Sine to square wave conversion

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

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

martin

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

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

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

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

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

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

John

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

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

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

Hello Jim,

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

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

Leon

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

I read in sci.electronics.design that Leon wrote (in ) about 'Sine to square wave conversion', on Tue, 8 Nov 2005:

...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?

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!)

If this is for a simple project, then you can inject the sine wave and a triangle wave (this can be generated with simple circuitry) through a comparator, and voila, you have a square wave.