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Posted: Thu Oct 16, 2003 11:51 am
by ShagMan
NiMH's definitely rock!
alkaline batteries are something like 600-800MAH.
Posted: Thu Oct 16, 2003 5:01 pm
by KrazyPlace
Snakeman wrote:Krazyplace , Young grasshopper has a question. If I use 4 AA battiers to get 6 volts how many MA Is that. Is there a way to see how many MA batteries produce. I want to do some flashlight project.
Snakeman...your not a grasshopper anymore! A mAh is a mA per hour. Theoretically a "D" Duracell battery will have 1.5V each and 15,000 mAh. The battery can discharge its power at various rates depending on the power consumption of the electronics. What that means is if you run 1 LED at 30mA then your battery will last 15000/30 = 500 hours (theoretically). More realistic is if you use 6 LEDs with 4 "AA" batteries (4x1.5V=6V, 3x2850mAh=11.4Ah) you should get 11.4Ah / (6x30mA) = 63.3 hours of run time. Not bad for a flashlight!
Try this link for a list of battery size vs mAh:
http://www.batteryspecialist.com/Mercha ... e=duracell
Posted: Thu Oct 16, 2003 5:18 pm
by Snakeman
That is what I was looking for. Thanks Krazyplace.
Posted: Thu Oct 16, 2003 5:26 pm
by KrazyPlace
How many LEDs are you going to use? There is a limit.
Posted: Thu Oct 16, 2003 5:33 pm
by KrazyPlace
KrazyPlace wrote:I just received 50 white LED for $13 shipped. The same company sells the blue ones too. I'll post the email address tonight after I get home. You guys ought to go in together...save some money. Radio shack has a 12.6V 450mA transformer for $7.99. The higher amperages (1A, 2A, 2.5A) are about the same price. They also have a 25.2V version that allows up to 6 LED in series....makes wiring easier.
Scott wrote:Your running 3 in series on two parallel circuits? Have you measured the voltage output of the transformer?
Voltage is not split when the line is split. What I mean is that if you have a 12.6V source and you have 10 parallel lines, then each line will have 12.6V available. Now you have to subtract "used" voltage if you place the LEDs in series, that is why SnakeMan used 3 LEDs (3.4Vx3=10.2V + resistor).
Snakeman wrote:no. Every thing that I read said it didn't matter how my circuits you run as long as you do not go over your MA output. I think the Leds I got run on about 25-30Ma my tranformer can handle up to 600ma.
SnakeMan was 100% right...the limiting factor is the amperage of the transformer. Most LED use between 10-30mA depending on how many volts you run through them. If you assume 30mA then a 450mA transformer will power upto 15 LEDs. A 2A transformer will power about 66 LEDs.
The email address is
cwithk@netvigator.com. I think they only sell 25, 50, 100 or more at a time, but email him and tell him what your looking for and ask for a price. The blue should be alittle more expensive, but not much.
Posted: Thu Oct 16, 2003 5:49 pm
by Snakeman
I'm not sure, what is the limit?
Posted: Thu Oct 16, 2003 5:54 pm
by KrazyPlace
I'm not sure! On that website it shows an approximate drain of 28mA for each battery, but that would be at the started mAh, therefore if you ran more the curve would be different, but I wouldn't think it would be much different. I think you can probably run twice the rating and still be OK. I think. Maybe. uuummmm? Not sure.
Posted: Thu Oct 23, 2003 1:06 pm
by Xster
Hey Jason, i was wondering if you received any of the LED's yet? Just wondering...and absolutely in no hurry.
John
Posted: Thu Oct 23, 2003 1:37 pm
by Snakeman
Haven't come in yet. It took a good week for my last ones to come in. I haven't checked the mail today so maybe they are in.
Posted: Fri Oct 24, 2003 7:02 pm
by Xster
Hey Jason, how many LED's came in today?
Posted: Fri Oct 24, 2003 7:05 pm
by Xster
Question answered, didn't see PM, duh.
Posted: Fri Oct 24, 2003 7:14 pm
by snoopdog
Yeah my popup killer never lets me see my PM's. Ack....
Posted: Fri Oct 24, 2003 11:57 pm
by Snakeman
Xster I just finished your lights. I hope they will not be too bright but if they are you can just put some duck tape over some of the leds. I'll try to get them to someone that can bring them to the meeting. Maybe you can try them out on Terrys tank so everyone can see how they look.
Posted: Sat Oct 25, 2003 12:44 am
by Xster
Thanks for everything Jason.
Did I mention that "YOU DA MAN!" But anyways, hopefully you can send it via someone tomorrow to the meeting. Looking forward to see what it looks like. No doubt I am going to try it out on Terry's tank.
Whoever brings it, gets a free frag!! (my choice)
Posted: Sat Oct 25, 2003 5:00 am
by tbmoore
I hope so..I want to see them. I need to wk on mine and might build some...Wish you could bring them yourself.