Help with power shifting

[xerowulf]

Hello! I am a relative electronics newb, and as such I need some help.

I want to put an Automotive EL (ElectroLuminescent) Cable through the back of a keyboard so that when it is on, it lights up the transparent keys from behind. I want to power it directly off the PS2 connector. However, we all know that the only power running to the Keyboard is +5V DC, and the EL Cable runs off the automotive standard's +12V DC...

Is there any way I can shift the power from +5VDC-> +12VDC?

Thanks in advance for any help possible, and I'm not afraid of soldering, so any solution whatsoever is acceptable.

 

[samcheetah]

how about using the MAX606/607 step-up converters

it would be able to step-up 5V to 12V

 

[Exo]

It can only handle up to 180mA load, so check how much current your EL cable requires.
also, it seems to be only available in SMD packages, wich might be a problem ?

 

[samcheetah]

It can only handle up to 180mA load, so check how much current your EL cable requires

yes i didnt consider that. xerowulf you should tell your current requirement. there are hundereds of possibilities for a 5V to 12V step-up switcher (search on google and see for yourself). maxim and national have quite elegant solutions for what u require. just a single chip and a couple of resistors and capacitors. see what amount of current u need and then look for the step-up converter.

 

[Exo]

thinking about it, you might have another problem...
The PS/2 keyboard interface is rated for 100mA max. So you shouldn't draw more current from your keyboards power supply then that.
As your keyboard itself will use somewhere between 10 and 40mA itself, there's only 60 left ...

 

[samcheetah]

i have a better idea. why dont u use 12V from the PSU of your PC. i have an old PSU which says that the yellow wire can provide 12V at 8A. see the sticker on your PSU for confirmation.

8A would be sufficient for EL tubes. u wouldnt want to worry about the current requirements and u wont have to build a step-up converter. just that u will have to run a wire from your case to your keyboard. that might look ugly. but hey, u have saved alot of bucks from building a step-up converter.

i hope that helps

 

[xerowulf]

x_X All your speak is greek to me...

Ok, well, for the time being I've decided to give up on this project until I can figure some other things out. I really don't want to run a wire from the Tower to the Keyboard; it takes away the cleanliness of it. I know they sell kits somewhere; maybe I'll look into one of those.

 

[Exo]

Even when using a kit you should check your current requirements. Like i said, the keyboard connecter is rated for 100mA max (the amount of 'power' you are allowed to take from it). If you take more from it you might blow a fuse inside your pc...

But the keyboard itself will off course use a part of those 100mA, typically around 20 - 40mA, so in the worst case there's only 60mA left...

If your project requires more current then this, then the only option is running an extra cable to your pc...

 

[Nigel Goodwin]

x_X All your speak is greek to me...

Ok, well, for the time being I've decided to give up on this project until I can figure some other things out. I really don't want to run a wire from the Tower to the Keyboard; it takes away the cleanliness of it. I know they sell kits somewhere; maybe I'll look into one of those.

I doubt a kit would use an EL panel, they are expensive and power hungry, the PS2 keyboard socket can't supply that kind of power.

 

[xerowulf]

See? Like this:

See, just like this:

**broken link removed**

Only bad thing is he's on vacation right now -_- however I think that is the route I am now going to pursue, instead of trying to figure out all the wiring and mA's and such. The keyboard is a no-name-brand one and didn't come with that information, and I don't spot any info on the EL wire packaging either. I'll probably wind out using the EL Wire I have already INSIDE my case; which means another fancy wiring project for me. I already have EL wire installed in the window I put in, and a neon tube... *shrugs* And I'm putting in some LEDs as well >.> So yeah. It's all cool; thank you all for your help, and when I get all of this wired (the tube and window EL Wire need to be rewired for a clean look - I first wired them when I was out of practice with the soldering iron o_0 so now they need to be redone)... When I get it all done I'll post pics.

Once again thanks for your help, and prompt responses.