Thanks to ALW for the Never Connected site.
What do you guys think of the principle and actual design? To me all is not quite clear but the main idea of using a switch to charge a cap for very short periods and only when the cap is not connected to the supplied circuit seems sound and not difficult to implement. Still, they're bound to be difficulties in the implementation.
What kind of switch to use? A MosFet? What about its own switching noise? The rest is also not so clear - swich to the rectified AC waveform or to another cap which is permanently charging? At what level of discharge to supply more 'juice'?
I wonder if any details of the patent application are known but it certainly will make a fun project.
What do you guys think of the principle and actual design? To me all is not quite clear but the main idea of using a switch to charge a cap for very short periods and only when the cap is not connected to the supplied circuit seems sound and not difficult to implement. Still, they're bound to be difficulties in the implementation.
What kind of switch to use? A MosFet? What about its own switching noise? The rest is also not so clear - swich to the rectified AC waveform or to another cap which is permanently charging? At what level of discharge to supply more 'juice'?
I wonder if any details of the patent application are known but it certainly will make a fun project.
I'm not a SMPS guy. But to me it sounds like a direct mains SMPS (stage 1), except there is this other stage (stage 2) on the output that turns on and absorbs energy from the resovior (inductor/cap) ONLY when stage 1 is off.
This sounds good in theory but don't we end up with the usual SMPS issues? Even assuming that there are solutions to these, why not just use a normal SMPS supply from the start? Mr. Pass has already pointed out that these may derive their benefits from the low primary:secondary capacitance of the switching transformers.
Where is the benefit?
This sounds good in theory but don't we end up with the usual SMPS issues? Even assuming that there are solutions to these, why not just use a normal SMPS supply from the start? Mr. Pass has already pointed out that these may derive their benefits from the low primary:secondary capacitance of the switching transformers.
Where is the benefit?
Hello -
If you are really interested in this, I would get a service manual for some of the recent high-end Panasonic DVD players. They used a technology called "Virtual Battery" that sounds to me exactly like "Never Connected" (at least from the superficial information available in the sales brochure). If they are the same (and I don't know if this is true) then Never Connected will have trouble getting a patent.
Best regards,
Charles Hansen
If you are really interested in this, I would get a service manual for some of the recent high-end Panasonic DVD players. They used a technology called "Virtual Battery" that sounds to me exactly like "Never Connected" (at least from the superficial information available in the sales brochure). If they are the same (and I don't know if this is true) then Never Connected will have trouble getting a patent.
Best regards,
Charles Hansen
Never Connected?? - Pull the other leg.
Had a look at the NC website and read Martin Colloms' review but nowhere could I find any real technical detail to make any real assessment. I take Martin's comments as being of little value since it can hardly be said that he is an unbiased reviewer. Martin has been known to "assist" in putting the best light on British products whether they are as good as he says they are or not. I dare say if this product had come out of any other country a local reviewer in that country would also have put it in the best light. Taking a review on the Accuphase PS-1200 Clean Power Supply http://www.audioasylum.com/audio/general/messages/65099.html as an example from the USA as an example, we can see that this USA product has similar benefits for audio to that claimed for the NC technology.
I did note that the remarkable NC power supply - which is supposedly "never connected" directly to the mains ac supply - is priced at UKP175 - per rail that is. A nice little earner if you are silly enough to pay that much for a number of units for each item of audio equipment. It may well produce clean power suitable for audio equipment but I doubt that it will be significantly better than a properly designed low impedance PSU which uses more conventional techniques - and at a far lower cost to boot.
How can a power supply which is "never connected" actually work? It is a physical impossibility for it to produce power - clean though it might be - without actually having some physical connection to some supply source. When it comes to ac mains supplies you can only get that power by some direct means of conversion. It is either an isolation transformer if you want the best safety, or a mains SMPS. Whichever way you go there has to be some connection to the mains supply - all the time, otherwise there would be huge voltage fluctuations which could give rise to even worse problems. Even if you can store some energy momentarily during which time the mains supply connection is interrupted and therefore "not connected" during this interruption, I can see no advantage in doing so. After the interruption is over the magical electronic "black box" still has to reconnect to the ac supply at some stage, otherwise it will stop working. The fluctuations created by this sort of operation might also produce far worse effects for other equipment than that produced even by the ubiquitous SMPS. Even these potential "noise producers" can be quite efficient when power factor correction is included and proper shielding and filtering is used when powering small signal devices such as in audio components.
Methinks this is just another high priced money earner for the gullible audio enthusiasts who have little technical knowledge.
Had a look at the NC website and read Martin Colloms' review but nowhere could I find any real technical detail to make any real assessment. I take Martin's comments as being of little value since it can hardly be said that he is an unbiased reviewer. Martin has been known to "assist" in putting the best light on British products whether they are as good as he says they are or not. I dare say if this product had come out of any other country a local reviewer in that country would also have put it in the best light. Taking a review on the Accuphase PS-1200 Clean Power Supply http://www.audioasylum.com/audio/general/messages/65099.html as an example from the USA as an example, we can see that this USA product has similar benefits for audio to that claimed for the NC technology.
I did note that the remarkable NC power supply - which is supposedly "never connected" directly to the mains ac supply - is priced at UKP175 - per rail that is. A nice little earner if you are silly enough to pay that much for a number of units for each item of audio equipment. It may well produce clean power suitable for audio equipment but I doubt that it will be significantly better than a properly designed low impedance PSU which uses more conventional techniques - and at a far lower cost to boot.
How can a power supply which is "never connected" actually work? It is a physical impossibility for it to produce power - clean though it might be - without actually having some physical connection to some supply source. When it comes to ac mains supplies you can only get that power by some direct means of conversion. It is either an isolation transformer if you want the best safety, or a mains SMPS. Whichever way you go there has to be some connection to the mains supply - all the time, otherwise there would be huge voltage fluctuations which could give rise to even worse problems. Even if you can store some energy momentarily during which time the mains supply connection is interrupted and therefore "not connected" during this interruption, I can see no advantage in doing so. After the interruption is over the magical electronic "black box" still has to reconnect to the ac supply at some stage, otherwise it will stop working. The fluctuations created by this sort of operation might also produce far worse effects for other equipment than that produced even by the ubiquitous SMPS. Even these potential "noise producers" can be quite efficient when power factor correction is included and proper shielding and filtering is used when powering small signal devices such as in audio components.
Methinks this is just another high priced money earner for the gullible audio enthusiasts who have little technical knowledge.
analog_sa said:
I would imagine they use two caps which are switched alternately. While one is connected to rectifying circuit, the other is connected to the supplied circuit and vice versa. If the frequency is high enough, the disruption in power supply in between switching is negligable as there are more caps downstream. It's pretty simple, or it seems to me
Never Connected technology
Peter, I suspect that your guess as to how it works is as good as mine. Despite the fact that NC claims to be new technology, I doubt very much that it is. It seems to me to use a variation of conventional switch mode conversion, but in the end it is still a stop-start operation with all the attendant fallibilities of this type of operation.
If it is so good, and all that the makers claim for it, then I would expect it to snapped up and used by all the medical equipment manufacturers and radar equipment manufacturers where ultra-low noise powers supplies are vital.
Peter, I suspect that your guess as to how it works is as good as mine. Despite the fact that NC claims to be new technology, I doubt very much that it is. It seems to me to use a variation of conventional switch mode conversion, but in the end it is still a stop-start operation with all the attendant fallibilities of this type of operation.
If it is so good, and all that the makers claim for it, then I would expect it to snapped up and used by all the medical equipment manufacturers and radar equipment manufacturers where ultra-low noise powers supplies are vital.
Yes, taking power from a capacitor is exactly what an SMPS does. The ac mains is first rectified and charges either one or two fairly large low esr caps to provide the low impedance source for the switcher. The idea is that the output load never really causes the stored voltage in the input reservoir caps to fluctuate to any degree. For audio equipment use an SMPS would have larger caps with lower esr and higher ripple current ratings.
Low noise power supplies
Personally, I would put more faith in using devices such as those available from http://www.soundlabsgroup.com.au/audiocom/audiocom_qpower.htm
The cost is much lower and the benefits would be indistinguishable from that claimed for NC.
Personally, I would put more faith in using devices such as those available from http://www.soundlabsgroup.com.au/audiocom/audiocom_qpower.htm
The cost is much lower and the benefits would be indistinguishable from that claimed for NC.
Older threads on the same subject:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=23723&highlight=
http://diyaudio.com/forums/showthread.php?postid=148291#post148291
Technics' "Virtual Battery" refers to a particular way of applying the voltage reference for a voltage regulator, and does not refer to the actual power source to the regulator.
hth, jonathan carr
http://www.diyaudio.com/forums/showthread.php?s=&threadid=23723&highlight=
http://diyaudio.com/forums/showthread.php?postid=148291#post148291
Technics' "Virtual Battery" refers to a particular way of applying the voltage reference for a voltage regulator, and does not refer to the actual power source to the regulator.
hth, jonathan carr
I triple dog dare you!
" I dare say if this product had come out of any other country a local reviewer in that country would also have put it in the best light. Taking a review on the Accuphase PS-1200 Clean Power Supply http://www.audioasylum.com/audio/ge...ages/65099.html as an example from the USA as an example, we can see that this USA product has similar benefits for audio to that claimed for the NC technology. "
Accuphase is a Japanese company, Sherlock. Some home court advantage.
Accuphase Laboratory, Inc.
2-14-10 Shin-ishikawa, Aoba-ku, Yokohama,225-8508 Japan
Tel. 81-45-901-2771
Fax. 81-45-901-8959
E-mail Accuphase
Mr. Carr posted a circuit but people want to sit around and discuus reveiwer bias instead of build one.
http://diyaudio.com/forums/attachment.php?postid=151191
" I dare say if this product had come out of any other country a local reviewer in that country would also have put it in the best light. Taking a review on the Accuphase PS-1200 Clean Power Supply http://www.audioasylum.com/audio/ge...ages/65099.html as an example from the USA as an example, we can see that this USA product has similar benefits for audio to that claimed for the NC technology. "
Accuphase is a Japanese company, Sherlock. Some home court advantage.
Accuphase Laboratory, Inc.
2-14-10 Shin-ishikawa, Aoba-ku, Yokohama,225-8508 Japan
Tel. 81-45-901-2771
Fax. 81-45-901-8959
E-mail Accuphase
Mr. Carr posted a circuit but people want to sit around and discuus reveiwer bias instead of build one.
http://diyaudio.com/forums/attachment.php?postid=151191
Sorry Fred, A slight oversight in my enthusiasm for the subject matter. In hindsight my example wasn't a very good one to use. I was simply trying to say that reviewers living in the country of origin of a new product technology tend to enthusiastically support the claimed virtues of that product whereas a reviewer not from the country of origin of the technology might be more objective.
Thanks for the link... however I can't see that there is any major advantage offered by the inclusion of the series transistor switches. They simply switch C4 and C5 into play on alternate half cycles. At least one of C4 or C5 is being charged on each half cycle so this PSU is always connected directly to the mains supply via the isolating transformer.
As I see it if you take the transistors and the second lot of schottky rectifiers away you wouldn't notice any difference in the effectiveness of this PSU.
Thanks for the link... however I can't see that there is any major advantage offered by the inclusion of the series transistor switches. They simply switch C4 and C5 into play on alternate half cycles. At least one of C4 or C5 is being charged on each half cycle so this PSU is always connected directly to the mains supply via the isolating transformer.
As I see it if you take the transistors and the second lot of schottky rectifiers away you wouldn't notice any difference in the effectiveness of this PSU.
Peter, the whole point of the claim made for the NC technology is that it is somehow better than other PSU's because it is "never connected" to the mains supply. So, to answer your question, yes it IS a vitally important issue.
Now, if we get down to the tin tacks of what are the design issues regarding such attempts to "build a better mousetrap" (read PSU), we should do some reading and see that it is a little more complicated than we have seen so far in this thread.
Read http://www.eie.polyu.edu.hk/~cktse/pdf-paper/PE-9505.pdf and we can see what Isao Shibazaki and others (maybe even NC) are trying to implement. Note that this paper is from 1995.
Now, if we get down to the tin tacks of what are the design issues regarding such attempts to "build a better mousetrap" (read PSU), we should do some reading and see that it is a little more complicated than we have seen so far in this thread.
Read http://www.eie.polyu.edu.hk/~cktse/pdf-paper/PE-9505.pdf and we can see what Isao Shibazaki and others (maybe even NC) are trying to implement. Note that this paper is from 1995.
In Isao Shibazaki's circuit, when C4 is being charged it is effectively isolated from the load. During this time C5 is supplying the load AND C5 is effectively isolated from the ac input. On the opposite half cycle C4 and C5 functions are reversed. From the load point of view, assuming that there is no leakage in the isolating components, I can see that there is isolation from the ac side of the supply during the time that either C4 or C5 is supplying the load. In my view this is somewhat different to "never connected" to the ac supply. If the qualification were "not connected to the ac supply while any storage capacitor is supplying the load" then I can see some argument can be made.
However, at the end of it all, the overall effectiveness of this supply, when considering the relatively low power it has to supply, will be no better than a simpler unit without the capacitor switching.
However, at the end of it all, the overall effectiveness of this supply, when considering the relatively low power it has to supply, will be no better than a simpler unit without the capacitor switching.
rherber1 said:
What is your point, actually? Do you want to discuss the technical details of NC (which are so far not disclosed), or do you want to discuss their product naming and marketing strategy. To me it seems to be the latter, and only that: what else could you talk about with no access to the units themselves and no insight into the actual circuitry.
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