Discussions of alternate "energizing"/charging PS units for use with UltraCap LPS-1 (not that any will make ANY difference to output)

[sandyk]

#4236

 

My "El Cheap-O LPS"* has been shut away in a closet, waiting so long to fulfill its special purpose (injecting power into the LPS-1) and now, that moment has finally arrived.

 

For those living under a rock over the past year, the El Cheap-O is a 9V/3.3A Chinese-made LPS wonder that can only be described as Der Spitzenklasse!!

 

*Trademark 2015, 4est

 

 

IIRC, it's not capable of anywhere near 3.3A and the heat sinking is far from adequate for continuous high current.

I presume this is the nice looking unit with the R-Core transformer that you are referring to ? It would most likely be a 30VA r-core and 3.3A would be the MAXIMUM A.C. current it is capable of supplying. If using a bridge rectifier, the DC current would be around 64% of that figure.

If it is, I think it may also use a LM317T voltage regulator which is only rated at 1.5A , and certainly wouldn't like supplying that current for too long without vastly improved heat sinking!

 

Alex

[kennyb123]

If you guys are referring to the attached, it's NOT suitable to use with the LPS1 !!!

 

Ugh. I figured this would do the job, so I omitted the Mean Well supply. It sounds like I might have risked overheating the El Cheapo had I been unaware of this. So thanks for the warning.

[sandyk]

Alex K.:

 

While I agree that it is smarter for folks to order the LPS-1 with the 7.5V/2.93A Mean Well (if they don't already have one that came with a REGEN), I do not think you are correct about the "El Cheapo" not being suitable. With a 9V input, the UltraCap LPS-1 only draws an intermittent 2A during each charging cycle. The web page for the "El Cheapo" claims 9V/3A, but even if it can't muster that, I am pretty sure it will handle 2A for the LPS-1.

 

But it is unlikely to make ANYTHING sound ANY different than with the Mean Well (back our blocking the SMPS' evil leakage current). Until people start reporting that Level V or VI SMPS units plugged into the wall--with their output not connected to anything--cause an effect they can hear, I will continue to say that the "energizing" supply for the LPS-1 makes ZERO difference to SQ.

 

For fun I am going to take 6 Mean Wells and plug them all into a powerstrip and plug that power strip into the socket right next to my DAC and preamp. If there is something to fear from SMPS units used for our isolated supply, I should hear that right away.

 

Alex C

I disagree with you on this one, and it has also been discussed previously elsewhere..

This design uses an LM317T which is normally rated for 1.5A maximum, and your specs say 9V at 2A.

You will see in the better photo that I have attached, that the heatsink is WAY too small for this kind of current and is likely to will get excessively hot unless beefed up.

 

Regards

Alex K

 

[sandyk]

BTW, if you decide to try this PSU for the LPS-1 with something that draws considerably more current than a Regen, it would be wise to check the heatsink temperature after a period of use. Not all voltage regulators gracefully shut down after running at an elevated temperature for a long period, despite what their specifications may claim, and may go short circuit and pass the full unregulated input voltage to the load.

 

Alex

P.S.

Also see post 122

[flkin]

I did not order Meanwell SMPS with LPS1 as I was planning to use iFi. This comment worries me and want to order Meanwell SMPS.

 

Wow, didn't know my short comment would turn into this larger issue how to supply the LPS-1!

 

Hi Audiocrazy, my experience is different from others on this site who say the iFi doesn't affect their systems. What I can do it only to relay my own singular experience with the 9V/2A iFi unit that came with my microRendu.

 

It simply doesn't work well. With it attached to a wall socket and powered, without being attached to any device, it causes a hum in my system (Airport Extreme - microRendu - RWAK240+ DAC - LIO DHT - YBA Passion 1000 mono blocks - Watt Puppies). This hum gets louder with volume levels and at normal listening levels is easily heard.

 

I have a dozen DC SMPS power supplies mostly cheap wall warts from Thailand, China and Japan. Of the wall wart SMPS units, a Japanese multi-volt unit had the lowest hum but it was still slightly audible. The iFi was the worst.

 

The supply that finally solved my hum problem was a linear lab unit made in China - the Mastech HY1803D. Zero hum even at loud volumes. Pitch black background in the music - that part perhaps caused by the microRendu :-).

 

Looking forward to trying this new LPS-1 which I have already purchased and plan to supply it with my Mastech which has sufficient oomph to run it and not cause hum issues at any volume level.

 

Why this occurs in my system but not to others I don't know. Perhaps the 2A3 triodes in the LIO DHT are more sensitive or perhaps its the battery operated RWAK240+ DAC running full balance connections. Or maybe its simply a defective iFi!

 

Anyway, the Mastech shows current consumption and I can set whatever voltage I want so it will be interesting to see what the actual current consumption of the LPS1 is.

[Blake]

And what about the El Cheap-O? I would volunteer mine and ship it to Uptone for testing. I know there are plenty of us who are using this LPS that planned to use it to power the LPS-1.

 

I may be misreading Sandy's posts but he seems to be speculating or making some assumptions on some of the specifications of this unit and testing the El Cheap-O would sort things out for once and for all.

[Jud]

Wow, didn't know my short comment would turn into this larger issue how to supply the LPS-1!

 

Hi Audiocrazy, my experience is different from others on this site who say the iFi doesn't affect their systems. What I can do it only to relay my own singular experience with the 9V/2A iFi unit that came with my microRendu.

 

It simply doesn't work well. With it attached to a wall socket and powered, without being attached to any device, it causes a hum in my system (Airport Extreme - microRendu - RWAK240+ DAC - LIO DHT - YBA Passion 1000 mono blocks - Watt Puppies). This hum gets louder with volume levels and at normal listening levels is easily heard.

 

I have a dozen DC SMPS power supplies mostly cheap wall warts from Thailand, China and Japan. Of the wall wart SMPS units, a Japanese multi-volt unit had the lowest hum but it was still slightly audible. The iFi was the worst.

 

The supply that finally solved my hum problem was a linear lab unit made in China - the Mastech HY1803D. Zero hum even at loud volumes. Pitch black background in the music - that part perhaps caused by the microRendu :-).

 

Looking forward to trying this new LPS-1 which I have already purchased and plan to supply it with my Mastech which has sufficient oomph to run it and not cause hum issues at any volume level.

 

Why this occurs in my system but not to others I don't know. Perhaps the 2A3 triodes in the LIO DHT are more sensitive or perhaps its the battery operated RWAK240+ DAC running full balance connections. Or maybe its simply a defective iFi!

 

Anyway, the Mastech shows current consumption and I can set whatever voltage I want so it will be interesting to see what the actual current consumption of the LPS1 is.

 

Re the Mastech, bunch of one-star reviews on Amazon (though to be fair the overall average is around four stars) of the general form "This POS burned out my expensive...." One review was entitled "Evil Box of Drama." So it seems QC might be tetchy.

[Albrecht]

Gents:

 

The 9V iFi iPower units that John and I have seem to work fine energizing the UltraCap LPS-1. When used for this purpose there seems to be zero sonic difference between it and the 7.5V/2.93A Mean Well tabletop that normally comes with the LPS-1. Since there is only a $15 difference between buying the LPS-1 with or without the Mean Well, perhaps some of you will find a better use for the iPower in your systems.

 

 

Lastly, I see ALL of your e-mails, and I will respond--to urgent ones first and then others as the days go. Client correspondence is VERY important to me, but it is also the least productive third of my days.

 

Thanks,

 

--Alex C.

 

Hi Alex,

 

So appreciate your comments regarding the feeder supply. Perhaps I've been reading too quickly, or perhaps I haven't been paying close enough attention, - but I just wanted to confirm that my TeraDak DC-30W-TOUCH DC9V 2.5A Linear Power Supply will work fine as a feeder supply for my newly purchased LPS-1.

 

Thanks so much, and congrats again....

[MikeyFresh]

Okay gents:

 

John and I just got off the phone. We both have digital programmable load units that we use for PS testing (the one I bought for him is fancier). And we both have iFi iPower 9V SMPS wall warts.

 

His came later, in the box marked 2.0 amps. Mine is the earlier one (courtesy of my friend Rich at Signature Sound), with the box marked 1.5A.

 

Setting aside the LPS-1, we just put our iPower warts directly onto our load boxes. Mine craps out completely at 1.6 amps, John's makes it to 2.1 amps.

 

There you have it. Sorry to report that whoever said that all the 9V units were always capable of 2.0A (and that it was just a test/certification thing) appears to be incorrect. Of course it is possible that my unit is an anomaly.

 

So at this point, those of you planning to use an iFi iPower to energize your UltraCap LPS-1 (for reasons of convenience as I have already explained it won't sound any better than the Mean Well), you need to check the label on your iPower. If it says 9V/1.5A, then it won't allow your LPS-1 to reach full current (but it is a charging mode level thing--the input is not otherwise related to the output).

If your iPower says 9V/2.0 amp then you fine for full function of the LPS-1.

We have not tested the iPower 12V/1.5A version, but that should be fine as well. Remember, the guidelines are: 7.5V/2.5A, 9V/2.0A, 12V/1.5A.

 

Honestly, the point of offering the LPS-1 without the Mean Well was mainly to save a few dollars (just $15) for the thousands of you that got the exact same supply with your USB REGEN. There are not going to be sonic differences between feeders--definitely not between SMPS--that's about 100% certain.

 

 

Very interesting.

 

It was I who mentioned iFi's stance that it was a testing certification thing, and while I haven't had time to look at all the relevant posts in this Head-Fi thread, I did find both the linked mention as well as a post from iFi themselves that was specific to the 12 volt model, where they confirmed all 12 volt models are capable of 1.8amps.

 

I'm sorry if it turns out I was passing misinformation, I did suggest end-users check directly with iFi, curious if anyone did that and what response they got.

 

I own more than one 9 volt iPower, and they do have different specs listed both on the packaging and on the units themselves.

[sandyk]

I may be misreading Sandy's posts but he seems to be speculating or making some assumptions on some of the specifications of this unit and testing the El Cheap-O would sort things out for once and for all.

 

 

What part don't you understand about it using a 30VA R-core transformer, which can be seen marked in the photo?

2 parallel windings of 9V will supply 3.3A A.C.

It uses 4 diodes in a bridge rectifier combination. The formula for DC output from a bridge rectifier into a capacitor gives a DC out of .62 of the AC input current. This gives a DC current of a tiny fraction over 2 Amps

Others have stated that this PSU actually uses an LM317T voltage regulator which is rated for 1.5A maximum

Even if they had used a 3A rated voltage regulator, the heatsink used is way too small for the desired current, and would get VERY hot. Going by the size in the photo , and checking the specifications of similar size heatsinks suggest that at the very best it will have a temperature rise of around 10C per watt of dissipated power.( around 5W at 2A current?) Add to that the ambient temperature at the time.

In reality, the heatsink shown in the photo is more likely to be rated at as high as 17c/W.

If you were to replace the existing regulator with a 3A rated type and squeeze in a taller heatsink of the same width, you MAY get close to 2A from it.

Try connecting an 8.2 ohm 10W across it's output , which will give a continuous current of just over 1A and let it run for a few hours to see how hot it gets.If possible, check that the output voltage remains close to 9V with a DMM.

If 'the heat sink doesn't get far too hot to hold your finger on it for more than 10 seconds, you MAY get away with using it.

[Blake]

Sandy, let me point out a few snippets from your posts:

 

"It would most likely be a 30VA r-core and 3.3A would be the MAXIMUM A.C. current it is capable of supplying. If using a bridge rectifier, the DC current would be around 64% of that figure...... If it is, I think it may also use a LM317T voltage regulator which is only rated at 1.5A , and certainly wouldn't like supplying that current for too long without vastly improved heat sinking!"

 

"..This design uses an LM317T which is normally rated for 1.5A maximum, and your specs say 9V at 2A"

 

These comments seem speculative to me. Simple as that. My post was not intended to be negative toward you or your expertise. You just seemed less than 100% certain in your posts and I would like to get to the bottom of this as I purchased my El Cheap-O solely for the purpose of powering LPS-1.

[sandyk]

You just seemed less than 100% certain in your posts and I would like to get to the bottom of this as I purchased my El Cheap-O solely for the purpose of powering LPS-1.

 

The transformer in the photo is marked 30VA. The PSU does use 4 diodes in a bridge configuration into an Input filter capacitor, which can be clearly seen in the photo. This means that the maximum current output from this nicely designed PSU which uses a superior R-core transformer is 2.048A. The full 2A output could be obtained if something like the LT1084 3A regulator was used instead, but the size of the heatsink would need to be increased .Other members have reported that it actually uses an LM317T, although I am unable to confirm this.

The industry standard LM317T is specified as 1.5A maximum, although the Fairchild version is claimed to have a slightly higher current output, although that is not guaranteed.

I am basing my comments on the published Uptone specification of 9V 2Amps

 

Why don't you try what I suggested about the 8.2ohm 10 W (PW10) resistor connected and running continuously for several hours and report back to the members ?

It wouldn't work nearly as hard when only powering a typical current design Regen installation though.

I would loved to be proved wrong as it is a nice looking, well designed PSU, despite the misleading specifications.

At the asking price I wouldn't mind having one to play around with myself ! It would cost me far more to put together one than that.

 

Recently I built a LM317T based PSU for audiophile neuroscience with a 9V and a 5V output to use with a Regen or a HDD.

Unfortunately, he decided to use it to power an external HDD for 24 hours continuously (poor HDD!) in order to "burn in" a component, and the LM317T eventually went short circuit due to overheating. I replaced the LM317T and fitted a larger heatsink, as well as putting a series voltage regulator before the output voltage regulator to reduce the voltage drop across it and ensure that it dissipated far less power, thus running much cooler.

A Voltage Regulator like this that goes short circuit normally passes the full voltage before regulation to the load, perhaps destroying it !

It wouldn't cause problems with the LPS-1 though, as when using a transformer such as this, the failure voltage will be only about 12V.

Click on the photo, then the resulting new photo for a clearer image where the 4 bridge rectifier diodes are more obvious.

[sandyk]

For further in-depth information please check the CA thread link below which also shows the schematic.

It uses the LT317 voltage regulator which has a maximum output of 1.5Amps according to the data sheet.

Alex

 

http://www.computeraudiophile.com/f6-dac-digital-analog-conversion/regen-power-supplies-el-cheapo-and-other-bits-25227/

[Blake]

I don't mean to clutter this thread with El Cheap-O discussion, but I do know that a number of us that planned to use it to power the LPS-1 so I do believe this is relevant. Also a disclaimer, I am a novice in this particular area. My goal is simply to clarify the specs of the El Cheap-O so we can determine if it can be used to power the LPS-1.

 

I removed the cover of my unit to investigate. I can report that the El Cheap-O does not use the LT317 voltage regulator. It uses the LT1083CP. For what it is worth, my Ebay seller said this unit has a 3.3A maximum as noted by SandyK, but said the continued current is about 2.1A. Further, he indicates that the regulator IC is fixed to the bottom of the case to further aid in heat dissipation.

 

Pics:

 

 

 

[charlesphoto]

As long as you're intent on using an el cheapo, is there any harm in using one size up, i.e. 70VAC 9V 4.4a? I use an eye cheapo on my Vortexbox and am fine with it. Picked the best spec'ced one I could find. I figure why go cheap on the cheap?

[Superdad]

In the interest of keeping the main UltraCap™ LPS-1 launch thread of getting cluttered with all the side conversations of suitability of other AC>DC converters that could be used to feed/energize/charge it, I have moved all posts on the topic over here.

 

As stated many times, the quality (noise, isolation, blockage of leakage current) of the output of the LPS-1 is 100% not affected by the the AC>DC converter that feeds it. Period.

It is also our stance that the vast majority of the evils of SMPS units in audio systems are due not to the high frequency switching noise they kick back into the AC mains as traditionally thought.

 

Modern Level V- and Level VI-certified units like the Mean Well we ship with the LPS-1 and REGEN suppress and spread their noise very high up (hundreds of Khz range), and traditional linear power supplies have their own diode switching noise down low (at multiples of 50/60Hz),and that big PS in your power amps really kicks a bunch in the wall (a big part of why power cord differences are more readily heard with power amps--they vary in filtering the harmonics going back into the wall!).

 

No, the evil of the SMPS is in the high amount of AC leakage current they transfer into the audio system (because their design requires use of what are called "Y" capacitors: read the first answer here: switch mode power supply - What does the Y capacitor in a SMPS do? - Electrical Engineering Stack Exchange). But in fact it takes more than one PS in a system (and combo of LPS or SMPS) for leakage current "loops" to form.

 

Please read this great post by John Swenson on the topic:

John Swenson's Tech Corner – UpTone Audio

 

Anyway, since the UltraCap LPS-1 does not EVER connect the output of its feeder supply (be it SMPS or LPS) to its clean DC output side (that's what the hassle and expense of the FPGA-controlled, opto-isolator filled, bank-switching scheme is all about), zero leakage current gets added into your system from the LPS-1 or whatever device it is powering.

An SMPS powering an LPS-1 might as well be powering your telephone answering machine.

 

So when considering what to energize the LPS-1 with, all that leaves is the choice between the high-spread harmonics of SMPS that is not connect to you audio system versus the low frequency harmonics (and transformer ringing) of cheap linear supplies (and the diode bridges those use are pretty nasty).

 

Very soon everyone will find out for themselves that when using our crazy new isolated supply the choice of the feeder really does not matter.

 

What does matter though is that whatever feeder/charging supply you use (ideally just the Mean Well that is normally included) meets the voltage and current specs we put forth. Otherwise your LPS-1 will not work properly. Again, those specs are:

 

7.5V/2.5A, 9V/2.0A, or 12V/1.5A--and it MUST be a REGULATED PS (all SMPS are, and most all of the linears that get considered are; but some of you may find an old unregulated transformer brick around--don't use that!).

 

And for those not well versed in power supplies, the current rating for units at any of those voltages is allowed to be higher. In other words, a 9V/3A or 12V/2A are also both fine. And hypothetically, if you had an 8V/2.5A or 11V/1.8A, those would work as well.

 

But nothing under 7.5 volts and nothing over 12 volts please. And check the current ratings.

 

Lastly, no feeder/charger (that meets the above specs) is going to change the maximum output current capability of the LPS-1. It is a 1A supply. (Today's first testing of many production boards has them maxing out at between 1.1-1.2 amps as expected)

[sandyk]

I removed the cover of my unit to investigate. I can report that the El Cheap-O does not use the LT317 voltage regulator. It uses the LT1083CP. For what it is worth, my Ebay seller said this unit has a 3.3A maximum as noted by SandyK, but said the continued current is about 2.1A. Further, he indicates that the regulator IC is fixed to the bottom of the case to further aid in heat dissipation.

You appear to have an upgraded version. The recent ads no longer mention 3.3A either.

Earlier versions were confirmed by our members in the other thread linked to, as using the LT317 so you would need to check that the designation of the actual voltage regulator used.

Note that I did suggest that the LT1083 could be used to increase the available current to 2.048 A which is a whisker away from the vendor's quoted figure of about 2.1A.

Perhaps members like 4est who have these earlier units could upgrade their units using the LT1083 if applicable ?

 

Alex

[Blake]

..you would need to check that the designation of the actual voltage regulator used.

 

To clarify Alex, are you then of the opinion that since my particular El Cheap-O has the LT1083CP (as shown in my picture), it can be used to power the LPS-1, with the only caveat being that I'd have to do the "finger touch" temperature test to determine if heat dissipation is sufficiently handled?

[sandyk]

To clarify Alex, are you then of the opinion that since my particular El Cheap-O has the LT1083CP (as shown in my picture), it can be used to power the LPS-1, with the only caveat being that I'd have to do the "finger touch" temperature test to determine if heat dissipation is sufficiently handled?

 

Hi Blake

If they have bolted the heatsink to the metal chassis as they claim with this version, then it will run a little cooler than with the original design. If you are only using it with the LPS-1 to power a Regen there should be no heat problems, as the Ultracaps will be getting topped up far less frequently. I assume that it won't have problems with a possible new Uptone Regen variant either.

If you also intend using it with other devices I would do the finger test with them. A very hot heatsink will also reduce the service life of the adjacent electrolytic capacitors

 

Regards

Alex

[Blake]

Hi Blake

If you are only using it with the LPS-1 to power a Regen there should be no heat problems, as the Ultracaps will be getting topped up far less frequently.

If you also intend using it with other devices I would do the finger test with them. A very hot heatsink will also reduce the service life of the adjacent electrolytic capacitors

 

Regards

Alex

 

Thanks for the info Alex. In my case the El Cheap-O will only power the LPS-1, and then the LPS-1 will only power my microRendu.

[sandyk]

Thanks for the info Alex. In my case the El Cheap-O will only power the LPS-1, and then the LPS-1 will only power my microRendu.

 

Incidentally, I noticed they have used a 10K trimpot instead of the marked 5K. Even when using a 5K trimpot the voltage adjustment would be very coarse, and hard to set precisely unless they have fitted a parallel fixed resistor under the PCB .

A 2K trimpot would have been better with a 9V version of this PSU.

[Superdad]

If you are only using it with the LPS-1 to power a Regen there should be no heat problems, as the Ultracaps will be getting topped up far less frequently.

 

While you are correct that his El Cheapo will likely suffice for an LPS-1 just powering a REGEN, it is not for the reason you state.

 

As we have said many times, the current draw load on the LPS-1's output does not directly affect the current drawn from the external "energizing" supply. And the frequency of bank switching (less often with lower output current) is not related to how much current the LPS-1 draws from the feeder supply.

 

However, there are two programmed modes, and the LPS-1 moves between them automatically and seamlessly. With an output draw of less than 0.5amps, the unit stays in a lower current mode (we thought it would be silly to draw 2 amps to create a half amp); above 0.5 amps the charging scheme changes to the high mode and the ratings we state for the feeder are then required.

Though I should also point out that load on the feeder supply is intermittent peaks, not steady at the max (again, not related to output draw!)

 

[The actual electronic schemes, parts, and programming of this is over my head; John explains all of these sorts of things to me in explicated detail, but I admit to sometimes glazing over and just listening for and discussing the functional ramifications of various design choices and tradeoffs. ]

 

(An example is the early, 1.5A version of the 9V iFi iPower SMPS that I possess: It works fine as long as the load on the LPS-1's output does not go above 0.5A. Even a fraction above that and my 1.5A-rated iPower fails--because the requirement then jumps straight to 2.0A.)

 

This also means that if someone puts the full USB 0.5A max-spec load on the 5VBUS of a REGEN's output (such as with a bus-powered DAC like the iFi iDSD), then that added to the tiny 50mA or so that a REGEN needs (for its hub chip and clock, etc.) might be enough to kick the LPS-1 into its full-current mode. And then an inadequate (i.e. not to our stated, required spec) feeder supply will not cut it.

 

---------

 

I wish to caution folks against speculating on the internal operation of the UltraCap LPS-1. It is a sophisticated design and guesses about it are more likely to be wrong than right.

 

---------

 

FPGA flashing, testing, and torturing of production boards has begun, and everything else is on track. Here are a couple of pics of the present programming/test station. The load box shows a board putting out 7V at 1.1 amps. (That unit has been sitting there for over an hour; I just forgot about it.)

 

 

[Jud]

there are two programmed modes, and the LPS-1 moves between them automatically and seamlessly. With an output draw of less than 0.5amps, the unit stays in a lower current mode (we thought it would be silly to draw 2 amps to create a half amp); above 0.5 amps the charging scheme changes to the high mode and the ratings we state for the feeder are then required.

 

Though I should also point out that load on the feeder supply is intermittent peaks, not steady at the max (again, not related to output draw!)

 

* * *

 

This also means that if someone puts the full USB 0.5A max-spec load on the 5VBUS of a REGEN's output (such as with a bus-powered DAC like the iFi iDSD), then that added to the tiny 50mA or so that a REGEN needs (for its hub chip and clock, etc.) might be enough to kick the LPS-1 into its full-current mode. And then an inadequate (i.e. not to our stated, required spec) feeder supply will not cut it.

 

 

So for me with an El Cheapo spec'd at 9V 3.3A, if the thing performs to spec I should be able to run a Regen powering an iFi micro-iDSD, especially if I run the micro-iDSD from its battery? (Does running the micro-iDSD from battery in fact eliminate any/all but minimal current draw by the DAC?) And if it's more like 2A, I guess I'll know; in that case I have a MeanWell.

[sandyk]

While you are correct that his El Cheapo will likely suffice for an LPS-1 just powering a REGEN, it is not for the reason you state.

 

As we have said many times, the current draw load on the LPS-1's output does not directly affect the current drawn from the external "energizing" supply. And the frequency of bank switching (less often with lower output current) is not related to how much current the LPS-1 draws from the feeder supply.

 

However, there are two programmed modes, and the LPS-1 moves between them automatically and seamlessly. With an output draw of less than 0.5amps, the unit stays in a lower current mode (we thought it would be silly to draw 2 amps to create a half amp); above 0.5 amps the charging scheme changes to the high mode and the ratings we state for the feeder are then required.

Though I should also point out that load on the feeder supply is intermittent peaks, not steady at the max (again, not related to output draw!)

 

[The actual electronic schemes, parts, and programming of this is over my head; John explains all of these sorts of things to me in explicated detail, but I admit to sometimes glazing over and just listening for and discussing the functional ramifications of various design choices and tradeoffs. ]

 

(An example is the early, 1.5A version of the 9V iFi iPower SMPS that I possess: It works fine as long as the load on the LPS-1's output does not go above 0.5A. Even a fraction above that and my 1.5A-rated iPower fails--because the requirement then jumps straight to 2.0A.)

 

This also means that if someone puts the full USB 0.5A max-spec load on the 5VBUS of a REGEN's output (such as with a bus-powered DAC like the iFi iDSD), then that added to the tiny 50mA or so that a REGEN needs (for its hub chip and clock, etc.) might be enough to kick the LPS-1 into its full-current mode. And then an inadequate (i.e. not to our stated, required spec) feeder supply will not cut it.

 

---------

 

I wish to caution folks against speculating on the internal operation of the UltraCap LPS-1. It is a sophisticated design and guesses about it are more likely to be wrong than right.

 

---------

 

FPGA flashing, testing, and torturing of production boards has begun, and everything else is on track. Here are a couple of pics of the present programming/test station. The load box shows a board putting out 7V at 1.1 amps. (That unit has been sitting there for over an hour; I just forgot about it.)

 

[ATTACH=CONFIG]29426[/ATTACH]

 

[ATTACH=CONFIG]29427[/ATTACH]

 

Alex C

I believe that we are saying pretty much the same here, although I didn't go into additional detail about the 2 modes I was aware of it. Perhaps I didn't word my reply as well as I could have ?

Kind Regards

Alex K

[Superdad]

So for me with an El Cheapo spec'd at 9V 3.3A, if the thing performs to spec I should be able to run a Regen powering an iFi micro-iDSD, especially if I run the micro-iDSD from its battery? (Does running the micro-iDSD from battery in fact eliminate any/all but minimal current draw by the DAC?) And if it's more like 2A, I guess I'll know; in that case I have a MeanWell.

 

As long as the 9V version of the El Cheapo can output at least 2.0A, then the LPS-1 will be able to output between 1.1-1.15 amps continuous guaranteed. That is well more than enough to power a REGEN that is in turn charging a 100% bus-powered DAC like the iFi iDSD.

 

I do not fully understand (or like) the iDSD's USB-bus/battery scheme--I wish the thing had a separate DC jack to power/charge it. But at least it does not seem to go over the USB spec max of 0.5A.

 

You mention "running the iDSD off its battery": I guess I do not know how you do that since anytime a USB cable (or REGEN output) is hooked up to it then you are providing it bus power (quite clean in the case of the REGEN's VBUS) and charging/running-off the battery.

 

Unless of course you are getting into interrupted USB Pin 1 cable games and running off of--and later recharging--the iDSD's battery that way.