Remote Living > Lighting
Led master class Parts 1 thru 5
OperaHouse:
There are plenty of small buck converters on ebay for less than $2 shipped. There is a KSS version for even less than a buck. The one idea I would like you to consider is using a BOOST converter to increase LED string voltage to greater than the battery. most regulators have a sense voltage of 1.2 to 1.7 volts. If you string all the LED in series, you can have a sense resistor create that voltage at desired current with acceptable loss. That voltage can be fed directly into the sense pin of the chip.
Mary B:
I was thinking along the lines of dc to dc converters that are setup as led drivers with a constant current output. The last is something leds like for long term life.
georgec:
--- Quote from: OperaHouse on March 19, 2014, 08:32:04 AM ---There are plenty of small buck converters on ebay for less than $2 shipped. There is a KSS version for even less than a buck. The one idea I would like you to consider is using a BOOST converter to increase LED string voltage to greater than the battery. most regulators have a sense voltage of 1.2 to 1.7 volts. If you string all the LED in series, you can have a sense resistor create that voltage at desired current with acceptable loss. That voltage can be fed directly into the sense pin of the chip.
--- End quote ---
I am somewhat familiar with boost/buck converters at least I read into it once, I gathered from previous posts that higher voltage all in series would be better, but how could that be practical for the entire house, you would only have one light switch all on or all off plus the voltage would be pretty high,
maybe each fixture could have all LEDs in series say for the sake of conversation 18 of them which would demand something like 72 v DC, now again I am not very familiar with electronics, and if there is a boost converter available to step up from 24 to 72v would be worth considering to be used as a central source, I assume transmission losses decrease as voltage increases, obviously current regulation I learned is more important for long life.
I best check ebay than get an idea of what is available
OperaHouse:
Seventy volts is certainly taking my advice to extreme. Because they use the more common lower voltage parts most boost converter
on ebay are limited to about 35V. One I like is about $7 and can be found by searching 150W boost converter. It has a one inch toroid
that you can wind more turns of wire on. I have an 18W ceiling LED that requires about 43V to operate. About eight extra turns, a high
speed diode, and a 2200uF electrolytic form a 15V boost circuit. That is placed in series with the boost converter to get me to 45V. It
is unregulated, but the LED acts like a zener anyway. This is installed in the bathroom and only operates at about 6W. More it would be
just too bright. I just got a 32W Philips DLM that operates at about 60V. I will be building the same type of system for that.
When you say 17 LED in series aer you talking about small ones? I have given up buying anything other than the 10W LED modules.
joestue:
whatever happened to OP?
last active November 02, 2012, 12:17:32 AM
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