relays

Old auto voltage regulators, pre-alternator, were (along with the field coil) vibrating-contact negative-feedback class D amplifiers. And you can still buy temperature controllers that include a relay to drive the heater.

Sure. Carbon mics can have huge power gains (especially the water-cooled ones!) I think the carbon amp was used in some very early telephone systems. Noise and distortion limited its utility.

John

Actually, no. Flipping the state of a latching relay can be characterized as both a minimum required energy and an average power. And the switched load can be measured in terms of both energy and power. And "power gain" can be defined various ways.

John

"Dweeb"? Isn't that what they call a permanent resident of downtown San Francisco ?:-)

...Jim Thompson

Heat? Cornered? I stand by my original commant that the power gain of a latching relay, averaged over time, is unbounded as the averaging time increases. Nothing else makes sense.

I'm a circuit designer, and it's my job to be careful.

John

No, that's "homeless substance abuser." I stepped over a couple of them this morning, on the way to fetch my latte and brioche.

John

Sno-o-o-ort! We don't have any of those out here in the "boonies" ;-)

...Jim Thompson

That's because you don't have enough tourists to provide the funding. We average about 20 tourists/year per actual resident.

John

Well, it all depends on the numbers. I have a dollar in the bank getting 5% interest, which is theoretically increasing without bound. Nonetheless, I modestly refer to it as a dollar, and not as the infinite wealth it someday shall be.

OTOH, in the everyday sense, I take "infinity" to mean "really, really big." Which is what the gain of a latching relay is, how I interpreted your remark, and that's more than close enough for me.

Cheers, James Arthur

Ah. The namecalling starts. You don't know the difference between an infinite number and an unbounded number, you don't know the difference between power and energy, and, having been caught in an error, you resort to personal attacks.

You might want to try adopting my attitude. I *like* it when someone catches me in an error. It allows me to more closely align my mental representation of the world with the way the world really works, and thus improves me. Yeah, that's right; I make mistakes. Especially when I stray from the kind of engineering I usually do. Only a fool thinks he knows everything, but in my experience it's not what you don't know that bites you; it's what you think you know for sure that isn't so.

Correction: Certain parties *showed by reference to a standard math textbook* that a quantity that has no upper bound may not qualify as infinite.

Please don't imply that "working engineers" do not accept the fundamental principles of mathmatics. That's just you.

You said infinite, which is not the same thing as unlimited/unbounded.

That isn't your original claim, but even with unbounded replacing infinite you are still wrong. That's like saying that my 1985 Subaru has 22,500,000 (and rising!) horsepower (it has a whopping 90 Hp engine and I have put 250,000 miles on it -- just enough to break it in). Here in the real world, my subaru spends an unbounded anount of *energy* overcoming friction, etc. but it doesn't have an unbounded anmount of

Nope. Only one way. It is the ratio of power in to power out. Power in, not energy in, so your original post that cited joules (joules are energy, energy isn't power) in and watts out was and still is dead wrong.

Further personal attacks will be considered to be evidence that you know that you cannot win on facts or logic.

You proved nothing.

What is the power gain of a latching relay?

John

I never said the switched power is unbounded; obviously it's not. I said the power gain is unbounded (infinite to me) because the average actuation power is arbitrarily small, depending on the time interval over which the overall experiment is done.

A few people are accusing me of misunderstanding the numerator, when they're misunderstanding the denominator.

If you disagree, post an equation for the power gain of a latching relay.

John

You also have to use equal time intervals. Otherwise you are comparing apples to beef steak. If switching takes 125 microseconds, you must measure 125 microseconds of the switched power. Then the power gain is quite finite. Only the energy gain of latching relays is transfinite.

So here is the question again. Do you have a control function, which controls more power than it takes to operate the control, and how do you make an oscillator with it? Can you make a controllable oscillator from a water wheel or a windmill?

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That'd