Five small and medium power supply evaluation can be safe?

This small power LED drive power evaluation, invited Guangdong KEGU five representative power production enterprises, invite the third party inspection agency - Foshan Voight Testing Technology Services Limited, from the safety and efficiency of EMC, etc., fully reveal the true power of the performance of small power LED driving performance.

Sample information table

The evaluation of the division Valley, Niu Bao, wisdom, and the source of the crown of a total of five LED drive power (product information as follows) for the constant current accuracy, voltage range, voltage, temperature rise test and structural inspection.

Constant current precision

The test is carried out in accordance with GB/T 24825, section 7.2. During the test, the input of the power supply is carried out using a trademark which is the maximum voltage of the input voltage range of 106% and a minimum voltage of 92%. The output load of the control device is determined by the maximum load and the minimum load declared by the manufacturer. Specific test results are as follows:

From the test data can be seen in the highest voltage and the minimum voltage, compared with nominal current there is 2mA in the same voltage fluctuation; frequency under different circumstances, there was 1mA volatility; overall volatility in the range of 0-2mA, the precision of constant current is still relatively high, can better adapt to the change of voltage and frequency the.

In the case of the minimum voltage, compared to the nominal current fluctuations of the 10-15mA, the maximum voltage fluctuations in the case of 12-15mA; the same frequency of different voltage, there is no fluctuation. Niu Bao this drive, the voltage change on the constant current accuracy has a greater impact, but it can better adapt to changes in the voltage frequency.

At the lowest voltage. Comparison of nominal current appeared 9-15mA fluctuations, the highest voltage situation is the emergence of 9-11mA fluctuations; the same voltage of different voltage frequency under the condition of no fluctuation, fluctuation in the range of 9-15mA. The change of driving voltage has a great influence on the constant current precision, and the voltage frequency has no obvious influence on the constant current precision.

In the case of the minimum and maximum voltage, the current of 8-10mA is compared with the nominal current, and the voltage is not tested at different voltages. The overall fluctuation is 9-10mA.

At the minimum voltage, compared with nominal current 7mA fluctuations, 2mA wave maximum voltage; voltage at the same frequency fluctuations, the overall volatility in the range of 2-7mA, the size of the voltage change has a certain influence on the precision of constant current, frequency change did not change significantly.

The evaluation of the five models, the output current is less than 10%, in line with the requirements. Although the valley power supply in the voltage frequency changes some fluctuations in the size of the voltage, the output current fluctuations are relatively small, the overall volatility is small, constant current accuracy is relatively high.

Two, voltage range

Measure the output voltage under rated output current. During the test, the input of the power supply is made of the highest voltage and the lowest voltage of the input voltage range. The output load of the control device is determined by the maximum load and the minimum load declared by the manufacturer.

In the case of the highest and lowest nominal input voltage, the output voltage is 1.7-3.7V with respect to the nominal voltage, and the same amplitude varies with the same frequency.

The highest and lowest in nominal input voltage conditions: voltage frequency is 50Hz, output voltage comparison of nominal amplitude 3-5.8V: voltage fluctuation voltage and frequency of 60Hz when the volatility is 3.1-5.8V, the frequency of the input voltage caused by slight impact on the power supply output voltage

The highest and lowest in nominal input voltage conditions: voltage frequency is 50Hz, output voltage contrast 0.5-3.9V nominal voltage fluctuation; 60Hz 0.5-4V fluctuation, slight fluctuations also have different frequency voltage frequency.

In the case of the highest and lowest nominal input voltage, the output voltage is 1.9-4.3V.

The highest and lowest in nominal input voltage conditions: voltage frequency is 47Hz, output voltage contrast 7.1-9.1V nominal voltage fluctuation, voltage and frequency of 63Hz, 4.6-9.1V on the same frequency voltage fluctuation; different output voltage caused by small amplitude fluctuations.

Three, withstand voltage test

Withstand voltage test.

Four, temperature rise test

The temperature of the above measuring points of the five products has not exceeded the limit, which is in line with the requirements.

Five, structural inspection

Wire pulling device

Independent LED driver power supply requires wire pull device, observation of the division Valley, Niu Bao, wisdom, and the source of the original crown five LED drive power supply, the input and output terminals are equipped with wire pull device.

Creepage distance and electrical clearance

1 live parts to the case of creepage distance and clearance requirements: creepage distance 6.2mm, clearance 6.2mm (based on the working voltage not more than 264V); creepage distance 6mm, clearance 6mm (based on the working voltage not more than 250V).

Actual measurement distance: Branch Valley 6.4mm, Niu Bao 6.8mm, wisdom view 7.7mm, ante source 7.6mm, collar crown 7.7mm. 6 products are in line with the requirements.

2 creepage distance and electrical clearance requirements between PCB board LN: creepage distance 3.1mm, electrical clearance 3.1mm (based on operating voltage no more than 264V); creepage distance 3mm, electrical clearance 3mm (based on operating voltage not exceeding 250V).

Actual test distance: Branch Valley 6.3mm, Niu Bao 6.3mm, wisdom view 4.6mm, ante source 5.8mm, collar crown 5.2mm. 6 products are in line with the requirements.

3 creepage distance and electric clearance requirement between the two fuses: creepage distance