Led driver selection help
- Thread starter royalbijoy
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royalbijoy
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Is cutter australia a reliable store? I get some unsecured transaction popups when I try to order? If it is good enough I can buy all the leds from there...
royalbijoy
New member
Going through user reviews, T5HOs seem to be a lot better than LED fixtures.... A lot many of users seem to have successful fixtures with a combination of LEDs and T5HOs... T5 have light hitting the corals from all sides, whereas leds are more of point source......The topmost tips of sps do good in led, but the whole sps does good in T5HO.... Any views on this?
Definitely, the heating and bulb replacement remains an issue with T5HO. But the question is, is it worth the extra 400$ that we spend on LEDs when we can just spend a few extra dollars on electricity bills every month and get good spread and coral growth with T5s?
Definitely, the heating and bulb replacement remains an issue with T5HO. But the question is, is it worth the extra 400$ that we spend on LEDs when we can just spend a few extra dollars on electricity bills every month and get good spread and coral growth with T5s?
Personally, LEDs are worth it over T5s. You can easily design your LED using the same principal as the Lani LEDs which prevents the shading you suggest. And lots of gently driven LEDs also gets you more light and less heat per watt than a smaller number of the same LEDs run at higher current (costs more to set up and can change the LED spectrum slightly, but that's easy enough to allow for).
Tim
Tim
"Is it worth the extra 400$ that we spend on LEDs when we can just spend a few extra dollars on electricity bills every month."
Its not just the $8 a month you save in electricity but also the $100 a year you save in bulb replacement. I recently spent about $280 on LEDs to replace the four 96w power compacts that cost about $130 a year to replace.
Its not just the $8 a month you save in electricity but also the $100 a year you save in bulb replacement. I recently spent about $280 on LEDs to replace the four 96w power compacts that cost about $130 a year to replace.
ghellin
New member
Yes Cutter is worth it, I have bought from them a few times and have known several others to as well. I have not ever heard of a bad experience. Now my bank did reject the transaction until I approved it because it was an international purchase, just an FYI.
For the LED/T5 debate. Colors with T5 and Halides are just insane period. However electricity and heat make them less attractive and LED's more so. LEDs are a must in my opinion, they just grow coral very well and if you choose the right LEDs you can get some amazing results. Sanjay Joshi has some really cool write ups that go into great detail and he loves his LEDs.
I personally love mixing T5 and LEDs to get the best of both worlds. The fixture I am building for my 180 will have 4 39 watt T5's and 130 LED's. Should look pretty nice IMO.
For the LED/T5 debate. Colors with T5 and Halides are just insane period. However electricity and heat make them less attractive and LED's more so. LEDs are a must in my opinion, they just grow coral very well and if you choose the right LEDs you can get some amazing results. Sanjay Joshi has some really cool write ups that go into great detail and he loves his LEDs.
I personally love mixing T5 and LEDs to get the best of both worlds. The fixture I am building for my 180 will have 4 39 watt T5's and 130 LED's. Should look pretty nice IMO.
royalbijoy
New member
Finally ordered all the stuff.. Till it arrives, I got to decide how to fix them over the tank. A quick question which I would like get answered,
Does the Power supply and drivers have to be close to the heatsink and the led canopy? I was thinking about keeping the power supply and the drivers in a separate box below the tank, away from the salt creep, and wires going to the leds on the top.
Is there anything that I a missing as most of the builds I have seen have the whole thing tied to the heatsink.....
Planning to control dimming with an arduino using a web server so that I use my mobile phone to change intensity.....
Does the Power supply and drivers have to be close to the heatsink and the led canopy? I was thinking about keeping the power supply and the drivers in a separate box below the tank, away from the salt creep, and wires going to the leds on the top.
Is there anything that I a missing as most of the builds I have seen have the whole thing tied to the heatsink.....
Planning to control dimming with an arduino using a web server so that I use my mobile phone to change intensity.....
royalbijoy
New member
Thank you. What would be current rating for the wires from the power supply unit to the Drivers? Would it be, Number of LEDs in the string x 1000mA + 1000mA for the driver, if I assume LDD1000H for all strings? Is it the single core thick wire normally used for DC applications?
If the LDD is 1A and the LED string is say 27V and you are running on a 36V power supply, the current from the PSU to that LDD is:
27 + 3V (for the LDD)
Mulitplied by the current to get the wattage so 30W.
30W from a 36V supply is
30/36
So for that string you need 0.83A. Do that for each string (obviously using the the appropriate fV and drive current) that will be drawing power over the wire (all strings if you are using one set of cables from power supply to all drivers) and that gives you the current the wire needs to carry. And i would make sure it can carry a damn site more, just to be safe
Tim
27 + 3V (for the LDD)
Mulitplied by the current to get the wattage so 30W.
30W from a 36V supply is
30/36
So for that string you need 0.83A. Do that for each string (obviously using the the appropriate fV and drive current) that will be drawing power over the wire (all strings if you are using one set of cables from power supply to all drivers) and that gives you the current the wire needs to carry. And i would make sure it can carry a damn site more, just to be safe
Tim
royalbijoy
New member
Thanks . That was useful. I have ordered Meanwell, 320w, 48v powersupply.
I have seen some threads where people mention that its best to be close to the max voltage of the strings, instead of going for a higher voltage power supply. They were saying the efficiency of the LDDs are max when the voltage matches the sum of led's fw in each string. Will that be something that I have to be concerned about? One of my LDDs will be driving just 4 LEds as they are the red colored ones which I do not want to max out... So the LDD requires just 4x3+3 = 15v, whereas the power supply is supplying 48v.
Going to the arduino output, do I need resistors to connect to the LDD? Is that for a precaution in case the pwm signal fails and the full voltage goes to the PWM input, driving the ldd at its max ? I do not have any overrrated ldd for any of the led strings and so even if the LDD PWM input was at max, my leds would still be safe.
How do I test the arduino outputs? If it were analog signals I could have measured the voltage using a multimeter. But with PWM outputs, how do I make sure the values are correct? I figured out I can write 255 and 0 to the pins to measure for 5 and 0 volts. But anything in between is still 5v..... I just need to verify stuff before connecting the drivers to arduino....
My plan is to control the lights using a webpage which should display each channel and allow increasing the intensity manually whenever required, overriding the time based auto setting stored in the arduino. Is the ethernet shield whatI require for this? I am yet to go through the arduino stuff, but wanted to buy all the stuff before I start working on it. I have ordered a Arduino UnO R3. Let me know the shields which I should be buying to make my web server running on a local network so that I can just open the page on my mobile phone and control the intensity. Does the web server come along with the ethernet shield or is it some kind of library that I need to flash into the firmware of the arduino to host a web server?
I have seen some threads where people mention that its best to be close to the max voltage of the strings, instead of going for a higher voltage power supply. They were saying the efficiency of the LDDs are max when the voltage matches the sum of led's fw in each string. Will that be something that I have to be concerned about? One of my LDDs will be driving just 4 LEds as they are the red colored ones which I do not want to max out... So the LDD requires just 4x3+3 = 15v, whereas the power supply is supplying 48v.
Going to the arduino output, do I need resistors to connect to the LDD? Is that for a precaution in case the pwm signal fails and the full voltage goes to the PWM input, driving the ldd at its max ? I do not have any overrrated ldd for any of the led strings and so even if the LDD PWM input was at max, my leds would still be safe.
How do I test the arduino outputs? If it were analog signals I could have measured the voltage using a multimeter. But with PWM outputs, how do I make sure the values are correct? I figured out I can write 255 and 0 to the pins to measure for 5 and 0 volts. But anything in between is still 5v..... I just need to verify stuff before connecting the drivers to arduino....
My plan is to control the lights using a webpage which should display each channel and allow increasing the intensity manually whenever required, overriding the time based auto setting stored in the arduino. Is the ethernet shield whatI require for this? I am yet to go through the arduino stuff, but wanted to buy all the stuff before I start working on it. I have ordered a Arduino UnO R3. Let me know the shields which I should be buying to make my web server running on a local network so that I can just open the page on my mobile phone and control the intensity. Does the web server come along with the ethernet shield or is it some kind of library that I need to flash into the firmware of the arduino to host a web server?
Last edited:
formula409
New member
Just remember there is like a 1.5v-2v drop from the input as the max voltage for the LDDs
Simply put, I wouldn't worry about testing them. If you really want to, test them by putting an LDD onto a single LED and then connecting it up to each PWM from the arduino in turn, with the arduino running a sketch that varies the PWM on each of the pins you will use. That way, you only have one LDD and one LED connected during testing. Otherwise, by an oscilloscope can get some fairly nice USB ones cheap. In fact, some multimeters even do PWM!
There are two reasons for hooking up resistors on the LDD PWM line. On is to pull the signal to ground if no PWM signal is available (arduino is rebooting or whatever) and prevents the LEDs coming on at 100%. The other is a safety to protect the arduino in case of some other component failure.
The LDDs are at their most efficient when given the fV of the LED string plus the 3V they need. But they'll manage fine at 48V in when they only need 15V and they will probably still be more efficient than adding another regulator.
Making the arduino network enabled is doable, but not as simple as doing the same with say a raspberry PI (but then controlling the PWM would be harder with rPI). You will have to do some googling on that one. Personally I'm leaving that for a (much) later stage...
Tim
can get some fairly nice USB ones cheap. In fact, some multimeters even do PWM!There are two reasons for hooking up resistors on the LDD PWM line. On is to pull the signal to ground if no PWM signal is available (arduino is rebooting or whatever) and prevents the LEDs coming on at 100%. The other is a safety to protect the arduino in case of some other component failure.
The LDDs are at their most efficient when given the fV of the LED string plus the 3V they need. But they'll manage fine at 48V in when they only need 15V and they will probably still be more efficient than adding another regulator.
Making the arduino network enabled is doable, but not as simple as doing the same with say a raspberry PI (but then controlling the PWM would be harder with rPI). You will have to do some googling on that one. Personally I'm leaving that for a (much) later stage...
Tim
royalbijoy
New member
Gorgok
New member
Calling it duty cycle sounds like it will give a 0-100 reading of the percent of time the signal is high compared to low. Not really sure what you want to measure the pwm for anyway, but that would probably be as good a reading as anything else.
Wire a string, run a sketch from 0-255 (with some delay!). If it blinks on from off and stays that way blindingly bright... its not working. If its almost pleasant to look at for a bit before blinding you silly its working.
If its not working, it might be wireing, not grounding the driver with the controller for example.
Wire a string, run a sketch from 0-255 (with some delay!). If it blinks on from off and stays that way blindingly bright... its not working. If its almost pleasant to look at for a bit before blinding you silly its working.
If its not working, it might be wireing, not grounding the driver with the controller for example.
royalbijoy
New member
@Gorgok , the reason for measuring is that the arduino I have ordered is some cheap sub 5$ stuff from ebay. Not really sure if it is going to work as expected. Dont want it to output full voltage to the leds and fry them up.... If I could measure the PWM changing from 0-255, that would be good enough to safely connect to the ldds and leds....To add to the problems, that would be the first time I am gonna work with arduino . So don't want to take a chance...
I have already fried a multimeter over the weekend doing silly stuff...
@tim, I see what you are pointing at... I am yet to receive the multimeter. Will have a look at it before using...
I have already fried a multimeter over the weekend doing silly stuff...
@tim, I see what you are pointing at... I am yet to receive the multimeter. Will have a look at it before using...
royalbijoy
New member
Guys need Advise on fixing the leds onto the heatsink. I'v got a huge heatsink with fans. It hasn't got slots for leds. So I need to drill holes on it. Will #4-40 3/8 inch screws be sufficient for screwing the starbase to the heatsink?
I have a hand drill at home. Not sure if it will be sufficient to drill through the heatsink.
I have a hand drill at home. Not sure if it will be sufficient to drill through the heatsink.
