Dammit. I read 'AA' not 'AAA'. Here's the datasheet:
http://data.energizer.com/PDFs/E92.pdf
Expect less than 1/2 hour of operation.
PLEASE HELP ME!! running a 3.6V Led
- Thread starter ben hughes
- Start date
http://data.energizer.com/PDFs/E92.pdf
Expect less than 1/2 hour of operation.
i have also had this thought and i'm getting parts in for this as we speak to test it. just having so much trouble finding the right risitor :'( the ones on ebay arn't very clear
How long will it last? That's hard to say without more info on the LED. What kind of case is it in? How much heat can it dissipate? It might make a real kick stuff flash light before the batteries run down. I have flashlights that are just batteries and LEDs, no resistor. And I replace LEDs about once a year, maybe 100 hours of operation a minute at a time.
Maybe you might get dozens of hours out of the LED, changing batteries often.
i'm based in wakefield town center - wf1 3rq
thank you so much for your help.
i'm testing the led connected to the 6v power supply now and it's working perfectly and been going over 2hrs so far so good sign or a worst case situation lol
What is the current drawn from the 6V Supply ?
You have gotten away with this so far because your AAA batteries have enough internal resistance to limit the current and not pop the LED, as I mentioned in your other thread where you called your 4 batteries a "6V supply". If you check your battery pack voltage, you will see it well under 6V and dropping.
AA batteries would give you more battery capacity, but very well might pop your LED, or at least cause it to overheat. The closer you get to a "6V supply" (one that does not dip below 6 volts) the greater the risk of ruining your LED and possibly creating a safety hazard from the heat.
The solution would be 4 AA batteries to give good life, with a buck converter (a "switcher") to protect your LED by limiting the current. Check out the forums of guys modding their flashlights. That is pretty much exactly what you're doing.
AA batteries would give you more battery capacity, but very well might pop your LED, or at least cause it to overheat. The closer you get to a "6V supply" (one that does not dip below 6 volts) the greater the risk of ruining your LED and possibly creating a safety hazard from the heat.
The solution would be 4 AA batteries to give good life, with a buck converter (a "switcher") to protect your LED by limiting the current. Check out the forums of guys modding their flashlights. That is pretty much exactly what you're doing.
Many cheap flashlights rely on the cells internal resistance to limit the current - it doesn't do the LED any good. Trying that with 4 cell isn't advisable!
AAA cells won't last long supplying 700mA - I'd go for a step up switcher and use 2 cells with much higher capacity.
A basic blocking oscillator would supply narrow pulses that transfer a finite amount of energy, but you have to rig it by trial and error to see how bright you can get it without it getting hot.
There is a sort of current controlled hysteretic buck regulator floating about the web - I think there's a copy in the Talking Electronics LED book.
thank you for the help on this. I'm still testing the led but so far it's now run for 5Hrs and 48 mins the led is 100% A ok and the power has been constant and the LED hasn't dimmed or faulted in any way . it's extra good cause i'm running this on the cheapest batteries i could get from the pound shop so i'm very impressed. I admit the life span of the LED will drop but i'm confidant with the results and output so far.
I will look at the data sheet though thank you
thank you all so much for your advice it's been great.
I think the best way for me to go on this would be with 2 x aa's he voltage will be much closer to what the LED needs being 2.0 - 3.6v so should run much better without damaging the Led. plus 2 x aa's should last longer then 4 x aaa's (maybe only slightly though) but overall i think 2 x aa's are the way to go. including the heat management i have in place these led's should last way past the target goal of 3000hrs, and not have any possible danger
I think the best way for me to go on this would be with 2 x aa's he voltage will be much closer to what the LED needs being 2.0 - 3.6v so should run much better without damaging the Led. plus 2 x aa's should last longer then 4 x aaa's (maybe only slightly though) but overall i think 2 x aa's are the way to go. including the heat management i have in place these led's should last way past the target goal of 3000hrs, and not have any possible danger
