There have been customers who purchased many brands of
12 volt 3 amp power supply, but all samples failed during the test. Later on-site analysis found that the customer used a self-dual voltage regulator to directly power the class 2 power supply 12v for testing. After power on, the voltage regulator was gradually increased from 0Vac to the rated operating voltage of the LED drive power.
This kind of test operation can easily make the
class 2 power supply 12v start and work with load when the input voltage is very small, and this situation will cause the input current to be far greater than the rated value, and the internal input terminal related components, such as fuses, rectifier bridges , Thermistors, etc., fail due to excessive current or overheating, causing the led dimmable power supply to fail.
Therefore, the correct test method is to adjust the voltage regulator to the rated operating voltage range of the
led dimmable power supply, and then connect the drive power supply for power-on test.
Of course, technically improving the design can also avoid the failure problem caused by such misoperation of the test: a starting voltage limit circuit and an input undervoltage protection circuit are set at the input end of the power supply for 12v led lights. When the input does not reach the starting voltage set by the led dimmable power supply, the drive power supply does not work; when the input voltage drops to the input undervoltage protection point, the power supply for 12v led lights enters the protection state.
Therefore, even if the operation steps of the self-dual voltage regulator are still used in the customer test process, the power supply for 12v led lights has a self-protection function and will not fail. However, before testing, customers must carefully understand whether the purchased LED drive power product has this protection function (considering the actual application environment of the LED drive power supply, most LED drive power supplies currently do not have this protection function).
