DiY LEDs - How to Power Them

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bseeds

Well-Known Member
kaivorth said:
5x CXB3590 3500k $200
5x Ideal 50-2303CR $15
5x Ideal 50-2300AN $10
5x 180mm pin fin heatisnk$100
5x reflector's
1x Meanwell HLG-240H-C1400B$70

Do I need 180mm pin fin heatsinks or can I go smaller?
Anything else you guys recommend to change or just order away?

Is there anything else Cree is coming out with that I should wait for?
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go to kingbrite ideal 50-2303cr +ideal 50-2300an +reflector kb-d82-90rf unit price is $39.6-$41.6 usd also a pairui driver lgsu250-c1400d $37.0 usd and heat sinks 133mm h70mm 50-60w$13.5usd screws and thermal patches free
 
B

bseeds

Well-Known Member
bseeds said:
go to kingbrite 3590 3500k ideal 50-2303cr +ideal 50-2300an +reflector kb-d82-90rf unit price is $39.6-$41.6 usd also a pairui driver lgsu250-c1400d $37.0 usd and heat sinks 133mm h70mm 50-60w$13.5usd screws and thermal patches free
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rob333

rob333

Well-Known Member
sanjuan said:
I'd prefer a large LES area.
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could u put a little input on les area also how do they look up next to a cree cxb or vero i no they are a little weaker in luman output but they say they are pretty close and for $9.85 a pack of 8 i thought i could easy make up the lose for the cree or vero output by running 2 compaired to one cree or vero let me no what u think man
 
sanjuan

sanjuan

Well-Known Member
I don't really know, rob. The marketing sheet is touting a small LES as a being a good thing--and it would be, for certain applications.
 
C

claypipe69

Well-Known Member
SupraSPL said:
There are many ways to design a DIY LED but here are the details of the wiring for constant current drivers. If you have no experience working with 120V wiring you should understand that it can be dangerous under certain conditions and you should study and gain a thorough understanding of the dangers before attempting your project or ask for help from an electrician. The most obvious thing is never work on live wires. Once your build is complete, a GFCI can help protect you from electrical shock in our wet growing environments and are available for $7 on eBay. Check your AC circuit for hot spots which is a sign of an overloaded circuit or a poor connection. This can occur in timers and in the connections of extension cords.
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Recommended tools:
Multimeter with 10A current measuring capability
Power meter - KillAWatt or EnSupra (no affiliation)
Wire stripper
Wire crimper
Slide Connectors
Heat Shrink Tubing

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The AC side

The AC power input has a hot and a neutral. This is important when wiring an LED driver. If you mix them up, the LEDs can glow a bit during lights out because the timer will cut the neutral instead of the hot and the LEDs may respond to ghost voltages and emf. In most homes the smaller side of the outlet is the hot wire (black) and the larger side is the neutral (white) so it is helpful to use a power cord that forces the plug into the correct polarity. If you install a switch make sure you switch the hot wire or use a double pole single throw switch. The driver should have labeling so you know which is the hot (Line) and which is the neutral. You can make the AC connections using molex connectors although that can get prohibitively expensive if you are making dozens or even hundreds of connections.

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The DC side

-Do not apply AC power to a driver that is not connected to an LED string
-Do not switch an LED driver on its DC side, but rather on the hot wire of the AC side.

-Constant current circuits operate with the LEDs connected in series.
-On the DC side of the driver there is a positive and a negative wire. Red is the positive and black or white is the negative.
-The negative wire of the driver goes to the negative side of the LED. (I find this unintuitive in a series connection)
-The positive of an led connects to the negative of the next LED in the series until the whole circuit makes a loop.
-If wired backward the circuit will not function and there is a possibility of damaging the LEDs.

-The driver will have a certain voltage range that it can operate within and this range may not be printed on the driver.
-The efficiency of the driver will vary depending the voltage of the LED string.
-To estimate the total voltage of the string, add the total vF or each LED in the string. If the voltage is of the LED string is too low the driver may flash. If it is too high the driver may flash or it may drastically reduce its current output.
-Each LED will operate it its own voltage but they will all operate at the exact same current.
-As each LED warms up its voltage will drop slightly.
-If you decrease the voltage load on the driver, its current output will rise and vice versa.
-As the driver warms up its current will drop (unless regulated). LED drivers are typically 75-90% efficient so they will heat up as they operate.
-As the current drops the LED voltage will drop slightly.
-Each driver may operate at a slightly different current +/-5% even if they are the same model.
-Adding a fuse that is lower than the maximum current of the LEDs may help protect the LED string in the event of a driver malfunction.
-It is critical that all connections and soldering points are secure. Flickering or arcing in the circuit can damage the driver or worse can destroy the entire LED string.

View attachment 3003741

For the DC connections you can use molex, wire nuts (not recommended), splices, closed end crimp ons or you can solder the connections and heat shrink them. In my case I use .25" bare (non insulated) crimp on slide connectors (quick disconnects) and once I have verified that the connection is very solid, I cover with heat shrink tubing leaving no metal exposed. They are cheap, secure, force the correct polarity, can be color coded and it makes your drivers and LED strings easily swappable.

View attachment 3003738

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Choosing a Driver - Drive Current

LEDs suffer from current droop which means that the harder you run them (higher current), they dissipate more power but become significantly less efficient. They also suffer from temperature droop. As the temperature rises they become less efficient and if run hot they will suffer significant lumen depreciation over time. Because we use our lights for long hours each day, efficiency becomes an even more important factor. Therefore it is recommended to run LEDs relatively soft and use more of them. This increases the up front cost for the LEDs but decreases the cost of drivers, heatsinks and electricity. The value point will vary depending on electrical costs and keep in mind that we expect LEDs to continue to improve in the coming years.

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Testing the String - Do this when the driver and heatsink are already warmed up and stabilized.

Once your driver and LED string is wired it is recommended that you verify the current (amperage) of the string. Very occasionally drivers malfunction and drive at a much lower or much higher current than specified. To check current your multimeter must be in series with the LED string (anywhere in the string on the DC side). Make sure your multimeter probes are plugged into the correct slot for testing current (amps). Make sure you do not apply power to the driver until the multimeter connections are secure in the LED string (slide connectors are helpful here). Record this number (example 700mA = .7A)

If you are curious about the efficiency of the driver, connect your multimeter in parallel in the LED string to measure voltage. The voltage measurement has to be taken from before the first LED and after the last LED in the string. The easiest place to do this is at the DC side driver connections. Make sure to move your test leads to the correct slots on your multimeter for measuring voltage or else you will short circuit the string. (Yes I have done this).

Once you have your volts and amps you can calculate dissipation wattage of the string. It is very simple volts X amps = watts. Next check your input wattage from the KillAWatt or EnSupra. Now divide your dissipation wattage by your input wattage and you get the driver efficiency percentage. Keep in mind that if you measure input wattage while your multimeter is in series with the string you will get a slightly incorrect figure. My multimeter adds .2-.3W.
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First things first Thankyou for the great information. My Question is can I run the leds off 12v dc only? As I am moving off grid my whole place will be deep cycle batteries 1 inverter for fridge. Solar panels, generator for bad weather to recharge batteries. All the lighting in the house will be led. Is there anything special I need to do to make my grow lights work, anything special I need? Your input would be greatly appreciated......would it be okay to disconnect the mains driver an connect to 12v dc supply?.
 
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D

Diysystem

Member
Just to check my math before purchase.

Driver LED trafo 150W, 48-215V, 700mA.

Clu046-1212 35v*0,7mA = 24,5w. 6 cobs in serie will be 147w and 35vx6=210v

Would this setup work on this driver? Thanks again.
 
nogod_

nogod_

Well-Known Member
Meh.

They are 5000k so good for a veg lamp.

Tiny cobs (6.5mm and 5w) means a lots of soldering or buying lots of holders if you can find them.

$9.85 for 40w (5w x 8cobs) @ 120lum/w
Not great but not awful, I would definitely pass.

rob333 said:
@SupraSPL i found these cobs floating around were i live for a good cheap price 9.85 a pack of 8 i no they aint no cree or vero but how do u think they would match up ?http://docs-asia.electrocomponents.com/webdocs/13d9/0900766b813d9c05.pdf
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mrbubble

mrbubble

Active Member
Hi guys quick grounding question,

I have 3 separate aluminum light fixtures (each with its own driver) that I want to power off of one power cable. I'm using the 5 hole wago connectors.

My plan is to solder 1 ground wire to each of the frames, connect those 3 wires using a wago, and connect that wago to the wago holding the grounds for the power cable and drivers.

I'm posing a picture of what I'm going to do. Is this right?
 

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