I have a 400-watt power supply and I am planning to adapt a molex connector to connect to a dingy little watch battery powered flashing LED so I can put it in my case... just a flashing light. I want the flashing light to be flashing whenever my computer is on, so I need to somehow wire the thing into my power supply. I know how to connect it to the power supply via a molex connector, but won't the power supply give it too much power, and then it will burn out? If there's a way you can think of turning it on with the watch batteries powering it instead of the computer's power supply, I would also be grateful. I know I'll need to know the current the LEDs in the light require, and put together a PCB, but I have no idea of what this thing requires. All I know is that it has two watch batteries in it.
well its pretty easy to work out... take a look at the total voltage produced by the two watch batteries, then if that is small i would think it would be around 3V you will need a resistor... please dont go connecting it straight away impatiently it will blow the LED i have done this many times what do you want to use it as? power LED?
Actually, I'm planning on using fiber-optics from the area of the LED's to different blades on my side-fan, I think that since it's a dual-LED flashing circuit that it would give a cool effect on the fan. I got it for free from my school years ago, it's meant to be worn on a shirt or something, but that looks pretty stupid I'm not good with electronics and wiring unless I have instructions, though, so things like "resistance" confuse me to no ends. I don't know how to work your resistance calculator ;/ Let me take the thing out of my case(I had it in there using it's built-in clip just to see what it would look like) and check the voltage the watch batteries are supplying... I can do that with a voltometer, right? Not sure how to work this thing to check the current, but I can figure it out. I've only used it to check for shorts in my circuits as of now >.>
Err, I messed around with our Radioshack multitester but couldn't figure out how to find the power the batteries gave off. It had all kinds of knobs and things, and I didn't know which one I needed for my reading. It had DC current, which is what the battery gives(right?) so, I tried that, but there were like 3 DC settings, 1k, 500, and 100 or something, and I had no idea what it meant by that, and each gave me a different reading.
If they are button batteries then i should say on the top (usually the shiney part) what voltage it is. If there are two batteries then just add the two voltages together and then you know what voltage it runs at .no need for a multimeter for that. btw if u want to check voltage with a multimeter you should turn the knob to the next highest voltage it could be. On mine one section is marked with a "V" (voltage). It goes in steps of 200m,2,20,200,1000. If you use one which is too low you would blow the fuse inside or break the whole thing if it is a cheapy one with no fuse.
Err, it says "AG(S, I think, maybe a 9 or a 3, though... smudged on both batteries ;/) PK Button Cell" on it.
Oh, I think they're 1 volt... http://www.blkfeather.com/productinfo.aspx?productid=66&categoryid=21&startpage=1 So that means they're 2 volts together, correct? Just making sure that the voltage increases with multiple batteries ;0
So the red wire from the molex is a 5 volt positive current, right? Then the negative current goes through the black wire? Just making sure I learn this correct.
http://www.bit-tech.net/article/68/ How do I find the mA rated current? I can't figure out what that would be ;/
im not quite sure about how to find the mA.Normally on button cells it would say what mA it provdes. Could u have a look?
is that each? normally when i use leds i just put in a resistor. i never worry about current and i havent fried any. I normally buy lights that you are spossed to put in cars which contain led/s. These have already been wired up with a resistor because car batteries run at 12v too. I shouldnt worry about the mA part. Just put in 0.14mA into the resistor calculator and it should be ok. (Dont sue me if its not )
