Potentiometer

[I like Cheese]

Hi guys

I have another question for you all. I have finished my build and the potentiometer is connected. Without the potentiometer I am getting 440w out of the wall, but with it I am getting 390w. Is this ok and normal ?

 

[gbauto]

That is an indication that you don't have enough resistance value for the pot. When the drivers see essentially infinite resistance on the dimmer circuit it runs at 100% driver output. As the resistance decreases, the driver interprets that as commanding a reduced output.

 

[I like Cheese]

Thanks forthe reply gbauto.

How can I fix it ? I suppose I can just disconnect it when I want the extra 50w.

 

[Rider509]

Cheese, measure the resistance of the pot with an ohm meter. I'm going to bet that you find max resistance to be less than 100k. I grabbed a meter and measured pots at Radio Shack when I bought mine and found two that were under spec.

 

[I like Cheese]

Measure the resistance of the pot with an ohm meter. I'm going to bet that you find max resistance to be less than 100k. I grabbed a meter and measured pots at Radio Shack when I bought mine and found two that were under spec.

Thanks for the reply Rider

It is a 50k as I am using it on 2 drivers, and it is from eBay. So you are probably right. I suppose I will just except it.

 

[Rider509]

Oh, that's right, a dual 50k. Maybe the other pot will give you the full 50k.

 

[I like Cheese]

Oh, that's right, a dual 50k. Maybe the other pot will give you the full 50k.

Ah. Very cool Rider I will try that.

 

[gbauto]

Just spit ballin' here-because you have a dual gang pot you could wire those two circuits in series so that when you twist the knob it doubles to 100k.

 

[Rider509]

He's running two drivers. He'd need a dual 100k to use one potentiometer to control both, or a single 50k.


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[I like Cheese]

Thanks for the help guys

I have decided to use it until I can get 1 that I know is 50k.

 

[Danielson999]

Hi guys

I have another question for you all. I have finished my build and the potentiometer is connected. Without the potentiometer I am getting 440w out of the wall, but with it I am getting 390w. Is this ok and normal ?

Sorry been busy. This is totally normal. If you have a B version Meanwell driver and you don't use the dimming, you will actually get over 100% of the rated power. I believe it's somewhere in the 5% area of bonus power. If you're running 2 hlg-185's which give you 200w of power each then 390 would be typical with 2 drivers. 440 would also be typical if you cap your dimming leads and don't use them.

 

[Rider509]

If you want every watt of output you could wire a SPST switch to interrupt the circuit through the potentiometer.


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