Wow. I looked just weeks ago at their finances, because I knew they had been on rocky ground earlier in the year, must have been only days before that announcement.
That is bad news for battery tech r & d for the elec vehicle and solar industries. Oh, and the audiophile customers too :/
i'm aware of the sale, but it hasnt stopped production or sales. seriously mate, do NOT trust online sellers, there is only 1 or 2 legit resellers/distributors of this product, but a LOT of greymarket that appear legit, unless the particular sellers cells have been verified independently, dont waste your money. i'll PM you a supplier
exactly, they dont and havent sold single cells for a long time. the link I sent you by PM is a legit distributor who makes EV fuel cells and kits as well as running an electric high speed motobike team, he still has stock and will continue to have stock. i'm not talking about RC products, those and stupid user error along with fake cells have been a massive headache for A123 and a big part of why we cant get cells more easily
RC is the largest fake cell market, I wouldnt touch them and there are numerous websites all over the world claiming to have A123 cells. please dont tell me you went to http://www.a123rc.com/ ? its bogus click the 'return policy' link down the bottom, just goes back to the home page, as do all of those links, like 'contact us' and a hotmail email account for something like this? hmmm
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In answer to the original question, here's a directly related application note by a person who builds and sells low jitter oscillators, Wenzel Associates.
He presents real data at the end, showing before and after noise levels.
Finesse Voltage Regulator Noise!
Bob
He presents real data at the end, showing before and after noise levels.
Finesse Voltage Regulator Noise!
Bob
x2
there is also a version of this circuit with an integrated clock and floating transformer coupled output.
these are actually based on the wenzel circuit, but with higher performance. the reg in the Max6126 application note gets a vote from me too at 6nV/Hz basically a flea with a follower and a lower noise reference to start with
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Just note that the filtering of this TL431 based 3.3V regulator (R11,C7) reduces the loop gain of the TL431's amplifier.
The TI Model for the TL431 doesn't include the reactive components. Basso built a model which comports to reality:
An externally hosted image should be here but it was not working when we last tested it.
I know, good point, but on the other hand...
The top circuit from Wenzel can likely be added to an existing design or product using an LM317, etc, as it barely drops the voltage. It is easy to build, it uses 5 resistors, a cap and transistor. Not bad for an "add on" 20-40 dB noise reduction. It would be interesting to see if this add on could be measured in terms lower jitter on a DAC output signal.
@jackinnj
Myself and a few friends have tested several regulators with quartz clocks.
Almost all of them prefered sound when clock was powered with opamp based shunt reg, very similar to Walt Jung's shunt presented HERE.
Few others prefered opamp based series regulator, similar to Maxim's Application note 3657 with low noise RRIO @ unity gain and PNP instead P-MOS.
Raw DC supply (12V):
Transformer -> Schottky diodes -> CRC (2200uF-56R-2200uF) -> 7812
Myself and a few friends have tested several regulators with quartz clocks.
Almost all of them prefered sound when clock was powered with opamp based shunt reg, very similar to Walt Jung's shunt presented HERE.
Few others prefered opamp based series regulator, similar to Maxim's Application note 3657 with low noise RRIO @ unity gain and PNP instead P-MOS.
Raw DC supply (12V):
Transformer -> Schottky diodes -> CRC (2200uF-56R-2200uF) -> 7812
I'm not pushing it, but doesn't your description above mate well with an oscillator, the subject of this thread?
yes it matches exactly to it. thats what I was saying without actually saying itnote that I was talking about the oneoclock/Demian Martin version that jackinnj was mentioning had loop gain issues
Here's a bode plot for one which I cobbled together -- from living resistors, caps and transistors:
An externally hosted image should be here but it was not working when we last tested it.
The problem with this one is that the TL431 really likes to see some significant current draw, i.e. over 10 mA to make it hum. This is discussed at length in Basso's book.
When I take Vcc down to 5V, with the R values illustrated and what I perceive as typical XO current draw, this particular regulator just poops out.
yeah well past modelling I gather it works well in reality and I view Demian Martin as being one of the audio worlds leading designers wrt clocking, he also has better instrumentation to measure phase noise/jitter than anyone here i'm aware of, so you'll excuse me if I take his word on the designs suitability and real world functionality over a model you knocked up. its also been built by quite a few people here on the forum and included on a couple fairly widely built PCBs
I do appreciate you taking the time, but this isnt a proposed design, its a proven design, besides the clocks i'm powering use more than 10ma
I do appreciate you taking the time, but this isnt a proposed design, its a proven design, besides the clocks i'm powering use more than 10ma
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