DC Step down drivers or AC/DC drivers?

I only just found out about AC/DC power supplies and DC/DC step down drivers.

Is there a benefit to using those over the AC/DC drivers that we see mostly here on RUI?
I like the cutter socketed DC/DC driver PCB that lets you swap in and out these little drivers, I am wondering though if the AC/DC drivers are more efficient.

I tried searching online, didn't find much that answered my question

Thanks

The LDH-45's are as efficient as the HLG series drivers. But unless you have a DC source to power them Like solar panels your going to lose quit a bit on a AC to DC power supply to power the LDH-45s. So if you have to convert AC to DC your not going to beat HLG's They will also be cheaper since you wont have to buy a AC to DC PSU.

Biggest advantage of LDD builds is not dealing with the HIGH VOLTAGE the HGL type drivers produce.
You can use lower AWG wire since you are only dealing with 36 volts (depending on cob).
Disadvantage is you can't run your COBs over 1500mA (biggest LDD driver currently available).

Wanna run a bunch of low cost (but still very good) COBs at 1000mA it does the job at reasonable cost.
Bridgelux Vero and Citizen 1212s very good choices at both 1000mA and 1500mA (1050 and 1400 HGL equiv)

JavaCo said:

The LDH-45's are as efficient as the HLG series drivers. But unless you have a DC source to power them Like solar panels your going to lose quit a bit on a AC to DC power supply to power the LDH-45s. So if you have to convert AC to DC your not going to beat HLG's They will also be cheaper since you wont have to buy a AC to DC PSU.

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Has anyone done a efficiency test or calculation to see how much is lost using the AC/DC power supply to run the LDD drivers?

The flexibility of being able to mix and match and change things up using these little low voltage drivers together in a bunch is pretty attractive.

PicklesRus said:

Has anyone done a efficiency test or calculation to see how much is lost using the AC/DC power supply to run the LDD drivers?

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Just look inside the datasheet of the power supply you are interested in. Good constant voltage power supply are as effective as constant current drivers but the fact that you still need a LDD behind it makes it less effective....

Schalalala said:

Just look inside the datasheet of the power supply you are interested in. Good constant voltage power supply are as effective as constant current drivers but the fact that you still need a LDD behind it makes it less effective....

Click to expand...

I was thinking that it would be interesting to have one power supply for say all of the lights on my vertical four level shelving unit.

I ended up buying a hlg-120h-c700a but I have lots more lights to buy so I'm still open to ideas

The eBay box in my sig I will revive soon, I thought maybe I should use these leds for that.

PicklesRus said:

Has anyone done a efficiency test or calculation to see how much is lost using the AC/DC power supply to run the LDD drivers?

The flexibility of being able to mix and match and change things up using these little low voltage drivers together in a bunch is pretty attractive.

Click to expand...

You dont really have to Ac to Dc PSU's come with a efficiency rating. Pretty much all of them run in the 74% to 89% range. So your not going to come close to a HLG series driver efficiency ,then you have to add in the DC to DC driver efficiency so it will drop it even lower. Not really the best way to run COBs unless you already have a DC source so you don't have to run a AC to DC PSU. Havent priced out AC to DC PSU's lately, but if it is still the same it will cost more to buy a set up like that. A decent brand named AC to DC PSU's are not cheap.

JavaCo said:

You dont really have to Ac to Dc PSU's come with a efficiency rating. Pretty much all of them run in the 74% to 89% range. So your not going to come close to a HLG series driver efficiency ,then you have to add in the DC to DC driver efficiency so it will drop it even lower. Not really the best way to run COBs unless you already have a DC source so you don't have to run a AC to DC PSU. Havent priced out AC to DC PSU's lately, but if it is still the same it will cost more to buy a set up like that. A decent brand named AC to DC PSU's are not cheap.

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Thank you for that info

The AC to DC power supply (Meanwell LRS-350-48 ) runs at 90% efficiency
The LDD chips: 97% at full load and 36VDC/48VDC input for LDD-H/HW

Don't know where you got your figures, but this combo runs cool unlike the HGL drivers.
Price is tricky and only way to compare is 'fully loaded' builds and comes out about the same or a bit cheaper for LDDs.

HalfBee said:

The AC to DC power supply (Meanwell LRS-350-48 ) runs at 90% efficiency
The LDD chips: 97% at full load and 36VDC/48VDC input for LDD-H/HW

Don't know where you got your figures, but this combo runs cool unlike the HGL drivers.
Price is tricky and only way to compare is 'fully loaded' builds and comes out about the same or a bit cheaper for LDDs.

Click to expand...

@robincnn mentioned hes used a Meanwell LPC 48V/54Vdriver to power the LDDs

This is a really interesting topic.

Just ti ask, is that meanwell power supply running at 90% regardless of load?

It doesn't say - but will correct the figure to 89% on the LRS-350-48 from the spec sheet (was looking a different spec sheet).
I'm running my Vero18s on LDDs and the LRS-350-36 (because they only need under 30 volts to run). And I'd recommend the LRS-150-xx because it doesn't have the cooling fan and passively runs cool even under almost full draw.

Haven't finalized my build thread yet, have 12 pages of notes to condense with the photos of build.
It's not pretty but am happy with it for the moment.

Previous build thread Well Buck You Too substitute CXB or 1212 COB and you get the picture...

It looks like cutter has some other options for voltage on LDD type drivers too that might fit the cobs voltage better.

HalfBee said:

It doesn't say - but will correct the figure to 89% on the LRS-350-48 from the spec sheet (was looking a different spec sheet).
I'm running my Vero18s on LDDs and the LRS-350-36 (because they only need under 30 volts to run). And I'd recommend the LRS-150-xx because it doesn't have the cooling fan and passively runs cool even under almost full draw.

Haven't finalized my build thread yet, have 12 pages of notes to condense with the photos of build.
It's not pretty but am happy with it for the moment.

Click to expand...

Can you link your thread here?

Edited for linking above - Those are all branded LDD style drivers, they only vary in current output. With the exception of the 1.5 which has a lower input/output range. Yeah... @welight can answer your questions on them and if they can be put into use with HGL or if they need their own power supply.

HalfBee said:

The AC to DC power supply (Meanwell LRS-350-48 ) runs at 90% efficiency
The LDD chips: 97% at full load and 36VDC/48VDC input for LDD-H/HW

Don't know where you got your figures, but this combo runs cool unlike the HGL drivers.
Price is tricky and only way to compare is 'fully loaded' builds and comes out about the same or a bit cheaper for LDDs.

Click to expand...

My numbers come from data sheets. " but this combo runs cool unlike the HGL drivers." this defies the laws of thermal dynamics. A AC to DC PSU running at 89% with a LDD running @ 97 % IS going to be around 86% total efficiency. So the LAw of Thermal Dynamics says 86% of the power going into the driver/ psu is coming out for the job. In this case the job of the PSU is to turn AC voltage to DC voltage. So 89% goes for the job 11% goes to heat. LDD 97% to job 3 % to heat. So lets take a look at a HLG running same wattage @ 94% efficiency produces 6% heat. So unless the HLG is broken No Way will LRS paired with a LDD put out less heat then HLG. In fact the LRS and LDD combo puts out double the heat.

To be honest, I have not used the HGL driver line and report the heat issues by comments heard.
Running LDD on both LRS-150-48 and LRS-350-36 there is little heat from power end of things.