LED Driver measurement – #2

In the quest for drivers for some 18W LED plates, I have placed 6 orders for non dimming nominally 300mA drivers for 18-24W LED plates.

The LED drivers originally supplied with the LED plates were rated at 180mA (10.8W) and measured 150mA (9.0W)

The tests here use an 18W LED plate, wired as 18 pairs of 0.5W LEDs in series for a total voltage of around 60V and 300mA for 18W.

Most orders have not arrived after several months, it appears some Chinese sellers are not shipping even though they have said they did. One shipment contained a single bare board with no details, it wasn’t ordered and without ratings was consigned to the trash.

Above is a test of one type of LED driver rated at 300mA ±5%. It supplies 237mA which is 21% less than 300mA, hopelessly low on specification. The other four purchased were within 1% of the same current.

Above is a test of another type of LED driver rated at 300mA ±5%. It supplies 236mA which is 21% less than 300mA, hopelessly low on specification. Only one unit was received and measured.

At every turn, the Chinese sellers attempt to cheat the buyer. All these are way outside the headline specification, and in all cases the seller cries tears of blood over refunding the money.

Should you trust Chinese sellers? If you haven’t measured the performance of LED lighting you have purchased, you don’t know if you too were cheated.

Having a collection of 240mA drivers suitable for up to 85V out, the next step is to buy some nominally 24W LED plates and use them together for expected LED power of 19W. Operating the LEDS at 80% of rated current should improve the life and luminous efficiency.