a question about resistors in an arc experiment

What an astounding concept. Maybe you could make that your sig file. Or your company motto.

John

You're just not used to guys who aren't hostile to women.

It is interesting to see you and JT play the little-boys-club game and try to chase women off. It's not the first time this has happened here. I'm siding with Sylvia because she stood her ground sensibly in pointing out that you were wrong, and because she totally shut down JTs ability to make an objective comment on a simple circuit... because he can't apparently stand to have a "girl" be right.

So yeah, as far as that goes, Sylvia rocks.

John

--- Here's the statement in its proper context, cheater:

"It doesn't make any difference whether it worked or not, the point was that an active negative resistance using its input signal as a supply would be the equivalent of a passive one."

Another use of it, in proper context, might be:

"It doesn't make any difference whether it worked or not, Larkin claimed, regarding his 555 trigger circuit, that: "The circuit was both original and correct.""

JF JF

Well, that's wrong too.

The polarity was flipped for some pin on a 555. The principle remains useful. The intent was to help. It does make a nice debounced pulse.

You are getting to be the village busybody, all dispute and clucking. In some threads, your posts are nothing but insults, to various people, with zero content. Do some electronics; you'll feel better.

John

You haven't been paying much attention then. This subthread has included discussion of a number of circuits that were intended to behave in the way a negative resistor (that is, one presenting total negative resistance) would behave. The debate (for want of a better word) has then centred on whether those circuits work as claimed, and the extent to which they can justifiably qualify as negative resistors given their various limitations.

But, hey, if you just want to insult me, and it makes you feel better, then go ahead.

Sylvia.

Which they always are, given that there is some capcitance between the leads. I visualise the voltage increasing until it reaches the breakdown insulation of either the resistor, or the air. In the latter case, we'd get an arc, which is where this thread came in.

Sylvia.

Both of the posted opamp-based neg-R simulation circuits are unstable if connected to a cap. The second one makes a nice exponentially-increasing voltage, V = e^(-T/RC), where R is negative, until the amp rails.

The first one certainly freaks out the opamp by ac-grounding its inverting input, doing I'm not exactly sure what. It would be stable for some small cap values.

John

I was paying attention to you denying that negative resistance was possible (indeed common), while refusing to acknowledge that you were the one using incorrect terminology.

Nope. I have no animosity toward you. Just don't be so pig headed.

You used words intended to malign me, rather than sticking to the point at issue. I can't say I care - I've been around Usenet long enough.

But be honest with yourself. When you're insulting someone (or at least trying to), recognise that you're doing it.

Sylvia.

or,

it

handy

ly

It would depend a lot on the op-amp. It is very possible to have an op-amp which is stable for any RC time constant formed that way. It just needs to have less than 90 degrees of phase lag all the way from DC to the bandwidth.

No sale. Nonsense rules do not show respect, they show disrespect. However, while a culture still understands the situation which led to a ritual, it has value as a reminder of group will to survive, and a particular method once used survive perceived tough times. Once that connection is lost, the value of the ritual is lost.

Has anybody ever made an opamp with a -3 dB/octave rolloff? That could be handy.

John

That's *exactly* the point. You won't stick to it, rather continue to argue an indefensible position.

You flatter yourself. You aren't important enough.

While i find muzak rarely irritating it is consistently banal, likewise i find Phil rarely entertaining and consistently anal.

For projective infinity kind of, for affine infinity no.

What is the difference in size is the set of irrational numbers versus the set of rational numbers? Explain your answer.

I can't think of any but it seems reasonable that somebody must have at least made one with less than 90 degrees of lag. 5 degrees of phase margin would be "doesn't oscillate" but 45 degrees would be much nicer.

It would also be nice to have some that are designed to work into inductive loads. A rail to rail power opamp would also be nice.