Sharpening a squarewave

I am currently generating audio frequency squarewaves in the audio editing software "CoolEdit". Although there are others that will do the same job.

However, I need something more harmonically pure for test purposes, ie. a squarewave that is perfectly rectalinear and has virtually instantaneous rise and fall times.

It needs to deliver a 12V swing and hold up under a 16 Ohm non-reactive load.

What type of circuit can I add to my soundcard output that will do this best?

Mark Roberts

Reply to
Mark Roberts
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"Mark Roberts"

** You must come up with actual rise and fall time figures.

If that doesn't strain your tiny brain too much.

** A power amp IC may be OK - depending on your rise and fall times.
** A "Schmidt trigger " will sharpen up the rise and fall times of your existing signals.

However, you MUST come up with actual rise and fall time figures.

Justify them too.

All sounds like a giant wank, so far.

....... Phil

Reply to
Phil Allison

An XR2206 would do it.

LOL...

Tim

-- "Librarians are hiding something." - Steven Colbert Website @

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Reply to
Tim Williams

A harmonically pure square wave??? Now, how in the world is that possible??

--
Dave M
MasonDG44 at comcast dot net  (Just substitute the appropriate characters in the 
address)

Life is like a roll of toilet paper; the closer to the end, the faster it goes.
Reply to
DaveM

"DaveM"

** No harmonic missing - of course.

Right out to f****ng infinity ..........

Beam me up Scotty .........................

...... Phil

Reply to
Phil Allison

It's "Scotty, beam me up"

martin

Reply to
martin griffith

--
???

ALL the evens missing. ;)
Reply to
John Fields

You mean like the second, the fourth, the sixth, and so on?

The simplest way to get a square wave with very good symmetry is to us a binary divider.

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--
Many thanks,

Don Lancaster                          voice phone: (928)428-4073
Synergetics   3860 West First Street   Box 809 Thatcher, AZ 85552
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Please visit my GURU's LAIR web site at http://www.tinaja.com
Reply to
Don Lancaster

Mark Roberts wrote: [..snip...]

Rectal-in-ear huh? You must be British!

View in a fixed-width font such as Courier.

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Reply to
Fred Bloggs

I am sort of surprised that nobody has already suggested this. If you have a comparitor to turn the sound card's output into sharper squarewave, you may still be off the 50-50 duty cycle mark. A good way to solve this is to use a flip-flop such as a 74HC74. This will give you a squarewave with the needed duty cycle but at 1/2 the frequency. Since the sound card can be programmed to make twice the frequency, you should be able to work with this.

There still can be a bit of timing shutter on the output of the sound card. This is likely to go away when the cycle of the signal is an integer multiple of the sampling rate. Since this is true at many values you can just be selective in what frequencies you use.

Reply to
MooseFET

[snip]

And then never actually used during the original series. "Scotty, beam me up" wasn't uttered until they put it in one of their movies.

--
Paul Hovnanian     mailto:Paul@Hovnanian.com
------------------------------------------------------------------
"Very funny, Scotty. Now beam down my pants!"
Reply to
Paul Hovnanian P.E.

I did hear, "Gentlemen, I suggest you beam me aboard" on the one with the neutronium doomsday machine.

Cheers! Rich

Reply to
Rich Grise

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