AC Power supply calibration

Calibrating an AC power supply is a crucial process to ensure that it provides accurate and stable output voltages and currents. Here’s a step-by-step guide to help you with AC power supply calibration:

1. Preparation

• Safety First: Ensure you’re working in a safe environment. AC power supplies can be dangerous if not handled properly.
• Tools and Equipment:
  • A calibrated multimeter (preferably with high accuracy)
  • An accurate load or resistor
  • A reference standard, if available
  • The AC power supply to be calibrated

2. Warm Up

• Turn on the AC power supply and allow it to warm up for the recommended period. This is usually around 30 minutes to an hour. This ensures that the power supply reaches its operating temperature and stabilizes.

3. Set Up the Equipment

• Connect the Multimeter: Connect your calibrated multimeter to the output terminals of the AC power supply. Set the multimeter to measure voltage (and current if needed).
• Load Connection: Connect a known load or resistor to the power supply. This load should be rated for the expected current and voltage.

4. Voltage Calibration

1. Set the Desired Voltage: Adjust the output of the power supply to a specific voltage (e.g., 5V, 10V, etc.).
2. Measure the Output Voltage: Use the multimeter to measure the output voltage from the power supply.
3. Compare and Adjust: Compare the measured voltage with the set voltage. If there is a discrepancy, adjust the calibration potentiometer or settings on the power supply as per the manufacturer’s instructions.
4. Repeat for Multiple Settings: Repeat the above steps at several different voltage settings (e.g., 10%, 50%, and 100% of the maximum output voltage) to ensure accuracy across the range.

5. Current Calibration (if applicable)

1. Set the Desired Current: If your power supply has current adjustment, set it to a specific current value.
2. Measure the Output Current: Use the multimeter to measure the current through the load.
3. Compare and Adjust: Compare the measured current with the set current. Adjust the calibration settings as necessary.
4. Repeat for Multiple Settings: Perform the calibration at different current settings to verify accuracy.

6. Check for Stability and Regulation

• Voltage Regulation: Adjust the load to different levels and observe how well the voltage remains constant. This checks the voltage regulation of the power supply.
• Ripple and Noise: Use an oscilloscope to check for AC ripple and noise on the output if your calibration requirements include this specification.

What is an Electronic Load?

An electronic load is a device that can mimic the behavior of a real-world load by drawing a specified amount of current from a power source. Unlike passive loads, which are fixed and require physical components like resistors, electronic loads are adjustable and can dynamically change their characteristics based on settings.

Key Features of Electronic Loads

1. Adjustable Load Parameters: You can set various parameters such as current, voltage, resistance, and power.
2. Modes of Operation: Common modes include constant current (CC), constant voltage (CV), constant power (CP), and constant resistance (CR).
3. Dynamic Load Testing: Capable of simulating transient conditions to test the response of power supplies under varying loads.
4. Measurement and Monitoring: Often include built-in meters to measure voltage, current, power, and sometimes other parameters like ripple and temperature.
5. Programmatic Control: Many advanced electronic loads support remote control via interfaces like USB, GPIB, or LAN for automated testing.

Applications of Electronic Loads

1. Power Supply Testing: Verify the performance and stability of power supplies under different load conditions.
2. Battery Testing: Evaluate the capacity, discharge rates, and performance of batteries.
3. Component Testing: Test components like capacitors and regulators to ensure they can handle specified load conditions.
4. Stress Testing: Assess the robustness of power sources and circuits by simulating extreme operating conditions.
5. Development and Research: Used in design and development phases to validate and refine power circuitry.

Using an Electronic Load

1. Setup

• Connect the Electronic Load: Connect the input terminals of the electronic load to the power source you want to test. Ensure proper connections to avoid damage.
• Connect Measurement Equipment: If needed, connect a multimeter or oscilloscope to measure the output voltage, current, and other parameters.

2. Configuration

• Power Up: Turn on the electronic load and the power source.
• Select Operation Mode: Choose the appropriate mode (CC, CV, CP, CR) based on your testing needs.
• Set Parameters: Input the desired values for current, voltage, power, or resistance. Adjust the settings as needed for your specific test.

3. Testing

• Perform Measurements: Observe the real-time measurements on the electronic load’s display or via connected measurement equipment.
• Monitor Stability: Check the stability and performance of the power source under different load conditions. Make adjustments as necessary to your load settings.
• Conduct Dynamic Tests: If performing transient testing, configure the electronic load to simulate dynamic changes and observe the response.