Announcing the next generation: UltraCap LPS-1.2 (Now 5/7/9/12V! ; Now with parallel LT3045 regulators!)

[JohnSwenson]

Unfortunately no, the LPS-1.2 is 1.1A and that's it. The design was optimized for 1A, anything higher takes a complete redesign, not just "bumping up" a couple parts. The transistors used for switching between banks will not work well at higher currents than they currently handle. Going to "beefier" transistors radically increase their capacitance which dramatically degrade the leakage current isolation. Increased current also means significantly redesigning the driver circuits to these transistors.

 

Once you start this process there is a huge cascade of effects and you wind up with a whole redesign in order to run at higher currents.

 

What this really means is that the LPS-1.2 is highly optimized for the best performance at the lowest possible price. There is no way to boost the current without completely redoing all that work. It would take a lot of work, and I can guarantee that it would be a lot bigger and cost a lot more money.

 

John S.

[JohnSwenson]

38 minutes ago, Adyc said:

A quick question. If I use LPS-1.2 to power a network switch, do I still need to use JSGT DC cable connected to the switch to stop high impedance leakage from network?

Yes, the OUTPUT of the LPS-1.2 is NOT grounded. The LPS-1.2 is isolated from input to output. The fact that the SMPS shipping with the LPS-1.2 keep high impedance leakage out of the LPS-1.2, it does not ground the output.

 

The specified switches only shunt leakage when the switch's power supply is grounded. Since the output of the LPS-1 is not grounded, it will not shunt the network leakage.

 

John S.

[JohnSwenson]

3 hours ago, agladstone said:

We all want an LPS-2.2 one day in the future to power our higher current gear! I know it sounds like a pipe dream and something that will likely not ever come to realization, but it would be a winner!  I would be glad to pay $900 - $1,000 range for one and I’m sure everyone else with DACs, etc that require larger current draw would too:) - I won’t hold my breath, but it would be a dream come true and another major sellout product for UpTone!! 

I want to stop working on power stuff for a while and get working on all the clock analysis stuff so we can get a good handle on all this clocking stuff and build some equipment where we really KNOW what is going on, I have a feeling this will be far more game changing than another power supply.

 

John S.

[JohnSwenson]

1 hour ago, sandyk said:

 

 Is the amount of effective capacitance the same at +5V as it is at +12V ?

Not that it probably matters anyway, given the large capacitance value of the Ultracaps.

The capacitor strings are exactly the same for all voltages, there are 7 ultracaps in series, each at 10F so that is 10/7 F per string all the time.

 

The string gets charged to 5V more than the output voltage. The output current pulls charge out of the string which causes the voltage across the string to drop. I arbitrarily chose 3V as the maximum drop, so when the string drops to 3V less than the charge voltage, the control circuit does a bank switch and the other cap string is connected to the output and the one that just got down to 3V below the charge level is now charged.

 

This minimum voltage across the strings is set to 1V above the output voltage of the bank regulator, which is 1 volt above the output regulator. The output regulator is always fed exactly 1V above its output. It varies for the bank regulator from 4V to 1V above the output voltage. This seems like a lot more power being dissipated by the bank regulator, but remember that a particular bank is only delivering power to the output half the time.

 

For a concrete example take 12V output, the capacitor string is charged to 17V (12+5), when that bank is connected to the output, the voltage is allowed to drop to 14V (17-3) at which point the banks are swapped. The bank regulator is set to 13V (14-1). The lowest point of the discharge cycle is 1V above the bank regulators output voltage. The output regulator is set to 12V (13-1) and always has exactly 1V from input to output.

 

As the output voltage is changed all these voltage points change as well so the voltage drop at each point in the system stays the same no matter what the output voltage.

 

So there are three adjustable voltage regulators and a bunch of ADCs monitoring the voltages all over the place in the system. This becomes way more complex because the charging system, the two banks and the output are all isolated from each other, you have to use opto-couplers to get control signals and data back and forth between them. What seems like a fairly simple system turns out to be a nightmare of complex details to make work.

 

John S.

[JohnSwenson]

2 hours ago, photonblur said:

Would the LPS-1.2 be compatible with a squeezebox touch

used as both a dac and server?

Yes it works great with an SBT, it makes a significant increase sound quality.

 

I'm not sure it can handle a USB powered hard drive plugged into the USB port though. I've never used my SBTs that way. If it is not powering a drive then yes it will work great with an SBT.

 

John S.

[JohnSwenson]

Hi All,

I finally had some time to take a production LPS-1.2 into the listening room and try it out! 

 

I have an ultraRendu powered by an LPS-1 (powered by a JS-2), feeding a Bottlehead DAC (DAC I designed about 5 years ago), The DAC was powered by the new LPS-1.2 (which was powered from the same JS-2).

 

I was not prepared for this. It was jaw dropping. I've been alternately crying, smiling like an idioot, and getting goose bumps. I thought I had this system sounding incredibly lifelike, wonderful to listen to, as good as it was going to get. Boy was I wrong! Just this addition of the new power supply on the DAC transformed it yet again.

 

First off was the bass, WOW, this has all got to be just perception but it seems like it is shaking the room much more, with less "boominess", that I didn't even realize was there. Not only does it sound "more there there" but I can now hear subtleties in the bass line I never noticed before. Like one song has TWO bass players, I never realized that before, now it is obvious.

 

The whole sound field seems much richer now. The transformation over time as my system improved, went from a kind of haze over the whole space which got energized by instruments and voices, like looking in fog, the light sources tend to light up the whole space, but individual source are spread out and indistinct. Then the fog went away and I could hear individual instruments and voices, but they were kind of grainy and the whole thing felt a little "thread bare". The previous incarnation, was filling out the sound field and the graininess was gone. But with the LPS-1.2 the whole sound field  is much richer and full and each sound source has so much more detail and finesse, like going to 4K HDR from DVD.

 

But it's not "etched" or hard or any other form of hyper detail, it is just organically "there", not hidden but not pushed forward either.

 

And this is just CD rips.

 

Summary:  WOW.

 

John S.

 

 

 

 

[JohnSwenson]

1 minute ago, austinpop said:

 

Hi John,

 

Very nice report. I'm looking forward to my LPS-1.2 now with even more anticipation.

 

One quick question for you. Have you tried driving the DAC straight from the JS-2? The JS-2 is no slouch. How would that compare to the JS-2 energizing the LPS-1.2 driving the DAC?

No, I have not done that recently, it is a little difficult to do right now, the connector on the starquad DC cable won't fit the JS-2. I would have to build another one with a different connector to try that.

 

John S.

[JohnSwenson]

5 hours ago, Superdad said:

(John decided to rewrite the entire codebase for the FPGA last week!)

--Alex C.

 

 

I know it seems like a long time ago, but it was just this week! I did in two days, Tuesday and Wednesday this week.

 

John S.

[JohnSwenson]

2 hours ago, Em2016 said:

 

Hi John S.,

 

What USB cable are you using there between your ultraRendu and your DAC?

 

Still using old faithful, the Supra High Speed Certified USB Cable?

 

Or have you gotten fancy ! :-)

 

Cheers

I'm using a USPCB, the ultraRendu sits behind the DAC, sitting on a book to get the height right. I'm using the DIY interconnects that are very flexible so I can bring them out between the DAC and ultraRendu. The only problem with that configuration is I can't see the lights on the ultraRendu. The system changes frequently and it would be nice to see the lights when I'm trying to get the system up and running in a different configuration.

 

John S.

[JohnSwenson]

3 hours ago, Em2016 said:

 

Nice, thanks John.

 

Are you using an Ethernet cable with a 90-degree connector or did you just sharply bend a stock standard ethernet cable?

 

Could you post a pic :-)

Just a regular Ethernet cable.

 

John S.

[JohnSwenson]

5 minutes ago, Em2016 said:

 

With the 90 degree USPCB to turn the ultraRendu on it's side?

 

I had trouble getting an ethernet cable in there when using the 'regular' USPCB but I just realised the 90 degree USPCB should solve that issue if turning the ultraRendu on it's side. An issues with doing that?

 

I used the regular one, but the 90 degree one is fine to use if it helps get things in and out. Just make sure the ultrRendu is properly supported so the USPCB is not supporting the whole thing.

 

John S.

 

 

[JohnSwenson]

6 minutes ago, rickca said:

@JohnSwenson or @Superdad can you please comment on the following Q&A from Farad Power Supplies designed by Mattijs de Vries from Pink Faun.  I'm not asking you to critique his product.  I just want your feedback on his comments about the downside of bank switching.

 

Why are you using the super capacitor power bank as smoothing capacitors and do you not switch between one bank while loading the other?

 

There are several reasons why we do not do this. First it means extra switching electronics in the supply lines, second it means that you are using only half of capacity of the super caps at a time. Third and maybe most important, it means that the final regulator does not get a constant voltage at its input, meaning different voltage drop, and therefore slowly varying power dissipation and temperatures all the time. This influences the output characteristics of the regulator, and the output power quality. Because in our supplies we use a choke smoothing and pre-regulation before the supercapacitor banks, noise residue will be minimal and also the necessity for switching.

I'll take the last part first, we don't just have one regulator, each bank contains its own output regulator, the output of THAT regulator is switched. The result is the final regulator DOES have a constant input voltage.

 

In my design the  primary reason for the bank switching is to block leakage current, this it does very well. Of course it also has extremely low output noise, and extremely low output impedance.

 

And yep, the bank switching makes it WAY WAY WAY more complicated!!!!!

 

Any design which is "just" using the supercaps as filter elements does nothing to attenuate leakage currents, they go right on through.

 

John S.