LED build design phase questions/suggestions

[anon32470837]

@Daytripr69

Digikey has them listed as active. Let me see if I’m right here i was looking at 560mm strips. They have a listed max amperage of 1.4A and a voltage of 19.5V that would make them 27.3W each correct?

Yes

@Daytripr69

Would a higher voltage be better? Also looking at some 1120mm that are the same amperage but run at 39v. Uggg this is harder than I thought lol

The total voltage doesnt really matter that much. Higher voltage strips will run very slightly cooler, but not enough to worry about. The critical thing is to be sure that the total voltage of the strips in series matches the max voltage of the driver.

In other words, if the strips are say 20 volts each, and you have 3 in series, then your driver needs to have a max voltage of around 60 volts. You can go a little over on the voltage if the driver is adjustable, but not much. Over voltage will kill a circuit much faster than over current. Over current makes for more heat, wich will shorten the life, but over voltage blows things up fast and lets the magic smoke out. I would try to keep the max driver voltage no more than maybe 10% over the total series voltage of the strips.

If you have those same 20 volt strips wired in parallel, then the driver needs to be a 20 volt driver.

Dont worry about the current. The driver will control that for you. You just need to be sure the max power of the driver is close to the max rating on all the strips added together. Series or parallel doesnt matter - just add up all the watts of all the strips and match the driver that way. Remember, you can safely over drive the drivers by maybe 10% easily, so you have some slop to work with.

@Daytripr69

I’m going to need a bunch of strips to match the lumen output of my hps which puts out 145,000 lumens. I would need 31 of the 1120mm strips at 4780 lumens as listed. What is confusing me is it says it will put out 175 lumen per watt, those strips work out to be 54.6w so that would make them put out 9555 lumen at max amperage. With those numbers I would Need 15 strips. What numbers do I go with? Would running say 20 strips at a lower amperage get me the same 145000 lumen or more?

Ive read a lot of debate about comparing lumins vrs watts when trying to compare HPS etc to LED’s. Most people seem to be happy just going by watts. If you have a 1000 watt HPS, then (depending on who you ask) a 500 watt to 700 watt LED should do just fine. I personally think 1/2 the total power is fine. You will be able to run the LEDs much closer to the canopy than HPS, so your effective lumins hitting the plants will be greater - inverse square law.

As far as the number of strips, I would err on the side of more strips running at lower watts. They will run cooler and last longer and be more efficient over all. The trade off is cost. The driver will be the same, based on wattage, but more strips cost more plus more wiring complexity, connectors, heat sinks, thermal paste, etc.