Anyway this will be a fairly low powered, 70W rig as I want to use it to grow some lovely herbs for my kitchen through the long, dark Scottish winter months and the running cost can't exceed what I would pay per-month in the supermarket.
I plan to use Mean Well HLG-120H-C1400B (1400mA, 54-108V)
with 4* Samsung LT-Q562A , 2ft, 40 diodes, 4000k.
These will be USD 75 from arrow.com (including the 20% new customer discount).
I found these 300mm*25mm*12mm heatsinks for USD 2.30 each which seems pretty good. I wish I could find 600mm ones but no one sells them.
https://www.aliexpress.com/item/COTS-Al ... eLevelAB=0
I plan to drive the strips at about 700mA, so not the most efficient but pretty good and will give about 79 lumens per diode or
12,600 lumens total output (I suspect you can't just add them all up but I don't know how else to show it).
I chose the driver as it will allow me to run the light in 4S2P in the future if I want to expand my set-up. Until then it is a bit risky as I will use a potentiometer with the Mean Well "resistance dimming" to vary the current output and it would only take a slight overenthusiastic twist of the pot to blow the Samsung strips' 900mA limit.
So my question is...is it possible to wire a fixed-value resistor in series with a variable resistor to achieve the dimming? The fixed value to limit the driver's output to 900mA and then the variable-resistor to vary the output between 140mA-900mA? If so do you know how I might calculate the resistor values or is it a case of trial and error?
Here is the ghetto shelf I'll be using once I clear it out. It's the one with the ruler, 18 inches of vertical height which should be OK for a wee grow.
![Image](https://i.imgur.com/t97UAC2.jpg)