Hello, can anyone recommend a heatsink for the LM338

[Someone]

I am building an LED light and need a variable voltage regulator that won't burn up with a 3.5A load.
I picked the LM338 because it seems like it would work well enough, but I don't know how big of a heatsink I would need.
Can someone give me suggestions?

 

[Supercap2F]

Howdy Someone! Welcome to the Forums!
We have a great resource on choosing heatsinks here: https://www.electronicspoint.com/resources/do-i-need-a-heatsink-how-big.29/ Written by the electrical guru, Steve.

Dan

 

[GPG]

What are your input/output voltages? Do you need the 338 to be a current regulator? TO3 package?