From the original patent ( NASA, Frank Nola) I remember the target was inductive AC motors and basically just reduced the voltage until a PF of 1 was achieved. This saved power in the Apollo command module, but in practice for energy savings more down to earth, proper start and run caps were just about as good. I do not understand at all how that would effect SMPS noise.
Thanks Fred.
I was being a bit simplistic by just putting a small series resistance in the voltage source so I would at least get some nice half wave ripple to tax the input stages. I could tell there are issues I want to look at like the charge time of big caps in the CCS. Sonicly, I am fine. I just don't want to have any rail to rail bouncing issues that let the magic smoke out. I will build a more complete PS model. That means I can't be lazy and I have to actually select the caps I will use.
I was being a bit simplistic by just putting a small series resistance in the voltage source so I would at least get some nice half wave ripple to tax the input stages. I could tell there are issues I want to look at like the charge time of big caps in the CCS. Sonicly, I am fine. I just don't want to have any rail to rail bouncing issues that let the magic smoke out. I will build a more complete PS model. That means I can't be lazy and I have to actually select the caps I will use.
I should have pointed out that what I was talking about is so-called active power factor correction. Utilities typically do passive PFC with capacitors and inductors to compensate for inductive and capacitive loads. But passive PFC cannot correct for nonlinear sources of bad power factor, like half-wave and full-wave rectification in power-consuming devices.
Cheers,
Bob
You are correct. Even PFC PC's put a lot of wide band noise on the ac line. It isnt just heavy loads, either. get the same hash from a little CD player. Here are some measurements I made a few years back. A CD player and a PC and a lamp dimmer are 3 examples of zillions. They ALL put noise on the ac line and the total of everything 'on' at the same time is an amazing amount of energy/junk which we are not prepared to remove in our A-V gear (will add too much cost to the product, if they did).
< before and after filtering. 
Note the freq of some home electronic gear are low enough to be difficult to remove.... line harmonics of significant levels (and at only 1.2A load).
Thx-RNMarsh
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The line harmonics will be largely removed by the PFC, but the wideband hash will not be removed by PFC.
The sources of this junk are indeed prolific.
Proper control of conducted and radiated emissions, both egress and ingress, does add some cost to equipment, but there is no excuse, other than snake oil and ignorance, for the expensive high-end audiophile gear to not manage it.
It is certainly a much bigger deal than just using expensive power cords
.Cheers,
Bob
The before and after is via my line filter. The -5100 prototype. Mid priced. Nothing good is cheap. After the economy crashed and left us with only the bottom feeder stores, like Wal-Mart and Best Buy, there was no place to sell them. But if you can find them on eBay, you'll likely get the best you can find in ac line filtering outside of heavy duty commercial units. The best one is the -7000. With two ultra high rejection isolation transformers (triple shielding techniques) and more complex filters and protection. I have some data curves around somewhere.
BTW-- the one which removes freq below 1KHz (but not 60Hz) was never built... I use that one in my home system. Sorry about that.
THx-RNMarsh
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The active PFC you are discussing must be a different circuit than the Nola. The schematic published in Popular Electronics was a triac controlled by an op amp and chopped the line. It was bound to make a lot of hash. I see the circuits in the patent are bit more complicated. Could one of you point me to the circuit in question?
I can;t find reference to the original patent. Circa Apollo time frame. Only newer ones
This one seems to be an update
https://www.google.com/patents/US7855524
I can;t find reference to the original patent. Circa Apollo time frame. Only newer ones
This one seems to be an update
https://www.google.com/patents/US7855524
While doing a Google search it made it appear that the monster high end line filter is still available. Doing a cursory search there were instances where no improvement in sound was found while in other applications like a house with aluminum wire they liked the unit. Seemed to be very dependent on the mains line problems before the unit.
I would think it is a bit obvious, a filter can't improve a LACK of problems. Most of us do not have such wonderfully clean lines.
A house with aluminum wire has the terrible potential to have some bad connections and arcing. A call to 911 frequently follows. Maybe not having a decent line filter is giving the resident a hint to look carefully before bad things happen. Then get decent filters.
I kind have a beef with the power line filter business. Power lines are designed to light bulbs and turn motors. Everything else, is the problem of unit maker. In the computer industry, we understand this and have large PDU's in the data centers to deal with issues and the commercial computer manufactures require this. In our house, above the big box level, I EXPECT the amplifier-cd-etc to be built correctly with the intention to be plugged into ugly power lines. I should not have to buy an external filter box. What excuse is there in a $1000, or $10K amplifier, not to have whatever is necessary to work in the environment for which they are intended?
A house with aluminum wire has the terrible potential to have some bad connections and arcing. A call to 911 frequently follows. Maybe not having a decent line filter is giving the resident a hint to look carefully before bad things happen. Then get decent filters.
I kind have a beef with the power line filter business. Power lines are designed to light bulbs and turn motors. Everything else, is the problem of unit maker. In the computer industry, we understand this and have large PDU's in the data centers to deal with issues and the commercial computer manufactures require this. In our house, above the big box level, I EXPECT the amplifier-cd-etc to be built correctly with the intention to be plugged into ugly power lines. I should not have to buy an external filter box. What excuse is there in a $1000, or $10K amplifier, not to have whatever is necessary to work in the environment for which they are intended?
tvrgeek,
Agreed! Seems that this should be a part of the design of all the power supplies of good audio devices.
I think that aluminum wiring in California is totally illegal after Alcoa tried that in commercial buildings back in the 70's and had to rip that all out. I would think that would be a national standard.
Agreed! Seems that this should be a part of the design of all the power supplies of good audio devices.
I think that aluminum wiring in California is totally illegal after Alcoa tried that in commercial buildings back in the 70's and had to rip that all out. I would think that would be a national standard.
Once every one is on board about the noise injected into the power lines and it is from within the home mostly, rather than incoming from utility company --- then the issue can begin to be solved. Its awareness and education. And, then its competing price for that item... it will increase cost of the gear. But, high end stuff isnt doing their job if they produce it, they should be able to clean it up, too.
Aas far as some hearing and not hearing... yes, it depends on the noise on the lines. It also depends on the filters and how good they are. For the Monster line the audiophile entry point is the 5100 model and above. lower priced models just cannot get it done as well or as thoroughly. Plus the protection is also progressively better and more thorough. Which is something you wont hear but will pay for (plus UL testing and Approval).
I've promised Linear Audio an article about this subject.
Thx-RNMarsh
Aas far as some hearing and not hearing... yes, it depends on the noise on the lines. It also depends on the filters and how good they are. For the Monster line the audiophile entry point is the 5100 model and above. lower priced models just cannot get it done as well or as thoroughly. Plus the protection is also progressively better and more thorough. Which is something you wont hear but will pay for (plus UL testing and Approval).
I've promised Linear Audio an article about this subject.
Thx-RNMarsh
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Yes, excellent article IMV. I will build a DC blocker shortly to solve this problem.
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