LED lamp is broken, put it down, things do
Using the multimeter, diode first gear test lamp bead is damaged. Then find a chip, CL BP OB or PI, NXP driver chip both at home and abroad, and design a constant current drive power supply. Of course also need to look at your desk lamp lights, string and how. General desk lamp is the output of 0.3-0.35 - A, your driver can be designed so that the output current.
Make a 3 to 7 w drive, can directly to the utility. Of course you should guarantee the lamp bead not burn
The LED lights down, connected to two wires, is is, negative negative, on two batteries.
