Yup. they point out two entities, non linear loads, and magnetic saturation.
Both trivial to model and understand. With powergen, it's more important what the load nonlinearities do to the system, not really how low they can get the voltage distortion.
Sincos resolvers are the best however. They can be accurate as all getout, and they are voltage sources, not power sources.
Jn
There's a big thread about powering turntable motors from amplifiers somewhere on here.
Some old tests with back to back isolation transformers (non shielded).
The “Live Probe” schematic is from a “Wireless World” article (sorry, I can’t find year/volume number/author)
George
The “Live Probe” schematic is from a “Wireless World” article (sorry, I can’t find year/volume number/author)
George
Attachments
Looks like a good and safe test method without using a specialized probe system.
Lots of noise shown in the audio band. Dont know the noise source(s) or if that is worse case or not. Now if you just throw a Cap across the secondary lines, it will cut that down a lot.
Then power something with it (DAC, preamp) and Listen again.
THx-RNMarsh
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What can I do, that's only as far as I can reach. You are a true giant of audio engineering.
I don't know ! Put Mr Marsh in your ignore list, stop this endless harassment by yourself, or ask for a medical help ?
This is boring for the others and creates a deleterious atmosphere.
And I admire the patience of mr. Marsh and his cold blood towards you.
May-i let-you remember the rule n°1 of this forum:
"Disruptive behavior of any sort, including offensive language, trolling, threadjacking, insults, intimidation, harassment or other disrespectful or antisocial behavior."
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And in circles we go.
Already mentioned most of the distortion is from the load. The figure 2 in the cite nicely shows the unloaded generator unit under test has just about .5% distortion. That seems to still be the baseline for AC power. Lots of reasons for the distortion. How much is really due to just the winding gap? I have no clue. From a practical aspect, the distortion test weeded out bad rewinds.
We could discuss the trivia such as how tight the windings are wound, how well balanced the rotating parts, down to the bearing runout.
If we cannot see further, that's because we are standing in the footsteps of a giant!
Has been for some time. Although Brinkman are trying to claim they were the first and technics are making a big song and dance there have been coreless motors for at least 35 years. Initially either for top or bottom of the line (Gluing coils to PCB is cheap). The late 70s was a torque war in DD land and whilst the ability of the SP-10 Mk3 to spin up a 10kg platter in a quarter turn was good for DJs and a great party trick it's no longer required.
I collected a load of DD motors to experiment with and started looking at some of the off the shelf advanced motor controllers from the likes of TI and then realised there are a load of other more important things to get right first and I needed to learn a lot more about motors. I did however decide that one day I would make a behemoth TT using a washing machine DD motor for giggles.
Only you would think so.
If you get up on your knees, you can reach higher. BTW -- is there something you want to say ? Maybe about power line noise removal methods?
THx-RNMarsh
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What about line noise on the line to the amp -> output -> 10:1 step up (assuming 12.6V filament transformer)?
No, there is no circle.
You stated that gaps were the dominant based on a high school summer job rewinding 45 year old generators, I pointed out your errors. Very simple.
The rest, floobydust, bearing runout indeed. Just drop ABEC 9's in..
Jn
Ed.. When you discuss things you are an expert in, I listen...
You would be well served to also adopt that stance..
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I guess what I'm really saying is..great, you have data..where is it?I have lot's of data. No I am not going to draw the -7000 schematic for you all. You can buy one and reverse engineer it, if you like. No, I am not going to tell what the material composition of the cores are, either.
Just build what you know or idea shown here and LISTEN. Put it on your CD and one on the DAC.
Got to git. Git out of Dodge City before sun-down. .
THx-RNMarsh
Jn
Pfft. A REAL nightclub DJ would hold the disk at the cue point, tun the gain up to 11, and spot the disk from zero to full speed timed correctly, in beat.
The only requirement there was that the platter maintain speed during the hold, and when I push the disk up to speed, the table cannot overshoot due to release of torque loading of the disk and finger from hold.
The 1200's sucked because from the jump they could not slip. I would load them and they remained locked until they broke.
The SL 51 series had lots of torque, and responded well to slip.
Ps. Oh, and another gripe.. The 1200's speed control was counter intuitive, the slide was wired backwards..what were they thinking???
Jn
Ps ...and if anyone thinks it's easy holding cue on a live cart with 3 kilowatts just waiting while you simultaneously listen to program, work the lights and fog machine, and hit on the hot chicks..I've a bridge to sell you...
Pps. What REALLY gets my goat is that China is sending a probe to the dark side of the moon...
WHAT!!! DARK SIDE!!! Didn't these journalists go to grade school???? The moon rotates!!!!
Idiots. Sigh..
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Sigh..
I recently had to explain to an EE that there is NOT a range of altitudes that are geosynchronous. He was trying to tell me that there was a band of about ten thousand miles where the satellites were geosynchronous...
And he was sure because he knew a friend who knew a friend..
We are all doomed.
Jn
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