It's an enormous thread with around 4,000 posts. I have printed out a couple of the schematics, but have to figger out which one is the definitive Salas!
Funnily enough I think if the regs output noise is not correlated with the load current, then it doesnt matter very much in and of itself.
To me that, means achieving that means very low output Z over a wide bandwidth is highly desirable, but after filtering out incoming crud and being 'reasonably' quiet over a nice wide bandwidth - there's no need to go mad on noise. Focus on regulation.
What I find most interesting about those PSRR plots is that the Belleson's is, as you observed, consistent. None of the usual PSRR degradation with increasing frequency, well, at least not within the test bandwidth.
Maybe this one is also interesting Peter Daniel use this one in the Shigaclone and his DAC.
http://www.diyaudio.com/forums/digi...ransport-shigaclone-story-92.html#post2519723
Regards,
Rudy
http://www.diyaudio.com/forums/digi...ransport-shigaclone-story-92.html#post2519723
Regards,
Rudy
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Hello jackinnj,
How are the measurements at the moment now.
Have you done comparisons with the other regulators, which regulator have the best papers ?
Regards,
Rudy
Hi Rudy,
Thanks for your interest in Belleson Superpower, I recently was made aware of this thread and will be responding to various posts as time permits.
I designed the regulator and my name is on the patent application. If the patent office moved faster I could perhaps give you a schematic but we're not ready for that yet. So we can discuss performance but I suspect most DIY readers are mostly interested in a schematic.
I can tell you there is no magic, no fairy dust and no snake oil. We spent 2 years in R&D on this device, including extensive characterization, before publishing the specifications. It's not a perfect regulator but is better all around than anything else we've tested, and we continue to make improvements and enhancements.
Regards,
Brian
Hi MatchASM,
Yes, noise is not as low as TeddyReg, which has a line of praise on our web site for this performance. However, in our analysis TeddyReg does not regulate very well, given it's DC shift with output current. It also has thermal dependencies and, I suspect, fairly high Zout due to its open loop design. Low noise is important, but it's not the only important spec.
The LM317 was tested with Cin=0.1uF, Cref=10uF, Cout=1uF, R1=270 Ohms, R2=2K Ohms, Vin=30V, Vout=10.8V. An 8 Ohm load was switched from Vout to ground using a D880-Y power NPN. The SPJ Superpower uses a standard D44H11 or D45H11 output transistor.
If you are planning to use regulators in parallel, I suggest the LT3080 or something similar, not LM317.
Regards,
Brian
Belleson, LLC
Ken,
With only 9 components in the basic design, the schematic is already simplified
.Brian
Belleson, LLC
Hi jackinnj,
Our measurements for PSRR are quite different from yours, see the graph. These measurements were taken with 1Vpp not RMS, and only to 5KHz.
Also see the spectrum comparison of a rectifier signal into a Superpower and the regulated output. This shows the nasty spectrum of the semi-sawtooth out of a full wave rectifier (red) and the clean signal (green) from the regulator. Measurements are referred to 0dB=2Vrms. The rolloff above 20K is due to a filter in the spectrum analyzer.
Given the large range of bad performance from several regulators, I suspect you are measuring something other than the regulator. At these levels of voltage it's easy to get poor measured results. It's easy for a measurement to be worse than actual performance and more difficult to make something measure better than it is. The most time consuming task we have when designing tests is to isolate the measurement system errors from the DUT errors. For example, we had PSRR problems with a particular type of test socket feeding through from input to output.
You don't say how your transformer test circuit is connected, is it possible that DC current is saturating the core and skewing the measurements? This could cause errors that depend on regulator current consumption.
We use an active driven source to feed the input rather than a transformer, and are working on a PSRR test circuit that uses an LM3886 to drive the input with DC+AC.
If you are interested, we can pick a couple of monolithic 3 terminal regulators to pass back and forth in the mail until we agree on a correlated measurement or until we tire of the exercise
.Regards,
Brian
Belleson, LLC
Attachments
Ken,
I suspect some other effect is being measured in the plots, not the Superpower under test. Or perhaps the device is damaged.
Brian
Belleson, LLC
I'm curious, how long has the application been in? I've had them take up to 3 years in the past to get a patent ruling. I wonder if they are better or worse now.
It will be 2 years in June and I've yet to be contacted by an examiner. What are your patents?
That particular application which took 3 years was on an internet-related device 16 years ago - and was ultimately rejected.. We also heard nothing the entire time, despite multiple tries by our patent lawyer to get an update.
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