Are hybrid parameters useful for design?

dangerous. The original use of the word by Young was satiric and critical of the coming social system in the UK. The problem is obviously with the self-perpetuating meritocratic ruling class and the relevance and consequences of their so-called measure of merit from a social science perspective. Here is an article written by Michael Young himself, but I doubt your reading comprehension is up to it.

thread , with his obvious fake Indian name, is a racist troll posting through the eternal-september site. As best as I can determine, among his many previous aliases, he is "Charlie E.". So, go right ahead and engage the poser in email conflab about how things are in India from the perspective of some incapable rotting away in a braindead hell hole somewhere.

He's been polite, and the question about h-params was reasonable.

I'm not a "sucker" because he hasn't cost me anything.

thread , with his obvious fake Indian name, is a racist troll posting through the eternal-september site. As best as I can determine, among his many previous aliases, he is "Charlie E.". So, go right ahead and engage the poser in email conflab about how things are in India from the perspective of some incapable rotting away in a braindead hell hole somewhere.

The OP is certainly NOT "Charlie E". How did you come to such a braindead conclusion.

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dge is dangerous. The original use of the word by Young was satiric and cri tical of the coming social system in the UK. The problem is obviously with the self-perpetuating meritocratic ruling class and the relevance and conse quences of their so-called measure of merit from a social science perspecti ve. Here is an article written by Michael Young himself, but I doubt your r eading comprehension is up to it.

his thread , with his obvious fake Indian name, is a racist troll posting t hrough the eternal-september site. As best as I can determine, among his ma ny previous aliases, he is "Charlie E.". So, go right ahead and engage the poser in email conflab about how things are in India from the perspective of some incapable rotting away in a braindead hell hole somewhere.

He's no Indian- and his conversation has been nothing but broad innuendo an d generalities. His understanding of meritocracy is that of classic white t rash American, that's the main giveaway, but you're the same so you didn't pick up on it.

thread , with his obvious fake Indian name, is a racist troll posting through the eternal-september site. As best as I can determine, among his many previous aliases, he is "Charlie E.". So, go right ahead and engage the poser in email conflab about how things are in India from the perspective of some incapable rotting away in a braindead hell hole somewhere.

generalities. > His understanding of meritocracy is that of classic white trash American, that's the main > giveaway, but you're the same so you didn't pick up on it.

Who cares who he is? He acts a lot better than a whole lot of folks around here, and apart from this sort of pointless one-upmanship and personal abuse, it's been an interesting discussion.

"On the internet, no one can tell you're a dog."

And of course "Fred Bloggs" is about as real-sounding a name as "Joe Doakes" or "John Doe", but I digress.

Cheers

Phil Hobbs

He's been polite, and the question about h-params was reasonable.

He's no Indian- and his conversation has been nothing but broad innuendo and generalities. His understanding of meritocracy is that of classic white trash American, that's the main giveaway, but you're the same so you didn't pick up on it.

Gee whiz, you sound like a round-the-bend angry s**t slinger. STFU.

his thread , with his obvious fake Indian name, is a racist troll posting t hrough the eternal-september site. As best as I can determine, among his ma ny previous aliases, he is "Charlie E.". So, go right ahead and engage the poser in email conflab about how things are in India from the perspective of some incapable rotting away in a braindead hell hole somewhere.

The 'Charlie E.' has used the same eternal-september header parameters- mor e than just the site.

You're another foreigner. In American usage, that is a declarative and not an interrogative.

All these flames from unknowns are just more of his aliases coming out of the woodwork...

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is dangerous. The original use of the word by Young was satiric and critical of the coming social system in the UK. The problem is obviously with the self-perpetuating meritocratic ruling class and the relevance and consequences of their so-called measure of merit from a social science perspective. Here is an article written by Michael Young himself, but I doubt your reading comprehension is up to it.

thread , with his obvious fake Indian name, is a racist troll posting through the eternal-september site. As best as I can determine, among his many previous aliases, he is "Charlie E.". So, go right ahead and engage the poser in email conflab about how things are in India from the perspective of some incapable rotting away in a braindead hell hole somewhere.

generalities. His understanding of meritocracy is that of classic white trash American, that's the main giveaway, but you're the same so you didn't pick up on it.

Hey, white trash pride! My dad was a milkman, and my mom a cafeteria worker, and I grew up in a poor section of New Orleans. (I was also born on the St Charles Avenue streetcar tracks, in the back of a 1936 Ford.)

Yup, back-to-back diodes, with the lower one about a 6 volt zener. And the mentioned controlled current sink (whose gain rolls off at high frequencies and low temperatures.) Add some capacitances, and some emitter series resistance, and that covers 98% of the cases. Add in a little output slope (the Early voltage) and some leakage if it matters, which it usually doesn't.

With a model like that, you can focus on the bits that actually matter in a specific situation. Most cases are so simple that you don't even need a calculator.

Okay, great! Thanks.

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even look at the datasheet? They're on bunches of others, mostly older, too.

I did a search and found that you are correct about hfe/Hfe/hFE. I had no idea that the capitalization meant anything. For all these years I thought hfe was just hfe. My mistake.

I hope you and the group will accept my apologies.

JohnS

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even look at the datasheet? They're on bunches of others, mostly older, too.

It doesn't matter much. hfe and hFE are similar, because transistors are fairly linear as current amplifiers. The range of beta on a data sheet might be 5:1 min/max, or some min and no specified max, so most people go with the min and try to design circuits that are tolerant of anything better. So this is rough stuff, not rocket science, so a lot of fancy math (like formal h-param matrix stuff) isn't justified.

I still remember that day (I must have been 11 or 12) when I finished assembling my Knight-kit oscilloscope, the first DC-coupled scope I'd ever had access to. I rigged it up to sweep the base current of a transistor and plot Ic vs Ib. It was a straight line. Something dawned on me that instant.

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even look at the datasheet? They're on bunches of others, mostly older, too.

I remember younger days as well but I guess I have not faced the required challenges.

Thanks.

JohnS

There is no need to apologize and you didn't make a mistake because for pra ctical purposes the ac-current gain and so-called static current gain are i dentical. This follows because IC in ratio to IB by factor hFE makes deviat ion in IC, ic, to deviation in IB, ib, that same ratio, of hfe=hFE. This is why the only distinction between hFE and hfe is one of analytical notati on, and /also/ why the datasheet specification is so widely used for both. And this has nothing to do with hFE variation with VCE, Early effect, and l evel of current injection IB.

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That's one reason the datasheets are becoming so scant on small signal info is because they provide a SPICE model. I don't see why you can't rig up pa rtial SPICE sims to test out things like the front end attenuation control loop before you actually start prototyping, and this stuff about testing a candidate circuit against environmental/operating extremes can get well bey ond what one would call prototyping.

practical purposes the ac-current gain and so-called static current gain are identical. This follows because IC in ratio to IB by factor hFE makes deviation in IC, ic, to deviation in IB, ib, that same ratio, of hfe=hFE. This is why the only distinction between hFE and hfe is one of analytical notation, and /also/ why the datasheet specification is so widely used for both. And this has nothing to do with hFE variation with VCE, Early effect, and level of current injection IB.

I'm not apologizing as much for my mistake as I am for my attack on John L. It was uncalled for considering my lack of technical knowledge in the matter.

Thanks for your input.

JohnS

practical purposes the ac-current gain and so-called static current gain are identical. This follows because IC in ratio to IB by factor hFE makes deviation in IC, ic, to deviation in IB, ib, that same ratio, of hfe=hFE. This is why the only distinction between hFE and hfe is one of analytical notation, and /also/ why the datasheet specification is so widely used for both. And this has nothing to do with hFE variation with VCE, Early effect, and level of current injection IB.

Hey, it's only a newsgroup. It's not life.

because they provide a > SPICE model. I don't see why you can't rig up partial SPICE sims to test out things like the front end > attenuation control loop before you actually start prototyping, and this stuff about testing a candidate >circuit against environmental/operating extremes can get well beyond what one would call >prototyping.

For one thing, there's no SA614 SPICE model.

For another thing, SPICE models don't contain guaranteed specs--only typicals. I've sometimes pulled typical specs out of SPICE models, e.g. the input capacitance of some op amp--but that isn't always easy, and it's not confidence inspiring at all.

Sometimes you have to do engineering evaluations. Cold spray and a heat gun are often useful.

Cheers

Phil Hobbs