| Author |
Message
|
| itstemo1 |
 Posted: Sun Mar 11, 2007 3:18 pm Post subject: I need help placing a switch on some LEDs |
 |
|
Forum Freshman
Joined: 10 Jun 2006
Posts: 88
|
Hello,
Okay so I am modding my computer case to have a switch to turn off all the lights that are attach to the fans.
I have 8 fans and in each fan there is 4 LEDs (32 LEDs). The problem is that I am scare of burn up the LEDs and because I have no general idea what voltage they are I am in a debate about doing it.
Also I needed advice in how should I set it up. I was thinking about having a serial circuit on each fan and then have a parallel circuit on to attach each fan. The problem is that I am not very keen about the difference between Serial and Parallel.
Also just the fans are made by ASPIRE.
_________________
If there was no religion in which Gods would be the main issue, war would now be a fight agaist the best scientific theory. |
|
| Back to top |
|
 |
| Guest |
| Posted: Sun Mar 11, 2007 3:37 pm Post subject: |
|
|
|
Led's each require a curent limiting resistor, usually if multiple led's all operate together they are wired in series with a single resistor.
Now series and parallel,
Tak a batterey and place a bulb directly across it's terminals, next wire another bulb directly to the battery contacts, and a third etc these are wired in parallel, remove one bulb and the others remain lit.
Now imagine a a single wire placed in a circle so that it's two ends are connected. - Cut the wire and place each end onto the two contactcts of the bulb, cut the wire in another place and attach the two ends to another bulb, then a third etc - this is wired in series (cut the wire in another place and join a battery into the circuit). disconnect one lamp and all the lamps will go out.
For your problem, how many wires are there going to each fan? if it is two then unless you take it to pieces you will only be able to turn the fan and leds off together. IF there are three or more wires then you need to disconnect them one at a time to see which one(s) are for the LEDs. |
|
| Back to top |
|
|
| itstemo1 |
| Posted: Sun Mar 11, 2007 3:50 pm Post subject: |
|
|
Forum Freshman
Joined: 10 Jun 2006
Posts: 88
|
Okay... So this is how it looks...
Each Fan has a LED and I can remove the two wires (Possitive and Negative of course).
My plan was to skip the resistor by dividing the voltage using Serial or was it Parallel between four LEDS in each fan.
I think I might just make a sketch of what it should look.
_________________
If there was no religion in which Gods would be the main issue, war would now be a fight agaist the best scientific theory. |
|
| Back to top |
|
|
| itstemo1 |
| Posted: Sun Mar 11, 2007 4:00 pm Post subject: |
|
|
Forum Freshman
Joined: 10 Jun 2006
Posts: 88
|
What about this... the power source is 12v DC
_________________
If there was no religion in which Gods would be the main issue, war would now be a fight agaist the best scientific theory. |
|
| Back to top |
|
|
| Guest |
| Posted: Sun Mar 11, 2007 4:14 pm Post subject: |
|
|
|
| You'll find none of them will light in that congufration, All diodes only conduct in one direction - Leds (depending on color) will need from 1.8 to 4.0 volts each, so I reckon it would be best to keep them in pairs. As you have drawn the diodes the Positive (from the battery or supply MUST be connected to the left hand side of the diode, (or each pair) The right hands side of Each pair MUST go through a resistor to the negative side of the battery. - Leaving out the resistor will destroy the LED - No question of it. Generally Red/Green/Yellow Leds require about 2 volts each whereas White/blue diodes require about 3-4volts. |
|
| Back to top |
|
|
| itstemo1 |
| Posted: Sun Mar 11, 2007 4:18 pm Post subject: |
|
|
Forum Freshman
Joined: 10 Jun 2006
Posts: 88
|
Well I think it is white... or better UV...
anyways... is there any way you can draw me a basic sketch of how it should be?
_________________
If there was no religion in which Gods would be the main issue, war would now be a fight agaist the best scientific theory. |
|
| Back to top |
|
|
| Guest |
| Posted: Sun Mar 11, 2007 4:21 pm Post subject: |
|
|
|
as you have shown the four pairs of diodes, just connect all the left hand sides together and then to the battery positive, with each right hand side going through a resistor, the other sides of the four resistors then going to the negative side of the battery, use 470ohm resistors.
THen you redraw it and I'll comment again.. |
|
| Back to top |
|
|
| itstemo1 |
| Posted: Mon Mar 12, 2007 12:04 pm Post subject: |
|
|
Forum Freshman
Joined: 10 Jun 2006
Posts: 88
|
Okay... So I kind-off got you instruction... well not really
so this new Circuit is labeled. Also I could add another 12volt supply if needed... like if one 12vold can't turn all 32 LEDs.
Direct Link to picture (in which it look better)
http://img.photobucket.com/albums/v371/itstemo1/led.png
Click on the image to view it at its original size
_________________
If there was no religion in which Gods would be the main issue, war would now be a fight agaist the best scientific theory. |
|
| Back to top |
|
|
| Guest |
| Posted: Mon Mar 12, 2007 12:18 pm Post subject: |
|
|
|
| Firstly you have shown the supply wire going from left to right, down and then back, which is shorting out the battery, so you need to 'snip it' at the right hand side. Secondly when you do this the top diodes will work but the bottom ones are all the wrong way round. - the switch should be connected to one side of the battery with the other to each string of LED's. |
|
| Back to top |
|
|
| itstemo1 |
| Posted: Mon Mar 12, 2007 12:22 pm Post subject: |
|
|
Forum Freshman
Joined: 10 Jun 2006
Posts: 88
|
Oh okay... I think I got it... I will make another one in about 20 more minutes... Got to do some HW
_________________
If there was no religion in which Gods would be the main issue, war would now be a fight agaist the best scientific theory. |
|
| Back to top |
|
|
| Guest |
| Posted: Mon Mar 12, 2007 12:23 pm Post subject: |
|
|
|
HouseWork eh? - good lad!  |
|
| Back to top |
|
|
| itstemo1 |
| Posted: Mon Mar 12, 2007 1:28 pm Post subject: |
|
|
Forum Freshman
Joined: 10 Jun 2006
Posts: 88
|
No actually Homework that was due at 4 (5GTM)
So what do you think about this?
http://img.photobucket.com/albums/v371/itstemo1/Lednew.png
Click on the image to view it at its original size
_________________
If there was no religion in which Gods would be the main issue, war would now be a fight agaist the best scientific theory. |
|
| Back to top |
|
|
| Guest |
| Posted: Mon Mar 12, 2007 2:15 pm Post subject: |
|
|
|
| That will work just fine, you may have to adjust the the resistor value, without the spec for the LED's (ie voltage and current) I cannot say, the value I have given you is on the conservative side, all the leds should light, with reasonable intensity. |
|
| Back to top |
|
|
| itstemo1 |
| Posted: Mon Mar 12, 2007 4:14 pm Post subject: |
|
|
Forum Freshman
Joined: 10 Jun 2006
Posts: 88
|
|
| Back to top |
|
|
| MacGyver1968 |
| Posted: Tue Mar 13, 2007 4:30 pm Post subject: |
|
|
Forum Bachelors Degree
Joined: 11 Aug 2006
Posts: 498
Location: Dallas, Texas
|
A potentiometer is just a variable resistor. The outside pins, (1&3) connect to the ends of the resistor. Pin 2 connects to the variable "slide" that moves up and down the resistor. So you would need to use 1&2, or 2&3. It's also a good idea to throw a small fixed resistor in series with it, so if you crank it all the way down to no resistance, you don't burn up the leds.
_________________
-Mac
..If it ain't broke...then you ain't tryin' hard enough.
http://www.myspace.com/macgyver1968 |
|
| Back to top |
|
|
|
|
