PPFD & Photon Efficacy of the LM301B vs LM561C

[unkle_psycho]

150lm/w would be great... especially if its 12v and can be chopped every 3 diodes.

problem with those flex strips is that they use resistors that result in a lot of efficiency wasted

Do you have any idea how much the resistors take? If they reduce resistance why does everyone use them? Is the security benefit they provide unimportant?

[tazztone]

Do you have any idea how much the resistors take?

i guess it's almost 1/3 of efficiency. because Bava shows their CV strips as 50lm/W lower than their CC ones:

i haven't taken the plunge on alibaba because i was wary of them.
mufue sells some flexible CC ones that are probably worth a try:

so if anyone has enough dough to pay for shipping, go for it and report the findings.

here is a video explaining flex strips quite good. it gets interesting at about 2 min into the video when he explains the role of the resistor of a CV-strip
https://youtu.be/FrRJoauDD5A?t=24s

[unkle_psycho]

I do kind of get what the dude is saying, but at the same time I get the feeling I need to dive a little deeper into just the basics. At moments my head starts to spin from rather simple concepts just because i'm not familiar enough with the basic blocks like constant current and constant voltage etc.

I do get that they balance the power between the leds, and how its necessary, but I can't say I understand how our vesta's avoid the same problem. I do feel its becoming time to finally wrap my head around the electrics side of things.

I googled vesta build and ended up reading a RIU post you were writing in. Lots of interesting stuff. I got this idea about creating a 'system efficiency' thread to start collecting ideas and hypothesis about system efficiency. I was blown away by the guy who used the excess heat to warm his water, in effect kinda doubling his lights efficiency.

[unkle_psycho]

Is constant voltage the same as wiring in series, and constant currant the same as wiring in parallel?

[tazztone]

I do get that they balance the power between the leds, and how its necessary, but I can't say I understand how our vesta's avoid the same problem.

i am in the same boat. let me know when you find out about it.
but CC is not quite the same as parallel wiring. most strips by samsung etc have a combination of series and parallel LEDs. but i don't know why they don't need a resistor. maxbe because of better binning so they all have the exact same internal resistance.

[majorana]

mufue sells some flexible CC ones that are probably worth a try:

Only problem with mufue is that they'd sell you an inferior chip. Proceed at your own risk.

I was blown away by the guy who used the excess heat to warm his water, in effect kinda doubling his lights efficiency.

A project I'll never get around to is building a Stirling engine/generator using that excess heat. Especially when growing during the winter.

[unkle_psycho]

Well i just had a revelation today telling someone how the entire efficiency question changes when you can use the heat. She noted that she uses electricity to heat the house 9mnths per year. I realized so do I, and when I was running the grow in my bedroom the heating system barely activated. When I moved my grow out a couple of days ago the heating system started working a lot again... even though its almost summer.

So living in a cold area I realize its a non issue. Even our summers usually don't go much over 20c, so the extra heat is still welcome, even if not necessary to heat the house. With my 730w plasma I could feel the plant did poorly if the tent door was left open.

I wonder how heat lost by leds compares to electrical heaters in efficiency... is there some magic in a heater, besides just converting 100% of electricity to heat? Is it comparable?

[Professor Xavier]

You can get a fairly accurate picture of that through the efficiency of the light. Some companies report their PAR Watts and their actual wattage from the wall or you can extrapolate it from other data (I would think lumens might help you more for your efficiency vs a heater comparison) Nearly all of your inefficiency is attributed to heat conversion. I say fairly accurate because a small amount of energy is converted into other forms of energy AND because near IR and IR light have interesting relationships with heat upon absorption.

"I wonder how heat lost by leds compares to electrical heaters in efficiency... is there some magic in a heater, besides just converting 100% of electricity to heat?"

Sir, if you have a 100% efficient electric heater, I will make us both very rich men. I might ask for a measly 1% increase of efficiency in our second year of business to keep things in motion though

[LEDG]

I was reading recently that electric heaters are actually considered 100% efficient.

[Professor Xavier]

I was reading recently that electric heaters are actually considered 100% efficient.

Which led me to some interesting reading. I apologize to the OP for the tangent.
The concept of the heaters being 100% efficient is based on the idea that any other form of energy produced by the heater will revert back to heat energy eventually and that this is within a theoretically closed system. Ie - Sound waves will reverberate within the closed system to create heat after dissipation as will all the light energy be absorbed and captured. The uniqueness of the "efficiency" stated for heaters in theory could also be applied to our LED lights for heat energy. They are also 100% efficient heaters under this logic - as those photons produced will eventually be transformed into a form of heat energy..... although the photons trapped via photosynthesis might have something to say aboot how long it takes that energy to be released.