Fun with multimeters

Dave Farquhar Uncategorized

I’ve been going through A+ training as I have time. Whether I go through with getting the certification will depend on whether my bosses think having someone with an A+ lurking in the corner is useful–by contract I can’t do much more than swap a keyboard or mouse, but in the meantime I’m picking up some stuff I haven’t had to think about in a very long time.

One thing I picked up is the proper use of an ohmmeter or ohm meter.

Testing American Flyer track
Here I’m using a multimeter to test a piece of vintage American Flyer electric train track. I should get infinite resistance between the two rails, so this piece shows symptoms of having a short in it. On a good piece of track, my multimeter would read “1.”

Ohm meters measure resistance. Frequently, you’ll have a tool that does several things, so you flip your multimeter over to ohms or resistance to turn it into an ohm meter. Then, if you need to test a cable, put the red lead on one pin, and the black lead on the corresponding pin on the other side. If you get infinite or higher-than-expected resistance, then the cable is bad.

When you’re testing for continuity, you need to do so with the power off. Testing for continuity on a live system will cause the multimeter to malfunction at best, and at worse, blow a fuse. That’s a tricky bit you have to remember if you’re doing component-level testing on a board–something of a lost art these days. You might be testing voltage on a live system, then when you don’t see what you expect, you might want to test resistance. Be sure to remember to shut the system down when you switch from volts to ohms to avoid damaging your multimeter.

Measuring the voltage and amperage of your train transformer’s output

Dave Farquhar Toy trains , , , , , , , , , ,

Sometimes you want to know how many volts your train transformer is feeding your trains, in order to avoid damaging the motors. And it’s also helpful to know how many amps you’re pulling from your electric train transformer, so you don’t damage the transformer.

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How I decide whether it’s time to stay or go

Dave Farquhar Uncategorized

Some of my coworkers and I are dealing with a crossroads in our respective careers. It’s caused us to have some conversations. And since I’ve moved around a lot more than anyone else in my office–I work with a lot of people who’ve spent their entire adult lives working for two or fewer employers–I’ve taken some questions.

I’ve never really had to think about whether it’s time to move on. I just seem to know. But I think now I realize how I know. Read more

Is landlording profitable?

Dave Farquhar Landlording, Saving money , , , , ,

Is landlording profitable? The answer is yes. Where people disagree, I think, is on the timing, and perhaps to a lesser degree, on the strategy.

My wife read an article yesterday on real estate investing that made her mad. I’d link to it, but I can’t find it today–maybe it was pulled. But the premise was that you shouldn’t invest in real estate, because being a landlord isn’t a quick way to get rich.

I agree with the second part. But the first part doesn’t logically follow. In fact, I don’t care who you are, probably the best thing you can do for yourself is forget about trying to get rich quickly. I speak from experience. Read more

Happy late birthday, OS/2

Dave Farquhar Retro Computing , , , , , , , , , , , , , ,

Twenty-five years ago this month, on April 2, IBM announced its new PS/2 computers and a new multitasking operating system to run on (most of) them–OS/2. They even lured a bunch of the actors from M*A*S*H to do an ad campaign for them.

It didn’t seem like it at the time, but that was the beginning of the end of IBM’s PC business.
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Let Eric Hosmer hit second

Dave Farquhar Baseball , , , , , , , ,

Yesterday, the Cleveland Indians humiliated the Kansas City Royals 8-3 in what really looked like a showdown between two bad teams. Neither team played especially well, but the Indians were less bad. And in any given game, less bad is all it takes to win.

The Royals fielded poorly in the first inning and that made the difference, but the makeshift lineup the Royals fielded made it difficult for them to catch up. And catching up wasn’t out of the question. The Indians didn’t have Cy Young or Walter Johnson out there; it was the aging Derek Lowe. Read more

Easier deep Firefox SQL optimization

Dave Farquhar Software , , , , , , , ,

Last year I examined ways to optimize Firefox’s SQLite databases. I’ve since found I like it better when I just put the Firefox profile in a ramdisk, but that may not be an option in all cases.

If you don’t want to go the latter route and would like to avoid the command line jockeying, give Speedyfox a look. And even if you’ve put Firefox in a ramdisk, this program can be useful. You won’t notice any speedup inside a ramdisk, but SQL optimization saves storage space, which is always at a premium inside ramdisks. Read more