The Wien-bridge circuit is named after German Professor Max Wien (1866 - 1938), whose name is not spelled Wein. (Wien, pronounced "veen", is how the city of Vienna is called in German, whereas Wein, pronounced "vain", means wine.)
Consult for more information on Max Wien.
Did your "intermittent" bulbs show this effect only when used in the Wien-bridge oscillator? Then your oscillator may have suffered from "squegging", a common problem when these circuits are run at higher frequencies and at low lamp power.
I'm sorry, I misspelled it. I'm usually very careful about that because it P's me off that I have to do searches with both spellings to get all the hits on the web. i'm a bit out of sorts right now.
The lamps were intermittent and could be measured on an ohmmeter, as the bulb was plinked wsith the finger.
Martin was correct about everything, except the improvised english phonetic code for "vine".
Considering he is a german that little mistake is understandable.
The english word vine means the tree/bush we get grapes from, and make wine from. The word vine comes from the same root as wine. (pun intended)
The w sound does not exist in continental european languages. The word wine is exclusively english. In other languages the wine is called vine, or vin.
When I was 10 years I started to learn english in school. I used to train on the w sound on the way to school. Whaaooouww, whaaooouu, wooaanderful!, whooaat?..
It was more like imitating a blues mouth harmonica than normal speaking. Very strange language, english.
There are a lot worse languages to learn. French and Danish have the "feature" that the end of every word is silent. This makes it a lot harder to learn, as the spelling has very little to do with the actual pronounciation.
English and Chinese are both based on words. Therefore they are similar in many ways. On the other hand, chinese and swedish have different melodies from english.
In english there is a preregulated melody, we learn it as the antepaenultima rule. It means that in english the tension is always on the third wowel sound from the end of the word, or the first wowel if there are fewer than 3 wowel sounds.
This rule creates a very regular melody, which has just two kinds of tension, full tension or no tension. The melody becomes very restricted. That is why english who hear swedish think it sounds like singing.
I have thought about this, and I see it as yet another example of how stiff minds are created and upheld by this cultural pattern we live in.
We are stressed up on purpose to keep our minds confused. We would relax automatically if there were not some people who try to stress us up. And why do they shout and fight and threaten on tv every day?
It is part of the old creationist tradition, to "create" strong minds, to create the holy spirit, to build it up through holy wrath, to create the eternal love and the holy matrimony, upholding gender roles and social power systems from the stone age.
Strong minds are driven by fears and obsessions, convictions and traditions, honor codes and shame, boredom and restlessness, violence and social dominance.
-- "Electricity is of two kinds, positive and negative. The difference is, I presume, that one comes a little more expensive, but is more durable; the other is a cheaper thing, but the moths get into it." (Stephen Leacock)
Austrian pronunciation is often quite different from Prussian... and if you take Yiddish too, which is a dialect of German with Hebrew and Slavic words thrown in, 'vain' is probably quite accurate. Vayter, nokh un gletsl vayn... oy!!
A subminature Variac with a little guy to twist the knob....
--
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that\'s close........[v].(301) 56-LINUX
Unless the host (that isn\'t close).........................pob 1433
is busy, hung or dead....................................20915-1433
Many years ago, the use of a simple pilot lamp was common to regulate current to crystal oscillators and maintain the gain in precision sine oscillators. The filament resistance is almost linear with a positive tempco from cold until just before the lamp just begins to glow. As the lamp glows brighter, the resistance grows by a factor of 10. Lamp life is reduced by something like the fifth power when you go beyond the rated voltage.
I did not read these sites, but I surely thought that 11th power was a little on the optimistic side of reasonable for life as a function of voltage, with "usual figures being around 12 to 13, and "alarmist" citable figures being 14 and even 16! And that this went both ways when the lamp is not a halogen one.
==============================
As for disadvantage of designing incandescent lamps to last longer: Suppose you got for free some magic lossless transformer to feed your 120V lamps 110V from a 120V line:
These lamps would have power consumption reduced by about 12% and light output reduced about 24, maybe 25%. Increase your electric bill by almost
16% to restore original light output and *how long* would the lamps have to last in order for you to achieve savings?
How about some numbers guessed by me: You originally had a 60 watt
120V lamp ("lightbulb"), and now you apply 109V to a 75 watt 120V 750 hour one that at 120V produces 1190 lumens. At 109V, the 120V-75W one consumes 65 watts and produces about 875 lumens, close to usual (870 lumens) for a 120V 60 watt one designed to last 1,000 hours.
The 75W 120V one at 109V should typically last, using -13 as an exponent, about 2600 hours. The 120V 60 watt 870 lumen one typically is designed to last 1,000 hours at 120V. Over 1,000 hours, that extra 5 watts of electric power consumption, at USA typical rate of 10 cents per KWH, costs 50 cents. If lightbulbs cost
50 cents you break even if you make them last forever at 109V - but with aging at about 39% of that at 120V, the break-even point here is if lightbulbs cost 50 cents /.61, or about 82 cents apiece. In my experience, I never had to pay more than 40 cents apiece for "regular" (A19) lightbulbs since I know a bit how to shop for them. One hint: Lowes!
There were congressional hearings sometime back, I believe in the 1960's or the early 1970's, into the "short" design life expectancy of "regular" A19 120V lightbulbs. It turned out that designing filaments to run hotter, even to the pouint of lasting only 1,000 or 750 hours, was economically justifiable even if no value was placed on labor for replacing lightbulbs.
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.