A Toronto eatery named "New York Subway" doesn't necessarily have anything at all to do with New York. ;-) But I'll bet a place called "Syriandipity" has something to do with Syrians.
Cool.
Best regards, Spehro Pefhany
-- "it\'s the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
Cadbury's sometimes gives you a little extra, at least in the UK:
"Half a million bars of Cadbury's chocolate suspected of being contaminated with salmonella have been eaten by the public over the past six months, the company admitted yesterday as it took seven of its most popular brands off the shelves."
Best regards, Spehro Pefhany
-- "it\'s the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
Chocolate is actually an anti-bacterial, and a Cadbury bar isn't, so perhaps some conclusion might occur to someone here.
John
Hmmm... let me try.
Induction heater:
120VAC for low level stuff 240VAC 1ph for power, and thus +/-160VDC for inverter +12V for control/protection circuit +/-16V (for regs) +12V, -6Vreg (reg, both for main circuit) UC3842 grabs +16V for 2 x isolated +12/-6V (gate drive)If you don't accept mains lines or grounds, then that's 11. *shrug*
Tim
-- Deep Fryer: a very philosophical monk. Website: http://webpages.charter.net/dawill/tmoranwms
Ahmmm...when you actually try this, with the constraints of an IC and its generic specification, it is indeed more difficult than one might think. As I noted, there are some tricks you can do, but there are problems with them. If you could be bothered to actually try to design an ic LDO in detail you would see what those issues are. You are not looking at the whole picture, principle because you haven't actually done the details.
Kevin Aylward B.Sc. snipped-for-privacy@anasoft.co.uk
"There are none more ignorant and useless,than they that seek answers on their knees, with their eyes closed"
This would come across as a whole lot less arrogant, and be far more useful, if you were to enlighten us as to those details. not all SED participants are IC designers. Besides, it sounds like there is some interesting stuff here to learn.
Cheers Terry
I am just stating facts. It really is true that if one does actually get down to the nitty gritty, rather that having just an overview of the basic principles, all sorts of problems crop up. The pros at analog devices, linear tech, TI etc are not all daft, although some might well be.
For me, the issue is the time it takes to explain these details, hence the tese comment.
For starters, a standard product has to deal with a huge range of possible conditions. In particular for LDOs, 1uf is a target chips often target, but they still have to be stable on 1000uf. A technique I have used to obtain "any cap" is to use a standard dual feedback loop. That is, a comp cap at an internal output, with a resister from this point to the external output. The dc feedback is taken from the external output. The issue with his is that it puts a resister in series with the output, and whilst not effecting accuracy as the dc loop includes it, it raises V dropout. This resister acts equivalently to putting esr in the load cap, which stabilises the loop.
Typical issues? A key spec is transient load response. It is hard to get fast load response and optimise the feedback for all load conditions. If the part was not so general purpose, it would be easier to optimise. This generic nature of standard parts is what is often missed by those claiming that they can do better, but haven't actually tried.
Kevin Aylward B.Sc. snipped-for-privacy@anasoft.co.uk
"There are none more ignorant and useless,than they that seek answers on their knees, with their eyes closed"
We commonly do discrete designs that our customers can load with arbitrary cable lengths and capacitances.
One of my favorite opamps is the LM8261, which did it right. I often use it as a "power supply", driving it as a follower or an inverter from a voltage divider off another precision rail, and powering the usual array of chips and bypass caps. Running in any of the usual closed-loop opamp configs, it will drive any capacitive load. They simply put the dominant pole at the output pin, which is pretty much what we usually do.
Of course it's not easy, but there's no excuse for any name-brand IC house to not get it right. They are, after all, supposed to be experts, and it disappoints me whan somebody like National or Analog Devices produces something medioicre or buggy.
John
The problem is that the current crop of young bucks have no "hands-on" experience, only simulators.
They can't even design and build their own audio equipment.
...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
Well, it _IS_ one of the four major food groups:
Cheers! Rich
Ellefino. WTF NAO?
Where's the roast chicken group ? There's one cooking in my oven right now.
Graham
Hello Jim, Hello John,
The proof in the pudding is that there are indeed several stable versions. Marketed with names such as "AnyCap". To me it almost feels as if a car company would market cars that stall in some situations and other that don't. Where the ones that don't cost more.
Yeah. Robert Widlar has passed away, Bob Pease is retired, and I guess they have "streamlined" their ranks a bit towards younger age. Not a good thing, usually.
Or even fix it. I had a hunch of that slightly before getting my degree. A student, also just shy of that coveted masters but with much better academic performance, asked me to fix the TV after lightning had hit the house. Would throw a crate of brewsky for the guys, so I agreed. Took
1/2hr tops and when trundling back home on my bike I just shook my head. Some diode, a cap, a fuse and a little bit of PCB trace, that was all.-- Regards, Joerg http://www.analogconsultants.com
Hello Kevin,
Which begs the question: Why does everything new these days have to be LDO?
Case in point: I just needed a very low Iq regulator to get a large battery voltage (24V) down to 5V. A device that would fulfill the Iq requirement of under 5uA and was available was the TPS71550. Had to actually burn off another 6-7V beforehand. It is an LDO and in that kind of application which is a very common scenario nobody needs an LDO. A truck battery doesn't go down to 5.5V or you'd have some serious problems. And if it ever does this means it won't make a difference whether the connected circuit works or not.
So, do engineers dream up these LDOs because it sounds nice and Marketing makes them do it?
-- Regards, Joerg http://www.analogconsultants.com
You're lucky.
One of my tasks as a kid helping in my Dad's TV repair shop was to remove the transformer from an apartment house CATV line amplifier that had been struck by lightning.
It was one of those multi-winding transformers with a bundle of wires coming out a hole in the bottom of its case.
When the lightning hit the potting compound boiled and blew out of the transformer into the chassis, then solidified :-(
...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
Thanks Kevin, that was informative.
Cheers Terry
you could try google. North Atlantic Oscillation, wot brings warm water up the east coast. the one that reversed in "the day after tomorrow"
Cheers Terrt
Want to see an example of today's "engineering"...
06.22.06 Electronic Design, pp59-60...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
So those of us who don't get the hard copy immediately rush over to
And guess what? No page numbers anywhere. So it's difficult to figure out which article you are referring to. Any hints, such as the author's name, or even the title, would be great!
Hmm... Linear has a 4GHz mixer further down the page I may take a look at. And Bob's mailbox looks interesting...
Regards,
Mike Monett
That's my biggest problem in finding a regulator these days - something that's cheap, and has a low Iq to keep a uC alive.
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