hahahahah I see how it is, but I see what your saying if no go its a small price to pay i'm trying to convert most of my lights over to ramp timers. after I did my first I really liked how it let me have viewable light for more than 8 hrs without having an algae farm.
now it says the LM317 is rated at 1.5amps does that mean if i don't wire the resistor to the middle pin it will limit at 1.5amps? if I wanted to make it simpler couldn't I just wire up 2 10 watt chips in parallel to it running them at 750ma? random thought.
second thought I had. since the groups of 4 will be wired in parallel could I just 1 bigger resister for the voltage drop? calculator I found recomended a 1ohm 8 watt for 4amps. so don't see any of that exact size but see 1 ohm 10 watt resisters, would this work to simplify the wiring if I just went with the resistor method?
Running parallel is problematic from 2 standpoints 1)variation in chips means variable output (amp dist. is "uneven") Some add current balancing circuit (basic transistors) but see no cost difference between that and a current regulator.
According to a calc if resistor is Zero Amp output is infinity..
or I assume power output of the ps.
It acts like it is not there..
1 Ohm = 1.25A out..
No, one needs a resistor.
Building 10 units is cheap and easy
Removing them just as easy.
you know it is kind of funny since the chips are already parallel/series arrays..
I don't think 1 large r Watt resistor on 2 parallel branches would be problematic and may work fine but you now get into resistence in parallel circuits..Prefer to just go to simple..
One "string", one resistor..just not complicated enough to do any other way..
simple I can do.............
As in standard diodes, the forward drop of LEDs decreases with increasing temperature. If one string gets significantly hotter than the other, its forward drop decreases and it begins to draw more current. This added dissipation heats it further, increasing its current and possibly leading to LED failure due to this thermal runaway. This situation requires that the voltage driving the strings is current regulated and is constant.