1. Introduction
The KUAIQU SPS-C Series DC Power Supply is a professional switching power supply designed for laboratory, electronics repair, and DIY applications. It features a compact, lightweight design with high precision 4-digit LED displays for real-time voltage, current, and power readings. This device offers stable output, automatic constant voltage (C.V.) and constant current (C.C.) switching, and multiple protection functions to ensure safe and reliable operation.
This manual provides detailed instructions for the safe and efficient use of your KUAIQU DC Power Supply. Please read it thoroughly before operation.
Figure 1: KUAIQU DC Power Supply (White model) with accessories.
2. Safety Precautions
- Ensure the power supply is connected to a properly grounded outlet.
- Do not operate the device in wet or damp conditions.
- Avoid violent impact or dropping the power supply.
- Always ensure the correct input voltage (110V or 220V) is selected for your region. This model is available in 110V or 220V input versions.
- Do not block the ventilation openings.
- Disconnect power before making any connections or adjustments to the output terminals.
- The device includes multiple protection functions: Over Voltage Protection, Over Temperature Protection, Over Current Protection, and Short Circuit Protection.
Figure 2: Built-in Safety Protections.
3. Package Contents
Your package should include the following items:
- 1 x DC Power Supply (all-metal body with ABS buttons)
- 1 x Power Cable
- 1 x Output Line (Gift)
- 1 x User Manual
4. Setup
4.1. Power Connection
- Ensure the power supply is switched OFF.
- Connect the provided power cable to the AC input port on the rear panel of the power supply.
- Plug the other end of the power cable into a suitable wall outlet. The power supply supports AC 110V or AC 220V input, depending on the model purchased. Verify your local voltage matches the unit's specification.
Figure 3: Available Plug Types.
4.2. Output Connections
- Identify the output terminals on the front panel: Output Negative (-) (black), GND (green), and Output Positive (+) (red).
- Connect your load to the appropriate output terminals using the provided output line or other suitable cables. Ensure correct polarity.
Figure 4: Front and Rear Panel Overview (White Model).
5. Operating Instructions
5.1. Panel Functions
The front panel features a 4-digit LED display for Voltage (V), Current (A), and Power (W). Control knobs allow for precise adjustment of output parameters.
- Voltage Display: Shows the output voltage in Volts.
- Current Display: Shows the output current in Amperes.
- Power Display: Shows the output power in Watts.
- C.V. Indicator (Constant Voltage): Lights up when the unit is operating in constant voltage mode.
- C.C. Indicator (Constant Current): Lights up when the unit is operating in constant current mode.
- V-COARSE / V-FINE: Knobs for coarse and fine adjustment of output voltage.
- A-COARSE / A-FINE: Knobs for coarse and fine adjustment of output current.
- POWER Button: Main power switch (located on the front for convenience).
- 5V/2A USB Port: Provides a 5V, 2A output for charging USB devices.
- OUTPUT Button: Toggles the main output ON/OFF. This allows you to set voltage and current without immediately applying power to the load.
Figure 5: Front and Rear Panel Overview (Black Model).
5.2. Adjusting Voltage and Current
- Turn on the power supply using the front POWER button.
- Ensure the OUTPUT button is OFF (indicator light off) before connecting a sensitive load.
- Use the V-COARSE and V-FINE knobs to set the desired output voltage. The V-COARSE knob makes large adjustments, while V-FINE allows for precise tuning.
- Use the A-COARSE and A-FINE knobs to set the desired current limit. For setting the current limit accurately without a load, you may need to short-circuit the output terminals temporarily (see Section 5.3).
- Once voltage and current are set, press the OUTPUT button to enable the output. The indicator light will turn on.
Figure 6: Coarse and Fine Adjustment.
5.3. Setting Current Limit (Preset Current)
To accurately set the current limit before connecting a load, follow these steps:
- Ensure the OUTPUT is OFF.
- Connect the positive (+) and negative (-) output terminals together using a short, thick wire (short circuit).
- Turn the A-COARSE and A-FINE knobs to their minimum settings.
- Turn the V-COARSE and V-FINE knobs to their maximum settings.
- Press the OUTPUT button to enable output. The C.C. indicator should light up, and the current display will show the current flowing through the short circuit.
- Adjust the A-COARSE and A-FINE knobs to set your desired current limit.
- Press the OUTPUT button to disable output, then remove the short circuit.
- You can now connect your load and enable the output. The power supply will limit the current to your preset value if the load attempts to draw more.
Figure 7: Preset Current Setting.
5.4. C.V./C.C. Automatic Conversion
The power supply automatically switches between Constant Voltage (C.V.) and Constant Current (C.C.) modes depending on the load. If the load resistance is high, the unit operates in C.V. mode, maintaining the set voltage. If the load resistance drops, causing the current to reach the preset limit, the unit switches to C.C. mode, maintaining the set current and reducing the output voltage to prevent overcurrent.
5.5. USB Charging Port
The integrated 5V/2A USB port on the front panel allows for convenient charging of USB-powered devices. Simply plug your device into this port.
Video 1: Product demonstration showing panel functions, coarse/fine adjustment, output control, and USB charging.
6. Maintenance
6.1. Cleaning
Wipe the exterior of the power supply with a soft, dry cloth. Do not use abrasive cleaners or solvents.
6.2. Cooling Fan
The power supply features an intelligent temperature-controlled cooling fan. The fan will only activate when the internal temperature exceeds 50°C (122°F). This design helps conserve energy and reduce noise during operation. Ensure the rear fan vents are not obstructed to allow for proper airflow.
Figure 8: Intelligent Temperature Control Fan.
6.3. Fuse Replacement
The power supply includes a fuse box on the rear panel. If the unit fails to power on, check and replace the fuse if necessary. Always use a fuse with the correct rating.
7. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No power / Unit does not turn on | Power cable not connected, wall outlet faulty, internal fuse blown. | Check power cable connection. Test wall outlet. Check and replace fuse if necessary. |
| No output voltage/current | OUTPUT button is off, output terminals not connected correctly, over-protection activated. | Press the OUTPUT button. Verify output cable connections. Check for activated protection (e.g., short circuit in load). |
| Output voltage/current unstable | Loose connections, faulty load, internal issue. | Check all connections. Test with a different load. If problem persists, contact support. |
| Unit gets hot, fan not running | Internal temperature below 50°C, fan malfunction, obstructed vents. | This is normal if temperature is below 50°C. Ensure vents are clear. If unit overheats and fan doesn't run, contact support. |
| Transistors burned out (as per user query) | Incorrect current limit setting, excessive load, short circuit in the load. | Always set the current limit appropriately for your load. Use the preset current function (Section 5.3) to avoid overcurrent. Ensure your circuit is correctly wired and free of shorts. |
8. Specifications
| Parameter | Specification |
|---|---|
| Input Voltage | AC 110V/220V 50/60Hz (model dependent) |
| Output Voltage | 0 ~ 30V / 0 ~ 60V / 0 ~ 120V (model dependent) |
| Output Current | 0 ~ 10A / 0 ~ 5A / 0 ~ 3A (model dependent) |
| Output Power | 150-500W (includes 500W) / 201-300W (model dependent) |
| Rated Capacity | 40-1000VA (includes 40VA) |
| Voltage Resolution | 100mV (0.01V display resolution) |
| Current Resolution | 10mA (0.001A display resolution) |
| Voltage Regulation (Line) | <5mV |
| Voltage Regulation (Load) | <5mV |
| Current Regulation (Line) | <3mA |
| Current Regulation (Load) | <3mA |
| Recovery Time | <500us (50% Load change, minimum load 0.5A) |
| Ripple & Noise | <5m Vrms, 100m Vp-p |
| Temperature Coefficient | <100ppm/°C |
| Voltage Display Precision | ±(0.5% of rdg + 2 digits) |
| Current Display Precision | ±(0.5% of rdg + 2 digits) |
| Operation Temperature & Humidity | 0 ~ 40°C, RH<80% |
| Storage Temperature & Humidity | -10 ~ 70°C, RH<70% |
| Package Dimensions | 12.48 x 8.23 x 5.08 inches |
| Weight | Approximately 2.6 lbs (1.8 kg) |
| Certification | CE, FCC |
9. User Tips
- Protective Film: A protective film is applied to the screen to prevent scratches during shipping. You can remove this film before use for a clearer display.
- Fan Operation: The cooling fan is temperature-controlled and will only operate when the internal temperature exceeds 50°C (122°F). This is normal behavior and helps reduce noise and save energy.
- Accurate Current Limiting: To prevent damage to sensitive components like transistors, always set the current limit (C.C. mode) before connecting your load. Use the short-circuit method described in Section 5.3 for precise adjustment.
- Accuracy Measurement: For accurate measurement of the DC power supply, do not connect any load and ensure your multimeter is correctly set to the DC voltage/current measurement range.
- Ohm's Law: Remember that Ohm's Law (V=IR) always applies. Cables can introduce slight power losses, which may cause minor differences in accuracy between the power supply display and external measurements.
10. Warranty and Support
KUAIQU provides the following warranty and support for this product:
- Free Replacement: Orders are eligible for free replacement within 30 days from the delivery date.
- Extended Replacement: For orders between 1 and 12 months from delivery, a partial payment of the order value may be required for replacement.
- Technical Support: Efficient after-sales service and technical support are available. If you have any questions or encounter issues, please contact KUAIQU customer service.
Our working hours are Monday to Friday, 9:00 AM to 6:30 PM Beijing Time. We aim to respond to inquiries within 30 minutes during working hours and resolve problems within 24 hours.
