Anyway to get 12v out of the Dimming Expansion Module?

[Sacohen]

I know the topic is strange, but I got some Chinese LED a while backon EBay and was going to connect them to my Meanwell LED's.

Well the white channel off one of them died.
The seller stopped seller this model and does not have the new model ready so he sent me 4 20 Reef Bar lights that run on 12V DC.

I one channel of 1 of them to the dimming module and it does dim from 0% to 100%, but unfortunate 100% equals 10v so I'm not getting full light out of them.

So that lead me to my topic question?

I'm guessing the answer is no, but it doesn't hurt to ask and maybe Roberto or Lee have some magic up his sleeves.

Thanks for the help.

[rimai]

How much current do they draw?
Be careful to not burn out the dimming module.

[Sacohen]

The PS says 12v 10a.
What's the limit of the dimming module?

[rimai]

Huh??
12v 10A?
That's 120W. That seems so excessive.
The dimming module can only output 40mA max.

[Sacohen]

Good to know.
It may be an overpowered PS although I did plug in a 12v 1.5a PS and it was a lot dimmer.

This is the light.
http://www.ebay.com/itm/Aquarium-LED-Li ... 871de08da5

18 3W LED's is 54W so it seems the PS is over powered.

[lnevo]

Isn't that what you bought the meanwell for in the first place?

The dimming module is to provide a dimming signal not to replace a power supply...

But this part is outta my league...i wish I knew more about electronics

[Sacohen]

You are correct, but the Meanwell LDD's put out 48v if I remember correctly and the is way too much voltage for these lights.

I know, but I thought since it puts out 10v that's close enough to 12v but I forgot about the Amps having an effect on it to,

[lnevo]

Wouldn't the power be based on the PS to the driver?

[lnevo]

There does seem to be a range on the input and output for the LDD

http://www.meanwell.com/search/LDD-L/LDD-L-spec.pdf

I forgot the difference between L and H..

[cosmith71]

Steve, are you using the dimming module as the only source of power for the lights? They won't work that way. You're going to blow out your dimming circuit. You'll need to use the AC adapter that came with the lights. If they don't have a specific port for dimming you won't be able to use the RA to dim them.

--Colin

[Sacohen]

There does seem to be a range on the input and output for the LDD

http://www.meanwell.com/search/LDD-L/LDD-L-spec.pdf

I forgot the difference between L and H..

I went back and looked at the specs of the LDD drivers and saw that.

Steve, are you using the dimming module as the only source of power for the lights? They won't work that way. You're going to blow out your dimming circuit. You'll need to use the AC adapter that came with the lights. If they don't have a specific port for dimming you won't be able to use the RA to dim them.

--Colin

Colin;

I'm coming to realize that. Everyone says there is no such thing as a stupid question, well this was one.
I wish I could just delete this whole thread.

I'm thinking of trying the 12v 10a PS that they supplied on the LDD drivers. Then run control wires from the RA.
That should work, or did I miss something?

[cosmith71]

Don't think so, since the dimming signal goes to the LDD drivers and not the power supply.

I'm not sure those lights are going to be dimmable. The only other thing I can think of is maybe some sort of voltage follower, assuming those lights get dimmer with lower input voltage.

--Colin

[Sacohen]

They do. The dimmers they supply are just a 12v Led dimmer like this.


So the PS goes to the circuit board I have the LDD drivers mounted to and then the RA sends a control signal out to the board and the board sends the appropriate % of voltage out to the lights.

I have one of the boards that were designed on ReefCentral

http://www.reefcentral.com/forums/showt ... dd+drivers

[cosmith71]

Hmmm, dunno.

How much current do those lights take, and what are your LDD's rated for?

--Colin

[Sacohen]

I have 4 1000ma LDD drivers.
The lights I'm not sure about, I'm trying to find that out now.

This is the light bar.
http://www.ebay.com/itm/Aquarium-LED-Li ... 871de08da5

[lnevo]

If the PS matches the specs for input on the LDD i see no reason why they can't be used.

[Sacohen]

According to the spec sheet that you linked to before.
http://www.meanwell.com/search/LDD-L/LDD-L-spec.pdf

The LDD's can accept an input voltage for 9 to 36v and the amp is dependant upon the # of lights connected.

[cosmith71]

An LDD outputs a constant current (1000mA, 700mA, whatever it's rated for).

It changes voltage dependent on the number of LED's attached.

And...

You have 54W of LED's. They use 12V. 54W/12v = 4.5A (4500mA).

Are these the permanent replacement?

--Colin

[rimai]

Can you plug the 12V power supply directly to the bar without the dimmer?
I have always been interested in knowing what those 12v dimmers are like inside.
The ecoxotic bars use the same thing.
I'm not sure if these bars have built-in drivers or simple resistors.
If the have built-in drivers, the LDD path may not work.

[Sacohen]

An LDD outputs a constant current (1000mA, 700mA, whatever it's rated for).

It changes voltage dependent on the number of LED's attached.

And...

You have 54W of LED's. They use 12V. 54W/12v = 4.5A (4500mA).

Are these the permanent replacement?

--Colin

Hopefully not. I'm trying to get my money back from the guy and use those funds to buy the Evergrows or even the ReefRadiance.

Can you plug the 12V power supply directly to the bar without the dimmer?
I have always been interested in knowing what those 12v dimmers are like inside.
The ecoxotic bars use the same thing.
I'm not sure if these bars have built-in drivers or simple resistors.
If the have built-in drivers, the LDD path may not work.

Plugging the 12v PS will give you the lights at full output.
I don't believe there are drivers in there it is the same LED dimmer that they were using to slow down the Jebao pumps when they first came out.

I think it's a variable resistor (potentiometer) that is reducing the voltage going into the lights and thereby reducing the brightness.

[AlanM]

The Meanwell LDDs, like Colin posted, always put out the rated current, and they basically turn it on and off quickly based upon the PWM signal you're sending it. So if you have a 1000mA LDD it will put out 1000mA at a voltage up to a volt or two below whatever you're supplying it with. Then the PWM signal makes it go on and off with a 10% duty cycle if you're sending it a PWM signal that is 5V 10% of the time..

You don't have to match it carefully to the drop of the LEDs on the output like you used to have to do with other driver technology. The LDD seems to float the DC- output up to whatever level results in a 1000mA output and just leaves it there.

If you have a potentiometer dimming 10A and 12V, that would be a ton of heat dissipated. That's normally not how you dim an LED, with a resistor/potentiometer, you dim it by regulating the amount of current being supplied by the power supply in some way.