Resistor vs Transformer update

He *is* a troll- not German at all, and posting from US under fake troll name using troll favorite Forte Agent- what is more- indicates familiarity with sed regulars.

I think you're both spot-on, which is why I bailed from the thread some days ago. I had my input: "Transformers." and OP didn't listen.

Guess that's another reason why it's so rewarding when they _do_. :-)

Cheers! Rich

MOVs are 19th century technology. They're crap. They wear out. They blow up. Get rid of them. I can't even imagine why anybody's still making the stupid things.

Use a Transzorb:

They come in AC varieties, which is just back-to-back diodes in one package. It's basically a Zener (or breakdown diode, or avalanche, or whatever the proper technical term is) that can handle huge transients without blowing up. And dissipating a transient doesn't "use up" a transzorb, like it does an MOV. (It just takes the heat and dissipates it over time.) I've used them, and I'll swear by them for transient protection. Unlike MOVs, which I've been known to swear _at_. ;-)

I don't work for Vishay, or GI, who used to make them (or used to _exist_ ;-) ); I'm just a happy customer. :-)

Good Luck! Rich

Let's not be hasty here - it takes a long time to even discover most of the possible mistakes, let alone make enough to ensure that there isn't another possible mistake! ;-)

And frankly, if that criterion really would apply, I'm about at the point where I know everything about everything. ;-P

Ergo, it's probably not true. )-; [ ;-) ]

Cheers! Rich

LOL.Face facts 99% OF the regs here are trolls Isn't the Pope German?

He might be the Pope as far as I can tell his IP address is in the Vatican.

lemonjuice

That is one of the myths you find in the Electrical Power community. I'd say the fact that they are used is proof of a superior engineering insight to the average Varistors come with different power and voltage specs. If you put the wrong MOV in a circuit it blows up and thank God that it does! But gosh if the WTC Towers could be blown up I wouldn't be surprised if MOVs can. About MOVs wearing out ... I don't know of anything in the Electronics field or any other field which doesn't.

lemonjuice

Sorry to disagree with you:

MOV's can be made into almost any size, with a lot of thermal inertia. Zeners can't. Personally if I was expecting many-joule transients I'd rather have 1 big honkin Kruggerrand-sized MOV than a pinhead-sized Zener. On digi-key they have MOV's good for up to 60,000 Amps, but the zeners only go up to 600 watts.

MOV's are typically used in applications where there are relatively few, low duty-cycle transients, such as turn-on/off transients. Obviously you shouldnt put in a surrpressor that's too small to handle the transients. But in the typical across-the-line application you don't see 300 volt transients many times a second. Or else you have bigger problems.

In any case the poor original poster should make sure he gets AC line-rated varistors, not some wimpy telephone line signal-rated ones. AND that he's talking about the right kind of varfistor-- sometimes that name is used for the negative-temp coefficient thermistors that are often right next to the AC line clipping varistors. You don't want to substitute one for the other.

"John Fields"

Ever get anything right - f*****ad ?

( snip idiotic 6MB pdf posted in lieu of fact )

As usual from a desperate bloody liar.

" John Fields Professional Bullshit Artist "

......... Phil

John Fields wrote: [snip]

I've seen a 14% 2MVA transformer before. A small fuckup at ABB, and the customer bought it because it was *cheap*

Cheers Terry

" John Fields Professional Bullshit Artist "

Says it all really.

Except for the fact he is Texas psychopath too.

......... Phil

John, check out Phil's webcam! ;-)