How to power a powerful LED with maximum efficiency?

Question

Batteries

Hello. I know two ways to power LEDs:
1. Through a current-limiting resistor. For a powerful LED, you need a powerful resistor, on which a lot of heat will be released.
2. Through a current stabilizer, such as LM317 in the appropriate mode . At the same time, a sensor resistor is placed at the output of the LM317 - also powerful, but already smaller (for example, 1W).

The second option, of course, is better, but it also warms up be healthy. Tell me, is there a way to limit the current to 700 milliamps at a voltage of 6 volts so that the radiator of the device does not burn the user's hand?

Answer 1

Different drivers, full of nature. There are both ready-made Chinese modules on the same di-extreme, and microcircuits.
how many volts at the input? 220? or constant type 36-60 volts? Is galvanic isolation necessary?
www.dianyuan.com/bbs/u/77/1805081242368855.pdf
www.supertex.com/pdf/datasheets/HV9961.pdf
www.supertex.com/pdf/misc/HV9961DB1.pdf
from China a week ago ordered
www.sunsky- online.com/product/default !view.do?subject.id=231906
www.sunsky-online.com/product/default !view.do?subject.id=231907

Answer 2

And a pair of AMC7135s connected in parallel (each with 350mA, max 6V just right) will not work by chance? Most of the Chinese drivers are assembled on them.