cheap, dimmable drivers by "thomas research products" + display

[sdfoster22]

I emailed Thomas research products about a month ago about dimming these drivers. They just emailed me back. Here is the answers they gave me.

First a chart.

Here are my questions, and their answers. Their answers are in blue.

[unkle_psycho]

I emailed Thomas research products about a month ago about dimming these drivers. They just emailed me back. Here is the answers they gave me.

First a chart.
image001.jpg

Here are my questions, and their answers. Their answers are in blue.

Screenshot_2018-06-25-13-15-15.png

Screenshot_2018-06-25-13-15-21.png

So what would work for three? 13.33k?

[sdfoster22]

I believe so. According to his answer. 40*(1/3)=13.33,

[unkle_psycho]

so if i choose under 13k, the lights will be dimmed by default, and if I choose over 13k the dimmer will not dim all the way down?

What sizes am I likely to find in a small component shop ran by an old man?

[sdfoster22]

Maybe a 10k or 15k. A 20k should work. It would just max out at around 70%.

If you get 13k you wouldn't have the extra .3 at the top. Measure the resistance. If it's 13k you could always add like a 500ohm or 1k ohm resistor to bumb it up a little.

[unkle_psycho]

So if I choose a potentiometer with more then 13.3, my light would be dimmed by default? Will certainly pass by to see what they have, next time i'm in town. I just go so rarely, that I would prefer to get things right.

I Don't want to loose on the potential max, would much rather have a limited range for tuning. I guess it's a dumb idea to group the dimming, since I wanted ultimate adjustability. I should just get 6 40k pots so I can adjust individually, if I grow a stretchy sativa, and an indica at the same time.

So I'll test the logarithmic pots I got last time, and if one is not perfect, I'll get 6x 40k.

[sdfoster22]

If you get above 13.3k you will hit max sooner on the dial. If you get below that you will not hit max. They also said a linear taper will work better than a logarithmic pot.

E.g., for 1 driver. If you get a 50k pot, it will hit max output at about 80% turn on the dial. If you get a 30k pot, you will get about 75% max output with the dial turned all the way up. This is with a linear taper pot.

[unkle_psycho]

Nice, I do have 2 linear pots I got a month back on tazztones advise, I still didn't try them, since I've been so busy, and my rebuild has been coming along so slowly.

[blubear43]

Can someone post a link to a pot that can be used with the 75w driver? Can I use this pot? I do have two in my stockpile of parts

https://www.rapidled.com/cased-potentiometer-with-knob/

[tazztone]

update: there are a few other very cheap drivers on digikey by Thomas research products:

for example 3.15A constant current, 10-30V, 96W for as low as $11.4 ($0.12 per Watt)
~ 5x cheaper than meanwell HLG of similar wattage, altough with 2-4% lower efficiency.
UPDATE: not sure if this one is dimmable. it looks like it is on the picture, but according to the datasheet only the ones with a D at the end of the product name are dimmable.

the others on the screenshot are dimmable