So I bought a few of these shop 4' led lamps from the local hardware store. Satco 62-928. I find they are a bit bright, So I thought I might be able to hack them. Indeed a simple circuit, Schematic and photos below. Link to shared folder.
formatting link
(Sorry dropbox flipped the photos over...) There are two one ohm sense resistors. (in parallel) with ~150 mV (DC) across them. (Measurements made with DMM in the presence of a lot of AC...10-20 V) Huh I said to myself If I lifted one of those the current would drop by half along with the light. It worked! AC current dropped from 0.336 A to 0.160 A. And light also fell by 1/2, 310 uA to 170 uA. (photo current measured with cheap photodiode and DMM in DC current mode.)
One thing I found puzzling is the sense R, sharing a terminal with the output. (feed to big inductor.)
George H.