What is load regulation in a switching power supply? How to measure it?
Load regulation rate refers to the ability of a switching power supply to stabilize the output voltage when the load changes. The smaller the load adjustment rate, the smaller the fluctuation of the output voltage of the switching power supply when the load changes, indicating that the stability of the switching power supply is better.
The load adjustment rate is usually expressed as a percentage, which refers to the ratio of the change in output voltage of a switching power supply from no load to rated load to the rated output voltage.
In order to accurately measure the load adjustment rate of a switching power supply, the following steps need to be taken:
1. Prepare testing equipment: A stable and reliable load device and an instrument for measuring output voltage, such as an oscilloscope or digital voltmeter, are required.
2. Connect the testing equipment: Connect the load device to the output terminal of the switching power supply, ensuring that the circuit connection is correct and there is no looseness or poor contact.
3. Load setting: Adjust the load device to the desired load state, gradually increasing or decreasing the load to cover the entire load range.
4. Measure output voltage: Use an oscilloscope or digital voltmeter to measure the output voltage of the switching power supply, and record the changes in output voltage during the load variation process.
5. Calculate load adjustment rate: Based on measurement data, calculate the ratio of the output voltage change of the switching power supply during load changes to the rated output voltage, which is the load adjustment rate.
During the measurement process, the following points should be noted:
1. Stable output: During measurement, ensure that the input voltage of the switching power supply is consistent with the ambient temperature and maintain it for a period of time to stabilize the output of the switching power supply, in order to more accurately measure changes in the output voltage.
2. Multiple measurements: Conduct multiple measurements and take the average to reduce measurement errors.
3. Load range: Try to cover the load range of the switching power supply as much as possible, including the change from no load to rated load, to comprehensively evaluate the load adjustment rate of the switching power supply.
4. Measurement frequency: Different measurement frequencies can be selected according to actual needs. Generally speaking, a switching frequency lower than that of the switching power supply can be chosen to avoid the measurement results being affected by the switching frequency.
