# i need help very badly

#### gg200

Apr 13, 2012
24
OK now that you appear to have two valid answers lets once again review what I had posted many post ago...

Now reading the above, you have the first two values needed, and should have an answer for me in regards to "........ Get this number, simple subtraction, got it? ........"

Post that answer and we move onto the next step...

I was going on but i got sleepy so i had to stop lol my meds made me sleepy, but now im back with the anwsers.

Ok lets begin.

The ps2 volts are DC 8.5 volts the source of volts, now minus the volts for the LED which is 3.5 volts.

Now, i get a number that = to 5. volts.

heres what you told me, i take that number 5. volts and i devided by the LED amps which i found out that is 20 amps = 0.25, something tells me that my next test will be finding out what the 0.25 means to my level of I Q, which is the world of electronics and the numbers with the dots and all those other ones in between.

What i am getting is this, we are deviding numbers backwords and not forword. so in the real world we take the big number and dvide that by the small. but in ohms law, the small number is first then the big number.

because the small number is the overall volts that the system is putting out on each part inside the pcb which is 5 volts.

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#### jackorocko

Apr 4, 2010
1,284
it is not 20 amps. it is 20milliamps the difference is quite a lot. About 3 decimal places!!!!!

20milliamps = 0.020 amps

Using ohms law, we can take the voltage drop across the resistor, which you said was 5V and divide that by the current we need through it which is 20mA. I did this for you below. Now you got your answer.
5V/0.020A = 250 Ohms.

edit: you can divide a small number by a big number. I don't know where you come up with some of the stuff you say, but who told you that in the real world you can only divide big numbers by small numbers? You should probably distance yourself from those oddities, they are not helping you.

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#### gg200

Apr 13, 2012
24
it is not 20 amps. it is 20milliamps the difference is quite a lot. About 3 decimal places!!!!!

20milliamps = 0.020 amps

if we can divide small numbers by big numbers then is this kind of deviding we are doing is in goups or a minus kind of deviding?

also when u say it is not 20 amps but 20MA and you say 3 decimal places difference, what kind of math is that and give me the name of it pls?

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#### jackorocko

Apr 4, 2010
1,284
it is not 20 amps. it is 20milliamps the difference is quite a lot. About 3 decimal places!!!!!

20milliamps = 0.020 amps

if we can divide small numbers by big numbers then is this kind of deviding we are doing is in goups or a minus kind of deviding?

also when u say it is not 20 amps but 20MA and you say 3 decimal places difference, what kind of math is that and give me the name of it pls?

are you for real? Get out your calculator. We know that 1000 milliamps = 1 Amp. So therefor 20 milliamps is 2 hundreths of 1 amp. or 0.020A. Do you not remember decimal place values, tenths, hundredths, thousandths, ten thousandths etc....

let's try this another way, you have 2 pennies, what is this value in dollars? Everybody understands money

#### gg200

Apr 13, 2012
24
yes i am for real im sorry if u feel that is odd, my schools never given me what i want to know and i get ignore in IEP meetings when i make these problems known.

they say special ed but its shxt and im a high level person and i cant even get the help i needed. so for you to ask me are u for real is a insult to me and to anyone else with this kind of problem

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#### jackorocko

Apr 4, 2010
1,284
yes i am for real im sorry if u feel that is odd, my schools never given me what i want to know and i get ignore in IEP meetings when i make these problems known.

they say special ed but its shxt and im a high level person and i cant even get the help i needed. so for you to ask me are u for real is a insult to me and to anyone else with this kind of problem

no one is insulting you(you are assuming way to much), but you are making it very hard for someone to try and help you because all you do is complain(not once have you really listened to anyone). I already gave you your answer. Go and fix the problem and let us know if it worked.

#### timothy48342

Nov 28, 2011
218
gg200 is for real.
To ask you if you are for real is an insult! I would take offense if someone said that to me. Let me see if I can help some.
(I hope I don't confuse things by stepping in.)

gg200, you said, "the only decimals I know is in money." So you know money. That's good, because this is similar.

The difference is that sometime people might say something like .5 and that is the same number as .50 The only differnece is that the "0" is missing. With money there are always 2 numbers to the right of the dot.(decimal point) When not working with money, we usually don't bother putting that "0" in there. That's why your batteries are labled 1.5V and not 1.50V. Also sometimes there is a reason to include extra numbers, like "1.603" That is 1 whole and 6 tenths and 0 hundredths and 3 thousanths. (Thousnaths are like small parts of pennies, but I think you get that now) If you see a number on your calculator like "1.6037735" you often don't need to pay any attention to anything after the first few numbers. Those other numbers represent something so small that they often don't matter. (They are tenthousants, hundrdthousants, millionths, and smaller and smaller)

You divided 5 Volts by 20 amps and got .25
That's like if you have $5 and divided it between 20 people and each person got a quarter. ($.25)

The only thing is it was supposed to be 20 milli-amps not 20 amps. (That's what jankorocko was saying about the 3 decimal places. Milli-amps are very differnet than amps, but only different is size, but still very different.)

20 milliapms is .02 amps. Milliamps are thousanths of amps, similar to pennies being hundrenths of dollars. Just type 20 on a calculator and divide by 1000 and you get .02 ( or 0.02 same thing)

So, 5 volts divided by .02 amps is 250 ohms. (That's where owms law comes in)

So if you have a 8.5V supply (8 and a half) and a 3.5V (3 and a half) volatge drop from the diode, leaving 5V (and no halves ), and you use a 250 ohm resistor then you will get 20mA (20 mA = .02 A) through the diode. Which I think is what you want.

-tim

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#### jackorocko

Apr 4, 2010
1,284
imagine if you had come here and acted with a little more humility and said something to this effect.

"I have this issue, i want to wire in an LED and need to know the value of the resistor. I can't do math very well because I have a disability and it won't matter to try and teach me. Can someone please help me with the answer?"

I will almost bet you would have had your answer 4 pages ago. Take this as a lesson and so won't the others in this thread. Have a good day, try not to be so angry next time.

edit: not to mention, I already gave him his answer 6 post ago. I was being helpful, or so I thought.

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#### gg200

Apr 13, 2012
24
no one is insulting you(you are assuming way to much), but you are making it very hard for someone to try and help you because all you do is complain(not once have you really listened to anyone). I already gave you your answer. Go and fix the problem and let us know if it worked.

i been doing that.

#### markm6164

Jan 22, 2012
118
@gg200. I have been reading this thread i find it clear you need to start at the very basics. I think it best you leave this thread for the moment and return after a little study. Here is a basic maths link to teach you about 10, 100 and 1000's and decimal places.

http://www.bbc.co.uk/schools/ks3bitesize/maths/number/decimals/revise4.shtml

Also is regards to your project either put it on the back burner for a while before you accidently damage something or hurt yourself or ask someone who is capible of doing it to either do it for you or help you.

#### gg200

Apr 13, 2012
24
everyone it looks like i have to take a braek from this becuase the stuff thats in this is stuff i was never teach at school. so i will take a break and study and hope and hope i get it, then i will return and share it to the people here.

to the good and bad people, i wish you the best. im not done with this but i will take i time out and come back to this post

thank you .

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