Self-commutated H bridge. Running at 400-600 Hz with DC up to 2 kV and output current up to 1 kA.
The original design uses three thyristors in each "leg" of the H. The reason is that fast thyristors were not available at 2 kV at the time of its conception and birth.
It seems to be time to...
I am running a column in the Swedish paper Elektronik i Norden http://www.elinor.se/hur-gammal-kan-elektronik-bli.html/ where different topics are covered. A Little like Bob Pease did in Electronic Design.
A question about elctrolytic capcitors and how capacitance changes with voltage was...
The ubiquitous rotating exciter with thyristors shorting the excitation winding to turn it into a starting winding has been used for decades. And mostly done its thing as expected.
The trigger units, we have had problems with Siemens and ABB ones, start to show problems. They are sometimes...
I never tried that subject line before. But I did add three exclamation marks for clarity and better understanding. Didn't I?
The problem:
Anyone seen a UUUUUUUUU task card for Dranetz?
Or, more realistic: How to proceed? The manual doesn't say.
I haven't used this one for more than fifteen...
About ten years ago, customers all over Sweden (and probably also in many other countries) noticed that their electric bills jumped sky-high after "intelligent meters" had been installed.
I did tests with three different brands of meters plus an old analog watt-meter (Norma class .5) and also...
The phone rang just before midnight. That is usually a bad omen - someone needing immediate help with some critical equipment. I am all for THAT kind of problems. But this was different.
One of the electrical guys was replacing a 4 kV motor, probably around a few MW size. The motor was...
I don't need the basics of ternary. But I need a reference to a text where it is shown how to add/subtract +1/0/-1, +3/0/-3 etcetera (in Excel would be nice) so I don't have to hand-calculate a zillion combinations. I started to make mistakes at +81/0/-81.
Google says a lot about ternary - some...
Need a simple device that can feel a contact closure and transmit the 1/0 state over around 100 m distance. More is better.
It shall be used for temporary check out of measurements and there is a demand for low latency, or at least consistent latency. Either less than around 500 us latency or...
I receive so many letters from guys that want me involved in sending them money. Or something. But Mr. Braunwalder Garland gets the prize: He asked me "Did you" (die, that is).
So, I answered him like this:
Thanks a lot for your kind letter, Mr. Braunwalder!
Yes, I died last year, not last...
Suddenly this morning, my keyboard or PC or whatever refused putting the same thing on screen as I pressed on the keyboard. A few examples. Paranthesis became * and (. AT in mail addresses became nothing, Exclamation mark works ! and period, too. Our diacritic letters, aa ae and oe, became {@...
There are sometimes minutes of pure joy and beauty. Not so often in engineering - but they do occur. Like yesterday.
We live in a very mineral rich part of the World, the Bergslagen in Sweden. Not far from us, to the west, is the Långban mine. One of the mineral-richest mines in the World. If...
An escalator went amok a few days ago. Started moving backwards with lots of people on it. Speed way above nrmal. Brakes didn't work.
Coupling bad, was my first thought. Today, there is a picture in the papers showing the coupling.
The press spokesman (yes, a male)said that the accident was...
Hello all! I have been absent for a few weeks. Not dead, not ill. Just a lot of work and no easy internet access. But, just you wait! Back again - with a load of questions.
The first one is this: Do Capstone gas turbine generators aged somewhere between 30 and 40 years have CSI inverters to...
Looking for a bunch of these processors. DIP difficult to find.
Any tips?
Gunnar Englund
www.gke.org
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Half full - Half empty? I don't mind. It's what in it that counts.
I found this waveform (measured L1-PE) in a 400 V grid:
Fifteen years earlier, I found this:
The ringing could also be seen on the MV side of the transformers.
The utility guys said there was nothing to see. Their Fluke and Dranetz analyzer didn't show anything. That is understandable as...
Anyone tested this?
Thoughts?
Gunnar Englund
www.gke.org
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Half full - Half empty? I don't mind. It's what in it that counts.
I did my first measurements on machines like these 15-20 years ago.
The exciter shorts out the excitation winding during start (high induced voltage due to high slip makes the control unit gate the thyristors on) and when near synchronous speed, the induced voltage is reduced so the thyristors...
A dominating business magazine (electroics) sent me a link to a book so I could brush up on measurement techniques. The book is sponsored by another company, known for modular instrumentation with a “no programming” programming language – which means that it is graphical instead of text based.
I...
I got soo tired when trying to connect to a little breadboard weighing around ten grammes and using test clips/cables with 1 mm2 Cu cables. The tiny EZE-hooks dont't work very well if you need to attach to female connectors and they can't be used to probe tiny IC pads.
So I took a tour around...
Needs: 4 rows 16 or 20 characters. No graphics. Light-emitting or reflective with background light. Light on/off/intensity selectable. Colour OK but not necessary. Mature technology.
Constraints: Shall work from -20C to around +50C. Lowest possible (<10 mA) power consumption. Life better than...
