is this wire good for my purpose?

[wayne]

right now im trying to use wire for two things... to extend the 12v power needed for a dual CCFL... and also for extending 4 LEDs

i am using this inside my network box... my network box is really just a milkcrate which i have modded to fit a cable modem, router, wireless router, splitters, and switch and a lot of cabling

im running this from a 12v transformer plugged into a household outlet... to keep the wires neat, i thought about using phone line wires (RJ-11)... would it be good to supply the 12v needed for the dual CCFL?...i know its good enough the LEDs right?, but i dont know about the 12v... the reason i chose RJ-11 wires instead of regular wires is because i think this is going to be easier to hide and neater to organize

[SarverSystems]

Too thin. Even the LEDs might be just a bit too much depending on what LEDs you have there.

Cat5 might be a better choice, but you're still not really using the right wire. You're trying to use data wire for electrical purposes.

[Jake]

Too thin. Even the LEDs might be just a bit too much depending on what LEDs you have there.

Cat5 might be a better choice, but you're still not really using the right wire. You're trying to use data wire for electrical purposes.


Man just spring the $3 or so for a spool of 18-22 gauge primary wire.

[OKANG]

If you're wanting to make wire management easier without buying additional wire, use some solid-core Cat5. I've used it several times for the very same reason and it works fine. It's only about 24 guage, but that's enough to power most case accessories. I even made a pair of speaker cables out of Cat5 (fingers still sore - http://www.venhaus1.com/diycatfivecables.html).

[wayne]

Man just spring the $3 or so for a spool of 18-22 gauge primary wire.
i chose the RJ-11 wire cus its a simple idea to keep it organized and stuff but i guess ill just get a spool of 18 gauge or something, i dunno that much tho

whats primary wire?

and also, where can i get it?

[wayne]

another quetsion

how much resistance do i need to drop 17v down to 12v?

i dont know how much current ill be using but the CCFL says 5mA and im probably using 4 LEDs

im sure the CCFL says 5mA, is it really that lil?... im guessing if it isnt, its just a typo or something

i want to know the resistance because ive checked online resistance calculators and came up with really low numbers like 6-12 ohms depending on how much current i put in

help help help, thanks

[delbert]

The CCFL's probably need more (bigger), but I think the LEDs would run off even smaller gauge wire.

[wayne]

cmon cmon, i needa kno this asap pleasee??

i need to know how much resistance is necessary to drop 17v down to 12v and for current, im not too sure but the adapter/transformer thing says 500mA and i need it to supply enough for a CCFL and possibly 4 LEDs

can someone pleasee help me please?

thanks :)

[SarverSystems]

You need to know the current drop to calculate the resistance needed.

If it were me, I'd go to Radio SHack and buy a 12V convertor, or possibly use the 17V as it is.

[Jake]

Where are you getting 17v from? (just wondering)

[NewBlackDak]

Where are you getting 17v from? (just wondering)
Wondering this myself aswell

[SarverSystems]

cmon cmon, i needa kno this asap pleasee??

i need to know how much resistance is necessary to drop 17v down to 12v and for current, im not too sure but the adapter/transformer thing says 500mA and i need it to supply enough for a CCFL and possibly 4 LEDs

can someone pleasee help me please?

thanks :)

Read it again.

[wayne]

are you saying feed 17v to a 12v CCFL?, isnt that kinda too much?

i found 17v from an adapter in my scrap box... it really says 9v but that reading is wayy off because i tested it with a multi-meter and found the voltage to be 17v instead of the 9v... so i decided since its really useless to me, to take it apart and use it as a powersupply for the CCFLs...

i dont know exactly what you mean by the current drop but the transformer label says its current is 500mA and my CCFL box requires 5mA... (kinda unsure about 5mA, seems too little, so if it is, im guessing its a typo on the box...sunbeam brand btw)

i havnt yet made up my mind whether or not to add the LEDs... the LEDs are not a big problem for me, for now i would like to just get the power to the right voltage for the CCFLs first

thanks

[wayne]

another question... ive calculated with the resistance calculator from bit-tech, that i need approx i think, 940ohms to drop 17v down to 12v... i have a lot of 470ohms resistors... should it work if i wire two resistors parallel to get 940ohms?.. ive tried but it doesnt seem to make a difference

thanks

[Teancum]

Yes, you can put two 470 Ohm resistors in series to get 940 ohms, but you'll probably be pulling enough current through them to fry them. Power = RI^2

[wayne]

Yes, you can put two 470 Ohm resistors in series to get 940 ohms, but you'll probably be pulling enough current through them to fry them. Power = RI^2
what do you mean?

i tried it and it still shows 17v

and on a side note, where can i buy a 12v converter besides radio shack?

[OKANG]

what do you mean?

i tried it and it still shows 17v

and on a side note, where can i buy a 12v converter besides radio shack?You can get them on ebay easily, and for a good price if you look hard enough.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=11168&item=6715920280&rd=1

That one is 48W and should power any accessory you're likely to use. Radio Shack is a ripoff. They'd probably charge $40-50 for something like that.

[wayne]

thanks for the link

i am proud to announce i have made progress!!!!

i found a 15v adapter... so i just hooked up as many resistors as needed to drop it down to 12v... turns out, i used 16 resistors of 470ohms each... does that sound reasonable to u guys??... btw, the adapter, 15v and only 350mA

as of now, im working on a fixture to hold 16 resistors... i need some comments and constructive criticism please

thanks guys :D

[zandor]

Umm... actually no. The voltage seen by the CCFL will be V * (R(resistors)/R(CCFL)). Also, unless you're using appropriately rated power resistors for this you may end up cooking the resistors, but with 7520 ohms of resistance that won't be happening in your case. 17V/7520 ohms = .0022 amps for a total power dissapation of .000087W. Your CCFL isn't going to light up on that. Unless you know the exact internal resistance of the CCFL, you really need a 12V supply. PSUs don't use a stack of resistors to generate thier output voltages. They use a more complex circuit, and I don't understand how it works as I didn't go that far in electronics classes. (this stuff is all from basic physics, actually)

[OKANG]

This topic really belongs in the Electronics section. I'm sure you'd get a better response there.

[Rondu]

Wayne, the adaptor (9V, 500mA) you were using is not regulated so will only give you 9V when you draw full rated load 500mA. When unloaded, the output voltage rises that is why you are getting a reading of 17V. It is quite likely that the CCFL will work fine if you just connect it to this supply, try it, it wont hurt anything.

[wayne]

Wayne, the adaptor (9V, 500mA) you were using is not regulated so will only give you 9V when you draw full rated load 500mA. When unloaded, the output voltage rises that is why you are getting a reading of 17V. It is quite likely that the CCFL will work fine if you just connect it to this supply, try it, it wont hurt anything.
so regulated means that when it says 9v, it will supply 9v even under load?

so unloaded makes the voltage go up?... i never heard of that... can someone verify this for me?... i just need a couple people to agree unloaded makes the voltage go up and ill try it

what do you mean it wont hurt anything... it says 17v and im hooking it up to a 12 v, i think it should fry

now im REALLY confusedd :confused: HELP!!!

[wayne]

This topic really belongs in the Electronics section. I'm sure you'd get a better response there.
if so, then mods, can u move this for me?, thanks

[SarverSystems]

so unloaded makes the voltage go up?... i never heard of that... can someone verify this for me?... i just need a couple people to agree unloaded makes the voltage go up and ill try it

what do you mean it wont hurt anything... it says 17v and im hooking it up to a 12 v, i think it should fry

now im REALLY confusedd :confused: HELP!!!

I can verify that unregulated power supplies are exactly that...unregular. Ha ha ha. Yeah, he's right though. The voltage will fluctuate depending on the load. Just make sure the invertors and lamps are plugged in BEFORE plugging it into the wall. That way the voltage won't be 17V when you hook em up, since there will already be a load on it.

Not only that, but I'd be willing to be the invertor will work just fine on 17V anyways, without any resistors.

[wayne]

so unloaded makes the voltage go up?... i never heard of that... can someone verify this for me?... i just need a couple people to agree unloaded makes the voltage go up and ill try it

what do you mean it wont hurt anything... it says 17v and im hooking it up to a 12 v, i think it should fry

now im REALLY confusedd :confused: HELP!!!

I can verify that unregulated power supplies are exactly that...unregular. Ha ha ha. Yeah, he's right though. The voltage will fluctuate depending on the load. Just make sure the invertors and lamps are plugged in BEFORE plugging it into the wall. That way the voltage won't be 17V when you hook em up, since there will already be a load on it.

Not only that, but I'd be willing to be the invertor will work just fine on 17V anyways, without any resistors.
alright, thanks... i ll try that wheni have time which is probably tomorow after school

[ocphangaz]

LM78M12

find for this regulator chip

http://www.national.com/VCatalog/view.cgi?command=sumEq&attr1=Bpn%3BLM78M12&attr2=0&q=25&m0=Category&i=PNumber&s1=PNumber%2F%2F1&s0=InputMax+Voltage%2F%2F1&a3=InputMin+Voltage%2F%2Fv%3A8&a1=SubCategory%2F%2Fv%3A8&a0=Category%2F%2Fv%3A8&s=943824319742&a2=InputMax+Voltage%2F%2Fv%3A8&a5=Output+Voltage%2F%2Fv%3A8&t=0&m2=Bpn&m1=SubCategory&c1=e%3A0%2F%2FSubCategory%2F%2F%3Aeq%2F%2FLinear+Regulators+-+Standard%2FNPN%3APositive+Voltage+-+Fixed&c0=e%3A0%2F%2FCategory%2F%2F%3Aeq%2F%2FAnalog+-+Regulators&a4=Output+Current%2F%2Fv%3A8&as=0&render=1&c=&domains=PNumber

[wayne]

i put a resistor on the 17v (as a load) and it seems to still show the same voltage

what do you mean the inverter on 17v wont have a problem... wouldnt it burn out?, if not, how?

[OKANG]

Good grief. Why make something difficult if it doesn't have to be? Buy a 12V adapter and be done with it.

[wayne]

Good grief. Why make something difficult if it doesn't have to be? Buy a 12V adapter and be done with it.
i dunno where to buy it... i usually buy everything i need online but right now my dads credit card is screwy so we gotta wait for the expiration thingy to be over.... also, the other only place i know to buy electrical stuff is radio shack and thats a total ripoff

i hear theres this new electronic shop opened near me, i might check it out over the weekend or something

the only reason i wanted to change the voltage in those adapters is because i have no use for them so i dint care if i changed the voltage as long as i dont need to run out and buy a new one

[wayne]

when my dads credit card clears up, i think i should get this

cheap and already prepared for me

http://xoxide.com/miposunocone.html

what do u guys think of that?... it says 1000milliamps... thats enough for dual CCFLs right?

[MONST3R]

everyone took the good stuff :(

[Format _C:]

Its regulated and enough for dual CCFL
http://www.bgmicro.com/prodinfo.asp?sid=0935127314814815678750255&prodid=PWR1150

[wayne]

alright, i tried using the 9v one that shows up at 17v under no load... it works fine... ive dedicated all day of election day to finishing this mod... did a LOT of progress..

it works under load but i dont know if it cuts its lifetime tho

ive hooked up sunbeam dual blue CCFLs and two green coolermaster fans and 4 LEDs... they all seem to work great

i ended up buying bellwire anyways, 22 gauge or 20, i dont remember but it worked REALLY well and was a lot easier to solder cus it was solid copper

just fyi, everything works out great... ill be finishing it all in maybe one or two days and taking pics over the weekend... then ill start a new thread for that but ill put a link in this one

thanks for all ur help guys

:D