New John Kenny Power Supply....

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13 hours ago, Digital Assassin said:

While researching power supplies for the microRendu, I stumbled upon the new John Kenny series of ISO products..

 

this battery power supply looks nice for 250 Euros.

 

https://www.ciunas.biz/product-page/iso-ps

 

 

That's awfully expensive for an LiFePO4 battery with ">2a" ... typically batteries are rated in Amp hours. Batteries are, you know, batteries.

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6 minutes ago, plissken said:

 

My point being is he doesn't know what he's talking about. 

 

What does a fully floated supply do for you? What problem do you have that it fixes? If you have said problem how do you know? 

 

LiFePO4 batteries are well known and perfectly good batteries for battery supplies. Typically rated at 3.2 V and can be placed in series for 6.4 volts etc. They can be purchased in all the known places.

 

Batteries are all "fully" floating power supplies. They have no leakage currents because there is no ground return.  Again, eu 250 might be awfully pricey for a battery unless its large.

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3 hours ago, plissken said:

 

And what is driving your LPS-1?

 

What would you say if I told you the LPS-1 doesn't eliminate any 60Hz AC leakage?

 

Why would it eliminate leakage in a loop that doesn't involve it? Also why would you draw a conclusion from a single graph? In the absence of a schematic, the graph is meaningless.

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Just now, plissken said:

 

I didn't draw a conclusion from an unknown. I know the layout of equipment involved. 

 

You posted the graph, at the very least post the schematic.

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Just now, plissken said:

 

I don't have to. Alex said it would stop the AC leakage through the ISOR. It doesn't regardless of system topology unless Alex shows us something else. 

 

Ok then you are  posting irrelevant and out of context graphs that have absolutely zero meaning without a schematic. 

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4 minutes ago, plissken said:

 

Isolation means 'To Isolate' ergo break the path of least impedance. 

 

Huh? what are you talking about. This is a statement which is entirely of out of context to this discussion.

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2 minutes ago, plissken said:

 

How so? The claim is that it breaks the AC loop. What would a schematic do for you in this instance? 

 

If I have a copper wired streamer or computer and I'm getting AC hum via a loop and I go with your optical isolation method to break the loop why would I need to see your Visio of your network layout? I just need to see the 60 Hz and the harmonics, as a measurement, disappear. 

 

Do you understand what a floating supply is? This thread is about a battery supply. You are posting graphs that are completely out of context and without a schematic so how could I possibly know what you are even being off topic about?

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Best I can tell the Keny "PS" is a pair of LiFeSO4 batteries in a box. Nominally 3.2 V and can be 6.4 V is series. No need to assume floating PSUs are expensive. Depends on what the markup is. Since the Ah are not specified, it's impossible to know and I'd assume a large markup. 

 

Battery PSUs are a great way to quickly test a floating supply.

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9 minutes ago, Les Habitants said:

I see it's offered in a 5 volt version too, maybe only that one employs a regulator?

 

The site claims that battery output is unregulated so don't know exactly which combos are used to get to 5v

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53 minutes ago, plissken said:

If you would like to see what your system is doing, I'll make available a small, portable computer with ARTA installed, and the Behringer UMC204HD. 

When using a cheap ADC to measure a DAC another variable is introduced into the system making it more difficult to know whether you are measuring reality vs artifact. 

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2 minutes ago, plissken said:

 

How do they stop the random chemical noise of the batteries at work discharging is what I would want to know. 

 

The chem reaction can be noisy. 

Not too bad with these batteries! ... and this can be a really easy and cheap and safe soln

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http://tf.boulder.nist.gov/general/pdf/1133.pdf

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14 minutes ago, plissken said:

Not sure what you mean by 'cheap'.

You are using it as a spectrum analyzer. Are HP/Agilent/Keysight just a huge waste   of $$$? Comparative  specs?

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1 hour ago, plissken said:

 

Is the Behringer / Arta incapable of reading voltages up to 20Khz? 

 

Last time I checked HP/Agilent/Keysight were scopes in the 100's of MHz range. 

 

Ah ... consider the range as a window which can be adjusted with down mixing. So, for example, one spectrum analyzer might have a range from 0hz to 100khz in 64 usec increments. ... and say -160 dB/Hz noise floor. 

 

So 20 to 20 kHz in what increments and what is the real noise floor?

 

So at say 100 MHz, signal might be down mixed and then frequency intervals are 64 milliseconds 

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1 hour ago, plissken said:

 

Learn something new every day: Ni-Cads can be quieter than Cap-Resistor chains IN CERTAIN applications. 

 

Just wanted to make sure that was clearly stated. Interesting read, thanks. 

 

Yes! ... and it isn't always immediately obvious what the "best" soln is... batteries are like a huge cap with high ESR ... one can follow the batts with a supercap, followed by a faster and faster cap to reduce effective ESR but if not done the right way the chain can introduce more noise. There are active circuits that can smooth noise as well.

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4 hours ago, plissken said:

 

What do you call the 60/120/180 etc sprurie? Why is it 60 Hz? 

 

When is 60/120/180 fundamental and even/odd harmonics not AC leakage or capacitance of some kind? Does the LPS1 prevent AC loop?

What is your interpretation of this?

 

 

 

 

Hmm...

 

I would try:

 

1) use a battery alone (without meanwell)

2) use a battery and plug the meanwell into something else

3) xformer isolate the spectrum analyzer

etc...

a) not enough info to draw firm conclusions,

b) big point: that leakage current is not typically just at the fundamental AC frequency rather higher frequencies generated by the switching circuitry.

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15 minutes ago, pkane2001 said:

 

There are only a few possibilities for leakage.

 

1. Through ISO-R

2. Through the common, in-the-wall wiring and ground

3. Through the air, RF/EMI

4. Through the AP power supply: this was already disproved

 

I asked Amir to redo the test with AP and ISO-R on independent circuits (one on a battery/UPS) to eliminate #2. He didn't think this kind of leakage was possible. Still looks possible to me, although not likely.

 

What is your definition of "leakage" and how are you measuring it? I've asked for a schematic. Simply measuring the output of a DAC is not measuring the leakage current.

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1 minute ago, pkane2001 said:

 

I didn't measure this. Amir did. He measured ISO-R powered by LPS-1, powered by MeanWell SMPS into a USB-powered DAC. He posted AP-generated power spectrum showing AC fundamental and harmonics at the output of the DAC. The fundamental was about 20dB above noise floor. When MeanWell was replaced with a lab linear power supply, these frequencies disappeared from the DAC output. You'll find a lot more details on the ASR thread, no reason to duplicate it here.

 

 

Well the graphs were posted here and you are talking about leakage here. If I wanted to participate in another discussion somewhere else I could and would. Some measurements were made but we have no reason beyond hand waving to determine that these are leakage currents. There are well known ways to analyze and measure leakage currents heck there are even standards that discuss this. It isn't good form to draw conclusions about things that aren't being measured, but who knows? Why would you draw conclusions about leakage currents when you are simply measuring DAC output? I mean thats more appropriately PSRR (I am assuming with the very little info I have). PSRR and leakage current are two different things.

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19 minutes ago, pkane2001 said:

 

How about you read the ASR thread, and then come back here so we can discuss your questions. It makes no sense for me to duplicate everything that's been tested and reported there. It's multiple pages of posts and contains many tests and multiple measurements.

 

I'm not really that interested. It is well known that SMPS like the meanwell can induce leakage circuits in equipment plugged into the same AC circuit. I fully trust that @JohnSwenson designed a perfectly excellent floating supercap supply. If there is a leakage circuit I'd seriously doubt its through the LPS-1.

I have many many times recommended that the analogue audio circuitry be isolated (I personally use both Topaz low leakage cap as well as the Equitech Q behind my best stuff). I also use Plitron transformers in the linear PSU's I've built. I go encourage folks to go out and get some NiCad batteries and use them when convenient.

 

I think the Meanwell issue is not that interesting actually and am wondering why it is still being discussed???

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8 minutes ago, pkane2001 said:

 

It's interesting because LPS-1 is sold with MeanWell SMPS. And because LPS-1 is claimed to eliminate all AC leakage currents and ground loops. Having AC frequency and harmonics introduced into the DAC output that didn't have them without these Uptone Audio products is, in my opinion, an important thing to know for someone considering their purchase (as I was).

 

 

If you were actually considering the purchase, you obviously would not use the specific  Meanwell ... or any other cheap SMPS ... instead you could use a "Medical Grade" SMPS or Linear Supply -- I don't know why it would need even to be regulated -- the supercap shouldnt remember how smoothly it was charged  

 

Again what does this have to do with battery supplies? and the point has been made over and over in other threads ... why the perseveration?

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3 minutes ago, motberg said:

My GUESS is that the JK battery PS unregulated version is using some type of "trickle-charging" method to hold the output voltage stable while the batteries discharge... not sure.. but he has offered this type of idea previously to improve the original Regen and was very well received from the folks I read who tried it.  Would multiple battery cells need to use some type of balanced charging system?

 

1) the trickle charger when left "connected" can transmit leakage current 

2) its recommended to use a balancing circuit with multiple cells -- can be tricky to charge and drain at the same time

 

3 minutes ago, motberg said:

 

Another comment - I have had other (kind of DIY style) battery supplies that sounded great (perhaps preferred in my system to the LPS-1), but they proved unstable and twice I had problems with cells overheating (once when I inserted a cell reversed polarity).. so to me a safe, plug and play, usable battery PS that could be preferable sound-wise in some systems to a regulated supercaps PS would have some value.

 

 

You can either use a switch to switch between charge and drain mode *or* dual bank battery supply -- see DIYAudio -- the LPS-1 is available and reasonably priced for what it does.