Date: Tuesday, August 26th, 2003, 05:56
Category: News, PowerBook 15-Inch
Want the sex appeal of a backlit keyboard but don’t have the cash for a new 17″ PowerBook G4? Russ White from
Small Dog Electronics walks us through the process of installing backlighting on other Apple portables.
Want the sex appeal of a backlit keyboard but don’t have the cash for a new 17″ PowerBook G4? Russ White from Small Dog Electronics walks us through the process of installing backlighting on other Apple portables.
There has to be a way to get a backlit keyboard into a TiBook or iBook.
Ironically, when Steve Jobs announced the backlit keyboard feature on the 17 inch, I had a working prototype of a backlit keyboard for my iBook, the actual backlighting was working at 100%. The hard part was finding a way to power it. I wasn’t very pleased to see that Apple had beat me to a workable backlit keyboard, but it was cool to see one actually work.
Admittedly, Apple used different technology than I did 😉
Apple uses Fiber-Optic technology to backlight the keyboard (I haven’t taken a 17 inch apart yet, so I don’t know the specifics of it). Whereas my design uses Electro-Luminescent (EL) sheeting, the same type of material used in the backlight for Timex Indiglo watches.
The advantage of EL is that it generates a uniform light over its entire surface. The sheet itself generates almost no heat, and the sheet is about the thickness of some heavy paper (card stock), so it can fit behind the keyboard without any need to rework the case or keyboard.
The drawback to EL is that it needs a rather bulky inverter assembly to power it. The 12 volt pod I got was about 3/4″ square and there was no way it was going to fit inside a 12 inch iBook. The case interior is really cramped, there’s no empty space to fit the inverter, also the inverter generates a lot of heat and makes a faintly audible squealing sound when it’s running.
I was just working on creating an external FireWire plug for it when Apple came out with their far more elegant solution. I’ve sort of let this project drop by the wayside, but I think I’ll revive it now that I have a TiBook 667 Gigabit, which does have more empty space inside it, not enough for a blocky inverter, but the company I bought the parts from seems to have a lower-profile 12 volt inverter available that should fit in the empty space.
As an added advantage, the TiBook’s lower case assembly can act as a heat sink, and the metal case should shield the squealing sound. It also has a conveniently located wiring harness I can tap power off of.
Voltage readings on the battery bay wiring harness were:
red, orange, yellow: 15v
white, green: 12v
Looks like a pretty straightforward setup, mount the EL sheet behind the keyboard, mount the inverter in the space behind the optical drive, run the inverter wires to the sheet and off the battery wiring harness (the 12 volt lines). Voila, a backlit keyboard in a TiBook.
Unfortunately, the 12 inch iBook seems too cramped for the EL sheet project, perhaps some form of LED based backlighting may be in order. The 14 inch does have more internal space, but it’s still pretty
cramped in there.
This is the company I got the EL sheeting from:
Here are some links to some other backlighting projects:
Originally printed in The Tech Tails, a weekly newsletter of Mac tech tips and troubleshooting from Small Dog Electronics in Vermont.
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