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Sinewave??

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Cherrytree
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Username: Cherrytree

Post Number: 61
Registered: 08-2005

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Posted on Monday, 24 October, 2005 - 01:49 am:   Edit Post Delete Post Print Post

}
Hi all,
me again!!
as I've mentioned about the Timer chip.. is square wave output, can it do a sine wave output?
with a bit of tweeking?? or is it dedicated to that damm square wavvvvee
cheers
CT
PS would it be sqaure to sine converstion used??
I'm only guessing here and a few bits of read up on..
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Miked
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Username: Miked

Post Number: 7
Registered: 05-2005

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Posted on Monday, 24 October, 2005 - 03:48 am:   Edit Post Delete Post Print Post

For a fairly decent tutorial about the 555 timer, with a few experimental circuits, you can take a look here:
http://www.uoguelph.ca/~antoon/gadgets/555/555.html
and if you really have some time to kill, you can look through the links on this page:
http://www.commlinx.com.au/schematics.htm
Down near the bottom there are a couple of links to references on converting square waves to sine waves.
Hope that helps -- have fun!
Mike
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Dean_huster
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Username: Dean_huster

Post Number: 96
Registered: 05-2005

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Posted on Monday, 24 October, 2005 - 02:56 pm:   Edit Post Delete Post Print Post

Running the square wave through a tight active filter will produce some decent sine waves, but if you want to vary the frequency, you have to track the filter, too. A low-pass filter may allow some frequency variation.

Why not just build a nice little Wein bridge oscillator for some really low-distortion sine waveforms?

Dean
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Microguy
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Username: Microguy

Post Number: 335
Registered: 09-2005

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Posted on Monday, 24 October, 2005 - 10:10 pm:   Edit Post Delete Post Print Post

CT, that MAX038 chip I told you about will give you a nice pretty sine wave, with about the same number of parts as the 555.
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Istedman
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Username: Istedman

Post Number: 32
Registered: 05-2005

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Posted on Monday, 24 October, 2005 - 11:38 pm:   Edit Post Delete Post Print Post

CT,

Take a look at this circuit at Circuit Exchange inernational (a good site)
http://www.zen22142.zen.co.uk/Circuits/Testgear/sinegen.htm

I built this a while ago, it was great. Very pure, the 3rd harmonic was 80 dB down and it beat a £200 function generator for purity. Oh I just used a 50 mA 24V bulb and it worked fine.

HTH,

Ian
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Cherrytree
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Username: Cherrytree

Post Number: 62
Registered: 08-2005

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Posted on Monday, 24 October, 2005 - 11:46 pm:   Edit Post Delete Post Print Post

}
Hi thanks,
for the replys, this is to Miked,
Yes I've looked at the website uoguelph.com
its pretty good but dont cover what I want..
thanks to dean Huster, Yes that would be a better approach
cheers to Mg yes Mg, I forgot about that chip thats true..
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Microguy
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Username: Microguy

Post Number: 339
Registered: 09-2005

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Posted on Tuesday, 25 October, 2005 - 01:29 am:   Edit Post Delete Post Print Post

You really should go ahead and get some samples from Maxim, I mean they're free, and you'll end up using them later.

And if you get the two samples, then you can make that sweep circuit you wanted.

I also think it's easier to use than the 555, more straight forward. You can do a lot with it, like individual resistors for positive/negitive wave (change the duty cycle), but you don't have to.

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