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Potentiometer Page

Posted: Tue Jun 19, 2018 3:37 pm
by Professor Xavier
Hopefully a few stickies can consolidate some knowledge on the topic.

Re: Potentiometer Page

Posted: Tue Jun 19, 2018 3:38 pm
by Professor Xavier
I found these two videos helped me greatly:


Re: Potentiometer Page

Posted: Mon Jun 25, 2018 7:27 pm
by Professor Xavier
Here is a cool post by SDFoster on a convo regarding POTS with Thompson Research drivers. All the credit goes to him for posting it; I thought it would be useful here.
sdfoster22 wrote:
Mon Jun 25, 2018 5:23 pm
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

Re: Potentiometer Page

Posted: Mon Jun 25, 2018 7:33 pm
by Professor Xavier
I think I messed up the pics in his post!

Re: Potentiometer Page

Posted: Wed Jun 27, 2018 7:49 pm
by infosponge
If you use a pot that's higher than what you need, for example I can't find a 40k pot so if I used a 50k, would I still get 100% of the power output? Will I still get 75W from the driver?

Re: Potentiometer Page

Posted: Wed Jun 27, 2018 8:47 pm
by sdfoster22
Yes. You will get 100% output at 75% turn of the dial.

Re: Potentiometer Page

Posted: Tue Jul 17, 2018 11:23 am
by Futuregrow
Just to expand on this potentiometer knowledge, pots tend to have two common marking code conventions to identify them by, as follows:

e.g. a 100kohm pot would either be known as B100K, or B104, both referring to the same thing. The B means linear taper, 100K means 100kohm, and 104 means 10ohm x 10^4

I found this information extremely useful when trying to find suitable potentiometers online.

Here's the article I found this information in:

http://www.resistorguide.com/potentiometer/

Re: Potentiometer Page

Posted: Sat Oct 27, 2018 2:37 pm
by Crusher
Hi guys!
So this may be an stupid question, and i used the now the awnser.. but i has been a while since i was tinkering with leds.. and i cant find a clear awnser on the net..
So.. when im using an constant current driver lets say a Meanwell hlg-120h-1400b and im dimming it with an 10k potmeter.. what changes? Is it the current or the voltage when i turn on the knob that in or decreases?
The harder i think about it the more confused i get.. I would say voltage becuase the driver has a fixed current not?

Re: Potentiometer Page

Posted: Sun Oct 28, 2018 9:15 pm
by Shimbob
Crusher wrote:
Sat Oct 27, 2018 2:37 pm
Hi guys!
So this may be an stupid question, and i used the now the awnser.. but i has been a while since i was tinkering with leds.. and i cant find a clear awnser on the net..
So.. when im using an constant current driver lets say a Meanwell hlg-120h-1400b and im dimming it with an 10k potmeter.. what changes? Is it the current or the voltage when i turn on the knob that in or decreases?
The harder i think about it the more confused i get.. I would say voltage becuase the driver has a fixed current not?
The current gets dimmed. See the specs for that driver, page 4 under additive resistance.

On another note, did you really mean a 10k pot?