DIY LEDs - The write-up

[Gold Stripe]

Better.

If you want to wire a 1 ohm resistor in line so that you can measure current without having to break the string then you would have the following:

Driver+ to resistor, resistor to LED+, LED- to LED+, LED- to LED+, LED- to LED+, LED- to LED+..............LED- to LED+, LED- to Driver-)

Make sure all your + and - are in the same direction. Then run diode and short tests.

 

[Ninja1]

Better.

If you want to wire a 1 ohm resistor in line so that you can measure current without having to break the string then you would have the following:

Driver+ to resistor, resistor to LED+, LED- to LED+, LED- to LED+, LED- to LED+, LED- to LED+..............LED- to LED+, LED- to Driver-)

Make sure all your + and - are in the same direction. Then run diode and short tests.

Yeah- Ill test things first b/c the instructions I got with my kit dont mention any resistors. However they do suggest test with multimeter and 2 10K pots.

 

[kirsto71]

Just a quick question. I am in the process of building three LED fixtures and i would like to mount the drivers remotely. How would i best determine the distance i can mount the drivers away from the LEDs to still ensure i have sufficient voltage.

I am hoping to mount the drivers approximately 3m away. I assume using heavy guage wire will reduce voltage drop?

 

[michael_in_nc]

Just a quick question. I am in the process of building three LED fixtures and i would like to mount the drivers remotely. How would i best determine the distance i can mount the drivers away from the LEDs to still ensure i have sufficient voltage.

I am hoping to mount the drivers approximately 3m away. I assume using heavy guage wire will reduce voltage drop?

I think the resistance is the only issue and it's pretty small. Google "wire gauge resistance chart". Top one is Wiki which has a chart of resistance (mOhms/meter) versus wire gauge. You just have to make sure you allow for the extra loss in the string for extra headroom at the driver output. The other factor might be current density, making sure the wire can handle the desired current safely.

 

[quartetman1]

Making my own LED lighting fixture.

Making my own LED lighting fixture.

Hi Everyone,

I am new to this thread. Clarification, I know this thread is for salt water reef tanks. If I am out of line asking about LED lighting for fresh water, could you please direct me to the proper thread. I want to make my own do it yourself LED lighting fixture for a 125 gallon fresh water tank to grow live plants. I read some of Soundwave's letters about making his own light fixture using LED lights. LED's use far less power than flourescent and they are now being used on semi-trucks, cars, and Amish buggies. LED's have very many lighting hours before burning out than compared to incandescent and flourescent lights. Obviously also much less electricity to run LED's. So if any of you or Soundwave could help me out on the number of LED bulbs, number of power supplies needed, heat sinks needed, cooling fans needed, etc, etc, that would be greatly appreciated. Please remember I want to grow thriving and reproducing live plants in a fresh water 125 gallon. Hopefully on down the road in several months I can give a good report on growing live plants from an LED lighting fixture.

The tank size is 6 feet long, 18 ½ inches wide, 21 ½ inches deep. Running 3 undergravel filter/pumps, 1 sump circulating pump, 1 Rena XP3 filter.

Thanks for your help, Ken

 

[Raven1645]

Just a quick question:

Would these optics work on these HP LEDS?

Optics (from the picture, they are black or white plastic with an opening in the centre where the lens is):

60° 20mm 1w 3w 5w LED Lens

diameter: 20mm
Angle: 60°
Condition: Brand New
Material: high quality plastic

Application:
Focus light, make the light looks much brighter;
Fit the 1W, 3W and 5W High Power LED




And this is the LED:

They are 3W high power with a small plate.
I believe they're 2cm x 2cm (plate included) high power, 120 degree beam.




Thanks!

 

[chris023]

Only getting about 100ma out of my drivers per string... why?

I have HLG-150H-48B driver running 4 strings of 12. I am running out of the driver to fuses, then resistors. The only thing I have a bit wired differently is I am starting with the negative (red) on the driver to the negative on the first LED, and coming out the positive on the last LED to the positive (black) on the driver. Didn't think this would make a difference as long as positive to positive and negative to negative...right?

I do have home depot individual quick disconnects in the wire from just after the resistors to the first LED. There is about 8 feet of 22 gauge wire between the drivers and the first LED (also using 22 gauge between LEDs). Wondering if the quick connects are dropping voltage, or the distance is a factor.

testing at the resistors using the 2 setting on the meter. Getting ~0.110 per string. Individual LEDs forward voltage is about 2.75 each LED (tested using the 20 setting on the meter).

pot is turned all the way up.

Any ideas on why such low ma? Thanks.

 

[chris023]

Well, I replaced the quick connects with twist on wire connectors. That didn't help.

Maybe it is the potentiometer? Since this application will eventually be hooked up to an ALC module, I bought a radio shack 10k-Ohm Linear-Taper Potentiometer. Maybe this was the wrong one? One thing I noticed is that I cannot dim all the way down, not even close to all the way. Seems like my adjustable range is very low. Does anyone know if this pot is okay to use with an HLG-150H-48B? Thanks.

 

[brassmonkyballs]

The only thing I have a bit wired differently is I am starting with the negative (red) on the driver to the negative on the first LED, and coming out the positive on the last LED to the positive (black) on the driver. Didn't think this would make a difference as long as positive to positive and negative to negative...right?

....but it does make a difference and Pos-Pos and Neg-Neg goes for the driver wiring too. If I'm reading this right you wired it backwards. You're calling the red wire from the driver negative....

Red wire coming from the driver is positive and that needs to go to the positive on the 1st LED.....thru resistor and fuse is fine.

Double check and let us know please. The driver has a number of protections built in and you probably didn't hurt anything...if it is in fact backwards.

 

[michael_in_nc]

Well, I replaced the quick connects with twist on wire connectors. That didn't help.

Maybe it is the potentiometer? Since this application will eventually be hooked up to an ALC module, I bought a radio shack 10k-Ohm Linear-Taper Potentiometer. Maybe this was the wrong one? One thing I noticed is that I cannot dim all the way down, not even close to all the way. Seems like my adjustable range is very low. Does anyone know if this pot is okay to use with an HLG-150H-48B? Thanks.

Looks like the pot is the problem. Google "HLG-150H-48B" and you will find the datasheet. PDF file a few down. If you look on about page 3, you will find the section on the dimmer by using an external resistance. The datasheet says 10kOhms is about 10% of rated current. Rated current is 3.2A, so that's about 320mA total output. So, for 4 strings, that'd be about 80mA. Pretty close to what you're getting. You need a 100kOhm pot or at least it looks like based on the d/s. "kOhms" is units of resistance.

BTW, I'm making these suggestions purely based on the d/s. I have not used this driver.

 

[michael_in_nc]

....but it does make a difference and Pos-Pos and Neg-Neg goes for the driver wiring too. If I'm reading this right you wired it backwards. You're calling the red wire from the driver negative....

Red wire coming from the driver is positive and that needs to go to the positive on the 1st LED.....thru resistor and fuse is fine.

Double check and let us know please. The driver has a number of protections built in and you probably didn't hurt anything...if it is in fact backwards.

I would doubt it's wired backwards if there is any current flow. Backwards on a diode = 0 current except for leakage which should be low. Also, the forward voltage is 2.75v, so it would appear to be on which also indicates correct wiring, just low current.

 

[chris023]

The only thing I have a bit wired differently is I am starting with the negative (red) on the driver to the negative on the first LED, and coming out the positive on the last LED to the positive (black) on the driver.

....but it does make a difference and Pos-Pos and Neg-Neg goes for the driver wiring too. If I'm reading this right you wired it backwards. You're calling the red wire from the driver negative....

Red wire coming from the driver is positive and that needs to go to the positive on the 1st LED.....thru resistor and fuse is fine.

Double check and let us know please. The driver has a number of protections built in and you probably didn't hurt anything...if it is in fact backwards.

My bad... I mis-stated my "red" and "black" in my orig post.
I am starting with the negative (Black) on the driver to the negative on the first LED, and coming out the positive on the last LED to the positive (Red) on the driver.

 

[chris023]

Looks like the pot is the problem. Google "HLG-150H-48B" and you will find the datasheet. PDF file a few down. If you look on about page 3, you will find the section on the dimmer by using an external resistance. The datasheet says 10kOhms is about 10% of rated current. Rated current is 3.2A, so that's about 320mA total output. So, for 4 strings, that'd be about 80mA. Pretty close to what you're getting. You need a 100kOhm pot or at least it looks like based on the d/s. "kOhms" is units of resistance.

BTW, I'm making these suggestions purely based on the d/s. I have not used this driver.

I would doubt it's wired backwards if there is any current flow. Backwards on a diode = 0 current except for leakage which should be low. Also, the forward voltage is 2.75v, so it would appear to be on which also indicates correct wiring, just low current.

I will definitely look for a pot with a min 0f 100k and try that.
As long as there is no issue with starting with the negative (Black) coming out of the driver, and it goes to the first negative LED, then it is wired correctly. Thanks.

 

[michael_in_nc]

I will definitely look for a pot with a min 0f 100k and try that.

I didn't look at the d/s that closely, but I think it would probably go to full power (max current) if you just remove the pot. An "open", I think is full power on the driver. Look at the d/s and see if it does indeed list a power level for "open" and ensure your wiring setup can handle it.

 

[chris023]

I didn't look at the d/s that closely, but I think it would probably go to full power (max current) if you just remove the pot. An "open", I think is full power on the driver. Look at the d/s and see if it does indeed list a power level for "open" and ensure your wiring setup can handle it.

I believe you are right, you are the second person to tell me that running without a pot will run at max. The d/s states 102-108% at 'Open'. I do believe my setup could handle that, I figured ~800ma per string (4 strings of 12) running at max. However, I don't think I want to run it at that level (at least not for very long). I will still go with a 100k pot to do some final balancing. Thanks for the help.

 

[brassmonkyballs]

I believe you are right, you are the second person to tell me that running without a pot will run at max. The d/s states 102-108% at 'Open'. I do believe my setup could handle that, I figured ~800ma per string (4 strings of 12) running at max. However, I don't think I want to run it at that level (at least not for very long). I will still go with a 100k pot to do some final balancing. Thanks for the help.

So are you using a POT and no voltage source? If so then yeah...thats the problem. You can use the 10k pot if you use a 10v source too. If just resistor then need 0-100k ohm Pot. But 10k ohm is supposed to be about 10% of rated output.

Earlier post said you can't dim it all that way down either?...that has me confused given you said only 100ma... So does it light up bright?

The HLGs do not dim to off. mine stays on about 10%

 

[TheFishMan65]

brass, the HLG have 3 dimming modes
- 1 - 10 volt voltage source
- 10 volt PWM signal
- or a 100k pot (no power source required)

 

[brassmonkyballs]

brass, the HLG have 3 dimming modes
- 1 - 10 volt voltage source
- 10 volt PWM signal
- or a 100k pot (no power source required)

right...thats what I thought i said....was just trying to confirm he's using a 10k pot with no power source.

 

[TheFishMan65]

No problem, maybe I read your post wrong. Just wanted to clear it up since I was probably not the only one confused.

 

[chris023]

So are you using a POT and no voltage source? If so then yeah...thats the problem. You can use the 10k pot if you use a 10v source too. If just resistor then need 0-100k ohm Pot. But 10k ohm is supposed to be about 10% of rated output.

Earlier post said you can't dim it all that way down either?...that has me confused given you said only 100ma... So does it light up bright?

The HLGs do not dim to off. mine stays on about 10%

I am using a 10k pot with no voltage. Turned all the way down, I get ~.065 - .070ma. Turned all the way up, I get ~0.100 - .110ma. minimal difference in brightness (which is not very bright to begin with). I will pick up a 100k pot today and try it out later. Thanks for helping out.