The Compass DéRose Guide to Universal Power Supplies: PowerBook™ to AdaptaPlug™ Adaptor

This page was written by Steven J. DeRose on 2003-04-14, and was last updated on 2003-04-14.

This page explains how to make a convertor that will let you run your PowerBook G3 or G4 off of a 24VDC supply that can take Radio Shack AdaptaPlugs, such as their voltage-adjustable item #273-1687 (runs on mains power), or #273-1827 (runs on 12V).

Warning: I've checked this out, but I could make mistakes, and I have no authority to speak on behalf of Apple, Targus, Radio Shack, or any other corporation. If you try this, you're trying it at your own risk. I recommend checking your result about 20 times by comparing to a manufacturer-supplied cable, before even thinking about plugging your laptop into a home-made one.

Parts

(obviously prices or anything else can change without notice -- this is just the info I got today off the Radio Shack website)

273-1742 Hobby Power Leads Adaptaplug

This end plugs into your power supply.

274-869 Mini Phone Plug

This plugs into your PowerBook G3. Stereo 3-conductor 1/8" solderless gold-plated. $3.99. Or you can buy two of them on a cord as item 42-2497, or two of a plastic plug version as item 274-284 , for the same price.

274-244 Gold-Plated 3-Cond. Plug (3/32)

This is the same as the last item, but fits a PowerBook G4. It doesn't seem to be readily available already on a cable. $2.99.

274-373 Inline Adapter

Accepts 1/8" stereo plug. Fits 3/32" stereo jack. If you make a cord for a G3, this will adapt it to work on a G4. $3.99.

Assembly

You may need a voltmeter or continuity checker to sort out which wires to connect. Connect one wire from the Adaptaplug socket to the base (the ring farthest from the tip) on your stereo plug -- this will go to the +24V side of the power supply. Connect the other to the ring in the middle -- this will go to the ground side. Leave the tip unconnected, and don't worry about the fact that there's no big cylinder around the whole thing.

Then test it (like I said, 20 times is about right) by putting a voltmeter on it and making sure you're getting 24V the way you should. Then try it out.

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