Ya it was volume and play and stuff but I am gping to use my big bulky one cause it workes better. Now I have a question does the drive only nead 5 or only nead 12 volt cause its kinda hard to supply it with both. Also is there a way to connect a lcd to the drive withought building a 30 doller controller.
normal cd drives use both 5 volt and 12 volt. but cd drives to notebooks only uses 5 volt. but you can just use this mini psu http://www.mini-itx.com/store/?c=10#p1802
I wish I could but 1. I nead it to be portable, I neaded to know so I could get the right amount of batteries. 2. It says not siutable for full size drives. Thanks anywho.
Ok I realy confused right now. Using bits calculator, to change 12 volts to 5 volts with resisters, it said I neaded a 140ohm resister. I put my multymeter on my power supply and the 12 volt line read 11.65. I then put the resister on and then it read 11.65. Ok so maybey the resister is messed up. Nope I tested it with a 510ohm resister and it read 11.65. I was starting to get confused so I stuck a 470kohm resister on and it read 11.13. WTF shouldnt it be a LOT lower. Am I doing something wrong.
how much current does your HD or CDrom consumes? For example, to power a 5V circuit using a 12V supply, a three-terminal voltage regulator is usually used. However, if you try to drop the voltage from 12V to 5V using only a resistor, then you need to calculate the power rating of the resistor as well as the resistance value Assume the current consumed is 100 mA (milliamps) in the following example. 7V must be dropped with the resistor. The resistance value of the resistor becomes 7V / 0.1A = 70(ohm). The consumption of electric power for this resistor becomes 0.1A x 0.1A x 70 ohm = 0.7W. Generally, it's safe to choose a resistor which has a power rating of about twice the power consumption needed.
I dont know is there an easy way to find out? Ya, I know most use a regulator but all I have got is my box of junk to use and I cant go through all of the little numbers on the regulators to see if they would work. It is much faster to go with resistors. Now that means (in the example) it would nead a 70 ohm resistor but if it is doubled a 140ohm . EDIT: My cd drive is a acer compact disk 40x cd drive, If that helps.
for a regular cdrom drive should be around 1.2A to 1.5A but look up the specification for your drive.
Ok so, 7v / 1.4a = 5ohm. So I nead a 5ohm resistor, then doubled 10ohm, right? Wouldnt that be black green black? If so why does the calcualtor say it neads to be green blue gold, is it acualy black green blue gold?
You need a 5 ohm resistor, i don't understand why you think you need to double it. A 4 band code for a 5 ohm 5% resistor would be green black gold gold BUT you can't have an E12 5 ohm resistor, so you would actually get a 4.7ohm, yellow purple gold gold, one. But you're gonna need a 10W resistor, which will have its value stamped on it And that resistor is gonna get hot.
This is funny how a small simple resistor is confusing me so. Ok so would these 10w resistors look like normal ones except with numbers instead of bands?
http://www.donberg.de/descript/1/1r55w.htm That's an idea of what a 10W wirewound resistor looks like. Personally, i would use a voltage regulator IC since you're unlikely to have a suitable resistor laying around anyway.
Ok, I got it wired up and all but now I dont want to keap taking out the batery then putting it back in(to charge), so I made a cable but then I thought it would be cool if I could charge it from usb. How would I get 12 volts(batteries) to charge off of 5(usb).
Well if you want to do that you'll need to use notebook drives or flash memory so that 12V power isn't needed.
i hope you dont think this is going to get very far... heres why: 1) using a resistor to get 5v from 12v is horribly inefficient, the hotter the resistor gets the more power is being dissipated as heat, and the shorter your 12v batts are going to last. pulling ~2a for a desktop CD drive will make a 5 ah battery last about 2.5 hours, and a 5ah battery is HUGE. if your using desktop parts and resistors for voltage drops, your going to get almost no battery life. 2) charging a 5ah 12v battery from USB would require a voltage tripler. when you triple voltage, you only get a third of current. USB can provide 500ma at 5v, therefore it can provide ~166ma (theoretical) at 15v. with inefficiencies present in any up-converter, you will be lucky to get 100ma. so at that rate, putting 5 amps back into the battery would take 50 hours. have fun with that even if you use a switching regulator to power the CD rom drive, your still going to need a huge battery, and another way to charge it, not USB. sorry to bust your bubble here, but its just not practical //jsd
Well I knew the usb was probibly not going to work, but with a 12 volt regulator and a 5 volt regulater shouldnt it last long? Darn what was that formula for calculating how long a battery lasts?
