I have made an assortment of LED task lights that I’ve clipped onto places where I need a small, low power light, such as my keyboard, workbench and kitchen counter. They typically have 3 or 4 LEDs and run off an AC adapter of about 5 volts.
I want to make a lamp with multiple LED banks, each mounted on its own steel or copper wire ‘gooseneck’ so it can be aimed at the point where light is needed. The power will be low, 4 LEDs at 64 milliwatts each is about a quarter watt. The 150 ohm current limiting resistors are about the same, for a total of a half watt per bank of 4 LEDs. The 6 volt adapter puts out 1/2 amp max, so it can handle 5 of these LED banks maximum. But then I was hoping for more, ten or fifteen seems more realistic. I may need 1.5 to 2 amps at 5 or 6 volts.