Sine to square wave conversion

[john jardine]

[...]

What program are you using?
My server seems to have lost some replies


martin

www.filter-solutions.com/

(Same here. I've been seeing 0% original posts and only about 70% otherwise.
Suspect my server company is chiseling on costs).
regards
john

 

[Jim Thompson]

[...]

What "-prog-" are you using?

www.filter-solutions.com/
regards
john

Expensive! Do you know anything about a program called "Elsie" ?

...Jim Thompson

 

[john jardine]

Expensive! Do you know anything about a program called "Elsie" ?

...Jim Thompson

Yes. It's (now) very pricey, I'm using an old version but is one of only 3
windows programs on this PC, I actually like using.
Till now hadn't come across Elsie. Seems lots of fun. Am going to download.
regards
john

 

[Joerg]

Hello Jim,

Mark IS the client ;-)

Cool. Haven't met any of my clients on Usenet yet, at least not in
English speaking forums.

I like Mark's word 'semi-disposable'. Reminds me of a story where some
EEs frowned when they saw a lack of heat dissipation capacity. The
answer was simply "Well, it ain't going to ever have to run more than
two minutes and then its all gone".

Regards, Joerg

 

[Jim Thompson]

Hello Jim,

Cool. Haven't met any of my clients on Usenet yet, at least not in
English speaking forums.

I like Mark's word 'semi-disposable'. Reminds me of a story where some
EEs frowned when they saw a lack of heat dissipation capacity. The
answer was simply "Well, it ain't going to ever have to run more than
two minutes and then its all gone".

Regards, Joerg

Ask me about my work with TOW missiles some time ;-)

...Jim Thompson

 

[Joerg]

Hello Jim,

Ask me about my work with TOW missiles some time ;-)

That would indeed be interesting. IIRC those live less than 30 secs.
When they were introduced I was still a student and quite frankly I
thought that this wire scheme would never be reliable. Seems it does work.

Regards, Joerg

 

[Riscy]

I have used 4 pole low pass filter for 40KHz which is sufficient for
this application. It give out nice sinewave output as long it fixed to
the specific frequnecy. You have to watch out for component tolerance
and drift with temperature as this may contribute distortion.
The alternative is to use DSS from analogue device, it give out nice
sinewave and lot of feature for very compact package...this device is
truly amazing for what it offer(!).

Good luck

 

[Jim Thompson]

Hello Jim,


That would indeed be interesting. IIRC those live less than 30 secs.
When they were introduced I was still a student and quite frankly I
thought that this wire scheme would never be reliable. Seems it does work.

Regards, Joerg

From 1970-1973 I ran the hybrid electronics group at Dickson
Electronics.

The TOW voltage regulator was a hybrid composed of a (gang me with a
spoon) uA723 plus a power boost transistor.

It was in a TO-3 package.

However, due to the short run time, we chose a steel package instead
of aluminum, due to steel's capability to store more heat... there was
NOTHING to heatsink to ;-)

...Jim Thompson

 

[Fred Bloggs]

The TOW voltage regulator was a hybrid composed of a (gang me with a
spoon) uA723 plus a power boost transistor.

What don't you like about the '723, it's still in mass produced open
frame linears to this day.

 

[Jim Thompson]

What don't you like about the '723, it's still in mass produced open
frame linears to this day.

Difficult to stabilize and still get good transient behavior over -55°
to +140°C when used with a boost transistor.

In later versions we used an OpAmp (actually, IIRC, it was a 709 ,
a TC'd zener (Dickson's primary product), and a pass device biased by
the I(VCC) of the OpAmp, to make a low-dropout regulator.

...Jim Thompson

 

[John Larkin]

Difficult to stabilize and still get good transient behavior over -55°
to +140°C when used with a boost transistor.

In later versions we used an OpAmp (actually, IIRC, it was a 709 ,
a TC'd zener (Dickson's primary product), and a pass device biased by
the I(VCC) of the OpAmp, to make a low-dropout regulator.

...Jim Thompson

There are times when the power pins of an opamp are more useful
outputs than the output.

John

 

[John Larkin]

I have used 4 pole low pass filter for 40KHz which is sufficient for
this application. It give out nice sinewave output as long it fixed to
the specific frequnecy. You have to watch out for component tolerance
and drift with temperature as this may contribute distortion.
The alternative is to use DSS from analogue device, it give out nice
sinewave and lot of feature for very compact package...this device is
truly amazing for what it offer(!).

Good luck

What's interesting is that they are cheap, and pretty much nobody else
is in the business.

John

 

[Joerg]

Hello Jim,

Difficult to stabilize and still get good transient behavior over -55°
to +140°C when used with a boost transistor.

But the old 723 was still one of the best regulators. I always liked its
noise performance and most RF pollution left it unfazed. When it comes
to linear regulators (which I really don't do much anymore) it is stil
my favorite.

In later versions we used an OpAmp (actually, IIRC, it was a 709 ,
a TC'd zener (Dickson's primary product), and a pass device biased by
the I(VCC) of the OpAmp, to make a low-dropout regulator.

In mil and med they still use a lot of the old stuff from Robert
Widlar's and Bob Pease's days. Because it works and they don't like
surprises (for good reason). Else some of the chips probably wouldn't be
around anymore. A half year ago that saved the bacon on one of my
projects where I really needed the LM331 V/F converter.

Regards, Joerg

 

[Jim Thompson]

Hello Jim,


But the old 723 was still one of the best regulators. I always liked its
noise performance and most RF pollution left it unfazed. When it comes
to linear regulators (which I really don't do much anymore) it is stil
my favorite.


In mil and med they still use a lot of the old stuff from Robert
Widlar's and Bob Pease's days. Because it works and they don't like
surprises (for good reason). Else some of the chips probably wouldn't be
around anymore. A half year ago that saved the bacon on one of my
projects where I really needed the LM331 V/F converter.

Regards, Joerg

That's why the MC1530, MC1488, MC1489, all the PLL stuff, and who
knows what else that I designed in the '60's are still being
manufactured ;-)

...Jim Thompson

 

[Joerg]

Hello Jim,

That's why the MC1530, MC1488, MC1489, all the PLL stuff, and who
knows what else that I designed in the '60's are still being
manufactured ;-)

Often there is even a contractual clause that requires a part to be
available decades from the design-in decision.

Longevity is the beauty of chip design. My analog circuitry usually
lives between 5 and 10 years in production plus who knows how long in
the field (I know one machine from 1988 is still cranking). One design
is now well past the 10 year mark and still in full production, with
another one following close on its heels. The 1st product is full of
CD4000. What blew my mind is that some sales engineer from the
manufacturer told me (about 15 years ago!) that these chips would be
obsolete soon. Knowing what else was out there with lots of these chips
in there I knew that wasn't true.

Regards, Joerg

 

[Leon]

Most military equipment has to have a life of at least 30 years.

Leon

 

[John Woodgate]

I read in sci.electronics.design that Leon <[email protected]>

Most military equipment has to have a life of at least 30 years.

....until it's deployed. Then it's a BAD insurance risk.

But it's crazy; since it will be so seriously out-of-date as to be
useless, if not actually dangerous to the user, about two years after it
was made, why make it to last 30 years in stores?

 

[Richard the Dreaded Libertarian]

Most military equipment has to have a life of at least 30 years.

Yeah, and they do that by practically overhauling everything on a
daily basis. Well, I was only in the USAF, as an avionics tech,
but there are hundreds, maybe thousands, of support personnel whose
only job is to keep the equipment operational.

Albeit, if you're a hobbyist, it's an exceedingly handy place to
get mil-spec parts. ;-)

Cheers!
Rich

 

[Ken Smith]

But it's crazy; since it will be so seriously out-of-date as to be
useless, if not actually dangerous to the user, about two years after it
was made, why make it to last 30 years in stores?

It depends on what it is. A 50 year old gun can still kill you plenty
dead if it has been well maintained.

Remember the last scene in Raiders Of The Lost Ark? A few hundred of
those boxes contained something I designed for the US navy in the 1990s.
Just this year, they decided to scrap them. They don't keep everything
forever. Some hightech stuff gets replaced.

 

[[email protected]]

Remember the last scene in Raiders Of The Lost Ark? A few hundred of
those boxes contained something I designed for the US navy in the 1990s.
Just this year, they decided to scrap them. They don't keep everything
forever. Some hightech stuff gets replaced.

You mean the Navy not only has flux capacitor time field modulators,
they've already scrapped the initial batch?

(Raiders of the Lost Ark dates from 1981, so getting your 1990's gizmos
into the boxes must have been some trick!)