One of the best practical jokes I heard about first hand was on an anal, tyrannical and bullying station boss.
One of the duties of the overnight tech staff was to sneak into the bosses office each night and tweak just one of the paintings just a few degrees.
A few months of this drove the boss near to madness I am told.
Dan.
One of the duties of the overnight tech staff was to sneak into the bosses office each night and tweak just one of the paintings just a few degrees.
A few months of this drove the boss near to madness I am told.
Dan.
A good comment! Everybody is entitled to his opinion, and the best way to oppose somebody else's different views is to sit down and make whatever to prove the validity of your own views. Instead of shouting where is your proof, if that0s what you want to talk about, then make one along my lines, measure it, listen to it and then come to tell me I'm wrong.
Ambient is 72F/22C
Temperature of the heatsink appears at ~110F, 20C higher than ambient.
Dissipation is ~4.35W
The heatsink is similar to a 2.5'' high Fischer SK129, which does 5 C/W.
4.35 times 5 makes ~22C above ambient.
Make the heatsink area 5 times as large, and temperature will be ~4C above ambient.
How smart you reckon that would be ?
Respect in these times of know-it-all Wikipedia readers is all but lost. Too many egos just can't take it. Petty minds first dispute your theory and then demand proof, which they don't have the knowledge to refulte themselves. Never mind that you may be referring to a proprietary circuit you have been working on for years and which has beem hailed by reviewers and the public and has been sold for years. Often without ever actually hearing it work.
Thanks a lot.
Not that I am DIYing anything. I was curious about given an Increased surface area would the 'whole' material be at constant temperature ? or Highest at the (lets say mosfet contact area) and less at far end of heat sink. There by heat propogation rate is increased. I was also thinking about new heatsink idea that would have a copper block whose area is ultrasonically welded to sintered Aluminum block with fins.
Thanks again and regards.
Mr EUVL wrote an article on that.
Audio magazine in Germany did a thermal scan of a Threshold SA/1e monaural in '91.
The SA/1 has a bottom + top row of 9 equally-distanced TO-3's mounted on a heat spreader, to which 4 identical heatsink sections are bolted.
During and after the heat-up, the color imaged heatsinks of the SA/1e look like a psychodelic LSD trip compared to the single-ended class A image you linked to.
The SE heatsink is in the order of 1.5''x1''x2.5''
The heatsink area of an SA/1e something like 8' high, and 16'' deep.
A small heatsink will be closer to a point source, only a point source will have uniform heat/temperature distribution.
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You're not seriously sticking to that story. The box has nothing functional in it. You could hang an N50 magnet in a large coil and get maybe uA at milliVolts. Look up geophones the application that started the high gain instrumentation amp business.
It is a stretch considering the MEG folks delusional since they support their claims with "measurements". After all they say it will work even in your basement.
That would be hard since I don't hear these things. I can clamp a cheap RFI damping ferrite over any of the cables in my system and I don't hear anything, so according to some I'm deaf or a liar.
John will now intercede and point out that I don't have any gear that could possibly resolve at his level.
So then I can just spew random ideas and claims, and these should be accepted as fact until someone goes to the trouble of proving me wrong - cool! Or does this just apply to an anointed few?
https://www.youtube.com/watch?v=EV4N2dk0cMk
Not to anointed anyone, only tothose who emphatically counter-claim that what was said is not so. Otherwise we come to a point of ridiculusness - if I say it does work, I have to prove it, while those who claim it doesn't work don't have to prove it.
Recently, I went through that situation, although not here - I posted a schematic of a two stage, passive EQ phono amp, and several local "geniuses" promptly proclaimed that the said schematic could not work at all. Then I posted the original picture scaned from a reputable German magazine which published the project, with serious measurements, and suddenly the "geniuses" were nowhere to be found. Perhaps the were unable to prove Burr-Brown (one of whose engineers made the device) to be wrong?
You're not seriously sticking to that story. The box has nothing functional in it. You could hang an N50 magnet in a large coil and get maybe uA at milliVolts. Look up geophones the application that started the high gain instrumentation amp business.
It is a stretch considering the MEG folks delusional since they support their claims with "measurements". After all they say it will work even in your basement.
It seems you have followed the claims a bit more than I care to. But if I get energetic may try to see how much power a small magnet and coil can provide. BTY the patent did start with a battery for the power source.
Some how I just don't think the costs of a patent and publicity will ever get paid back before the failure to perform catches up.
That will be greater emf then, not current, for any given rate of change of flux. Current available depends only upon what might limit it, such as external load or self resistance of coil - or upon the resultant mechanical impedance affecting ability of the generator to move
That will be greater emf then, not current, for any given rate of change of flux. Current available depends only upon what might limit it, such as external load or self resistance of coil - or upon the resultant mechanical impedance affecting ability of the generator to move
The oldie of maximum power transfer occurs when source impedance matches the load. Now this doesn't work for most sources but in this case is relevant. A bigger magnet efectively lowers the source impedance not only by greater flux but also allows more close coupling.
Optimum power generation occurs when the magnetic losses equal the resistive loses.
Ever consider what would happen to a nuke plant if the source actually matched the load?
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They used to openly solicit $3,000,000 from rich widows, etc. for the benefit of society as a whole. The secrecy is usually necessary so the "biggies" don't get a hold of it and suppress the technology. Yadda, yadda, it goes around and around.
Great idea! Crowd funding for my anti gravity space ship! Can I interest you in a ticket for the first public flight?
Bill,
My only experience with energy harvesting is in unwanted energy when measuring loudspeakers. Every consultant specifies that the impedance of every loudspeaker must be measured and recorded. This actually tells me they have never tried it! When I use a TOA ZM-104 impedance meter to measure a loudspeaker in a stadium, it gives me a decent reading on the woofer. It however swings wildly on the horn loaded compression driver, which can be a 30% efficient transducer. As the meter applies around a volt to the device under test that would be .125 watts. So the back energy would be at least .04 watts from the outside noise and wind. Now that is probably more than you would get sitting on a shelf, but hey it is something.
Lucky,
You are indeed correct in all the theory, so let us leave it at a larger magnet will increase the power available. Do let me know if you ever do a motor or generator design.
Now the test question for the floor. If I have two identical transducers except one has 20 turns on the voice coil with a DC resistance of 4 ohms and a rated impedance of 8 ohms and the other has 40 turns with a DC resistance of 8 ohms and a rated impedance of 16 ohms, when driven by a appropriate band limited source of pink noise at 2.83 V RMS with a crest factor limited to 6 dB, which one will be louder? (Measured 1 m on axis.)
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