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Newbie wants to Step-Up +5v to +12v

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xerocalibur

New Member
Hey,

I'm a complete newbie to electronics; I do know how to solder and I have hooked up some 12v lights inside my PC case.

I want to do a keyboard modification and have neon light string running through it, behind the keys. I have the keyboard, and the neon light string, etc., I just don't have the 12v needed to run the string.

I know I could hook up a 9v battery and hide it in the keyboard, with a switch, and it would most likely work -- however, the string would not be as bright as it could be.

I would like to know if there's any way to make a 5v to 12v stepup converter that is small enough to fit inside the keyboard?

I found these three links:

**broken link removed**

https://www.elexp.com/t_dc-dc.htm

and

**broken link removed**

but everything on those sites is greek to me, and I have no idea if I can attain any of those parts at a local Radioshack (which, I know, is horrible for electronics parts, but it's all I have locally)...

So! Any help would be GREATLY appreciated.

-Sincerely yours,
Xero

P.S. If it wouldn't be too troublesome, please tell/explain what it is in the circuit that connects to which, or simply state that, as again -- I am a complete newb and I don't know what those diagrams mean.
 
why not just use a "wall-wart" transformers. (those big rectangular guys that plug into a wall outlet with a small round connector on the other end). using a 9 volt wont last very long.
 
neon light string running through it

Not sure what your Neon String is, but I've never seen Neon bulbs that operate on 12 Volts. Are you sure there Neon?
 
Because the whole point behind doing something like this is to make it neat and clean -- having yet another cable coming from the keyboard won't suffice in that notion. I want to keep it all contained.

Also, that would require another outlet, which means one less outlet for PC/Printer/etc.
 
chemelec said:
neon light string running through it

Not sure what your Neon String is, but I've never seen Neon bulbs that operate on 12 Volts. Are you sure there Neon?

It's actually EL wire, sorry. Electroluminescant. And yes, there're neon tubes that run off of 12v automotive that can be adapted to run off a computer's 12v molex, but that's off the subject.

So yeah, 12v automotive EL Wire, which again, can be run off a molex -- but I want to keep it all neat and clean.
 
el wire does NOT operate at 12V. it's the inverter that requires 12V, wire operates at some 100-150VAC at frequencies 50-5000Hz.
**broken link removed**


good luck...
 
I'm assuming you are drawing the 5V from the keyboard's PS/2 port. Note that the PS/2 port does not support a lot of current. Over-drawing current may even spoil your motherboard. An alternative power source is recommended here.
 
They make some EL inverters that run off 5V.

But the point is this. You need significant power to run neon. Power requirements for EL is fairly small for small areas. You have somewhat limited power from a USB connector and a whole lot less from PS2. Converting 5v to 12v would mean that a 12v 100mA load would consume at least 240mA from a 5v source.

There is no really quick & easy solution. You'll need a "boost converter", or it may be called a "boost regulator". There are some ICs which can do it, they are a bit uncommon though.
 
Well seeing how most keyboards use 100mA, driving a neon on top of that would drive the ps/2 to overheat, blowing up some drop out regulators, possibly damaging the Vcore status.

USB can drive 500mA at 5 volts nominal some more but risky. I am not sure what currents are required to drive your neon.

But the only practical way which may sound to you off subject is integrate the use of the 12 volt supply off the computer.
 
I've never used any neons or EL. but the ccfl I ripped out from a spoilt scanner easily tipped the current meter of my bench supply at 500mA.
 
Why dont you rip out the keybords cable and get one whith 2 more wiers than the original cable,then conect one side to the keybord and the neon (thats what the 2 more wires are for)the other to the original keybord calbe and conect it to a wall-wart.So now you shod have a signle cable runing to the back of your PC

If you want to complicate thing a bit more insted of a wall-wart to power you Neon lamp use the computers 12V to run it.Yust conect it the same way you did your lamps

I wud also put an filter cap (1000-3000uF) where the 12V conects to the calbe(to get rid of interirences)

Checkmate maby it uses an big cuent on start up?To charge up caps or to provide the high strike voltege of the tube(i think my flourescent lap needs 700V to strike but then it can run on minimum 100V(its for 220V mains))
My agfa scaner has an 16V 900 mA wall-wart to power it(it proboly uses max 500-700mA) .
 
The current reading on my bench supply shows 500mA at steady-state, not transient, using the invertor provided with the scanner which I ran at 12V. Considering that the scanner still has to power a motor, I would say that the wallwart's current specifications is usually under-specified, and scanner manufacturers are merely exploiting this point to provide cheaper wallwarts.
I don't know about you, but I've encountered 2 dead walwarts belonging to perfectly working scanners. Maybe this explains it.
 
well a small wall-wart powering my spekers dyed and the spekers ware at normal volume (my new spekers have the power suply in them,so it a bit miore dificult to fix it)!

I didnt have that problrm whith my scaner but it gets warm (about 40 °C)

I wodnt recomend hundrets of volts (maby even AC) stremin around the keybord

I seen a computer
keybord that has transparent keys and they are lighted from behind like a keybord on your mobile phone
 
"Someone Electro"

do you read your posts before submitting?
 
Ha ha, it is kind of funny.

I hope you have a computer left to turn on. The way your posts look you must have been 4 times more drunk than me and drinking under the influence while operating a a keyboard :p .
 
Greek Translation

Ok. I checked your first website and I understand what you mean about greek. All it is telling you is how the chip works. If you click the image you see a schematic of just what the chip is. It is 3 stages as described, an oscillator, a power stage and an error detector that functions as your regulator to keep the output at 12v. If you don't understand the kind of explanation it is giving you are you sure you want to muck around in your computer to add a novelty item like this (just a personal observation). I'm sure the other 2 sites you listed are along the same line. Good luck.
 
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