Sharpening a squarewave

[Mark Roberts]

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

 

[Phil Allison]

"Mark Roberts"

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.

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

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

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

** A power amp IC may be OK - depending on your rise and fall times.

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

** 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

 

[Tim Williams]

An XR2206 would do it.

LOL...

Tim

 

[Eeyore]

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?

Your sound card output is band limited for very good reasons. It won't make a
truly sharp squarewave.

Graham

 

[DaveM]

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

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.

 

[Phil Allison]

"DaveM"

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

** No harmonic missing - of course.

Right out to fucking infinity ..........

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





....... Phil

 

[martin griffith]

"DaveM"


** No harmonic missing - of course.

Right out to fucking infinity ..........

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





...... Phil

It's
"Scotty, beam me up"


martin

 

[John Fields]

"DaveM"


** No harmonic missing - of course.

 

[Don Lancaster]

"DaveM"




** No harmonic missing - of course.

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.

http://www.tinaja.com/magsn01.asp


--
Many thanks,

Don Lancaster voice phone: (928)428-4073
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com

 

[Fred Bloggs]

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

ie. a squarewave that is perfectly rectalinear and has virtually
instantaneous rise and fall times.

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

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

View in a fixed-width font such as
Courier.

 

[Phil Allison]

"Don Lancaster"

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

** Why.

Since their absence would be no surprise to anyone.

Just like your brainless ASD fucked crap.

**** head.



...... Phil

 

[MooseFET]

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?

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.

 

[James Beck]

It's
"Scotty, beam me up"


martin

Damn it Jim, I'm a doctor, not a breakfast cereal.....

 

[Paul Hovnanian P.E.]

[snip]It's
"Scotty, beam me up"

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.

 

[Rich Grise]

[snip]It's
"Scotty, beam me up"

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.

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

Cheers!
Rich