not operate the unit in wet or damp conditions.
• Ensure proper ventilation. Do not block the cooling fan or vents.
• Do not exceed the maximum output current or voltage ratings.
• Use appropriate gauge wiring for DC output connections to handle the rated current.
• This unit contains high voltage. Do not open the casing unless you are a qualified service technician.

3. Package Contents

Verify that all items are present in the package:

• MegaWatt S-350-12 DC Power Supply Unit
• Switched 120 Volt AC Power Cord

4. Product Features

The MegaWatt S-350-12 power supply offers the following key features:

• Adjustable DC Output: Provides a regulated output voltage from 10V to 15.5V DC.
• High Current Capacity: Delivers 30 Amps continuous and 33 Amps peak current.
• RF Filtered Output: Designed with highly filtered output to minimize RF hash, suitable for sensitive radio equipment.
• Efficient Cooling: Features a double ball bearing cooling fan for effective heat dissipation and quiet operation.
• Input Voltage Versatility: Operates on 120V AC or 220V AC (47Hz to 63Hz).
• Protection Features: Includes over voltage and short circuit protection.
• Shielded Design: Fully shielded for use in radio environments.

5. Setup

Follow these steps to set up your MegaWatt S-350-12 power supply:

5.1 Connecting AC Power

1. Ensure the power supply is placed on a stable, level surface with adequate ventilation around all sides.
2. Verify the AC input voltage switch (if present, typically located near the AC input terminals) is set to your local mains voltage (120V or 220V). Note: The product description indicates operation on both 120V and 220V AC. If no visible switch, the unit may auto-sense or require internal configuration. Consult a qualified technician if unsure.
3. Connect the provided switched 120 Volt AC power cord to the AC input terminals (L, N, and Ground) on the power supply. Ensure connections are secure.
4. Plug the AC power cord into a grounded wall outlet. Do not switch on the power supply yet.

5.2 Connecting DC Load

The power supply features a terminal block for DC output connections.

1. Identify the positive (+V) and negative (-V) terminals on the power supply's output block.
2. Connect your DC load (e.g., HAM radio, CB radio) to these terminals, ensuring correct polarity. The positive terminal of your equipment connects to +V, and the negative terminal to -V.
3. Ensure all connections are tight and secure to prevent arcing or poor contact. For high current applications, use appropriate wire gauges (e.g., 10 AWG for 30 Amps).

5.3 Adjusting Output Voltage

The MegaWatt S-350-12 features an adjustable voltage output. A small potentiometer (labeled +V ADJ) is located near the output terminals for this purpose.

1. With the power supply connected to AC mains but without a DC load connected, switch on the power supply using the switch on the AC cord.
2. Using a digital multimeter, measure the DC voltage across the +V and -V output terminals.
3. Carefully insert a small Phillips head screwdriver into the +V ADJ potentiometer.
4. Slowly turn the potentiometer clockwise to increase the voltage or counter-clockwise to decrease it. Note: This adjustment can be very sensitive. Make small, precise turns.
5. Adjust the voltage to your desired level (e.g., 13.8V for most HAM/CB radios).
6. Once the desired voltage is set, switch off the power supply and connect your DC load as described in Section 5.2.

6. Operating Instructions

6.1 Powering On/Off

• To power on the unit, ensure all connections are secure, then use the switch on the AC power cord.
• To power off, use the switch on the AC power cord. For extended periods of non-use, it is recommended to unplug the unit from the wall outlet.

6.2 Parallel Operation

The MegaWatt S-350-12 can be operated in parallel with other identical units to increase the total available amperage. To do this:

1. Ensure all power supplies are set to the exact same output voltage using a multimeter.
2. Connect the positive output terminals of all units together.
3. Connect the negative output terminals of all units together.
4. Connect your load to the combined positive and negative bus.
5. Ensure all units are powered on simultaneously.

Example: Two units in parallel provide approximately 60 Amps continuous, three units provide 90 Amps, and so on.

7. Maintenance

The MegaWatt S-350-12 is designed for reliable operation with minimal maintenance.

• Cleaning: Periodically inspect the cooling fan and vents for dust accumulation. Use compressed air to gently clear any blockages. Ensure the unit is unplugged before cleaning.
• Ventilation: Always ensure the unit has clear airflow around it to prevent overheating.
• Connections: Periodically check all AC and DC connections for tightness and signs of corrosion.

8. Troubleshooting

If you encounter issues with your power supply, refer to the following table:

9. Specifications

10. Warranty and Support

For warranty information or technical support, please refer to the documentation provided with your purchase or contact MegaWatt directly through their official website or customer service channels. Keep your purchase receipt as proof of purchase.