Adding potentiometers to Chinese LEDs

kschweer · Feb 1, 2013

Hey guys I just got some replacement LEDs for my Chinese fixture (blueline 120w) and I figured since it is apart can I add 2 potentiometers? Any feedback would be great
Thanks
-Kevin

Reefing8EZ · Feb 1, 2013

I would assume that most likely the stock drivers in your fixture are not dimmable.
You would also have to swap the drivers to add potentiometer..

kschweer · Feb 1, 2013

I kinda figured that just thought I would ask. Thanks for the quick response I appreciate it

cdness · Feb 1, 2013

Yeah chances are if it doesn't have pots you can't add them... However, check the model number on your driver and see to be sure. Modify at your own risk of course.

dwilliams87 · Feb 1, 2013

I'm not 100% sure on this, but if I'm not mistaken, you should be able to put a potentiometer in series with the LED's and use the pot to pull more voltage to the pot thus dimming your LED's. The only difference with the drivers that are dimmable is they have two wires that allow you to place the pot not on your led strand. I can't see how this wouldn't work since current doesn't change in a series circuit, only Voltage. Changing the voltage to each led, then lowers the wattage they would be putting out, dimming them. If anyone thinks that is incorrect please let me know.

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Reef Breeders · Feb 1, 2013

Do not wire a potentiometer into your string. The drivers put out excess of 70-100V, and they will melt your potentiometer in most cases. Remember, resistance equals heat. You need a dimmable driver to interface with a potentiometer.

kschweer · Feb 1, 2013

Thanks guys. Figured I would ask while I had the fixture apart

fragmatic · Feb 1, 2013

dwilliams87 said:
I'm not 100% sure on this, but if I'm not mistaken, you should be able to put a potentiometer in series with the LED's and use the pot to pull more voltage to the pot thus dimming your LED's. The only difference with the drivers that are dimmable is they have two wires that allow you to place the pot not on your led strand. I can't see how this wouldn't work since current doesn't change in a series circuit, only Voltage. Changing the voltage to each led, then lowers the wattage they would be putting out, dimming them. If anyone thinks that is incorrect please let me know.

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Sorry but no. The drivers that are designed to dim have a control circuit portion that limits the voltage out put of the amplifier. That pot is NOT just in series with the pot. It is not the voltage that will harm the pot it is the current. The reason the pot has 0 to 10 volts is because the control voltage of the driver is looking for 0 to 10 volts DC to tell it how much voltage and/or current to supply to the load. The pot in this design method has hardly any current, it could be provided with voltage from 1 to 6 AAA batteries and work just fine for some time.