Well after owning my Model M keyboard for nearly a decade, I decided that my key-cap cleaning and case wiping wasn’t enough. So I carefully removed the keyboard itself from the keyboard case and cleaned everything I could reach. This isn’t typically blog-worthy, but this is the legendary IBM Model M keyboard; the one true keyboard. So much has been written about this wonderful piece of engineering that I won’t elaborate. Wikipedia does a good job of it: Model M

I love my keyboard, and use it frequently. I do a lot of work on laptops these days and the Apple low profile aluminum keyboard is slowly winning me over with is sweet short throw sweetness. But the tactile feel and sound of typing on a Model M is a thing of beauty.

Sheldon

The original plan was to add a 5 volt regulator in the Dension cradle cable. I was planning to add it about 6 inches from the connector and heat shrink it when I was done like some sort of cable goiter. As I was checking out the back cavity of the cradle I realized that the regulator would damn near fit inside it. However, with the metal attachment bracket it wouldn’t quite fit. I ground down the metal bracket and sanded down the regulator a bit and everything fit perfectly. I added filter caps before and after the regulator to suppress noise and called it as day. The cradle is working well and is ready to install. As usual, pictures are below.

Last night I installed the voltage divider assembly into the Dension cradle.  I thought I had some fine soldering tools but my smallest Metcal iron tip looks like a Louisville Slugger next to the 30 pin cock connector pins.  It took some steady hands (which apparently I don’t have either), and some good diffuse light to make these connections.  I used a strand of silver plated copper wire to make the connections, and a piece of the full stranded wire to make the power connection to the voltage divider assembly.

It would have been a little less kludgy to make a new circuit board with the proper resistor divider traces on the board, but I’m not sure that I can make a boar with traces fine enough to reliably fit the connector.  I am also concerned that I couldn’t get the connector off the existing board without damaging it.  So this is the result.  It seems to work quite well at this point.

The next step is to step down the power coming into the cradle from 12(ish) volts to 5 volts.  A linear regulator doing this job would be dumping more power into heat than it provides to the iPhone for charging, which not only may overload the factory head unit, also requires the linear regulator be heat sunk somewhere.  V-Infinity has a really snazzy switching regulator that has an efficiency of about 92%. This means that during full charging, the regulator will only dissipate about 0.2 watts and will not need a heat sink.

Sheldon

This resistor divider kludge marks the official start of modifying a pair of Dension Ice Link iPod cradles for use with 3G iPhones.  The Dension Ice Link is a cradle that fits a variety of Apple iPod models (and iPhones).  It plays audio out from the iPod through an OEM car stereo, and charges the iPod unless you have a 3rd gen nano, 2nd gen iTouch, or iPhone 3G.  These new models charge via USB only, and these old Ice Link systems only charge via FireWire.  With a little kludging, that problem is easily solved, and for $7 on ebay, these systems are a steal. 

Sheldon