1. Product Overview
The EARNMee 3005MS is a variable DC power supply designed for laboratory, workshop, and educational applications. It provides adjustable voltage from 0-30V and current from 0-5A, featuring a 4-digit LED display for real-time monitoring of voltage, current, and power. This unit includes an 18W USB fast charging port and multiple protection functions to ensure safe and reliable operation.
Figure 1: Front view of the EARNMee 3005MS DC Power Supply, highlighting its adjustable voltage/current, quick charge, precise display, and safety protection features.
Video 1: A 360-degree view of the EARNMee 3005MS DC Power Supply, showcasing its compact design and various ports and controls from all angles.
Key Features:
- Lab-Grade Accuracy: 1% basic accuracy with 0.01V voltage resolution and 0.001A current resolution. Supports Auto CV/CC mode and offers stable output with low ripple noise (≤1%).
- Compact and Portable: Ultra-portable design (195x102x80mm) weighing only 0.8kg, suitable for mobile workbenches.
- Precision Adjustment: Adjustable DC voltage (0-30V) and current (0-5A) with an 18W USB fast charging port.
- Clear 4-Digit Display: Simultaneously displays voltage, current, and power values in real-time.
- Full Protection: Built-in overload, short-circuit, and over-temperature protections. Includes memory function, physical output ON/OFF switch, and keyboard lock.
2. Product Components
Familiarize yourself with the various components and controls of your DC power supply.
Figure 2: Detailed view of the power supply's front and rear panels, indicating the output voltage display, output current display, output power display, fast charging USB interface, output ON/OFF switch, C.V. constant voltage indicator light, C.C. constant current indicator light, encode knob for voltage, button lock indicator light, encode knob for current, output negative (-), output positive (+), power switch, AC input, cooling fan, and fuse box.
Front Panel Controls and Indicators:
- Output Voltage Display: Shows the current output voltage.
- Output Current Display: Shows the current output current.
- Output Power Display: Shows the current output power.
- Fast Charging USB Interface: 18W USB port for charging devices.
- Output ON/OFF Switch: Controls the power output to the terminals.
- C.V. Indicator Light: Illuminates when the power supply is operating in Constant Voltage mode.
- C.C. Indicator Light: Illuminates when the power supply is operating in Constant Current mode.
- Voltage Encoder Knob: Adjusts the output voltage.
- Current Encoder Knob: Adjusts the output current.
- Button Lock Indicator Light: Indicates when the control buttons are locked.
- Output Terminals: Positive (+) and Negative (-) terminals for connecting loads.
Rear Panel Components:
- Power Switch: Main power switch for the unit.
- AC Input: Connector for the AC power cord.
- Cooling Fan: Provides active cooling for the internal components.
- Fuse Box: Contains the protective fuse for the unit.
3. Setup Instructions
- Unpacking: Carefully remove the power supply from its packaging. Verify that all components listed in the package contents are present: power supply unit, AC power cord, and test leads.
- Placement: Place the power supply on a stable, level surface with adequate ventilation. Ensure that the cooling fan on the rear panel is not obstructed.
- Power Connection: Connect the supplied AC power cord to the AC Input on the rear panel of the power supply and then to a suitable wall outlet. Ensure the power switch on the rear panel is in the OFF position before connecting.
- Initial Power On: Flip the power switch on the rear panel to the ON position. The display should illuminate.
- Output Connection: Connect the test leads to the output terminals on the front panel. The red lead connects to the positive (+) terminal and the black lead to the negative (-) terminal.
4. Operating Instructions
4.1 Adjusting Voltage and Current
The power supply features encoder knobs for precise adjustment of voltage and current. The 4-digit display provides accurate readings.
Figure 3: Illustration of the encoder adjustment knob operation. Press the knob to select the digit (0-9) you wish to adjust, then turn the knob to change its value. This allows for fine-tuning of both voltage and current settings.
- Setting Voltage:
- Ensure the output is OFF (press the ON/OFF switch if it's lit).
- Press the Voltage Encoder Knob to select the digit you wish to adjust (the selected digit will blink).
- Rotate the Voltage Encoder Knob clockwise to increase the value or counter-clockwise to decrease it.
- Repeat for other digits as needed to set the desired voltage.
- Setting Current:
- Ensure the output is OFF.
- Press the Current Encoder Knob to select the digit you wish to adjust.
- Rotate the Current Encoder Knob clockwise to increase the value or counter-clockwise to decrease it.
- Repeat for other digits as needed to set the desired current limit.
- Activating Output: Once voltage and current limits are set, press the Output ON/OFF Switch to enable the power output. The display will show the actual output voltage, current, and power.
- Output Reliability Test: The following video demonstrates the output reliability using a multimeter.
Video 2: Demonstration of the EARNMee 3005MS DC Power Supply's output reliability, showing voltage and current measurements on a multimeter. This video illustrates the stability and accuracy of the power supply's output.
4.2 Using the USB Fast Charging Port
The front panel includes an 18W USB fast charging port for convenient charging of compatible devices.
Figure 4: The 9V2A USB quick charge interface on the power supply, demonstrating its capability to fast charge a smartphone with an output power of up to 18W.
- Connect your USB-compatible device to the USB port on the front panel.
- The power supply will automatically detect and provide up to 18W of fast charging power to the device.
4.3 Safety Features
The EARNMee 3005MS is equipped with multiple protection functions to safeguard both the device and connected equipment.
Figure 5: The five powerful protection functions integrated into the power supply: Over-voltage Protection, Over-current Protection, Over-power Protection, Over-temperature Protection, and Short Circuit Protection, ensuring stable performance and extended service life.
- Over-voltage Protection (OVP): Prevents damage from excessive output voltage.
- Over-current Protection (OCP): Limits the output current to prevent damage to the load.
- Over-power Protection (OPP): Shuts down the output if the power exceeds a safe limit.
- Over-temperature Protection (OTP): Protects the unit from overheating.
- Short Circuit Protection (SCP): Automatically cuts off output in case of a short circuit.
- Keyboard Lock: Prevents accidental changes to settings. Activate by pressing and holding the appropriate button (refer to Figure 2 for location).
- Memory Function: The unit recalls the last settings used upon power-on.
5. Maintenance
- Cleaning: Disconnect the power supply from the AC outlet before cleaning. Use a soft, dry cloth to wipe the exterior. Do not use abrasive cleaners or solvents.
- Ventilation: Ensure the cooling fan and ventilation slots are free from dust and obstructions. Regular cleaning of these areas can prolong the life of the unit.
- Storage: When not in use for extended periods, store the power supply in a dry, dust-free environment.
- Fuse Replacement: If the unit does not power on, check the fuse located in the fuse box on the rear panel (refer to Figure 2). Replace with a fuse of the same type and rating if necessary. Always disconnect the AC power cord before attempting fuse replacement.
6. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No power/Display off | Power cord not connected; Rear power switch off; Blown fuse. | Check power cord connection; Turn on rear power switch; Replace fuse (refer to Maintenance section). |
| No output voltage/current | Front panel output switch off; Output terminals not connected; Overload/Short circuit protection activated. | Press the front panel ON/OFF switch; Ensure test leads are properly connected; Check load for short circuits or excessive current draw. Reduce load or adjust current limit. |
| Voltage/Current cannot be adjusted | Keyboard lock activated. | Deactivate keyboard lock (refer to Operating Instructions). |
| Unit overheats | Poor ventilation; Excessive load. | Ensure ventilation slots are clear; Reduce load or operating time. |
7. Technical Specifications
| Parameter | Value |
|---|---|
| Brand | EARNMee |
| Model Number | 3005MS |
| Output Voltage | 0-30V (Adjustable) |
| Output Current | 0-5A (Adjustable) |
| Output Wattage | 150 Watts |
| Voltage Resolution | 0.01V |
| Current Resolution | 0.001A |
| Basic Accuracy | 1% |
| Ripple Noise | ≤1% |
| USB Fast Charging | 18W (9V2A) |
| Display | 4-Digit LED (Voltage, Current, Power) |
| Cooling Method | Air (with intelligent temperature controlled fan) |
| Item Dimensions (L x W x H) | 7.68 x 4.02 x 3.15 inches (195x102x80mm) |
| Item Weight | 1.76 Pounds (0.8kg) |
| Protection Functions | Over-voltage, Over-current, Over-power, Over-temperature, Short Circuit |
8. Warranty Information
This EARNMee 3005MS DC Power Supply comes with a 1-year warranty from the date of purchase. This warranty covers defects in materials and workmanship under normal use. It does not cover damage caused by misuse, accident, unauthorized modification, or improper installation.
Please retain your proof of purchase for warranty claims.
9. Customer Support
For technical assistance, troubleshooting, or warranty inquiries, please contact EARNMee customer support. Refer to the product packaging or the official EARNMee website for the most current contact information.
When contacting support, please have your product model number (3005MS) and purchase details ready.