M.A. Hochberg’s Technology for Teaching

I almost put the word “calibrate” in the title of this post. It is the correct term but it sounds so intimidating. Calibrating sounds precise and technical and that you need special tools and expertise to do it.

In this case, all it means is charging your laptop battery, letting it rest, draining it, etc. To keep your battery in good shape and extend its life, you should calibrate it every six months or so.

Here is a simple explanation of what to do. It’s from one of my favorite newsletters, Small Dog Electronics.

How to Calibrate Your MacBook or MacBook Pro Battery
By Dawn@smalldog.com

PowerBook G4 (15-inch Double-Layer SD), MacBook, MacBook Pro, and MacBook Pro (17-inch)

With these computers, follow these steps to calibrate your battery:

1. Plug in the power adapter and fully charge your PowerBook’s battery until the light ring or LED on the power adapter plug changes to green and the onscreen meter in the menu bar indicates that the battery is fully charged.

2. Allow the battery to rest in the fully charged state for at least two hours. You may use your computer during this time as long as the adapter is plugged in.

3. Disconnect the power adapter with the computer still on and start running the computer off battery power. You may use your computer during this time. When your battery gets low, you will see the low battery warning dialog on the screen.

4. Continue to keep your computer on until it goes to sleep. Save all your work and close all applications when the battery gets very low, before the computer goes to sleep.

5. Turn off the computer or allow it to sleep for five hours or more.

6. Connect the power adapter and leave it connected until the battery is fully charged again.

Tip: When the battery reaches “empty,” the computer is forced into sleep mode. The battery actually keeps back a reserve beyond “empty,” to maintain the computer in sleep for a period of time. Once the battery is truly exhausted, the computer is forced to shut down. At this point, with the safe sleep function introduced in the PowerBook G4 (15-inch Double-Layer SD) computers, the computer’s memory contents have been saved to the hard drive. When power is restored, the computer returns itself to its pre-sleep state using the safe sleep image on the hard drive.

From Apple’s Knowledge Base article #86284:
http://docs.info.apple.com/article.html?artnum=86284

Some projectors, such as certain Hitachi models, let you know when it is time to clean the air filter.

Others projectors, such as certain Epson models, simply tell you that it is overheating and past time to clean the air filter.

While projector manuals say to clean the filter after every 100 hours of use, it’s a good idea to check it every month, especially if your room gets dusty or if you have an outside door or keep your windows open.

How you clean the filter varies with each projector but the basic principals are the same.
1.    Turn off the projector and let it cool down.
2.    When cool, unplug the power cord.
3.    Find the filter. It is usually on the side or bottom of the projector. It looks like a thin, flat sponge, usually covered by a plastic grid.
4.    Remove the filter. On Epson projectors, the grid is attached to the filter. On other projectors, the filter and grid are separate pieces.
5.    Clean the filter by either vacuuming it or washing it under running water. If you wash it, let it dry thoroughly.
6.    Before replacing the filter, look inside the opening when the filter was. If it is dusty, vacuum it out also.
7.    Replace the filter. Plug in the power cord and you are done.