Soekris Dam Dac

[nige2000]

is there such a thing as amp hour to farad conversion?

the heater coil died in the ps900 handpiece
decided to try one of these
http://www.ams-electronics.co.uk/shop/s ... handpiece/
got a few tips too there is 3 different temp ranges i got cool and really hot
both tips work exceptionally well
slightly prefer the really hot ones as there a smidge faster to work with
definitely prefer them to the stock tips and handset and the bonus is there's no heater coil its all in the tips which are similarly priced with an even larger selection

[jkeny]

is there such a thing as amp hour to farad conversion?

Nope they're measures of two different things - one is charge & the other capacitance

the heater coil died in the ps900 handpiece
decided to try one of these
http://www.ams-electronics.co.uk/shop/s ... handpiece/
got a few tips too there is 3 different temp ranges i got cool and really hot
both tips work exceptionally well
slightly prefer the really hot ones as there a smidge faster to work with
definitely prefer them to the stock tips and handset and the bonus is there's no heater coil its all in the tips which are similarly priced with an even larger selection

This fits the Metcal solder station?

[nige2000]

is there such a thing as amp hour to farad conversion?

Nope they're measures of two different things - one is charge & the other capacitance

just trying to figure what the capacitance of a a123 cell is

comparing a supercap to a a123 is not unlike the difference between small a123 and big a123 in sq

the heater coil died in the ps900 handpiece
decided to try one of these
http://www.ams-electronics.co.uk/shop/s ... handpiece/
got a few tips too there is 3 different temp ranges i got cool and really hot
both tips work exceptionally well
slightly prefer the really hot ones as there a smidge faster to work with
definitely prefer them to the stock tips and handset and the bonus is there's no heater coil its all in the tips which are similarly priced with an even larger selection

This fits the Metcal solder station?

yes there compatible
http://sonatechnologies.in/sona/wp-cont ... al-OKi.pdf

the rumours/chitchat on forums is that thermaltronics was started up by some of the metcal engineers as soon as the patents were up
and there basically thermaltronics stuff is more or less a clone

[jrling]

just trying to figure what the capacitance of a a123 cell is

comparing a supercap to a a123 is not unlike the difference between small a123 and big a123 in sq

Interesting. Although I am not exactly sure what you mean by that? Which is better?

Have you tested supercaps? Presumably a couple in series at 2.5V giving a 5V output? What size?

Is not the interesting difference between supercaps and A123 for our use, the speed they react to changes in current demand from the audio device? I read that supercaps are the quickest device in that regard, have very low ESR and if looked after are everlasting. Their only disadvantage v. A123 is that their 'Stored Energy' not being float charged is quite limited. I still harbour doubts over float charging in real time as a concept, in that surely as the charger is in parallel with the A123/supercap, any noise from the charger is passed directly to the audio device? I would love you to disprove that statement!

nige2000 wrote:
is there such a thing as amp hour to farad conversion?
Nope they're measures of two different things - one is charge & the other capacitance

Prof.Keny sounds like the answer I would have been given by my Physics teacher at school - appended with "Silly Boy"!

But perhaps I could put forward a slightly different answer/question, which nige may have been asking -

Supercaps do have a rated 'Stored Energy' figure. Maxwell's Supercaps are as follows (in Watts per Hour):

BCAP0650 - 0.66 Wh
BCAP1200 - 1.22 Wh
BCAP1500 - 1.52 Wh
BCAP2000 - 2.03 Wh
BCAP3000 - 3.04 Wh

Looking at the A123 26650 datasheet, they are rated at 2.4 Ah and 3.3V. I calculate that to be 'Stored Energy' of 8 Wh - assuming of course there is no deterioration in the battery's output over an hour which is unlikely.
Actually, I thought the disparity would be much greater in favour of the battery.

Just to finish the picture, ESR comparatives are
A 123 26650 -(1kHz AC typical) - 6mΩ
BCAP3000 - 0.29 mΩ
which is probably why the supercap is 'faster'.

Jonathan

[jkeny]

just trying to figure what the capacitance of a a123 cell is

comparing a supercap to a a123 is not unlike the difference between small a123 and big a123 in sq

Interesting. Although I am not exactly sure what you mean by that? Which is better?

Have you tested supercaps? Presumably a couple in series at 2.5V giving a 5V output? What size?

Is not the interesting difference between supercaps and A123 for our use, the speed they react to changes in current demand from the audio device? I read that supercaps are the quickest device in that regard, have very low ESR and if looked after are everlasting. Their only disadvantage v. A123 is that their 'Stored Energy' not being float charged is quite limited. I still harbour doubts over float charging in real time as a concept, in that surely as the charger is in parallel with the A123/supercap, any noise from the charger is passed directly to the audio device? I would love you to disprove that statement!

I guess a full set of measurements that characterises both supercaps & LiFePo4 batteries is what's needed but I doubt we will see this. However, caps have a resonant frequency called the Self Resonant Frequency (SRF) above which the device is no longer has any impedance - in other words it lets noise through unabated. This is why it's usually recommended to parallel different value capacitors together, usually the one with the highest SRF (smallest capacitance) closest to the PS pins of an active device - the idea being to suppress the PS noise over a wider bandwidth than one cap alone.

In all our experience with LiFePo4 batteries, this seems to not happen - it's role as a capacitor inherently covers a wide bandwidth & it is quite unique in this regard. This is just extrapolating from my & Nige's experience in it's noise suppression role in the various places it has been used & found to benefit matters with lower noise results - from KHz to GHz signalling

nige2000 wrote:
is there such a thing as amp hour to farad conversion?
Nope they're measures of two different things - one is charge & the other capacitance

Prof.Keny sounds like the answer I would have been given by my Physics teacher at school - appended with "Silly Boy"![/quote]Thanks but I hope I don't come across as some somebody who thinks I'm superior or know-all - I'm just asking questions & delving into what interests me & sometimes I bring it back here - hopefully in an interesting way that doesn't put anybody down? No question is silly - questions asked are often the way one does some research & discovers things that hadn't occurred to you before. So, I would never mean "silly boy" - it's arrogant to assume that one knows everything

But perhaps I could put forward a slightly different answer/question, which nige may have been asking -

Supercaps do have a rated 'Stored Energy' figure. Maxwell's Supercaps are as follows (in Watts per Hour):

BCAP0650 - 0.66 Wh
BCAP1200 - 1.22 Wh
BCAP1500 - 1.52 Wh
BCAP2000 - 2.03 Wh
BCAP3000 - 3.04 Wh

Looking at the A123 26650 datasheet, they are rated at 2.4 Ah and 3.3V. I calculate that to be 'Stored Energy' of 8 Wh - assuming of course there is no deterioration in the battery's output over an hour which is unlikely.
Actually, I thought the disparity would be much greater in favour of the battery.

Just to finish the picture, ESR comparatives are
A 123 26650 -(1kHz AC typical) - 6mΩ
BCAP3000 - 0.29 mΩ
which is probably why the supercap is 'faster'.

Jonathan

What I think Nige was getting at was the effectiveness of each device as a noise suppression device. He mentioned the smaller LiFePo4 battery having about the same noise suppression effectiveness as the supercaps so I see where the capacitance comparison comes from.

One thing that I think has to be considered & it's something I've been interested in for a long time - is the effectiveness of noise suppression in the low frequency spectrum - I think this is an overlooked area in audio - low frequency noise & it's effect on audio performance - I'm talking about very low frequencies (VLF) here - noise below a couple of hertz, maybe even noise as low as 0.1Hz.

I have a feeling, based on some clues from other areas that controlling this noise is crucial. I note for instance that a well known expert in oscillators, known online as Jocko Homo, has been saying for a long time that the performance of clocks at these low levels is what audibly differentiated them.

This is a pretty complex area as all devices generate VLF - it's called 1/F - in other words the noise increases as the frequency decreases. Now, it may be that batteries are superior in this area than capacitors, I don't know but I suspect so. It may not be the absolute level of this noise that counts but the elimination (or reduction) of noise fluctuation in this frequency range that counts. Again, my gut feeling on this is that it all relates back to auditory perception & how we perceive such fluctuations (we don't hear them directly but I believe they have a secondary effect on the "naturalness" of the reproduced sounds we hear.

[nige2000]

Glad you two arent marking my physics exam
Didnt mean it in a literal sense
I was looking of an ilogical answer in relation to how we can compare batteries to supercaps

So far i conclude that comparisons of lifepo4 vs 100f supercaps x2 on oscillators that the supercaps are second best
But have no problem using them in places where batterys wont suit


Like the pc it seems its all about noise control
I think of it like a flood method

[rickmcinnis]

I would think, for all intents and purposes, in this conceptual game that a constantly charged A123 26650 would have "infinite" .capacitance and the smaller one would have a fraction in proportion to its capacity of infinite capacitance.

Has anyone measured the amount of AC across a float charged battery? That would tell us pretty quickly how effective the battery is as a filter capacitor. I know I never have.

[jrling]

One thing that I think has to be considered & it's something I've been interested in for a long time - is the effectiveness of noise suppression in the low frequency spectrum - I think this is an overlooked area in audio - low frequency noise & it's effect on audio performance - I'm talking about very low frequencies (VLF) here - noise below a couple of hertz, maybe even noise as low as 0.1Hz.

I have a feeling, based on some clues from other areas that controlling this noise is crucial. I note for instance that a well known expert in oscillators, known online as Jocko Homo, has been saying for a long time that the performance of clocks at these low levels is what audibly differentiated them.

This is a pretty complex area as all devices generate VLF - it's called 1/F - in other words the noise increases as the frequency decreases. Now, it may be that batteries are superior in this area than capacitors, I don't know but I suspect so. It may not be the absolute level of this noise that counts but the elimination (or reduction) of noise fluctuation in this frequency range that counts. Again, my gut feeling on this is that it all relates back to auditory perception & how we perceive such fluctuations (we don't hear them directly but I believe they have a secondary effect on the "naturalness" of the reproduced sounds we hear.

Very interesting and thanks, John.

I read this thread where Jocko Homo contributed - http://www.diyhifi.org/forums/viewtopic.php?f=2&t=1681 (and don't recommend wasting your time on it as 90% is just mud slinging - aren't we fortunate to have Tir NA manners).
There were no suggestions as to how to improve 1/f really.

Have you been working on that objective and can share any tips to follow?

Thank
Jonathan

[jrling]

Glad you two arent marking my physics exam
Didnt mean it in a literal sense
I was looking of an ilogical answer in relation to how we can compare batteries to supercaps

So far i conclude that comparisons of lifepo4 vs 100f supercaps x2 on oscillators that the supercaps are second best
But have no problem using them in places where batterys wont suit


Like the pc it seems its all about noise control
I think of it like a flood method

Pleasure! Unlike me, you get a school report that says - "Nigel has bundles of enthusiasm and an enquiring mind, that the school is proud of and keen to encourage."

Had either of you considered (like me) or even tried combining 26650s feeding Supercaps as a PSU? Could be best of both worlds or perhaps neither. I am tempted to try, although at present don't have equipment needing 5V supply.

Jonathan

[jrling]

I would think, for all intents and purposes, in this conceptual game that a constantly charged A123 26650 would have "infinite" .capacitance and the smaller one would have a fraction in proportion to its capacity of infinite capacitance.

Has anyone measured the amount of AC across a float charged battery? That would tell us pretty quickly how effective the battery is as a filter capacitor. I know I never have.

Good suggestion Rick. I have a feeling you will be reporting back soon and I look forward to that.

Jonathan

P.S. My Maths teacher would have said - "half of infinity is infinity."! Someone had to say it.