capacitor

Are 80plus power supplies worth it?

Dave Farquhar Hardware , , , , , , ,
Are 80plus power supplies worth it?

Are 80plus power supplies worth it? Extremetech just that question recently. Based on their conclusion, not usually, at least not solely for power savings. But it’s an easy way to get a box built to stricter tolerances with higher-quality electronics. Read more

Model railroading with your Droid: Solving electrical issues

Dave Farquhar Android, model railroading, Toy trains , , , , ,

Electrodroid is an Android app designed for electronics hobbyists, but it has uses for model railroaders too. Its LED calculator is invaluable when using LEDs to light buildings, cars, locomotive cabs or headlights, or for other projects. Knowing the input voltage, you can then determine what resistors to use to protect the LED.

The voltage drop calculator is useful too, if less obvious. Read more

The trouble with Dell

Dave Farquhar Hardware , , , , , , , , , ,

Note: I wrote this in mid-2010 and, for whatever reason, never posted it. I found it this week. Although the information in it is no longer fresh and new, it’s still useful, so for that reason, I’m posting it now.

Dell is standing on some shaky ground right now. Bill Snyder has a good summary of the problem.

In recent years, Dell computers have, shall I say, made me nervous. Some of it’s been concrete. Some of it’s just been touchy-feely. Now one of those touchy-feely problems is more concrete. Read more

Replacing bad capacitors in failed electronics

Dave Farquhar Saving money , ,

If you’ve had a piece of electronic gear fail in the last few years, there’s a good chance it’s due to one or more bad capacitors inside. The problem most infamously reared its ugly head on motherboards produced in the middle of the previous decade, but that’s just a place where it’s highly visible. If you had a DTV converter box, a DVD player, or some other device fail in the same timeframe, it may have had the same problem.

If I had a failed motherboard, I’d probably just swap the motherboard. I’m more inclined to fix an LCD monitor or a DTV converter box. Read more

I didn’t cause the depression

Dave Farquhar Saving money , , , , , , , ,

Various analysts are blaming the current depression on people like me. The reasoning goes like this: I have money in the bank, therefore, I should be out spending it, for the greater good, to stir the economy.

Let’s correct that right now.People like me “hoarding” cash didn’t cause this depression. I played by the rules. I didn’t lie on my mortgage application. I bought less house than the bank said I could afford, because I didn’t see how I could make that payment and still buy groceries. I bought a Honda Civic because I didn’t see how I could afford a car that cost $25,000 or $30,000 and I really didn’t see how I could afford to put gas in it. I made this decision when gas cost $1.59 a gallon in Missouri.

Basically, I made a budget and then I made the decision to stick with it. It wasn’t rocket science. Any time I thought about buying something, I sat down with a spreadsheet, entered in all the money I paid out each month, entered what I made, and figured out if the money left over was enough to buy whatever it was I wanted.

We were due for a depression, or at least a recession, at the beginning of the century. The dot-com boom and Y2K was a bonanza, but then two things happened. Y2K came and went, the world didn’t end, and people quit buying survival supplies in large quantities. Meanwhile, these startups failed to come up with viable business plans, continued to spend money faster than the government, and ended up going out of business. This hurt those companies, but it also hurt companies like Cisco and IBM and Intel, because as these companies went bust, their inventory of technology equipment, some of it unused, went on the market at bargain prices. There was no reason to buy a new Cisco router from CDW when you could buy the same thing, still sealed in the package, from a liquidator for half the price.

Then 9/11 happened and it really looked like we’d get our recession. But the government slashed interest rates, changed bank regulations, and encouraged people to buy like there was no tomorrow. GM started offering 0% financing on its cars in order to move them. Soon you could get free financing on anything but a house, and interest rates on houses were ridiculously low. And anyone could get a loan. Republicans loved it because it made the economy go boom-boom again. Democrats loved it because people at any income level could get mortgages.

But the problem was that many of these loans had onerous terms and conditions, and just because you could afford the payments one day didn’t mean you’d be able to afford them in two, three, or five years after some of the back-loaded terms kicked in. Of course, nobody worried about that because they were living the high life.

And then it all fell apart. It wasn’t quite as rapid as it seems. I think people started having problems paying their bills in 2005 or so, but it didn’t quite hit critical mass yet. It hit the smaller banks first. I know because the banks who had my mortgage kept going under, and every year or so, a slightly bigger bank would end up with my mortgage. But those weren’t any match for this monster either. Countrywide got my loan in 2007, but Countrywide wasn’t a dinky little bank. It went under, and when I made my final house payment, that payment went to Bank of America. Now it looks like even the mighty Bank of America might make me look like the kiss of death.

But that wasn’t the only problem. These bad loans got packaged up and re-sold. And somehow, these bad loans got higher grades than they deserved. A guy working as a slicer at Arby’s making $9/hour living in a $150,000 house isn’t a good investment. When everything’s going right, he can afford to make his payments, but the minute something goes wrong, he’s going to start missing payments and might not ever recover. So unless the guy gets a decent job, he’s not going to be able to afford to stay in that house. Yet somehow, a bank could package a bunch of loans like this and spin it as a grade-A investment.

Imagine me going around to my neighbors’ houses on trash day, filling boxes with trash, and selling the boxes, legally able to tell the buyer that the box contains something valuable. That’s great, until someone opens the box and realizes it’s just a box of trash.

No, this depression wasn’t caused by people like me. It was caused by people living beyond their means for too long, and not being able to pay the piper when the time came.

There’s another word for what’s happening right now, besides recession or depression. That word is “correction.” When the economy has been going in one direction for too long, it corrects itself. Sometime in the future, there will be another correction, and the economy will start improving again.

But I read my ultimate proof yesterday. Supposedly, if people like me would just spend their money, things would get better. So why does someone walk into a Jeep dealership with $24,000 in cash, intent on driving home in a new Jeep, and end up driving himself and his still-heavy wallet home in his old car?

And let’s look at people like me one other way. When I nearly lost my job in January, I had almost six months’ worth of income in the bank and a plan in place to be able to live off it for a couple of years, potentially. It wouldn’t have been a comfortable living, but it would have been doable. There would have been no need for me to go collect unemployment. I would not have been a burden on society. And when I retire, I’ll retire with enough money to get me through the rest of my life, with or without Social Security. I won’t be a burden on society either.

People who save their money might not spend it at the most opportune time for everyone else, so they might fail to even the economy out like a capacitor evens out electrical power. But they are never, ever a drag on society.

If you think you can do it so much better, then do it yourself

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

I’ve noticed a disturbing trend lately on the Classic Toy Trains forums. It seems like every time a new issue hits the street, someone has to find an article that has something wrong with it and point it out.It started a few months ago when my friend and mentor Joe Rampolla published an article about adding a capacitor to a toy train to make it stall less often and run more smoothly. The claims, as far as I can tell, were false (I had my longtime friend Steve DeLassus, who has a degree in electrical engineering from Washington University, check them out).

But practically every month since then, someone’s publicly taken issue with something in the magazine.

It’s not about a vendetta against a single author. One issue it was Joe. But last issue it was repair expert Ray Plummer’s advice on repairing a Lionel 2037. This issue it’s the legendary Peter Riddle’s article about getting Lionel’s TMCC and MTH’s DCS (two rival control systems) working together on the same layout.

In the case of each of these articles, the things the author said to do work. There might be an alternative way to do them. But that’s the nature of the hobby. Doesn’t it seem like Model Railroader publishes an article at least once a year about making trees, and not one of those articles has been a repeat since at least 1972 (and possibly 1942)? And if you were to read a complete run of Railroad Model Craftsman, you could probably find another 50 different ways to make trees.

Fifty or a hundred people having different ways to do it doesn’t make the guy who wrote the first article about making trees wrong.

In the case of Ray Plummer, what Plummer said matches what my local repair guy said and did when my Lionel 2037 had problems. When the pilot truck is adjusted within specifications, the 2037 and its many cousins run just fine. Plummer’s critic said the pilot truck is a poor design, and when you lengthen the truck to change its pivot point, it works more reliably.

That’s possible. I don’t know the theory behind pivot points. One of my best friends happens to be a mechanical engineer and maybe he could confirm that for me.

What I can say is that Plummer’s advice preserves the historical integrity and collector value of the locomotive. While modifying the pivot point probably wouldn’t make the locomotive worth any less to someone who just wants to run it, it would make it worth less to a collector.

I can also confirm that Plummer’s advice worked just fine on the locomotive that once belonged to my Dad. It’s almost as dependable as my Honda now.

As far as this month’s article to hit the avalanche of criticism, I don’t use any command control system on my layout and I have no interest in doing so. So I don’t have any experience that would back him up, and neither do either of my engineer buddies.

But I trust Peter Riddle. Riddle has written more than a dozen excellent books about trains. Wiring is a subject that confuses almost everyone, but I’m confident that a fifth grader could read one of Riddle’s books on wiring and understand it, then proceed to wire a Lionel layout effectively. Seriously.

I’ve heard the argument presented in these arguments that if an author is wrong about one thing, the reader loses confidence in everything he says. I don’t buy that argument. Riddle’s advice that the Lionel 1121 switch is a good match for early Marx locomotives isn’t entirely correct. From my own experience I know a Marx locomotive will bounce if it enters the switch from a particular direction.

So do I doubt what Riddle says on the other 95 pages of the same book? No. I also know from experience that the things he says on the other 95 pages work. And I know that even though that Marx locomotive bounces through the switch 33% of the time, it doesn’t derail every time it bounces. So maybe he’s never seen the problem I observed.

I’ll daresay there’s at least one mistake in every computer book I’ve ever read. It doesn’t mean I stop reading computer books. I’ve been wrong once or twice before too. Just ask my boss.

Actually, come to think of it I’d really rather you just took my word on that one.

This criticism bothers me on another level too. Writing an article and getting it published isn’t an easy task. For most people it probably takes about 40 hours’ worth of work. CTT pays $70 per page, and a typical article is 3-4 pages long, so you do the math.

How many people want to spend a week of their lives writing an article only to have some self-styled expert rip it apart in five minutes? Is it worth putting your neck on the line for $300?

Most reasonable people would say no.

I’m sure this is largely an ego thing. Most people regard published authors as special people. So when someone knows something that a published author doesn’t, it must make for some kind of a high.

But the price is also high. How many great ideas languish in the mind of a would-be author, never to see the light of day, because the benefits just don’t outweigh that onslaught of criticism if it happens?

So the next time you catch a mistake in print, that’s great. It means you know enough to be an author. So think of something you know better than anyone else and go write an article and advance the hobby.

Of course, criticism is easier than craftsmanship. Zeuxis made that observation 2400 years ago, and it’s just as true today as it was then. Unfortunately.

Beware the leaky capacitors

Dave Farquhar Hardware , , , ,

In case you haven’t heard about it elsewhere, there are some recent motherboards having problems with leaky capacitors.

Basically, the problem is the electrolyte in the capacitors becomes chemically unstable, the capacitor pops and starts leaking, the capacitor stops doing its job, and system stability falls out of the sky.

An EE can do a better job of explaining what a capacitor does, but in my very limited electronics background, every project I ever did used capacitors to eliminate noise or smooth out current.

Abit has come out and acknowledged the problem, but other manufacturers are also said to be affected, including Asus. So this isn’t a problem limited to cut-rate boards, although it wouldn’t surprise me if the cut-rate boards also are affected, because the issue stems from cheap Taiwanese knockoffs of a costlier Japanese design.

Identifying problem boards can be difficult, because the affected caps generally are unlabeled, but not all unlabeled caps are problematic. And, as you can see, my usual advice of sticking with a big-brand motherboard doesn’t save you in this case.

I recall a few years ago an article on one of the newsy tech sites like Cnet or ZDNet said some older models of Soyo motherboards could develop this problem. At the time, Soyo declined to comment. So this isn’t exactly a new problem. If anything, it seems to be cyclical.

If you do have a board that develops the problem, you can probably get it replaced under warranty. If not, a skilled technician can de-solder the bad caps and replace them with higher-quality ones. One technician who performs the service charges $50, which seems very fair to me for de-soldering and re-soldering 28 connections.

It’s definitely not a good first electronics project to try yourself though. If it’s something you want to learn how to do, practice on an old, obsolete motherboard or modem or sound card first. And, naturally, I won’t claim any responsibility.

If you develop the problem, this could also be the excuse you’ve been looking for to upgrade, seeing as it’s getting easy to find new motherboards for $60 or so.

You can read more about it in this IEEE Spectrum article.

Umm… Don’t water-cool your power supply

Dave Farquhar Hardware ,

I saw a thing on Slashdot this morning about water-cooling your power supply. One word: Don’t.
I’ve worked inside a power supply twice–both times to replace a dead fan. One time I touched a heatsink that picked up a charge from somewhere–either a voltage regulator or a capacitor. Anyway, it really didn’t feel good. Beyond that, it made me jump.

Not a project you want to undertake if you don’t know what you’re doing. And if you do know what you’re doing, you probably already know it isn’t something you want to do be doing. Anyone who uses the word “electric” to describe something pleasant has obviously never experienced anything electric flowing through them.

I’ll pass, thanks.