two strange filter problem?!

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One:i have designed an active two order Sallen-Key butterworth low pass filter. here ,i made C1=C2=C=220pf, R1=R2=R=1k ohm. i use the formulation calculate corner frequency(-3dB), f=1/(2*pi*RC),what i get is about 720khz. but i use Altium Designer 6.7 to simulate it , the point at the 0.707(full scale is 1)is about 450khz. so i feel puzzled. i don't know how to send you the circuit i draw, but i can promise my circuit is right, if not ,i will swallow dozens of AVR MCU to suicide!
Two:about simple RC high pass filter. In China , the textbook tell us capacitor can stop the DC, so they said this capacitor is "stop DC"capacitor in some circuit. but i think this is the wrong concept. without a resistance, it can't form the base high pass filter, if you consider the air is a super large resistance ,it really is, but the RC constant will be huge. in my experiment, i only use a 10uf capacitor and then directly connect the operational amplifier(NE5534), as i have imagined, the operational amplifier have about 1Mohm or bigger input impedance, then the sine wave falls off very slowly. then , i use 0.1uf capacitance, it is faster within my patience.But!!!!!!!
if it became the really AC signal ,there is nothing amazing~~. The problem is it falls below the GND level!!This is the amazing thing i want to know why??!!if you tell me how to let you know the circuit , i will show it to you

Our Martians are beginning to learn AVR

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Altium Designer costs a couple thou a seat. Your company bought that fair and square?

Imagecraft compiler user

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I am student, nothing in my pocket. i crack the software , so it is free to me.

Our Martians are beginning to learn AVR

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Amazing indeed! Perhaps send a bug report to Altium since your circuit is right.
Impedance of free space is 377 Ohms so I do not think that is a consideration here.
Post circuit diagram if you wish progress.
http://en.wikipedia.org/wiki/High_pass_filter

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yyw794 wrote:
I crack the software , so it is free to me.

And you sleep well at night?

I just spent $800.00 for software that there are cracks for all over the Internet.

Then you come here telling us that you cracked some high dollar software and, you want us to help you solve your problems???

No help here!

Sleep well!!!

You can avoid reality, for a while.  But you can't avoid the consequences of reality! - C.W. Livingston

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Troll or criminal? Either way, I'm gone. (my guess is the former)

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come on. my softwares in my computer are all free. there is crack file of every software in the web. i just use it.
What i want to clarify is not everyone is rich as you are. i am in a developing country, maybe you can pay little in your earning, but it costs a lot in our income.
for instance, if you and i do not spent any money in a month, you can buy a car in several months, but what we need is 10 years!!
you know that is why we student have to use the "free" software. you are in the rich country, do you know what is bitter and hunger?
another way, Microsoft does really know there are lots of pirate software in China, but do they forbid us to use??no ! the more we use , the more influence your software is, then , more technical articles relate to the software , finally, your software is known by everyone, then , you can do what ever you do!
In china, many softwares are not only free, but also they force you to install, for what? for the influence.
so, i use Altium Designer freely is not a bad thing.
that is what i want to say, if not , i have no need to tell you the truth, remember, every country has its owner unique character, don't try to use the MSC
51's program into AVR without a change.

Our Martians are beginning to learn AVR

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yyw794 wrote:
come on. my softwares in my computer are all free. there is crack file of every software in the web. i just use it.

By our laws, that makes you a thief!
Here, you wouldn't be a poor student, you'd be put in jail for steeling another persons livelihood.

yyw794 wrote:
...every country has its owner unique character...

And how do you think we should respond to these statements?

Slave labor, corruption beyond infinity, pirating of intellectual property!!!

Unique Character? No! I'm afraid not! This is unacceptable character!!!

You can avoid reality, for a while.  But you can't avoid the consequences of reality! - C.W. Livingston

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Can I just say how much I love Altium Designer. We just recently bought six seats including one seat of the full blown deal (includes a bunch of FPGA stuff). Truly an amazing product.

Go electric!
Happy electric car owner / builder

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No help here. I know sallen-key filters but I am not going to say anything.

Jim

 

Until Black Lives Matter, we do not have "All Lives Matter"!

 

 

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Just in defense of the theft (I think that using cracked software for bussines is really this). When I was at university, I found that the ones that supplied cracked protel (that was the name back then) were the same distributors with the allowance of Altium (or which was their name before). Of course, they wouldn't confirm that in front of a tribunal, but that was a simple but easy policy hidden behind that: if students get used to that program, when they grow up they would buy a legal copy to use in theyr company. That remembers me Microchip policy.

Of course, that worked very well here, in Spain, where probably only the companies pay the software (I didn't know of any that uses unlicensed software). But reputation/unique ways to do things of other countries is not the same...

BTW, Altium is a great program, since I'm using it since I was at the uni. Of course, we have all the required licencies for all seats. Amazing.

Guillem.

Guillem.
"Common sense is the least common of the senses" Anonymous.

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Seems to me that you don't hire Bill Gates to work, after all. Hiring implies payment.
I expect nearly everyone has, at one time or another, used software that is not 100% legal, or copied a CD/Compact Cassette/eight track/wax cylinder, but attempting to justify theft because of your financial circumstances makes no sense. We are all poorer than somebody, even Bill Gates is poorer than the guy who owns Comp USA, so by your logic that would make it OK for Bill to steal stuff from Comp USA.

Four legs good, two legs bad, three legs stable.

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This putz can kiss my a!! as well. Carl is correct in his view of China as well. He just forgot to include that the bulk of the security threats to us is from China. For all we know this putz could be designing something 'destructive'.

The only help this putz gets from me is being pulled out of the gene pool :evil:

I would rather attempt something great and fail, than attempt nothing and succeed - Fortune Cookie

 

"The critical shortage here is not stuff, but time." - Johan Ekdahl

 

"Step N is required before you can do step N+1!" - ka7ehk

 

"If you want a career with a known path - become an undertaker. Dead people don't sue!" - Kartman

"Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?"  - Lee "theusch"

 

Speak sweetly. It makes your words easier to digest when at a later date you have to eat them ;-)  - Source Unknown

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB, RSLogix user

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yyw794,

There is a huge collection of free software, and you can find it in
https://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&t=38183
I think you can find some nice simulators in that collection. If you persist in using cracked software, it will be difficult to find help here.

Nard

A GIF is worth a thousend words   They are called Rosa, Sylvia, Tricia, and Ulyana. You can find them https://www.linuxmint.com/

Dragon broken ? http://aplomb.nl/TechStuff/Dragon/Dragon.html for how-to-fix tips

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Don't get too personal, guys.

If you disagree with yyw794's choices / moral, that's allright. Refrain from posting then.

Nard
moderator

A GIF is worth a thousend words   They are called Rosa, Sylvia, Tricia, and Ulyana. You can find them https://www.linuxmint.com/

Dragon broken ? http://aplomb.nl/TechStuff/Dragon/Dragon.html for how-to-fix tips

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thank you ,Plons, you are really a nice person!!
and thank you for the link you give me which includes lots of free softwares, i will try to use it instead of the illegal ones.
maybe i am younger than most of you , you are the eldership to me , and i will listen to your advices and correct my fault, i love GNU, so i will go for it.
Anyway, jgmdesign's argument is too radical!! you can yell at me anyway you like, but please give some respect to my motherland.
what i am researching is ultrasonic generator in flip-flop bond field, do you(jgmdesign) think it is harmful to you??
my elder people , i will follow the right way you give, thank you for everyone here (except jgmdesign)

Our Martians are beginning to learn AVR

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yyw794: I understand your position, as a student money is tight and student/trial versions not always readily available. Many of us do have the problem that their work is used/pirated without payment, often from China and for profit (for the chinese company). Bragging about what we perceive as stealing is not a good introduction !

jgmdesign: China has its share of problems and I don't agree with many of its policy decisions. But the same is true of the US. I for one feel much more threatened by the US than by China.

Markus

Markus

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Markus
I respect your reply, and I can agree that the opinion of the U.S. is not very good at the moment. Keep well my friend.

yyw794
Take your motherland and stick it.
I stand by my statements, and shall say no more

Jim

I would rather attempt something great and fail, than attempt nothing and succeed - Fortune Cookie

 

"The critical shortage here is not stuff, but time." - Johan Ekdahl

 

"Step N is required before you can do step N+1!" - ka7ehk

 

"If you want a career with a known path - become an undertaker. Dead people don't sue!" - Kartman

"Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?"  - Lee "theusch"

 

Speak sweetly. It makes your words easier to digest when at a later date you have to eat them ;-)  - Source Unknown

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB, RSLogix user

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Quote:
I for one feel much more threatened by the US
Is this because the US is powerful and willing to wield that power, OR because the US is wishywashy, i.e. prone to schizophrenic oscillations between resolve and internal disagreement?

I've worked in China a fair amount; truth is you can buy most any software, movie DVD, or music CD for 8-16 yuan ($1-2$).

Naturally, my coworkers and I discussed this issue at length (mostly regarding movies). Fact is the studios hire Chinese firms to cheaply reproduce the DVDs for sale in other markets knowing full well that the night shift will pump out bootleg copies for domestic consumption.

A similar situation occurred in the US of the 1800's. In that case the lawless pioneers were quite active in producing and consuming bootleg copies of printed media, often copyright pieces from England and elsewhere. Printing presses were setup and the results sold cheaply to the locals without any consideration for the authors.

Of course bootlegging is wrong, but I am pretty sure many software vendors are glad "their" s/w is pirated more than their competitor's; especially in the growth market that is China.

For the OP you would be advised to keep your cracking a secret; it is nothing to brag about.

C: i = "told you so";

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This is the General Electronics Forum. Not meant for discussions about politics etc.

If you (in general, not specifically) want to discuss this further, do it in the OffTopic forum.

I will lock this thread.

Nard,
moderator

A GIF is worth a thousend words   They are called Rosa, Sylvia, Tricia, and Ulyana. You can find them https://www.linuxmint.com/

Dragon broken ? http://aplomb.nl/TechStuff/Dragon/Dragon.html for how-to-fix tips

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