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Mystery revealed: UpTone Audio "UltraCap™ LPS-1"

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Jud   
@ John S.:

 

If you had the Mean Well SMPS and the "el Cheapo" LPS, which one would you'd rather use with your forthcoming UltraCap™ LPS-1 to power a microRendu?

 

Regards,

 

Guido F.

 

Not John.

 

The impression I get, having read it being repeated several times by Alex (perhaps also by John, not sure) is that the LPS-1 won't pass any garbage from the supply that powers it, so the choice is pretty much purely which supply injects less noise back into the AC mains. I believe that would be the El Cheapo.

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Unless I'm reading this incorrectly, a different way to think about the price is that this power supply when combined with the new microrendu gives you everything that two power supplies plus a Regen and a Sonicorbiter would have gotten you!

 

At least I hope that's the case as it is where my next two purchases will likely be. :)

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jtwrace   
Not John.

 

The impression I get, having read it being repeated several times by Alex (perhaps also by John, not sure) is that the LPS-1 won't pass any garbage from the supply that powers it, so the choice is pretty much purely which supply injects less noise back into the AC mains. I believe that would be the El Cheapo.

 

That's correct. All the SMPS or LPS that's plugged into the LPS-1 is doing is charging the Ultracapacitors. That's it. The input quality of the power supply means NOTHING for the output quality.

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rickca   
Gee Rick, you are always so nosey. ;) Just kidding, it is a fair question.

I certainly wasn't asking you to tell me what you're paying John. That's none of my business. I don't think it's unfair to include significant R&D engineering costs in the product price. We are buying both the design and the implementation.

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Superdad   
I certainly wasn't asking you to tell me what you're paying John.

 

I know you weren't Rick.

 

I don't think it's unfair to include significant R&D engineering costs in the product price. We are buying both the design and the implementation.

 

Well now you are making me feel guilty--I should pay John more! :)

 

But with two kids in college and this "fancy" new production space in under construction…

 

 

IMG_0658.JPG

Edited by Superdad

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sbgk   

In general ultracapacitors do not have a hard end of life failure similar to batteries. Their end of life is defined as when the capacitance and/or ESR has degraded beyond the application needs.

Cap failure under typical use condition

image011.gif

 

https://www.tecategroup.com/ultracapacitors-supercapacitors/ultracapacitor-FAQ.php

 

Does this reduction in capacitance over time cause any concerns ?

 

The article says cycle life > 500,000, but scale in above graph is 5000 H, which isn't that long.

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John,

 

Very kewl!

 

Question... is the output floating such that it gains a ground reference when it is connected to the powered component so that it could be used either as a positive or a negative supply?

 

That would make it double kewl!!!

 

Greg in Mississippi

 

YEP!

You can hook the positive of one to the negative of the other and get:

1) a bipolar supply (+ and -) if you use the connection between them as the output "ground"

2) double the output voltage using the two in series.

 

For number two you could get 12V by setting one to 5 and the other to 7. Many combinations here.

 

Because the outputs are completely isolated from each other AND the charging side you can do all kinds of things with these.

 

John S.

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Yes, 18W should be more than sufficient. I understand it pulls 1A to 1.4A nominal?

Lets hope it also pass the inrush voltage swing.

 

The 1.4A is the current that charges the ultracap strings. What the LPS-1 pulls from the feeder supply is dependent on its voltage. It takes 18W, the current is whatever is necessary to give 18W at the feeder voltage.

 

Because the charger is a switching regulator the power remains constant, so the current changes with voltage. Kind of like the way transformers work.

 

BTW there is no inrush current from the LPS-1, the charger is a constant current source so it just pulls 1.4A, so the current from the feeder will be the appropriate current for that voltage, no large inrush current.

 

John S.

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In general ultracapacitors do not have a hard end of life failure similar to batteries. Their end of life is defined as when the capacitance and/or ESR has degraded beyond the application needs.

Cap failure under typical use condition

image011.gif

 

https://www.tecategroup.com/ultracapacitors-supercapacitors/ultracapacitor-FAQ.php

 

Does this reduction in capacitance over time cause any concerns ?

 

The article says cycle life > 500,000, but scale in above graph is 5000 H, which isn't that long.

 

We talked with the manufacturer about this and it turns out the degradation is actually caused by the temperature of the internal materials, which is determined primarily by the current flowing through the capacitor. Our use of the capacitors is WAY WAY below what they were designed for, so the upshot is that they should last a very long time.

 

In our use, as the capacitance decreases it just shortens the time between switches, you will never even notice it.

 

John S.

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Superdad   
YEP!

You can hook the positive of one to the negative of the other and get:

1) a bipolar supply (+ and -) if you use the connection between them as the output "ground"

2) double the output voltage using the two in series.

 

For number two you could get 12V by setting one to 5 and the other to 7. Many combinations here.

 

Because the outputs are completely isolated from each other AND the charging side you can do all kinds of things with these.

 

John S.

 

Man, now you are trying to put me in the custom 'Y' cable business! ;)

There could be an additive "Series" cable and then another one that would have to have a 3-pin jack for positive, negative, ground bipolar connection.

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I like the idea of using the FPGA to control the data is receives from the various points on the circuit via ADC, they would need to be isolated from the circuit they are measuring to prevent leakage back the measuring point? Few other points to raise, just speaking out for now.

 

 

As raised by sbgk, the temperature that the super capacitor is rated like all large electrolytics affects the lifetime of the caps, as well as the amount of voltage applied to the cap.

 

 

If you use this calculator from Illinois Capacitors, the calculation is dependent on the two values. Not sure at the design temperature John Swenson rates the LPS-1, but definitely not more than rated (!). At first I entered values for 60C for the cap and ambient of 22 and only received some 8000 hours, egads. The voltage on the cap depends on the ratings of course, from Illinois, the voltage rating is quite low around the 2.5V something. If you only apply say 1V or 1.5V, the lifetime hours increase to the sky, some several hundred thousands hours which is a lot better! If several caps are in series, the output voltage of 7V can be achieved comfortably and the lifetime of hours is reasonably long.

 

 

All the above is looking good, there's one other issue of the feeder power supply. That output needs to be regulated to a point to avoid damage at startup due to overshoot especially on a 12V supply. See post. I'm OK with this requirement but to find a PSU capable of this feature is another matter as for manufacturers to stick to the regulation figure as promised. As a safeguard, would the recommend action be if you doubt the supply to use a 9V only?

If a cheapie SMPS is used for the front end, it sends back shite through the AC and the current draw in this case is not load dependant anymore but a constant (higher) value. This means the use of a regulated linear supply to feed the LPS-1 as advised is a better option.

 

In this case, the LPS-1 can be considered an isolator first, and it regulates the output as a bonus :) Any garbage from the load device will only circulate in the output stages of the LPS-1 and not find its way back the main AC and contaminate.

 

 

Will there be any plans to build the LPS-1 into the JS-2 to avoid multiple connections and connector nightmares? Alternatively create a "JS-2 mono" with only the one output?

 

 

One other question, is the output of the LPS-1 short circuit proof? A supercap can discharge energy very well.

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Superdad   
I like the idea of using the FPGA to control the data is receives from the various points on the circuit via ADC, they would need to be isolated from the circuit they are measuring to prevent leakage back the measuring point? Few other points to raise, just speaking out for now.

 

…snip, snip..

 

One other question, is the output of the LPS-1 short circuit proof? A supercap can discharge energy very well.

 

Hi Gary:

 

I am sure John will address your questions in full.

There are a number of things about the design that you appear to be misunderstanding. There are 11 opto-isolators on the board and 4 separate ground planes. No noise carom the FPGA or switching regulators on the "dirty" side can contaminate the output side.

 

John's comment about overshoot of a feeder supply was just an admonishment to not use an unregulated 12V brick. The spec on the input regulator that the feeder supply feeds is something like 18V.

 

Truly no plans to build an LPS-1 into a JS-2...

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Doak   
When I use ultracap to power the regen which in turn powers my Usb dac, would the ultracap have enough capacity to power both?

 

What are the power requirements of your DAC?

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Superdad   
When I use ultracap to power the regen which in turn powers my Usb dac, would the ultracap have enough capacity to power both?

 

Yes, a REGEN--powered by an UltraCap LPS-1, or really any supply capable of powering a REGEN--is able to provide full USB 5VBUS power to your DAC or DAC/headphone amp.

 

USB 2.0 max allowance for a single device to draw is 500mA (0.5 amps), but the 1A ultra-low-noise regulator we use in the REGEN for the 5VBUS can easily provide 800mA+ to those rare devices that exceed the industry spec (such as the PUC Lite converter).

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Hi Gary:

 

I am sure John will address your questions in full.

There are a number of things about the design that you appear to be misunderstanding. There are 11 opto-isolators on the board and 4 separate ground planes. No noise carom the FPGA or switching regulators on the "dirty" side can contaminate the output side.

 

John's comment about overshoot of a feeder supply was just an admonishment to not use an unregulated 12V brick. The spec on the input regulator that the feeder supply feeds is something like 18V.

 

Truly no plans to build an LPS-1 into a JS-2...

 

No real misunderstandings, just a guess since there but a brief description so far in the thread. If the optos are used for voltage measuring feedback, the LED needs a modulation so as to provide some kind of PWM on the other side to interpret the value. There are a few approaches of course, the modulation would need to be on the output (load) side, which is not nice, but a quick google search revealed optically isolated voltage sensing modules a plenty like this one. The input impedance is G Ohms so it's invisible to what's being measured. Not dictating what should be done, just to narrow down what methods are used for measuring/feedback for interest.

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I like the idea of using the FPGA to control the data is receives from the various points on the circuit via ADC, they would need to be isolated from the circuit they are measuring to prevent leakage back the measuring point? Few other points to raise, just speaking out for now.

 

 

As raised by sbgk, the temperature that the super capacitor is rated like all large electrolytics affects the lifetime of the caps, as well as the amount of voltage applied to the cap.

 

 

If you use this calculator from Illinois Capacitors, the calculation is dependent on the two values. Not sure at the design temperature John Swenson rates the LPS-1, but definitely not more than rated (!). At first I entered values for 60C for the cap and ambient of 22 and only received some 8000 hours, egads. The voltage on the cap depends on the ratings of course, from Illinois, the voltage rating is quite low around the 2.5V something. If you only apply say 1V or 1.5V, the lifetime hours increase to the sky, some several hundred thousands hours which is a lot better! If several caps are in series, the output voltage of 7V can be achieved comfortably and the lifetime of hours is reasonably long.

 

 

All the above is looking good, there's one other issue of the feeder power supply. That output needs to be regulated to a point to avoid damage at startup due to overshoot especially on a 12V supply. See post. I'm OK with this requirement but to find a PSU capable of this feature is another matter as for manufacturers to stick to the regulation figure as promised. As a safeguard, would the recommend action be if you doubt the supply to use a 9V only?

If a cheapie SMPS is used for the front end, it sends back shite through the AC and the current draw in this case is not load dependant anymore but a constant (higher) value. This means the use of a regulated linear supply to feed the LPS-1 as advised is a better option.

 

In this case, the LPS-1 can be considered an isolator first, and it regulates the output as a bonus :) Any garbage from the load device will only circulate in the output stages of the LPS-1 and not find its way back the main AC and contaminate.

 

 

Will there be any plans to build the LPS-1 into the JS-2 to avoid multiple connections and connector nightmares? Alternatively create a "JS-2 mono" with only the one output?

 

 

One other question, is the output of the LPS-1 short circuit proof? A supercap can discharge energy very well.

 

I ran the numbers for the caps we are using under the conditions we are using them at and it comes out to be around 70 years, that should be sufficient.

 

Yes, the output is short circuit proof. There are two mechanisms, the regulators limit the current to about 1.5A and an ADC measures the output current, the FPGA will disconnect the bank from the output regulator if it gets too high. So if you short the output you will get about 1.5A for a few miliseconds then the output shuts down completely. The LED will start blinking red when an over current is detected. It will try and reconnect every few seconds, when the short is removed it will continue normally.

 

Any regulated 12V supply should be fine for feed supply (as long as it supplies the correct current).

 

John S.

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Jiffi32   
Man, now you are trying to put me in the custom 'Y' cable business! ;)

There could be an additive "Series" cable and then another one that would have to have a 3-pin jack for positive, negative, ground bipolar connection.

 

Yes please! We know how much you enjoy making good quality cables by hand!! :-)

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The 1.4A is the current that charges the ultracap strings. What the LPS-1 pulls from the feeder supply is dependent on its voltage. It takes 18W, the current is whatever is necessary to give 18W at the feeder voltage.

 

Because the charger is a switching regulator the power remains constant, so the current changes with voltage. Kind of like the way transformers work.

 

BTW there is no inrush current from the LPS-1, the charger is a constant current source so it just pulls 1.4A, so the current from the feeder will be the appropriate current for that voltage, no large inrush current.

 

John S.

The inrush statement of mine was merely tied to the risk of frying the LPS-1 if the feeder was not regulated. I now understand that the LPS-1 could survive <18VDC.

How about building a choke on the LPS-1 input mitigating any damage?

 

Have you been able to stress test the iFi iPower yet?

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