Regulators, should they get warm?
- Thread starter Pitto
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wakibaki
Newly Enlightened
Warm is cool.
w
w
Qoose
Enlightened
We have an oxymoron!
Yenster
Newly Enlightened
They will get warm due to inefficiencies. I don't know of any regualtor/driver circuit that operates at 100% efficiency...they will typically range from 90% to 50%...so some energy is dissapated in the regulator...which means they will get warm.
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great. just what i was hoping.
i am running 2 p4's in parrellel off 1 regulator.
https://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=2982
with an imput voltage of 9.6v.
typically this will be dropped to 9v if i use AA's or 7.2V if i use AA NMH 2500ah rechargeable.
G
i am running 2 p4's in parrellel off 1 regulator.
https://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=2982
with an imput voltage of 9.6v.
typically this will be dropped to 9v if i use AA's or 7.2V if i use AA NMH 2500ah rechargeable.
G
Yenster
Newly Enlightened
Pitto,
You may be experiencing low efficiency due to the large voltage drop from your input of 9.6V down to the 3.7V of those two LEDs when running in parrallel. And also, each LED would only get about 375mA. That regulator is designed so that you can run those two LEDs in series and drive each LED at 750mA, so long as you have that 9.6V input. You should then see better efficiency and less heat in the regulator...and much brighter light.
You may be experiencing low efficiency due to the large voltage drop from your input of 9.6V down to the 3.7V of those two LEDs when running in parrallel. And also, each LED would only get about 375mA. That regulator is designed so that you can run those two LEDs in series and drive each LED at 750mA, so long as you have that 9.6V input. You should then see better efficiency and less heat in the regulator...and much brighter light.
Illum
Flashaholic
YEAH NEVERMIND, I KINDA WALKED IN CIRCLES ON THAT ONE 
I wanted to remind that any circuit creates heat, like the friction or the impedance of forcing a large amount of water through a series of little pipes....but thats basically repeating the "inefficiency" part over again
I wanted to remind that any circuit creates heat, like the friction or the impedance of forcing a large amount of water through a series of little pipes....but thats basically repeating the "inefficiency" part over again
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Yenster
Newly Enlightened
Illum, I'm not sure what you're saying here. I was discussing the efficiency aspect of the regulator. Are you talking about the LED efficiency? Also, I'm ignoring the efficiency of the wires leading to, and from, the regulator/driver circuit since it's pretty small in comparison.
Illum
Flashaholic
I just realized that the heat created from wires may be negligible in comparison...and no I wasn't responding to your post
Yenster
Newly Enlightened
I just realized that the heat created from wires may be negligible in comparison...and no I wasn't responding to your post
OK...cool. Thanks.
Heres the wierd thing, i had rigged it up so the leds were in series, and only one led lit up
:duh2: so i re rigged it up so that both leds are rigged in parrellel and both leds lit up? oo:dont ask me how, i thought when rigged in series, its either all on or all off, but it wasnt the case.
i am all new to Led's and regulators, the originals were burnt out when i wired them in series the first time, i am using drop in modules.
thanks for all the feedback so far.
G
Yenster
Newly Enlightened
Heres the wierd thing, i had rigged it up so the leds were in series, and only one led lit up
dont ask me how, i thought when rigged in series, its either all on or all off, but it wasnt the case.
i am all new to Led's and regulators, the originals were burnt out when i wired them in series the first time, i am using drop in modules.
thanks for all the feedback so far.
G
Hmmm.....
Your wiring should go from the +driver to +LED1. Then from -LED1 to +LED2. Then from -LED2 to -driver.
In the above wiring, which LED lite up? If it was LED1, then you've got a grounding issue in LED1...which means LED2 wouldn't get any power.
If it was LED2, then I really don't have any idea how that can be.
wakibaki
Newly Enlightened
THe only way you can light one LED of 2 in series is if you got a short across one LED. Think about it.
w
oh, and you wanna be careful who you call a oxymoron, you simile.
w
oh, and you wanna be careful who you call a oxymoron, you simile.
Yenster
Newly Enlightened
I'm thinking it has to be LED1 that lights up. Cause I don't see how LED2 could light up if LED1 doesn't...no matter how it's shorted.
Illum
Flashaholic
could it be shorting through the heatsink assuming both LEDs are mounted on something conductive?
LED1 LED2
+----|>|----|>|---+
wakibaki
Newly Enlightened
There are no other topologies which could be conceivably described as '2 LEDs in series and only one lights up'. And no. Either LED can be dark.
w
Sometimes I wonder why the world is going to Hell in a handcart. Sometimes I'm absolutely sure I know why.
Yenster
Newly Enlightened
There are no other topologies which could be conceivably described as '2 LEDs in series and only one lights up'. And no. Either LED can be dark.
w
Sometimes I wonder why the world is going to Hell in a handcart. Sometimes I'm absolutely sure I know why.
Wakibaki, I was trying to be rational and believe that Pitto was trying to wire these LEDs in series. Like I wrote earlier, if Pitto had wired according to what I described, then the only possibility would be a grounding issue and only LED2 can be dark. I'm thinking either Pitto will discover the grounding issue, or discover the wiring mistake.
Yenster
Newly Enlightened
Right, that's what I'm suspecting, that there's is a grounding issue and that's why I believe it's only LED2 that can be dark.
well thats pretty much covered it all.
i will pull it all apart tonight and check everything, if its a grounding problem with led1, i will re wire it so led1 becomes led2 and then both should light up.
i will keep you posted, thanks for the info
G
