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Functional Casemods?
attercoppe asks: "I'm looking for opinions and advice from Slashdot readers on a case mod idea. I'd like to install a second (small, low heat, no fan) power supply to run a single CD drive. The idea is to basically integrate a CD player into the case, allowing me to ditch my bookshelf stereo (yay convergence!). But I want to be able to use it without having the computer booted (to avoid waste heat and all the associated fan noise - PS, CPU, and two 4" fans). The question is, can I wire an existing drive, and maybe one of the supplemental fans, into both the existing and the new power supplies? Will one PS get feedback from the other through the drive? Do I need a switch to choose which PS to use? I know I won't be able to use the sound card... that's ok. No, I won't have a tuner for radio - that may come later. Tips, ideas, ridicule?"
...ridicule?
You've come to the right place.
-CowboyNick
This is just my guess but, I don't think you'll generate enough heat from one CD-ROM Drive to need to worry about getting a Fan Spinning, the Power supply fan should be more than enough.
Sounds cool though, you plan on just plugging the speakers into the CD-ROM's Headphone plug, or using amplified speakers hooked up to the audio out connector?
your First Post was DENIED! Ha ha ha!
As far as audio out goes, you can splice the audio out cable that runs out the back of the soundcard to whatever you are using to amplify the setup, it outputs a standard line-level signal, so it's perfectly usable, and will save you from having an unsightly cable running out the front from the headphone jack.
:)
You can get small, fanless power supplies that will give you 12v, you might want to check around hobby supply places, if you get lucky you might find one for pc components with a molex connector, but chances are your most likely find will be a non-pc power supply, which you can use just fine, you'll just need to make sure the voltage and current levels are the what the cd-rom expects, and probably splice an old molex connector to it to connect to the cd-rom properly.
Good luck in your utterly useless venture
I would expect such blatant racism on Fark, but on Slashdot? Mods please ban this asshole.
Connecting outputs of two power supplies directly is a sure way of blowing up one or the other. Think about it this way: one is outputting 5.00V, the other one is 5.02V. You connect them together and the 0.02V difference will have to be resolved. The wires have negligable resistance (let's say 0.01 Ohm), so you will have (I=U/R) current that is 0.02 V / 0.01 Ohm = 2 A ! Doing nothing than disspicating from both PSUs. In real life 5V +/- 5% will give you 0.5 V max difference, and the wires are not much, so it will actually be likely to dissipate much more than my example.
You can connect diodes from both PSUs, pointing towards the CD, but the diodes have a 0.7V drop...
Or you can just buy that MSI barebones system, that already has the functionality that you crave...
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i've seen an actually device that fits into a bay and does just what you want plus radio and *possibly mp3. it also had a nifty set of controls and a multiline lcd.
transmission_err
Wouldn't this be cheaper and easier?
"Freedom means freedom for everybody" -- Dick Cheney
I haven't seen a cd-rom drive that has a headphone plug or play/stop/ff/rw buttons in years. I'm not really sure i understand why they took that feature away, but it really was convenient as hell to be able to plug your headphones into the cd-drive and not have to run 'em around back to your soundcard or into one of your computer speakers. (anyone know why that plug went bye bye?)
[Fuck Beta]
o0t!
Just get an MSI mega pc.
You can turn on and off the computer and still use the home theater section independently.
Not that I recommend hacking your power supplies, but here is an idea.
If you are woried about having both Power Supplies configured to power a single device like a Hard Drive (so it runs when either ps is on) you could try putting diodes on the leads from each of the power supplies to the device. Its DC after all...
That way current will only travel in the intended direction, and not back into the switched off ps... Your power supplies may already have protection against this sort of reverse current flow.. Of course there will be a small voltage drop across the diodes, but this should not be a problem.
Oh, just make sure you use diodes rated for the load current and reverse voltages. ie dont use signal diodes for this application!
Why having 2 PSU to the CD? The second one (only for CD) will be able to always power it if the primary is only connected to th MB. Since the CD and MB talk to each other only through the IDE cable, and this cable is meant to convey signals (ie, no current), there shouldn't be any problem with the minimal different voltages both PSU will supply. Of course, that means having the second one always on if you want to use the CD at the same time than the computer.
Of course, if it all burns in giant flames, don't point me...
First, get an external CD-ROM drive. Get one that fits your needs and can function as a stand-alond CD player. I have a Panasonic PCMCIA one, which just happens to show up on the listing when I looked. If you want a single enclosure solution, you can build some sort of cradle for the portable CD drive to peek out of the top of your case via a hole. Be sure to leave enough area for the drive's door to open, but keep it snug enough to use weather stripping from your local hardware store to keep the dust or (ack!) liquids out. Plan this carefuly and do some research.
Now grab yourself some kind of amplifier or powered speakers (recommended). If you're really good, you got yourself a kit and added that to your custom case - advanced users only!
Just plug the headphone out of your CD drive into whatever you are using as an amplifier. Since you may want to use your computer's sound card for MP3s and such, get whatever kind of audio adapter you need to plug both the headphone from the CD drive and the sound card audio out into the amplifier/speakers. The ideal way to do this would be with a passive mixer which could lead to more case modding as well.
If you got a PCMCIA drive, then whatever computer you use should have the appropriate hardware if it's a laptop - make sure. USB may be better, but get whatever you like. This leaves it wide open for you to use any computer you wish.
The disadvantage of this idea is having three different things that want to be plugged into a wall. Don't go splicing electrical cables unless you have worked professionally as an electrician and can build out a transformer circuit.
Another disadvantage is that it could end up taking more space than you would like. That department's up to you. I don't have plans or anything, but I would probably make some kind of "flattish" enclosure with the motherboard to one side and the drives and else on the other. I don't think I would use any of the peripheral slots on the motherboard (all in one). You'll have to find a slim power supply, which may not be easy.
Just my 2 cents. Sounds like an interesting project. Good luck!
US Democracy:The best person for the job (among These pre-selected choices...)
There is only one input for power on the CD-Rom drive, how do you expect it to feedback into the other PSU?
3 373055/ if you have no idea what I mean by removing SCSI devices from the scsi tables.
/dev/sdb and remove it from the system"
To better answer your question, I have a Dual P2 running linux as a file server. It has 3 9 gig SCSI drives connected to it, but they are so damn huge (full height) that I had to bolt them all together with sheet metal and sit them outside the dual p2's case. Not to mention the huge amount of power they suck down, and the huge amount of heat and noise they generate. (You thought a 7200 RPM was loud. You should her some old 10 platter 4500's!)
Anyway.... the 3 SCSI drives are all powered off an old AT power supply. The Dual P2's run off an ATX. You can do this. There is nothing wrong with it. As long as you turn on the drives before the PSU running the motherboard, you can run as many PSU's as you can handle. In fact, I even have my linux box hooked up in such a way that as long as I umount the drives and remove them from the Linux SCSI tables, I can power down the drives independant of the CPU and power it up and re-add them when I want to use them.
see http://www.geocrawler.com/archives/3/58/2000/2/0/
Speaking of which, does anyone know how linux maps the devices by lun, SCSI ID, host etc to the device names like sda, sdb etc? It would make m job easier if I could say "get the ID:HOST:LUN etc for drive
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Sounds OK. a 12 volt wall wart of some type would do it. You could get one made for a notebook or one of the small 12 volt warts made for EPIA systems. But why not just build up a silent fanless EPIA system and leave it on all the time. You could do a lot more stuff and it'd be about as quiet as the drive by itself...
This sig kills fascists.
There's only been one product ever made that does everything you want: the Apple PowerCD.
/
http://www.applefritter.com/accessories/powercd
Too bad they don't make em anymore. They're really rare and expensive collector's items.
You can of course power an EPIA Mini-ITX from a normal ATX supply (and even in a normal ATX case). Of course it won't be super-quiet, but it will still use much less power than an Intel/AMD alternative... people who are more concerned by cost+power use than size+fan noise can still build a system for not too much money, making these great systems for 'off-the-grid' use.
The EPIAs are really nice systems ... quite amazing to see something so small just boot up, let alone run 'proper' programs! (Wonder when they'll go full-circle and print a keyboard straight on the board so you can use them early-80s-home-computer-stylee... :)
The floating-point on the current fanless boards isn't too speedy (main effect: ssh logins take a little longer than you'd expect, nothing that's a real problem though). The EPIA boards with processors with the newer 'Nehemiah' core with faster FPU and hardware pseudo-random number generator (and more pipeline stages, SSE, better cache) currently all have fans - would be nice to see a board based on the ESP7000 (fanless Nehemiah chip) sometime..
Heh heh, you could put the bookshelf unit... inside the case. And run the power cord out from the side. And have the speakers outside the case. Heh heh. And if it doesn't fit, disassemble it. And mount it sideways if you have to. I mean it, like, already has a power supply and drive unit and all. And, like, doesn't cost money. Which is good. Totally.
the easiest way I can see is having a converter from a 110 wall outlet to a 12 / 5 molex plug. then you can connect that to yer cd drive and bobs yer mothers brother. you can even put a Y connector on the molex to connect to yer other PSU so you can select the source. Now that you have power, just run a line off the bottom (get the specs and solder a line there (its not that hard)) and you can have the line run anywhere. I would take one of the front panels to the case and botch it to the front of the cd drive then solder another set of leads to the opening button (on the bottom (also not hard)) this way it is hidden and looks sleek. I have something similar in my case, but with only one PSU. I have a series of switches that allow me to turn on specific pieces of hardware or lights. its kinda kewl but i have to not forget to turn somethings on before others, or else I get quite the mess.
Anyway, have some luck with the project, and modding is about 2 things. Coming up with something new, and Voiding the Warrenty.
while(1) { fork(); };
Btw, your 2c sounds like my $20!!
See my journal, I write things there
Just take an old computer ps, build a box and slap the car stereo and ps into it.
One of the guys I worked with at Dell had this rig set up in the testing lab. Even had a set of speakers with wireless remote that would let him turn them up/down/off from across the lab.
You can even wire up a set of jacks and get a splitter allowing you to hook the computer speakers to the car stereo and the PC at the same time. If you get a set of car stereo speakers and mount them in the box and slap a handle on it, you've got instant portability.
I'm planning on doing this for my workbench in the garage. I'll likely just use a jigsaw and cut a slot out for the stereo and mount the speakers in the bench as well.
I would've done the same thing with a marine-grade boat stereo and speakers in the master bath, had our homebuilder allowed me to wire the house up.
Cruising the internet on my TI-99/4A @ a whopping 300 baud!
My existing computer doesn't have a case, you insensitive clod!
Use a second PSU (from whatever, Wall Wart, OEM, but probably a PC) and connect the Ground and +5V and/or +12V lines to the CD drive as needed (The label on the drive should say what it needs).
As you want to use the drive in IDE/SCSI mode as well you will need to connect the ground of your new PSU to the ground (not the case) of the PC. Simplest way is to get an unused powerconnector from each PSU and connect the black wires together.
Do not connect the other colours (for reasons explained above), but do connect the grounds, otherwise you stand a fair chance of burning out the IDE/SCSI cable.
Remember, voltages are relative to each other, 5V means nothing unless you have a common ground. Most PSUs have a floating ground level, so two different PSUs could have their ground potentials many tens of volts apart. This is not good. Hook the grounds together and they will harmlessly agree with each other.
Why spend a little money when you could spend a lot?
....
1) make the PC quieter -- replace it with a tiny Shuttle, go nuts with the mods at http://www.quietpcusa.com, store it behind baffles under your desk.
2) Get a Slimp3 hooked up to your existing bookshelf or to one of those super-tiny amplifiers. Some people even skip the external amplifier entirely and hook their Slimp3 up directly to powered speakers.
3) Rip and sell your CDs.
4)
5) In Soviet Russia, Natalie Portman gets all your profit -- but trust me, there will be enough of it to buy hot grits by the dumptruck load, and I think we can all guess where those grits are going to go.
"Nothing was broken, and it's been fixed." -- Jon Carroll
NewQ 3379 Platinum 4 Channel Enhancer, Equalizer and FM Radio, with a Remote and Vacuum Fluorescent Display!
Fits in a 5 1/4" drive bay too.
It only requires 12V power from a power supply, so you can hack that, and you can wire the analog output of a CD-ROM drive to the NewQ's Line-In. Have fun.
"I can't give you a brain, so I'll give you a diploma" - The Great Oz (blatently stolen sig)
I am not sure about the dimensions but a car cd player deck should expect 12 V, as long as your powersupply can provide enough watts. and then you have a built in 40x4 watt or so amplifier and all the controls not available on a cd-rom. You could even hook the preout into the sound card. I know it probably wouldnt work (power requirments) but if did that would be cool)
These folks make exactly what you are looking for... NewQ 3379. It can be powered by an external power supply or the internal power supply of the computer.
The MSI Mega PC is a barebones kit that has an inbuilt CD/media player that powers on/off seperately from the PC, complete with it's own home stereo style LCD display. All you need do is add your processor, RAM, etc. and have it working...
It occurred to me recently to wonder why no one (to my knowledge)ever brought out an audio cassette deck designed to fit in a 5.25" bay.
I see even classic Slashdot is now pretty much unusable on dial up anymore.