"Help!" for: Electronics

[King Ramna]

I do have a problem w/ my setup. I can only run 2 Led's. If I add another the lights will become dim. I have it running in series.

 

[thatdecade]

For brightest results, always run in parallel. One resister per LED.

 

[King Ramna]

I will give it a try, i hate using 2 9v for 4 led's. I can use the other for a fan or voice changer.

 

[thatdecade]

S73L105,
EL wire or sheet is ok. It is a little more complicated because it requires an inverter. 12V inverters are most common because of PC and Cars, but you can also find 3V or 4.5V, AAA or AA inverters. Using a lower voltage inverter is great because you don't need a large battery pack and the battery life is just as long.

Cheaper prices are on ebay. AA battery pack, 10 feet of white EL wire. You do have to wait about 1 month for shipping from Hong Kong
http://cgi.ebay.com/3m-EL-Wire-whit...560?pt=LH_DefaultDomain_0&hash=item27b58fbc90

I would think that EL sheet instead of wire would be better for a costume, this white EL sheet can be cut into 14 separate light sheets with a normal scissors. The inverter is already wired to illuminate 6 sheets. Just cut, then plug and play.
http://www.e-clec-tech.com/jupakita.html

I like the experimenter kits, because they come with full instructions on how to cut any shape sheet you want and wire things properly.

 

[thatdecade]

I will give it a try, i hate using 2 9v for 4 led's. I can use the other for a fan or voice changer.

Can connect all 4 LEDs to your 9V battery. A single 9V can power around 30 LEDs. I've done this, however each LED does need it's own resister, I used 500 ohm.

 

[King Ramna]

Have you ever messed around with Arduino circuit board stuff?

 

[tazzy]

alright again noob question I m try to make a notebook on everything so whenever I need I can go back and look at the list ok i looked at all kinds of LED but not sure how you figure what Resistor match that what not. so far I find is those kind Led

300 -
1000 -
1200 -
1300 -
1500 -
1600 -
2000 -
2400 -
2500 -
3000 -
3200 -
3500 -
4000 -
4500 -
4600 -
5000 -
5600 -
6000 -
7000 -
7500 -
8000 -
9000 -
10000 -
12000 -
13000 -
15000 -
18000 -

Or ya could teach me how to figure it out in easy way so I dont have to come back and bug ya and feel stupid Thank you so much again.

 

[MW Immortalking]

Have you ever messed around with Arduino circuit board stuff?

I'm about to

 

[MW Immortalking]

alright again noob question I m try to make a notebook on everything so whenever I need I can go back and look at the list ok i looked at all kinds of LED but not sure how you figure what Resistor match that what not. so far I find is those kind Led

300 -
1000 -
1200 -
1300 -
1500 -
1600 -
2000 -
2400 -
2500 -
3000 -
3200 -
3500 -
4000 -
4500 -
4600 -
5000 -
5600 -
6000 -
7000 -
7500 -
8000 -
9000 -
10000 -
12000 -
13000 -
15000 -
18000 -

Or ya could teach me how to figure it out in easy way so I dont have to come back and bug ya and feel stupid Thank you so much again.

Wait you need a resistor for each of those values? Or you can only find those values?

 

[ventrue]

Or ya could teach me how to figure it out in easy way so I dont have to come back and bug ya and feel stupid Thank you so much again.

Ohm's law is your friend.

Or you could just google yourself a resistor-for-LEDs-calculator and let it apply the law for you.

 

[thatdecade]

LED Resister Selection - HOW TO
Lots of words and no pictures, enjoy

Summary: Read the Current number on the LED packaging. Divide the voltage of the battery by the current number. That is the resistance you want.

Example 1:
Two AA batteries = 3V
LED needs a Current of 20mA

3/.02=150 ohm
150 is a common and easy to find resister value.

Example 2:
Three AAA batteries = 4.5V
LED needs a Current of 12mA

4.5/.012=375 ohm
375 is NOT a common and easy to find resister value. You will not find a 375 ohm resister. In this case choose the nearest value resister you can find. I like to choose on the low side, 330 ohm or 360 ohm are much more common and will work just as well.

Example 3:
One 9V battery = 9V
LED needs a Current of 18mA

9/.018=500 ohm
500 is a common and easy to find resister value. 470 or 510 will also work.


Already have a resister and want to know if it will fry your LED?
You should never increase the current number by more than 50% beyond what the LED is rated.

Example 4:
Four AA batteries = 6V
LED needs a Current of 20mA
Already have a 220 ohm resister.

6/220=0.027
That is 27mA, this is perfectly fine. A 300 ohm resister would be ideal (6/0.2=300), but your LED will be fine with the 220 ohm resister you already have.

Example 5:
One 9V battery = 9V
LED needs a Current of 20mA
Already have a 150 ohm resister.

9/150=0.06
That is 60mA. THREE TIMES MORE THAN THE LED CAN HANDLE. Use a larger resister to decrease the current. A 9V battery and a 150 ohm resister will destroy an LED in a very brief period of time.

Example 6:
Two AA batteries = 3V
LED needs a Current of 22mA
Already have a 500 ohm resister.

3/500=0.006
That is 6mA. This is way to little of current, use a smaller resister to increase the current. At 6mA even if the LED turns on, it will be very dim.

 

[tazzy]

ok I think i got it. but question now is lol how do you know how many volt is in those aaa and aa and d and c? of course 9v is easy since its 9 lol :/ and thank you so much for lesson

 

[MW Immortalking]

1.5V in Alkaline
1.2 in Ni-Mh and Ni-Cd

EDIT: YEAY 200th Post on my Bday!

 

[calladar]

this thread is awesome... sorry i have to say it. i have learned more about the led here than anywhere and discovered i did my leds wrong and surprised they are working at all. thank you thatdecade this has broken it down in a way i understand and can figure out. i never could wrap my feeble mind around the math.

 

[thatdecade]

calladar,
I am glad you found it useful.

MW Immortalking,
congrats on the 200th post! yay!!

ok I think i got it. but question now is lol how do you know how many volt is in those aaa and aa and d and c? of course 9v is easy since its 9 lol :/ and thank you so much for lesson

tazzy, the voltage can also be found printed on the battery itself. The voltage is stated as a number followed by a v.
Ex: 1.5V 1.2V 9V 12V

Once you know the individual battery voltages, just add them up for a battery pack. AA and AAA batteries are both 1.5V, have four of them? 6V

 

[tazzy]

this thread is awesome... sorry i have to say it. i have learned more about the led here than anywhere and discovered i did my leds wrong and surprised they are working at all. thank you thatdecade this has broken it down in a way i understand and can figure out. i never could wrap my feeble mind around the math.

I cant say this better than he did. I total agree with him. I have learned lot from this site than others. *KISS the 405th* I Love this site but more most those people give their time to teach us! Thank you soo much!!

Thank you thatdecade and MW Immortalking!!

And CONGRAT on your 200th!

 

[tazzy]

ahh alright I ll start look at the batterys I think I total got it Thank you soo much

 

[tazzy]

Ok other question whats best to stay in range for LED if you want to add on armor or helmet? without blind someone with just one led lol

 

[Waynehead]

I agree Thatdecade you FN rock man i will be looking at this thread alot now thanks to you.........lol you have to get kinda upset answering the same question over and over i had all the same questions but i simply read the thread and got all my answers and would like to say thanks man.....

WEEZY

 

[Late to the meeting]

How would one go about riging a speaker system in side his Helmet.....
p.s. I have an EOD helmet put to gether but without fiber glass or resin the the part that gives it a gamaske look would be a sick place to put the speakers