I can't find a comparison of various DC-DC CC/CV buck modules, for example googling XL4015 xl4005 lm2596 review does lead to anything that helps me understand their strengths and weaknesses, and which to choose.
Looking to permanently modify an 110V AC lamp containing an LED so I can use it in my 12V car. I realize I could probably just plug the lamp's AC/DC adapter into my 12VDC to 110VAC inverter, but I'm not interested in that.
My plan is to cut the lamp's DC power cord and wire it to some or another buck converter, wired to a cigarette lighter outlet.
The lamp assembly cannot be disassembled without destroying it, so I don't know much about the LED.
Full size image: https://i.stack.imgur.com/0b1La.jpg
The lamp cord plugs into the AC adapter, which plugs directly into the wall outlet. The label on the adapter says Intertek, 7V, 430mA, KMV-070-030-NA-2.
I plugged the cord half way into the wall adapter, then probed the prongs on the end of the cord with a multimeter, 6.75V 200mA.
Here are two modules that I considering, but am just guessing that they would be appropriate. I selected them because they are small (though space is not an issue) and they provide adjustable constant current and voltage output, and have higher max amps than I need. Besides different buck ICs, they seem to have different coil types. I'm not sure how to interpret either of those differences.
Full size images are here:
Info from sellers: Price $3 $4 IC Mfr TI XLSEMI IC model LM2596 XL4005 Op-Amp TI LM358 Input voltage: 7V-35V 5-32V DC Output Voltage: 1.25V-30V 0.8-30V DC Output current: 3A max 50W/3.5A Sustained 75W/5A Peak Efficiency: 92% max Switching freq: 150KHz 300KHz Output ripple: 50mV max Load regulation: ± 0.5% Voltage regulation: ± 2.5% Operating temp: -40 - +85℃ Size: 48x23x14 mm 51x26x14mm
Datasheets from mfrs: